'•THE RELATIONSHIP BETWEEN THE CRUDE
FIBRE CONTENT OF PASTURE GRASS AND
*
THE VOLATILE FATTY ACIDS OF 
THE RUMEN CONTENT OF WHITE 
FULANI ( ZEBU) CATTLE”
T H E S I S
SUBMITTED FOR THE DEGREE OF 
DOCTOR OF PHILOSOPHY IN THE 
DEPARTMENT OF ANIMAL SCIENCE 
FACULTY OF AGRICULTURE, FORESTRY 
AND VETERINARY SCIENCE 
UNIVERSITY OF IBADAN
by
ADETOWUN KIKELOMO ADEBANJO, B .Sc. ( IFE)
SEPTEMBER 1972
UNIVERSITY OF IBADAN LIBRARY
ACKNOWLEDGEMENTS
I  w ish to  express my profound g ra t itu d e  to  
P ro fesso r  V .A . Oyenuga, Head o f  th e Department o f  
Animal Science fo r  h is  guidance both in  th e ch o ice  
o f su b jec t and th e  su p erv is ion  o f  my work. My 
thanks a lso  go to  Dr. A.U, Mba, who came in  v e ry  
t im e ly  to  g iv e  a u se fu l guidance during my lab ora ­
to ry  and f i e l d  work.
I  a ls o  express my thanks to  Mr. H. Ogungbesan 
(S en io r  F ie ld  S t a f f ,  Grade 1 ) ,  and the e n t ir e  
Techn ica l S t a f f  o f the Department o f  Animal 
Science fo r  th e ir  a ss is tan ce  during the p rogress 
o f the work.
I  should a lso  l ik e  to  thank Mrs. P . Toye, 
who typed the th e s is .
UNIVERSITY OF IBADAN LIBRARY
C O N T E N T S  PAGE
AC KNOWLEDGEMENTS 
Chapter X
1.1 General In trod u ction  — ------------------------------  1
1.2 Importance o f Pasture in  N ig e r ia — --------- — 1
1.3 Importance o f  Pastu re on l iv e s to c k  feed in g  3
1.4 V a r ia t io n  in  q u a lity  o f  pastu re-----------------  5
1.5 Some important N ige r ian  grasses and legumes 5
1.6 Crude f i b r e  as an undefined component o f
Pastu re herbage--------------- ------------- ----------— 11
1.7 E f fe c t  o f c lim a te  and s o i l  on the crude 
f i b r e  content and pastu re p roduction  in
th e t r o p ic s ----------------------------------    15
1.8 M ilk  f a t  content o f the Zebu c a t t l e ----------- 19
1.9 F ib re  content o f  t r o p ic a l  pastu re herbage
and v o l a t i l e  f a t t y  a c id  p rodu ction --------- — 23
Chapter 2 ^
LITERATURE REVIEW---------------------------------------------  27
2.1 D iges tion  in  th e ruminant — — — -------    27
2.2 Absorp tion  in  th e rum inant--------- - — ----- - 41
2.3 Synthesis o f  f a t  in  the rum inant-------------- 52
2.4 S tru c tu re  and Com position o f  m ilk  f a t - ------ 61
x
UNIVERSITY OF IBADAN LIBRARY
Page
2.5 Measurement o f ruminant fe ed in g  s t u f f s ------ 66
2.6 Measurement o f V .F .A .----------------------------------  76
Chapter 3
MATERIALS AND METHODS
3..1 H is to ry  and Management o f the Experiment ail
P lo t s -----------------------------------------------------------   78
3.2 The White Fu lan i (Zebu) c a t t l e — --------   81
3.3 Health o f  the Animals----------------------------------  83
3.4  P lan  o f the exp er im en t--------------------    83
3.5 Feeding o f  Animals and Sample C o l le c t io n - -  84
Chapter 4
BOTANICAL ANALYSIS
4.1 In trod u c tion — ---------     87
4.2  Method o f A n a ly s is - - ------------ -— --------------—  88
4.3 R esu lts  and D iscussion --------------------------------  88
Chapter 5
MICROBIOLOGY
5.1 In tro d u c tion ----------------       94
5.2 Method o f  A n a ly s is --------------------------------------- 95
5.3  R esu lts and D iscussion --------------------------------  97
i i
UNIVERSITY OF IBADAN LIBRARY
Page
mmmrntmmmm>
Chapter 6
CHEMICAL COMPOSITION OF TREATMENTS 
H, J , K, AND L AT 4 AND 12W EEKS.
6.1 In trod u ction -----------------------------------------------  102
6.2 A n a ly t ic a l methods-------------- --------------- ----- 103
6.3 R esu lts -------------------------------------------------------  105
6.4 D iscussion ---------------------------------    116
Chapter 7
VOLATILE FATTY ACIDS
7.1 In tro d u c tio n ------------ -— ------------------— ------  121
7.2 C o lle c t io n  o f  Samples------- --------    121
7.3 A n a ly t ic a l p ro c ed u re --- -— - - - — ---------------  123
7 .4  R e s u lt s - - - - - ---------------------- ---- -------------- ----- 124
7.41 Rumen liq u o r
T o ta l V .F .A .-----------------------------------------------  125
In d iv id u a l V .F .A .----------------     126
A/P------- ------------    128
7.42 Rumen liq u o r
T o ta l V .F .A .-----------    136
i i i
UNIVERSITY OF IBADAN LIBRARY
Page
D iscussiona nd Summary— --------    164
In d iv id u a l V .F .A .----- -----    167
A/P---------------------------------------------------------------- 167
Chapter 8
MILK CONSTITUENTS
8.1 In trod u c tion -------------------- -----------------------— 169
8.2 M ilk  C om position -------- -— ------------------------- - 170
8.3 A n a ly t ic a l method— -------------------------------------  178
8.4 R esu lts ------------------------ ---- ------ -------------------- 180
8.5 D iscussion ----------------------------------------------------  201
Chapter 9
AMMONIA AND UREA PRODUCTION
9.1 In trod u ction — -----   210
9.2 D eterm ination  o f  urea and ammonia------------ - 217
9.3 A n a ly t ic a l procedure------------       218
9.4 R e su lts ------------  ----         218
9.5 D iscussion  and C on c lu s ion ----------------------— 232
UNIVERSITY OF IBADAN LIBRARY
Page
Chapter 10
"IN  VITRO" DIGESTIBILITY STUDIES
10.1 In trod u ction -----------------------------    236
10.2 Rumen l iq u o r ----------------------------------------------  238
10.3 A n a ly t ic a l procedure--------------------    239
10.4 R esu lts -------------------------------------------------------  240
10.5 D iscussion-------------------   252
Chapter 11
DIGESTIBILITY TRIALS
11.1 In trod u ction ----------------------------------------------  254
11.2 D eterm ination o f C r203 in  fa e c e s --------------  255
11.3 A n a ly t ic a l procedure---------------------------------- 255
11.4 R esu lts -------------------------------------------------------  257
11.5 Chromic ox id e  reco ve ry ------------------------------- 263
11.6 C o r re la t io n  and reg ress ion  equ ations-------  265
11.7 D iscu ss ion -----------    268
APPENDIX-----------------------------------------------------------------  272
LITERATURE CITED----------------------------------------------------  346
v
UNIVERSITY OF IBADAN LIBRARY
LIST OF TABLES
Table Page
4.1 Mean Dry M atter B otan ica l Com position o f
Treatment Swards------------------------------------------  90
5.1 RESULT Ruminal Protozoan and B a c te r ia l
Counts---------------------------------------------------------   98
6.1 Mean Chemical Com position o f treatm ents
H, J, K and L . cut at 4 and 12 weeks---------  107
7.1 Ruminal V .F .A . ,  pH, A ce tic/ P rop ion ic  
r a t io  (A/P) o f treatm ents (J )  at 
d i f f e r e n t  sta.ges o f growth fe d  to  Zebu
c a t t l e ----------------------------------------------------------- 129
7.2 Ruminal pH, T o ta l V .F .A . and in d iv id u a l 
V .F .A . ,  and A ce tic/ P rop ion ic  (A/P) ac id  
r a t io  o f treatm ent (H) at 4 and 12 weeks
o f  growth fe d  to  Zebu C a t t le -------- ------------  135
7.3 Ruminal V .F .A . , pH, A ce tic/ P rop ion ic  (A/P) 
r a t io  o f  treatm ent (J ) at d i f f e r e n t  stages
o f growth fe d  to  Zebu C a t t le -------------------—  138
7.4  E f fe c t  o f tim e o f sampling on the pH,
T o ta l V .F .A .,  in d iv id u a l V .F .A . A ce t ic/
P rop ion ic  a c id  r a t io  and T o ta l V .F .A . in  
b lood  serum by Zebu C a t t le  fe d  t r e a t ­
ments (H) at two stages o f grow th---------------  156
7.5 E f fe c t  o f  time o f  sampling on the pH,
T o ta l V .F .A . A ce tic/ P rop ion ic  ac id  r a t io  
and T o ta l V .F .A . in  b lo od  serum by Zebu 
c a t t l e  fe d  treatm ent (J )  at th ree stages
o f  growth------------------------------------------------------ 157
v i
UNIVERSITY OF IBADAN LIBRARY
Page
7.6 E f fe c t  g f tim e o f sampling on the pH,
T o ta l V .F .A . ,  in d iv id u a l V .F .A . A ce t ic/
P rop ion ic  ac id  r a t io  and T o ta l V .F .A . 
in  b lood  serum by Zebu c a t t l e  fe d
treatm ent (K ) at th ree  stages o f  growth----  153
7.7 E f fe c t  o f time o f sampling on the pH,
T o ta l V .F .A .,  in d iv id u a l V .F .A . A ce tic/
P rop ion ic  ac id  r a t io  and T o ta l V .F .A . 
in  b lood  serum by Zebu C a t t le  fed
treatm ents (L ) at th ree  stages o f grow th-- 159
7.8 Ruminal V .F .A ., pH, and b lood  V .F .A . o f  
Treatments H, J , K, and L. a t 4 weeks
o f  age fe d  to  Zebu c a t t l e -------------------------- 160
7.8 Ruminal V .F .A ., pH, A ce tic/ P rop ion ic  R a tio ,
(A/P) and b lood  V .F .A . o f treatm ents H ,J,K ,
and L at 8 weeks o f age fe d  to  Zebu c a t t l e  161
7.8 Ruminal V .F .A .,  pH, A ce tic/ P rop ion ic  
R a tio  (A/P) o f  treatm ents H, J, K and L.
a t 12 weeks o f age fe d  to  Zebu C a t t l e l ------ 162
7.9 Ruminal V .F .A . pH, A ce tic/ P rop ion ic  
r a t io ,  (A/P) and b lood  V .F .A . o f  t r e a t ­
ments H ,J, K and L at d i f fe r e n t  stages
o f  growth fe d  to  Zebu c a t t l e ---------------------- 163
The Com position o f m ilk  0 f  var ious 
Species accord ing to  Eckles e t a l (1943) 173
8 .1 M ilk  C onstituen ts according to  Jenness
.. (1959) 171
8 .2 1 Comparison o f  m ilk  con stitu en ts  o f Cows 
fe d  H, J , K and L when fou r (4  weeks)
(% )------------------- -------------------------------------------- 181
v i i
UNIVERSITY OF IBADAN LIBRARY
Page
8.22 Mean % m ilk con stitu en ts  o f cows fe d
treatm ents H, J , K and L at 4 weeks----------- 182
8.31 Comparison o f  m ilk  con stitu en ts  o f 
cows fe d  treatm ents H, J , K and L
a t tw e lve  weeks (12  wks. )  ------------------------- 134
8.32 Mean % m ilk  con stitu en ts  o f cows fe d
treatm ents H, J , K and L a t 12 weeks------- - 185
8.41 Comparison o f m ilk  con stitu en ts  o f  cows
fe d  H, J , K and L a t fou r xveeks (4 w lcs .)--  187
8.42 Mean % m ilk  con stitu en ts  o f cows fe d
treatm ents H, J , K and L a t 4 w k s , ------—  187
8.51 Comparison o f m ilk  con stitu en ts  o f 
cows fe d  treatm ents H, J , K and L a t
e igh t weeks (8  w ks.) (% )------------------------- 1®9
8.52 Mean % m ilk  con stitu en ts  o f cows f e d
treatm ents H, J , K and L at 8 w ks.------------ 189
8.61 M ilk  com position o f d i f f e r e n t  breeds
compared w ith  th e N iger ian  Zebu Cows-------- 19 1
8.62 M ilk  com position  o f  d i f fe r e n t  breeds
compared w ith  th e N iger ian  Zebu Cows
(% )-— — ....................................—  - ..............—  1^2
8.63 M ilk  composion o f  d i f fe r e n t  breeds 
compared w ith  the N iger ian  Zebu Cows
(% )..................... - .....................................................-  193
8.64 M ilk  com position  o f  d i f fe r e n t  breeds
compared w ith  the N ige r ian  Zebu Cows
( % ) - - - .........- ......... - - - - - - ............... - ............... —  194
v i i i
UNIVERSITY OF IBADAN LIBRARY
age
L iv e  w eight changes o f Zebu c a t t l e  
during the experim ent---------------------------- 196
Summary o f mean Y ie ld  and Chemical 
com position  o f m ilk -------------------------------- 209
Ammonia n itrogen  (mg/100 ml rumen 
l iq u o r )  produced by Zebu c a t t l e  fe d  
two treatm ents cut at 12  weeks------------- 220
Ammonia n itro gen  (mg/100 ml rumen 
l iq u o r )  produced by Zebu c a t t l e  fe d  
fou r treatm ents cut at 4 w eeks------------- 222
Ammonia n itro gen  (mg/100 ml rumen 
l iq u o r )  produced by Zebu c a t t l e  fe d  
treatm ents H, J, K and L at 4 w ks,------- 224
Ammonia n itrogen  (mg/100 ml rumen 
l iq u o r )  produced by Zebu c a t t le  fe d  
H and J at 8 weeks------- ------------------------- 226
Ammonia n itro gen  (mg/100  ml rumen 
l iq u o r ) produced by Zebu c a t t l e  fe d  
two treatm ents cut at 12  w eeks------------- 228
Urea n itrogen  (mg/100 ml b lood  serum) 
produced by Zebu c a t t l e  fe d  two t r e a t ­
ments cut a t 4 weeks------------------------------ 230
Urea n itrogen  (mg/100 ml b lood  serum) 
produced by Zebu c a t t l e  fed  fo u r  t r e a t ­
ments cut at 4 w eeks----------------------------— 231
Urea n itrogen  (mg/100 ml b lood  serum) 
produced by Zebu c a t t l e  fe d  fou r t r e a t ­
ments cut at 8 weeks---------------------- ------- 233
IX
UNIVERSITY OF IBADAN LIBRARY
Page
10.1 Comparison o f ' in  v i t r o ' Organic 
M atter d i g e s t i b i l i t i e s  o f  t r e a t ­
ments H, J , K and L at fou r stages
o f  growth w ith  Zebu c a t t l e - --------- ------------ 244
10.2 Chemical com position and 'in  v i t r o * 
d i g e s t i b i l i t y  o f  o rgan ic  m atter o f 
s in g le  stand grasses a t 4 weeks p lan ted  
on U n iv e rs ity  o f Ibadan Farm (% Dry
m a tte r )-------------------------------------------------------  250
10.3 Chemical com position  and ' i n  v i t r o * 
d i g e s t i b i l i t y  o f  organ ic m atter o f  
s in g le  stand grasses at 8 weeks p lan ted  
on U n iv e rs ity  o f  Ibadan— ----------------    251
11.1 Mean D ig e s t ib i l i t y  c o e f f ic ie n t s  o f  fou r  
treatm ents cut at 4 weeks by Zebu
c a t t le  (% )------------------------      258
11.2 Mean D ig e s t ib i l i t y  c o e f f ic ie n t s  o f fou r 
treatm ents cut at 12 weeks by Zebu
c a t t le  (% )--------------------------------------------------  262
x
UNIVERSITY OF IBADAN LIBRARY
CHAPTER 1
1.1 General In trodu ction
Pastures are d i f f e r e n t  from natu ra l grasslands, in  
that they a te g e n e ra lly  used fo r  l iv e s t o c k  p roduction . In 
developed  cou n tries  and in  many governments and u n iv e r s i­
ty  farms in  the tro p ic s  pastures are u su a lly  enclosed  by 
fen ces , and are r o t a t io n a l ly  grazed . Some pastures are 
included  in  crop r o ta t io n  in  a rab le  farm ing, w h ile  others 
are used in d e f in i t e ly  fo r  g raz in g  and they form permanent 
pastu res. R o ta tion  pastures and permanent pastures are 
found in  Europe, America and A fr ic a  and other pa rts  o f  the 
w orld.
1.2 Importance o f Pasture in  N ig e r ia
The v e g e ta t io n  o f N ig e r ia  was mapped out by Keay (1953 ). 
The Savannah occupies a t o t a l  area o f 309,000 square m iles 
in  N ig e r ia , about 83% o f N ig e r ia 's  t o t a l  land area (Oyenuga, 
1957). The Savannah in  N igeria, is  d iv id e d  in to  fou r 
zones, namely Sahel, Sudan, Northern guinea and Southern 
guinea. There are some sm all areas in  the South where grass 
has invaded farm c le a r in g s . The grasslands in  N ig e r ia  are 
lo ca ted  in  the Savannah. The grasses found in  the Savannah are
1
UNIVERSITY OF IBADAN LIBRARY
-rr is tid a  s t ip o id e s , S ch oen o fe ld ia  g r a c i l is  , Cenchrus b i f l o r u s ,
Cencfarus p r i e u r i i , Ctenium ele  gans, E ra g ro s tis  trem u le , 
ennisetum p ed ic e lla tu m , Andropogon psendapricus t Andropogon 
ray anus, L ou d e tia , Hyparrh^nia ru fa , Hyparrhenia cyanescens, 
.-parrhonla subplumosa, Hyparrhenia d is s o lu ta , Cymbopogiri 
irgan teu s, Imperata c y l in d r ic a , B rach ia rla  spb . Thelopogcn 
Diegans , D ig i t a r ia  gay ana , Pennisetum p o ly s t  achyont 3 e ta r ia  
sphacela ta , S e ta r ia  p a l l id i fu s c a , Pennisetum purpureum, 
-ndropogon tectorum and Panicum maximum.•
This natural grassland  is  lo c a ted  in  Northern p a r ts  
z f  N i g e r i a . ' The Savannah forms the c h ie f  source o f  food  
fo r  w h ite  Fu lan i (Zebu) c a t t le  in  the North . In N ig e r ia  
:c th  in  the North and South, th ere  are no p a rce ls  o f  land 
set as ide m ainly fo r  g ra z in g . The grasses fe d  to  l i v e ­
stock have not been seeded or f e r t i l i z e d ,  to  improve p ro - 
ta c tion  and q u a lity  o f  the herbage fo r  animal fe e d ..
Improved pastures are on ly  found in  goverrment owned 
ranches and D airy Farms.
There is  a very  good opportu n ity  to  improve 
pastures in  N ig e r ia . Pastures are fundamental to  
increased  food  production  and to  the con serva tion  o f  s o i l  
and w ater.
2
UNIVERSITY OF IBADAN LIBRARY
1.3 Importance o f pastu re on l iv e s to c k  fe ed in g
The Graminae is  the most im portant o f  a l l  p lan t 
fa m il ie s  from an economic p o in t o f  v iew  because o f i t s  
im portant products * For instance c e re a ls  such as wheat, 
m aize, r i c e ,  b a r le y , o a ts , m i l le t ,  guinea corn as w e l l  as 
others o f  minor importance belong to  th is  fa m ily . They 
form the s ta p p le  foods o f  man in  a l l  pa rts  o f  the w orld . 
C erea l seeds, apart from p rov id in g  food  fo r  man are a lso  
used fo r  l i v e  stock  and th e ir  f o l ia g e  is  a lso  used as l i v e  
stock  fe e d . Numerous sp ec ies  o f  grasses form the c h ie f  
source o f  food  o f  dom estic and farm anim als. They are 
grown as fodders  or pastu re crops fo r  va riou s animals in  
d i f f e r e n t  parts  o f  the w orld .
The grass fa m ily  is  a ve ry  la rg e  one con ta in in g  over 
300-400 genera and over 4,000 - 5,000 sp e c ie s . I t s  members 
are w id e ly  d is tr ib u te d  a l l  over the w orld . Some grow in  
a l l  parts  o f  the world where f lo w e r in g  p la n ts  a lso  e x is t ,  
and they may th r iv e  w e ll  from sea l e v e l  to  p la ces  w ith  
p erpetu a l snow. They however, do w e ll  in  the open where 
th ere is  p le n ty  o f  a ir  and l i g h t .  Only a few  spec ies  o f  
grasses are o f  a g r ic u ltu ra l im portance.
Grasses form im portant n a tu ra l v e g e ta t io n  in  some p laces
3
UNIVERSITY OF IBADAN LIBRARY
around the w orld , and may form la rg e  expanse o f  v e g e ta t io n  
in  some parts  such as the P r a ir ie  o f  America, Pampas o f  
A rgen tin a , and Savannah o f  N ig e r ia .. There a re  many grasses 
and legumes in  N ig e r ia  that are be ing used and can be used 
as improved pastures fo r  l iv e s to c k  fe e d in g . The good  and 
prom ising grasses fo r  l iv e s to c k  fe e d in g  are Gamba, G iant 
s ta r ,  Bahama, Kyasuwa,Elephant, Guinea, D ig i ta r ia ,
Cenchrus. and B ra c h ia r ia . The good and prom ising legumes 
fo r  l iv e s to c k  fe e d in g  are Centrosema. S ty lo sa n th es , and 
A lyce  c lo v e r .  Some o f  these grasses and legumes have been 
used su cces s fu lly  in  a g r ic u ltu ra l s ta tio n s  and farms 
throughout the Country, both fo r  d a ir y , b ee f and horse 
production-.
Even though th ere  are few p lan ted  pastures in  N ig e r ia ,  
the re s u lts  obta ined  from government farms have proved  th a t 
the pastu res cam perform  as e x c e l le n t ly  as those in  o ther 
p a rts  o f  the w orld . N ig e r ia 's  l iv e s to c k  depend on na tu ra l 
pastures and most o f  them do not ge t enough n u tr ien ts  from 
these pastu res , p a r t ic u la r ly  during the non-growing or 
dry season when they fe e d  on sub-maintenance ra tions and 
so many o f  them become lean  and em aciated.
4
UNIVERSITY OF IBADAN LIBRARY
1.4 Variation  in qu a lity  o f Pasture
The qu a lity  o f a pasture is  usually  judged by it s  
carrying capacity o f grazing c a tt le , the performance of 
the ca tt le  in  terns o f m ilk, beef and growth and calving  
percentages o f the animals. To be able to produce a good 
y ie ld  per acre and good pa la tab le  fodder fo r  animals 
pasture qu a lity  depends on such factors as good crop 
husbandry, f e r t i l e  s o i l ,  and clim ate.
In the trop ics extensive grazing is  the ch ie f form of 
land use fo r  livestock  production. The r a in fa l l  in  these 
areas are low and v a r iab le  and lead to poor pasture y ie ld .  
Usually there are two growing seasons in the year, the 
period o f good r a in fa l l  and abundant growth a lternating  
with the period o f low to no r a in fa l l  and poor growth,
1.5 Some promising N igerian  grasses and legumes 
Guinea grass. Panicum maximum (Jacq)
The genius Panicum is  a la rge  and important one in  
A fr ic a . I t  contains a considerable number o f species which 
grow in varying hab itats . Rattray (1960) observed some 
species growing in  very wet and very dry p laces, while some 
grow on land from sea lev e l to p laces o f high a lt itu d e s .  
Oyenuga (1960) and M ille r  (1963) observed guinea grass to
5
UNIVERSITY OF IBADAN LIBRARY
be a part o f n a tu ra l grassland in  N ig e r ia .  Davies and 
Skidmore (1966) rep o rted  that i t  is  the best known t r o p ic a l  
grass c u lt iv a te d  experim en ta lly  or on a la rg e  s c a le  through­
out the t r o p ic s .  Oyenuga (1957; 1960) in  h is  in v e s t ig a t io n s  
found guinea grass to  be a tu fte d  p e ren n ia l grass w ith  
heigh ts ranging between 3 f t  and 1 0 ft . I t  i s  heavy y ie ld in g ,  
i t  has high n u t r i t iv e  va ltie  arid is  r e s is ta n t  to  drought.
I t  is  p a la ta b le  to  l iv e s to c k  and is  s e le c t i v e ly  grazed  by 
l iv e s to c k  when included  in  pastu res . Guinea grass reaches 
i t s  maximum development under m oist, warm co n d it ion s , where 
the s o i ls  are f e r t i l e *  I t  grows toge th er  w ith  Pennisetum 
t-rpureum and Panicum turgidum in  su b-desert areas t and 
? anlcum repens in  marshy areas (R a ttra y  1960) ard 
■--.dropogon te c  to r  urn and Imperata c y c lin d r ic a  in  N ig e r ia , 
Cyenuga 1960). Davies and Skidmore (1966) recogn ised  two 
main groups o f  guinea grass throughout the trop ics ; The 
la rg e r  and the sm aller typ es . The la rg e r  type is  very  
good fodder grass that is  propagated v e g e ta t iv e !y  on a 
commercial b a s is , and i t  req u ires  wide spacing. The sm aller 
type is  grown from seeds. Seed form ation  in  guinea grass 
as poor s in ce  the g rea te r  percen tage o f  the seeds produced 
are not v ia b le .  Guinea grass is  an apom ict, (Davies and 
l---idmore, 1966) and i t  can be es ta b lish ed  as a permanent
6
UNIVERSITY OF IBADAN LIBRARY
pasture where the dry season is  not too  se ve re . Guinea 
grass has been in trodu ced  to  South Am erica, C en tra l 
America, A s ia  and A u s tra lia  from i t s  home in  West A fr ic a *  
Elephant g rass . Pennisetum purpureum (Schum).
I t  is  a t a l l  growing fodder grass indigenous to  N ig e r ia  
I t  produces broad lea ves  and is  h igher y ie ld in g  in  the 
w ette r South than in  the d r ie r  Northern N ig e r ia .  Oyenuga 
(1957) and Davies and Skidmore (1966) rep orted  i t  to  be a 
deep ro o t in g  and drought r e s is ta n t  g ra s s . Elephant grass 
has been used in  East and South A fr ic a  to  p reven t s o i l  
e ro s ion . U su ally  i t  i s  r e s t r ic t e d  to  the margins o f  lakes 
and r iv e r s  and other permanently wet areas and in  zones 
w ith  annual r a in fa l l  ranging between 45 inches and 60 
inches. R a ttray  (1960) rep orted  i t  to  be a c h a ra c te r is t ic  
grass o f  the m oist c lim a te  o f  the c o a s ta l zone. Elephant 
grass grows in  some woodland or savannah o f  va ry in g  d en s ity  
which has been d er ived  from t r o p ic a l evergreen  fo r e s t  o f 
the h igh r a in f a l l  b e l t  that extends from the Sudan and 
Uganda in  East A fr ic a ,  through the B e lg ian  Congo (Z a i r e ) ,  
the C en tra l A fr ica n  R epu b lic , the Republic o f  the Congo, 
the Republic o f  Gabon, the Republic o f  Chad, to  S ie r r a  
Leone in  West A fr ic a .  I t  spreads as fa r  south as Angola,
UNIVERSITY OF IBADAN LIBRARY
Southern Rhodesia and Nysaiand* I t  is an apomict that 
crosses d a s i ly ,  and i t  i s  propagated v e g e ta t iv e ly .
G iant S tar Grass,
Cynodon p lectostach yu s (P i l g e r )  Giart s ta r  grass o r ig in a te d  
from East A fr ic a  where many v a r ie t ie s  o f  i t  e x is t .  I t  i s  
a p eren n ia l grass w ith  good s to lon s  which roo t r e a d ily  and 
ra p id ly  on the ground to  form a dense mat. I t  produces' 
v e r t i c a l  branches which ra r e ly  grow above 4 f t  (O luba jo 
1969). I t  grows w e l l  in  the t ro p ic s  and i t  to le ra te d  
heavy g ra z in g , and wet and dry c lim a tes  as w e l l  as a wide 
range o f t r o p ic a l  s o i l s .  Ggor (1961 ); and Davies and 
Skidmore (1966) found i t  to  combine w e ll  w ith  legumes l ik e  
Centrosema. G iant s ta r  is  a deep ro o t in g  t r o p ic a l  grass 
th a t needs high s o i l  f e r t i l i t y  to  p e r s is t  as a s o le  crop .
I t  i s  one o f  the t r o p ic a l  grasses th a t respond w e l l  to  
n itrogen  and phosphorus f e t i l i z e r s .
Centrosema pubescens (Bentham)
I t  is  a deep ro o t in g  herbaceous p e ren n ia l legume 
w id e ly  used in  grass and legume m ixtures, in  parts  o f  
t r o p ic a l  A fr ic a  in c lu d in g  N ig e r ia . I t  was in troduced 
from South America (M i l le r  and Rains, 1963). I t  w i l l  
clim b at times and when thvs supported i t  produces more 
seeds. The germ ination o f  i t s  seeds is  poor even a ft e r
8
UNIVERSITY OF IBADAN LIBRARY
s c a r i f ic a t io n .  I t  is  b e t te r  su ited  to  high r a in fa l l  areas 
and i t  p e r s is t s  in  the dry season. I t  becomes woody a f t e r  
one yea r, so i t  is  b e t te r  grown as a companion legume. I t  
combines w e ll  w ith  Cynodon p lectostachyu s (M i l le r  and Rains 
1963); Cyenuga (1957 ); and C h lo r is  gayana, M e lin is  m inu ti- 
f l o r a  and Panicum maximum. I t  covers the s o i l  w e l l ,  s in ce  
i t  has a very  rap id  growth, and can e lim in a te  com p lete ly  
a l l  weeds when i t  i s  f u l l y  e s ta b lis h ed . I t  i s  p a la ta b le  
to  g ra z in g  c a t t l e  e ith e r  as s o le  p lan t (Whyte, Moir and 
Cooper 1953), or as a p a rt o f grass/legume (Oyenuga,1957). 
I t  f ix e s  n itrogen  in  the s o i l  and th e re fo re  in creases  the 
n itrogen  content o f  the grass . I t  i s  one o f  the s e l f  
p o l l in a t in g  legumes in  A fr ic a  (D avies and Skidmore, 1966). 
S ty losan thes g r a c i l i s  (H .B .K )
The common name fo r  th is  legume is  s t y lo .  I t  i s  a ls o  
known as B ra z il ia n  lu cerne because i t  o r ig in a te d  from 
t r o p ic a l  South Am erica. I t  is  one o f  the most im portant 
pastu re legumes used throughout N ig e r ia .  Adegbola (1965) 
showed that i t  can be grown su cc es s fu lly  as pure stands or 
in  a m ixture w ith  grasses such as Andropogon gayanus t 
d i f fe r e n t  sp ec ies  o f  Cynodon t and M e lin is  m in u t if lo ra .
9
UNIVERSITY OF IBADAN LIBRARY
H o r re ll (1964) a lso  reported  s t y lo  as one o f  the best 
legumes that improved the y ie ld  o f u n fe r t i l i z e d  pastures at 
S e re re . M i l le r  and Rains (1963 ), and Adegbola (1964) showed 
that is  does w e ll  w ithout in n ocu la tion , and th a t c a t t l e  
w i l l  g raze  i t  s e le c t iv e ly  during the dry season when the 
grasses are le s s  p a la ta b le  in  Northern N ig e r ia .  C a re fu l 
graz in g  encourages, i t  to  spread, but i t  r a r e ly  su rv iv es  the 
long dry season in  the extreme north . I t  is  su perio r to  
Centrosema pubescens and Desmodium in  terms o f  n u t r it iv e  
va lu e in  Northern N ig e r ia  (M i l le r  and Rains, 1963).
H edrick (1961) rep orted  that s t y lo  can be used as l iv e s to c k  
fe e d  in  the dry season in  Southern N igeria .. Adegbola (1964; 
1965) showed that i t  can be used fo r  s i la g e  when grown 
w ith  some g rasses , and when grown as pure stands i t  can be 
cut and fe d  as hay during the dry season in  the South.
Th is was a lso  found to  be in  o ther parts  o f  the w orld  
(V iv ia n , 1959). G rinding S ty lo  in to  a meal fo r  l iv e s to c k  
fe ed in g  during the dry season in  the South was suggested by 
Nwosu (1960 ). I t  is  a t r i f o l i a t e ,  s e l f  p o l l in a t in g  p lan t 
that can be propagated by cu ttin gs  in  the high r a in fa l l  
areas o f the South (Nwosu, 1961) and from seeds which 
need s c a r i f ic a t io n  to  encourage good germ ination . The
10
UNIVERSITY OF IBADAN LIBRARY
seeds are sm all and pigm ented. The co lou r ranges from 
b lack  to  y e llo w , and the l ig h t e r  co lou red  seeds germ inate 
more r e a d ily  (Cowdry and Verhoeven, 1961), Ode (19 70 ), 
F oster (1961) and G i lc h r is t  (1967) showed that depth o f  
sowing is  ve ry  im portant s in ce deep sowing causes slow  
ra te  o f  germ ination . A depth o f  1^ inches has been found 
to  be the best at Moor P la n ta tion  in  Western N ig e r ia ,
2 .5 cm in  Northern N ig e r ia  and Queensland. F e r t i l i z e r s  
l ik e  phosphorus and su lfu r  (H o r r e l l  and Court, 1965; 
G i lc h r is t ,  1967; H o r r e l l  and Newhouse, 1966; Qada, 1972) 
improved y ie ld  o f  s t y lo  and pure stands and as s ty lo/ g ra ss  
m ix tu res .
1.6 Crude F ib re  as an undefined component o f  Pasture 
Herbage
"Crude f i b r e "  was a term evo lved  by the Weende 
Chemists about a Century ago. Crude f ib r e  co n s is ts  o f  that 
p a r t  o f  p la n t that cannot be d ig e s ted  by d i lu te  a lk a l i  and 
d i lu t e  a c id s . I t  th e re fo re  con ta ins a m ixture o f  substances 
in  va ry in g  p ro p o rtio n s . The replacement o f  crude f ib r e  
determ ination  by a d e ta ile d  a n a ly s is  o f  p lan ts  in to  
d is t in c t  chem ical groups l ik e  p e c t in s , l ig n in ,  c e l lu lo s e ,  
h em ice llu lo se , s ta rch , sugars, crude p ro te in  and ash was 
advocated by Van Soest (1966, 1967), Richards and Reid 
(1953 ), Deinum and Van Soest (1969 ). Th is d e ta ile d
11
UNIVERSITY OF IBADAN LIBRARY
a n a ly t ic a l procedure is  however ve ry  expen sive .
I t  is  g e n e ra lly  b e lie v e d  th a t crude f ib r e  i s  r e la te d  
to  fo ra g e  q u a lity .  Th is is  tru e  to  some ex te n t, but i t  is  
ve ry  u n sa tis fa c to ry  measure o f  fo ra g e  q u a lity  because o f  i t s  
v a r ia b le  com position  and d i g e s t i b i l i t y .  I t  is  some times 
more d ig e s t ib le  than the n itrogen  f r e e  e x tra c t  which is  
supposed to  be the most d ig e s t ib le  fr a c t io n  o f the fo ra g e .
Crude f ib r e  com position  va r ie s  a p p rec iab ly  between 
sp ec ies  and w ith in  sp ec ies  at d i f f e r e n t  stages o f  growth. 
This was shown in  the re s u lts  o f in v e s t ig a t io n s  c a r r ie d  
out by Oyenuga (1957; 1959; 1960), Armstrong, Thomas and 
Cook (1950 ), Woodman, Evans and Norman (1934 ), and A rnold  
Kivimae (1966 ).
G en era lly  crude f ib r e  con ten t in creases w ith  advance in  
stage o f  m atu rity  o f  fo ra g e s , but i t  may d e c lin e  a ft e r  
reach ing the peak, (Oyenuga, 1958; Ademosun,1970; Ademosun 
and Baumgardt, 1967; W ilson and C a rr ick , 1966; and 
K ivim ae, 1966). Oyenuga and O lubajo (1966) obta ined 
crude f i b r e  range o f  31-38%, and Ademosun (1970) ob ta ined  
a range o f  29-34%, w h ile  Ademosun and Baumgardt (1967) 
ob ta ined  a w ider range o f  22-51%.
12
UNIVERSITY OF IBADAN LIBRARY
The crude p ro te in  o f  most fo ra ges  decreases w ith  age 
and frequency o f  c u tt in g  w h ile  the crude f i b r e  in creases 
w ith  age. Th is was shown by Arm strong, Thomas and Cook 
(1950 ); Woodman, Evans and Norman (1934 ); T i l l e y  and Terry  
(1964 ); W hite, Johnston and Armstrong (1964 ); and Oyenuga 
(1 9 5 8 .) Smith (1969) ob ta ined  more crude p ro te in  in  the 
f i r s t  regrowth than in  the second regrowth o f  Hyparrhenia 
v e ld  o f Northern Rhodesia.
The l iv e s to c k  in  N ig e r ia  and in  most parts  o f  A fr ic a  
and the tro p ic s  depend on the na tu ra l grassland  fo r  th e ir  
fe e d  supply. The l iv e s to c k  in du stry  i s  l im ite d  by the 
gen era l m a ln u tr ition  in  the dry season caused by the 
seasonal d e c lin e  in  the n u t r it iv e  va lue o f  the na tu ra l 
grass land . The n itro gen  content o f the pastu re herbage and 
the s tru c tu ra l con stitu en ts  o f which crude f ib r e  is  a major 
c o n s t itu en t, p la y  v e ry  important r o le  in  determ in ing the 
n u t r i t iv e  va lue o f  the grassland . Low crude p ro te in  content 
and high crude f i b r e  content lea d  to  lower fe e d  in tak e  and 
poor animal p rodu ction , p a r t ic u la r ly  in  the dry season.
When the fe e d  va lu e  was ca lcu la ted  w ith  crude f ib r e  
as an index substance, r e l ia b le  va lues were ob ta ined  u n t i l
13
UNIVERSITY OF IBADAN LIBRARY
e a r ly  f lo w e r in g . The va ry in g  conten t o f  the s l i g h t ly  so lu b le  
carbohydrates and crude f ib r e  during the v e g e ta t iv e  p e r iod  
con tr ib u tes  to  the d i f f i c u l t i e s  o f  es tim ation  o f  the fe ed  
va lu e .
Most p re d ic t io n  equations fo r  n u t r i t iv e  va lu e  are 
based on reg ress ion s  o f d i g e s t i b i l i t y ,  vo lu n tary  in ta k e , or 
n u tr it iv e  va lue index w ith  one or more chem ical components. 
The use o f  crude f ib r e  to  estim ate d i g e s t i b i l i t y  o f p ro te in  
or c e l lu la r  contents is  not v a l id .
Richards and Reid (1953) rep o rted  high n ega tive  
c o r re la t io n s  between the amounts o f  d ig e s t ib le  dry m atter 
and crude f i b r e .  High n ega tive  c o r r e la t io n s  were a lso  
observed between the fa e c a l con ten ts o f  crude f ib r e ,  and 
the d ig e s t ib le  dry m atter content o f  the herbage used.
Only sm all amounts o f the dry m atter o f fo ra ges  and fa eces  
were unreso lved  by the a n a lys is  o f l ig n in ,  h em ice llu lo se , 
c e l lu lo s e ,  p e c t in , s ta rch , sugars, crude p ro te in , ash and 
eth er e x tr a c t .  These d e ta ile d  analyses are expensive even 
though the con stitu en ts  rep resen t d is t in c t  chem ical groups.
The replacem ent o f crude f ib r e  a n a lys is  w ith  an 
an a lys is  fo r  l ig n in ,  and the measurement o f  t o t a l  
carbohydrates by d if fe r e n c e  would r e s u lt  in  the grouping
14
UNIVERSITY OF IBADAN LIBRARY
o f n u tr ien ts  groups having more meaning b io lo g ic a l ly  than 
the p re s en tly  employed proxim ate a n a ly s is .
1.7 E f fe c t  o f  C lim ate and s o i l  on crude f i b r e  content 
alnd pastu re production  in  the Trop ics
T ro p ic a l s o i ls  are formed on land su rfaces th a t a re , 
g e o lo g ic a l ly  speaking v e ry  o ld  (D avies and Skidmore, 1966). 
The na tu ra l dra inage o f  t r o p ic a l  s o i ls  is  ve ry  poor. The 
s o i ls  are shallow  because they have become compact below 
the su r fa ce , and p la n t roo ts  p en etra te  w ith  d i f f i c u l t y .
I f  the parent rock is  r ic h  in  iro n , th e compact la y e r  forms 
l a t e r i t e .  They are ve ry  low in  p lan t n u tr ien ts  because 
they have been exposed to  leach in g  fo r  m illio n s  o f  y ea rs . 
The p la n t n u tr ien ts  are almost a l l  con ta ined  in  the s o i l  
o rgan ic  m atter at the su rfa ce , and in  the p lan t deb ries  on 
the s o i l  su rfa ce , and in  the p lan ts  growing on the s o i l .
In E q u a to r ia l reg ions the tra n s p ira t io n  o f pastures 
can be as high as 90 inches at sea l e v e l ,  f a l l i n g  to  45 
inches at 8,000  f t .  above sea l e v e l ,  but in  th e tro p ic s  the 
annual r a in f a l l  is  le s s  and u su a lly  a p p rec iab ly  le s s  than 
the amount needed fo r  tra n s p ira t io n . T ro p ic a l pastures 
have the q u a lity  o f be ing a b le  to  w ithstand  drought fo r  
months and are rap id  growing and rap id  seed in g . T ro p ica l
15
UNIVERSITY OF IBADAN
LIBRARY
grasses are much deeper ro o t in g  than tem perate g rasses .
Some w i l l  extend th e ir  roo ts  as fa r  down as 15 f e e t  or 
more fo r  example G iant S ta r Grass, and w i l l  e x e r t  a su ction  
greater than 15 atmospheres fo r  a depth o f  a t  le a s t  12 f e e t ,  
r h is  is  below  w ilt in g  p o in t .  B r it is h  pastu re grasses r a r e ly  
roo t below 4 f e e t  and w i l l  not dry s o i l  to  w i lt in g  p o in t .
The f a i n f a l l  in  the tro p ic s  is  v a r ia b le  and th ere  are 
two seasons, the ra in y  and dry seasons. There i s  good 
pasture growth during the ra in y  season. Animals have enough 
and even more than enough o f  good food  to  e a t .  The excess 
pasture herbage is  s to red  as s i la g e  or hay. Animals gain  
w eigh t r a p id ly . In the ra in y  season a lso  most o f  the good 
top s o i l  is  washed away by f lo o d s  and the s o i l  becomes 
poor and th is  leads to  poor pastu re production  as time goes 
on, p a r t ic u la r ly  in  h i l l y  a reas . Good management, 
con tou ring , r id g in g , and manuring or f e r t i l i z a t i o n  w i l l  
then be needed to  b r in g  the land to  good production ,
P e r e ir a  and B eckley (1953 ).
In the dry season most o f  the pastures have become 
straw  and shrubs. They cannot supply enough good m a te r ia l 
to  graz in g  anim als, so the animals fe d  on the poor 
q u a lity  pasture herbage lo s e  weight
16
UNIVERSITY OF IBADAN LIBRARY
Grown grasses and Natura l grasslands respond ve ry  
• e l l  to  f e r t i l i z e r  treatm ents (D avies and Skidmore, 1966; 
Pou ltney, 1959; Smith, 1961, 1964); and to  m ixing w ith  
legumes (H o r r e l l ,  1964; Moore, 1962; M otta, 1953)*
The pastu re herbage conta ins h igher crude f ib r e  at the 
young stages o f  growth, and the crude f ib r e  con ten t may not 
3e too high at m atu rity  (Whyte, Moir and Cooper, 1959).
The p ro te in , m inerals and v itam in  conten ts o f t r o p ic a l  
pastures are a lso  low (M ilfo rd  and Minson, 1965b). Deinum 
(1966) rep orted  that the crude f ib r e  content o f  herbage 
dry m atter was decreased by l ig h t  in te n s ity  and in creased  
by tem perature. In the fre sh  m atter i t  was in creased  by 
both . The crude f i b r e  con s is ts  o f  the c e l lu lo s e  o f  the 
parenchymatous c e l l  w a lls  and o f  p a r t  o f  the l ig n in  and 
h em ice llu lose  from the vascu lar bundles. Water shortage 
decreased crude f ib r e  content o f  g rasses .
Because o f  the la rg e r  concen tra tions o f  carbohydrates 
in  the c e l l s  a t h igher l ig h t  in te n s ity ,  the amount o f  crude 
f ib r e  in  r e la t io n  to  the t o t a l  dry m atter y ie ld  is  low er. 
The sm a ller con cen tra tion  o f  carbohydrates in  the c e l l s  at 
a h igher temperature causes the crude f i b r e  con ten t to
17
UNIVERSITY OF IBADAN LIBRARY
in c rease . Where con d ition s  fo r  growth are good, pastu re 
y ie ld s  in  the t r o p ic s ,  and a lso  the output in  terms o f 
animal p roduction  compare fa vou rab ly  w ith  those o f 
temperate co u n tr ie s . Th is was shown by the re su lts  o f 
many workers (Sm ith, 1961; 1964; Moore, 1962; P e re ira  and 
3eck ley , 1953; P e r e ir a , 1959; P ra tt  and K n igh t, 1964; and 
M otta, 1953). The q u a lity  and y ie ld  o f  pastu re in  N ig e r ia  
and o th er pa rts  o f the t ro p ic s  decrease w ith  frequency o f  
cu ttin g  (Oyenuga, 1959a; b ; 1960a; b ; A k in o la , Chheda and 
Mackenzie, 1971; Ademosun, 1970; and P a tte rson , 1933.)
The ca rry in g  ca p a c ity  o f  pastures depends on the 
q u a lity  o f the pastu re . During the ra in s  the good and 
abundant growth su pp lies  enough food  m a te r ia ls  fo r  anim als. 
The animals th e r e fo r e  gain  w e igh t. During the dry season 
when the pastu re grasses have d ec lin es  a p p rec iab ly  in  
q u a lity  and d i g e s t i b i l i t y ,  the animals lo s e  w e igh t.
Pasture grasses seeded w ith  legumes produce good q u a lity  
animals and the average d a i ly  l i v e  w eight in crease  per 
animal w i l l  be good. C u lt iv a te d  land d iv id ed  in to  
paddocks and r o ta t io n a l ly  grazed  w i l l  g iv e  good in crease  
in  l i v e  w eigh t o f  the anim als. The pastures may be
18
UNIVERSITY OF IBADAN LIBRARY
f e r t i l i z e d  to  produce b e t te r  q u a lity  fo ra g e , or hay p lus 
some supplements fe d  to  in crease l i v e  weight ga in s . Rota­
t io n a l graz in g  o f f e r t i l i z e d  pastu res gave good l i v e  w eight 
gains in  Kenya (P e r e ir a ,  1959). Hay plus n itrogen  supple­
ments improved l i v e  w eigh t gains o f  animals in  Northern 
Rhodesia (Sm ith, 1961), w h ile  herbage y ie ld  was in creased  
and improved in  q u a lity  by f e r t i l i z e r s  in  Kenya (P ou ltn ey , 
1959). M ixtures o f  pasture grasses w ith  legumes increased  
pasture production  and reduced the ra te  o f  d e c lin e  in  
p ro d u c t iv ity ,  a t S e re re , East A fr ic a  (H o r r e l l ,  1964).
With good q u a lity  pastu res, few er number o f  acres 
w i l l  be needed per animal.
1.8 M ilk  f a t  content o f  the Zebu c a t t le
The Zebu c a t t l e  in c lu d in g  the w h ite  Fu lan i c a t t l e  in  
N ig e r ia  produce m ilk  o f  high b u t te r fa t  con ten t. The m ilk 
o f  the Zebu c a t t le  in  A s ia , Eastern and Southern A fr ic a  
were analysed by va r iou s  workers (Mason and Maule, 1960; 
W illiam son and Payne, 1959); and th e b u t te r fa t  content 
found to  range from 4-7%. In v e s t ig a t io n s  c a r r ie d  out in  
N ig e r ia  (O la loku , 1968; Adeneye, Oyenuga, and O la loku , 1970; 
and O la loku , Egbuiwe and Oyenuga, 1971) showed the b u tte r -
19
UNIVERSITY OF IBADAN LIBRARY
f a t  con ten t to  range from  3-9%. On th e average the W hite 
Fu lan i c a t t l e  produce m ilk  o f  over 5% b e t t e r fa t  c o n te n t .
The W hite Fulani C a t t le  are b e tte r  as b e e f than as d a iry  
animals (Oke, 1961) because they do not produce enough m ilk  
to  madce d a iry  farm ing econom ical. Imported breeds o f 
c a t t l e ,  H o ls te in s , F rieS ian s and J erseys , from AmefiCa and 
Europe are cu rren t ly  being in troduced in to  government and 
some U n iv e rs ity  farms to  in crease  production  and to  produce 
crosses which w i l l  produce more m ilk .
There are many fa c to r s  that a f f e c t  the y ie ld  and 
com position  o f  m ilk* Some o f  these fa c to r s  are the age o f  
the dam, the o ld e r  dams produce more m ilk , the l i v e  weight 
o f  the cow and tim e o f  c a lv in g , i t s  h ea lth , the number o f 
c a lv e s , the c lim a te  and p lane o f  n u tr it io n , and b reed .
In N ig e r ia  and t r o p ic a l  C ountries in  g en e ra l, rep o rts  o f 
in v e s t ig a t io n s  (Oke, 1961; Deinum, 1966; W illiam son and 
Payne, 1959; Davies and Skidmore, 1906; Sm ith, 1961; 1964; 
M ilfo rd  and Minson, 1965a, b; Minson, Whyte, M oir and 
Cooper, 1959; Pa terson , 1933; Oyenuga, 1957; 1959; 1960; 
Payne and Hancock, 1957; P e r e ir a  and B eck ley, 1953; P e re ira , 
1959; M otta, 1953; Pou ltney, 1959; H o r r e l l ,  1964; , ....
20
UNIVERSITY OF IBADAN LIBRARY
B irch , 1964; and P ra t t  and K n igh t, 1964; Enlow and Dutton
1954); showed that the c lim a te , p lan e o f  n u tr it io n  and
breed are the major fa c to r s  a f fe c t in g  the y ie ld  and compo
s it io n  o f  the Zebu C a t t le .
E f fe c t  o f  C liraate on Zebu C a t t le ,  milk, y ie ld  and 
m ilk  com position  '
Temperature in  the t r o p ic s ,  (N ig e r ia  is  one o f  the 
t r o p ic a l C o u n tr ie s ,) V aries  w id e ly  and is  g e n e ra lly  h igh . 
The id e a l tem perature accord ing to  W illiam son and Payhe 
(1959) should be between 50° and 80°F, Very high tempera 
ture causes r i s e  in  r e c t a l  temperature, and a d e c lin e  in  
fe ed  in tak e , in  p rod u ctive  processes l ik e  growth, m ilk 
and b e e f p roduction  and change in  m ilk  com position .
The len gth  o f  daytime fo r  g ra z in g  i s  long in  the 
t r o p ic s ,  but the ambient a ir  tem perature, p a r t ic u la r ly  in  
the dry season, depresses a p p e t ite , reduces fe e d  in tak e , 
and g ra z in g  tim e. The animals are su b jected  to  strong 
s o la r  ra d ia t io n  and they p r e fe r  to  r e s t  under shades 
p rov id ed  by the few  tre e s  in  the paddocks or open g rass­
land . C a t t le ,  both young and o ld , in  the tro p ic s  and 
tem perate areas graze  during the day time (G od frey , 1961)
21
UNIVERSITY OF IBADAN LIBRARY
Most o f  the animals r e s t  about noon when the tem perature 
is  h ig h es t, and grazin g  is  broken by frequ en t r e s ts  more in  
the a fternoons than in  the mornings, p a r t ic u la r ly  by the 
younger animals. O lder animals g ra ze  con tin ou s ly  than the 
younger ones. A l l  these lea d  to  slow  growth, low u t i l i z a ­
t io n  o f  pastu re , low production  in  terms o f  b e e f and m ilk  
and long ca lv in g  in t e r v a l .
The animals g ra z in g  th e savannah o f N ig e r ia ,  and 
other t r o p ic a l  na tu ra l grasslands, except those in  govern­
ment s ta t io n s , r e c e iv e  no supplements e ith e r  in  the dry or 
ra in y  seasons. Their perform ances a re  poor in  terms o f 
production  o f  b e e f and m ilk . These natu ra l grass land 
p rov id e  sub-optim al fo o d  p a r t ic u la r ly  in  the dry season.
The animals do not grow as ra p id ly  as expected  and they 
show a lte rn a te  gain  and lo s s  in  w eigh t. The m ilk  product­
ion  is  ve ry  low  and the fib rou s  pasture herbage they fe e d  
♦
on lea d  to  the production  o f  m ilk  o f h igh  b u t te r fa t  con ten t. 
P ro te in  is  the more im portant con stitu en t o f  m ilk  needed 
by man although b u tte r fa ta n d  m ilk  p ro te in  a re  both o f  
commercial im portance in  d a iry  in du stry .
22
UNIVERSITY OF IBADAN LIBRARY
1.9 F ib re  content o f t r o p ic a l  pastu re  harbage and 
v o la t i l e  f a t t y  a c id  production
Crude f ib r e  and other s tru c tu ra l co n s t itu en ts , excep t 
l ig n in ,  are degraded by the m ic ro flo ra  in  the r e t ic u lo -  
rumen o f  the ruminant in to  f a t t y  a c id s , and gases; and w ith  
in c reas in g  age the pastu re herbage becomes le s s  p a la ta b le , 
more fib ro u s  and le s s  d ig e s t ib le  due to  in creased  crude 
f ib r e  and s tru c tu ra l con stitu en ts  p rodu ction . The 
s tru c tu ra l carbohydrates o f grasses represen t a con s id era ­
b le  p o rt io n  o f the p lan t dry m atter. I t  ranges from about 
one th ird  o f the dry m atter in  the young plaint to over h a lf  
o f  the dry m atter in  the mature grass (W a ite , Johnston, 
and Armstrong, 1964; A rnold  K ivim ae, 1966; Richards and 
Reid , 1953; Van S oest, 1966; Ademosun and Baumgardt, 1967).
A c e t ic  a c id  forms the major p a rt o f  th e t o t a l  acids 
produced in  the rumen (B i l l s ,  K h a tr i, and Day, 1963;
S torey  and M illa rd , 1965; Jennings, 1957; Ademosun and 
Baumgardt, 1967.)
The amount, ra te  and p rop o rtion  o f  the f a t t y  acids 
depend on the type o f  fe ed  o f fe r e d  the anim als. In  
supplemented feed s  the a c e t ic  a c id  production  is  ju s t  over 
h a l f  o f the t o t a l  ac id  produced in  the rumen (D on e fe r,
23
UNIVERSITY OF IBADAN LIBRARY
Lloyd  and Crampton, 1963; S tan ley , M orita  and Ueyaraa, 1964; 
Tayu ond, 1961). For such feeds the acetic ac id  to  p rop ion ic  
rc id  r a t io  narrows down to ju s t  over 2 . In h igh ly  fib ro u s  
feeds more a c e t ic  a c id  i s  produced and th e p rop ion ic  and 
b u tyr ic  acids con ten ts f a l l .  The a c e t ic  acid  to  p rop ion ic  
acid  r a t io  in creases  and may be as h igh as 7 in  h igh ly  
fib rou s  and unsupplemented feeds (Arm strong, 1964). With 
arjcreasing m atu rity  o f  pastu re , animals tend to  in crease  
th e ir  fe ed  in tak e , and th is  in crease  in  fe e d  in tak e  causes 
a reduction  in  d i g e s t i b i l i t y ,  and in creased  fa e c a l  loss  
-.rmstrong, 1964; Armstrong and B la x te r , 1964). The 
decrease in  d i g e s t i b i l i t y  and fa e c a l  lo s s  are more in  
poor q u a lity  fe e d s .
The f a t t y  acids produced in  th e rumen from the 
s tru c tu ra l carbohydrates and other fe e d  components are 
absorbed and u t i l i z e d  fo r  energy, maintenance, m ilk  f a t  
syn th es is , and depot fa t  syn th es is , (C ra p le t , 1963;
.Armstrong, 1964; Armstrong e t a l,,1 9 5 8 ; 1957 a, b , c ) .
.-.cetic and b u ty r ic  acids a re  l ip o g e n ic , (Maynard and L o o s l i ,  
1962; T y le r ,  1958; West, Todd and Mason, 1968; and 
Crampton, 1956)# w h ile  p rop ion ic  ac id  is  g lu cogen ic ,
24
UNIVERSITY OF IBADAN LIBRARY
•hen more a c e t ic  ac id  is  produced then more f a t  w i l l  be 
deposited in  the m ilk  and body depots. This may be one o f  
tme reasons why the m ilk f a t  in  the White Fu lan i (Zebu) 
r a t t le  in  N ig e r ia  is  h igher than th at o f the F r ie s ia n .
-hen more p rop ion ic  ac id  is  produced and the a c e t ic  acid  
r ; p rop ion ic  a c id  r a t io  i s  sm all, more p ro te in  and less  fa t  
is  deposited  in  the m ilk . The ruminant animal has a fo u r -  
zaambered stomach, namely rumen, reticu lum , omasum and 
eronasum. These compartments develop  from the embryonic 
stomach and not from the oesophagus. The rumen, reticu lum  
i_-jd omasum are not g lan du la r, and they rep resen t the fo r e -  
stomach. Food eaten is  macerated and w e ll  mixed in  the 
rumen, w h ile  the rumen, reticu lum  and omasum su b ject the 
food to  d ig e s t io n  by m icro-organism s b e fo re  passing i t  to  
the glandu lar abomasum and then through the in t e s t in a l  t r a c t .  
Z m  rumen req u ire s  a la rg e  amount o f water fo r  i t s  normal 
f-m otion in g . Th is exp la in s  in  p a r t , the enormous s a liv a r y  
sec re t ion  o f ruminants, and in d ica te s  that ruminants should 
have access to  water a l l  the tim e.
Rumination embraces the m echanical fa c to rs  o f  d ig e s t io n  
•hereby fo od  in  the stomach is  r e g u rg ita te d , rem astica ted ,
25
UNIVERSITY OF IBADAN LIBRARY
r in s a l iv a t e d  and re-sw a llow ed . These four-phases w ith  a 
s i i l l  pause a f t e r  re -sw a llow in g , make up a c y c le  o f
: - ; iC ~ iv e  o f the th es is
The present work is  c a r r ie d  out to  in v e s t ig a te  the 
1ir ion sh ip  between the crude f ib r e  content o f fou r  fo ra ges  
rl-.e v o la t i l e  f a t t y  a c id  com position and m ilk  fa t  o f  the 
Fu lan i (Zebu) c a t t l e .
26
UNIVERSITY OF IBADAN LIBRARY
CHAPTER 2
LITERATURE REVIEW
2.1 D ig es tion  in  th e Ruminant
McCarthy and K es le r  (1956) in  th e ir  in v e s t ig a t io n s  on 
the young ruminant found that a t b ir t h ,  and fo r  a sh ort tim e 
a fte rw a rd s , the c a l f  r e l i e s  on g lucose fo r  i t s  major energy 
needs. L a te r , the g lucose le v e l  in  the b lood  begins to  f a l l  
w h ile  the con cen tra tion  o f  v o la t i l e  f a t t y  ac ids in  the b lood  
in c rea ses . At th is  time rumen a c t i v i t i e s  in crease  as w e ll  
as the c e l lu lo s e  d ig e s t io n  o f  the fe e d *  The rumen, 
reticu lu m , omasum, abomasum a lso  undergo some development 
b e fo re  the v o la t i l e  f a t t y  acids can be absorbed at the 
maximum ra te .  .. Becker, M arsha ll and D ix  Arnold  (1963 ), 
Godfrey (19 61 a ), a ls o  found th a t the volume o f  th e  omasum 
in creased  60 times between 10 and 150 days o f  age. Sutton , 
M cG illia rd  and Jacobson (1963 ), G odfrey (1961b), Wardrop 
(1961 ), Benzie and P h il l ip s o n  (1957) observed that the 
forestom ach e p i th e l ia  developed  ra p id ly  to  adu lt form when 
rougha'ge was g iven  e a r ly  to  c a lv e s .
. Kameoka and Morimoto (1954) in  th e ir  in v e s t ig a t io n s  
on th e  adu lt ruminant rep orted  that a l l  the d ig e s t ib le  crude 
f ib r e  o f  the fe e d  disappeared from the forestom ach o f  the
27
UNIVERSITY OF IBADAN LIBRARY
RUMEN
O E S O P H A G U S
SMMl INTESTINE
RETICULUM
OMASUM
RUMEN
Schematic representation .of'.tile organs that comprise 
the stomach o f the ruminant: rumen, reticulum, omasum, ami 
abomasum. (After Scientific American (1958), 198, 34.)
UNIVERSITY OF IBADAN LIBRARY
;a a t. But Gray (1957 a; b ) in d ica ted  in  h is  work that 70% 
z z s appeared in  th e rumen, 17% in  the caecum, and 13% in  the 
cc lcn . There is  no c e l lu lo s e  or starch  d ig e s t io n  in  the 
aiceiasum or sm all in te s t in e s  (G ray, and W e lle r , 1954 a; b ) .  
r ie y  a lso  observed that s ta rch  is  degraded in  the omasum.
*
I<enority (1961 ), D ehority  and Johnson (1961; 1962) and 
- achards and Reid  (1953) rep o rted  that c e l lu lo s e ,  hemice- 
l l _ io s e  and p e c t in  d ig e s t io n  a re  in flu en ced  by the m aturity  
zz the fo ra g e . In the mature fo ra g e  these con stitu en ts  
t-ecome le s s  d ig e s t ib le  as a r e s u lt  o f  l ig n in  form ing a 
ph ys ica l b a r r ie r  between the p lan t h em ice llu lose  or p e c t in  
and the rumen b a c te r ia . " In  v i t r o "  and " in  v iv o "  s tu d ies  
showed th a t b a l lm i l l in g  in creased  the amount o f  c e l lu lo s e  
d iges ted  in  the rumen, and th is  in crease  became la rg e r  w ith  
advancing m atu rity  and l i g n i f i c a t i o n  o f  the fo ra g e . 
Campling, F re e r , and Balch (1963) rep orted  that the 
in flu en ce  o f  g r in d in g  on the vo lu n ta ry  in tak e  and the 
d i g e s t ib i l i t y  o f  the d ie t  w i l l  depend on the ex ten t to  
which both th e re te n t io n  time and ra te  o f  breakdown o f  
d ig e s ta  in  the gut are a lte r e d  by the g r in d in g . P e l le t in g  
increased  the percen tage o f  p rop ion ic  a c id  and the t o t a l
28
UNIVERSITY OF IBADAN LIBRARY
concen tra tion  o f the rumen acids (Jorgensen and Schu lty , 
1963; Shaw, Ensor, T e lle ch ea , and Lee , 1960; Bensadoun, 
P a lla d in e s , and Reid , 1962; Sa lsbury, H oefer and L iseck e , 
1961; Van S oes t, 1959; S tan ley  and M orita , 1964; and Balch, 
1958). P e l le t in g  a lso  increased  the b lood  sugar le v e ls  
(Jorgensen and S ch u lty , 1963; Shaw, Ensor, T e lle ch ea  and 
Lee, 1960); but decreased m ilk  f a t  and percen tage o f  a c e t ic  
ac id  in  th e rumen l iq u o r  (B alch , Ba.lch, B a r t le t t ,  Cox 
Rowland and Tem er, 1954b; Hawkins, 1963; B ishop, L o o s l i ,  
Trim berger and Turk, 1963; Van S oes t, 1959). B eardsley 
(1964 ); Moore (1964 ); Bishop e t  a l .  (1963 ); reported  that 
p e l le t in g  increased  the ra te  o f fe rm en ta tion  in  the rumen, 
fe e d  in tak e  and fe e d  e f f ic ie n c y  which then r e s u lt  in  
in creased  m ilk  y ie ld  and d a ily  l i v e  w eigh t ga in . P e l le t in g  
a lso  causes in crease  in  the degree o f unsaturation  o f  body 
fa t  (Shaw e t a l . ,  1960) and a decrease in  the dry m atter and 
crude f ib r e  d i g e s t i b i l i t y  (Moore 1964). When high roughage 
was fe d , the molar percen tage o f  a c e t ic  a c id  was g rea te r  
than when low roughage was fe d , (B ishop e t  a l. ,  1963). But 
Balch e t  a l .  (1963) working w ith  cows and fe e d  low in  hay 
but high in  con cen tra te  reported  th a t even when the hay 
in take was on ly  4 l b #i per day, the m ilk  fa t  content d id  not
29
UNIVERSITY OF IBADAN LIBRARY
f a l l  because i t  was fe d  along w ith  a concen tra te  cube 
having the p h ys ica l p rop erty  o f  roughage. A con cen tra te  
m ixture w ith  h igh ly  d ig e s t ib le  carbohydrate l ik e  sta rch  
caused a f a l l  in  the fa t  content o f  m ilk* Starch in  f la k e d  
maize is  thought to  a f f e c t  the rumen f l o r a .  Even when hay 
was fe d  in  the ground form , the f a t  content o f  th e  m ilk 
f e l l  con s id erab ly . The g rea te r  depression  in  m ilk  f a t  w ith  
fla k e d  maize than w ith  the others ( in  fla k e d  maize the 
sta rch  granules are raptured and the sta rch  p a r t ly  
d e x tr in iz e d  by passage between r o l l e r s )  is  thought to  be 
a ssoc ia ted  w ith  the e f f e c t  o f  the sta rch  on the f l o r a  o f 
the rumen. G en era lly , a d ie t  low in  hay and high in  con­
cen tra te  causes a f a l l  in  m ilk  f a t  con ten t, a high iod in e  
va lue and low er so ften in g  p o in t and a lso  a lower R e ich ert 
M e isse l v a lu e . Shaw e t  a l .  (1959) rep orted  th a t concen tra­
tes  w ith  even low er le v e ls  o f  roughage produced m ilk  w ith  
on ly  s l ig h t  decreases in  the m ilk  f a t  con ten t. The 
p h ys ica l p rop erty  o f  roughage i s  not found in  straw .
Balch (1953) rep orted  that r e la t i v e l y  more p rop ion ic  a c id  
was produced from the d ie t  con ta in in g  f in e ly  ground hay 
than from the long-hay d ie t .  The r e s u lt  o f  Gray e t  a l .  
(1958) showed that on ly  w e l l  d ig es ted  m a te r ia l reached the
30
UNIVERSITY OF IBADAN LIBRARY
omasum and abomasum from the rumen even in  the p e r iod  
im m ediately a f t e r  fe e d in g . For th is  reason th e exten t o f 
d ig e s t io n  in  the rumen cou ld  not be determ ined from the 
changing c o e f f ic ie n t s  in  the rumen i t s e l f ,  but was in d ica ted  
by the more constant va lues in  the omasum and abomasum.
The ex ten t o f d ig e s t io n  o f c e l lu lo s e  in  the rumen o f 
sheep fe d  wheaten hay and wheat straw  was about 30%, on 
wheaten hay about 40%, and on lucerne hay more than 50%.
The ex ten t o f d ig e s t io n  o f pentosans and s o lid s  in  the 
rumen was ve ry  s im ila r  to  that o f  c e l lu lo s e .  Badawy (1958) 
rep orted  that the r e t ic u lo  rumen sac 5 hours a f t e r  fe ed in g  
was found to  con ta in  74% o f the t o t a l  dry m atter o f the 
whole d ig e s t iv e  t r a c t .  Owing to  dehydration , the dry 
m atter percen tages were con s id erab ly  h igher in  the omasum 
and the co lon  than in  the other pa rts  o f  the t r a c t ,  the 
omasum having the h ighest va lu e . The h ighest va lu es fo r  
the lower v o l a t i l e  f a t t y  acids as m i l l i  eq u iva len t per 
100 ml contents or as a r a t io  t o  l ig n in  corresponded to  
the main s it e s  o f  m ic rob ia l a c t i v i t y ,  mainly the r e t ic u lo  
rumen sac, caecum and co lon . The mean t o t a l  d ig e s t io n  
c o e f f i c ie n t  o f  energy was 68%. Rogerson (1958) a ls o  
rep orted  that the rumen and reticu lum  togeth er con ta ined ,
31
UNIVERSITY OF IBADAN LIBRARY
x  a dry matter bas is  approxim ately two th ird s  o f  th e  
a^gesta found in  the a lim entary t r a c t *  There were in d ic a ­
tions th a t, as the amount o f  roughage in  the d ie t  decreased, 
•the p rop ortion  in  the omasum and sm all in te s t in e  decreased, 
S ecretion s in to  the sm all in te s t in e  re su lted  in  g rea te r  
r r a n t it ie s  o f d ig e s t ib le  n u tr ien ts  in  the conten ts o f  th is  
section  than in  those o f  the abomasum, and in  some 
instances an even g rea te r  weight o f wet d ig e s ta  was found 
-ban the w eight o f  fo o d  in ges ted . Increases in  the qu an tity  
o f n itrogenous m a te r ia l c o n s titu ted  th e g rea te s t  change, 
although in creases in  f a t  and carbohydrate con ten t, 
togeth er w ith  the h igher p ro te in  va lu e , r e s u lted  in  
s u b s ta n t ia lly  enhanced energy va lu e .
Researches in to  the fe ed in g  frequency were c a r r ie d  out 
by Knox and Ward (1961 ); Put nan,. G u tie rre z , and Davis (1961 ). 
The form er reported  a s ig n i f ic a n t  in c rease  in  v o l a t i l e  
f a t t y  a c id  con cen tra tion  when fe ed in g  frequency was 
increased  from 2 to  8 times a day. Putnan e t  a l .  (1961) 
fed  ca lv e s  2 and 10 times a day and a lso  observed an 
in crease  in  the average v o la t i l e  f a t t y  a c id  con cen tra tion s . 
The in creases  however were not s ig n i f ic a n t .  When the 
animals were fe d  2 times a day th ere  were two peaks one
32
UNIVERSITY OF IBADAN LIBRARY
to  two hours a f t e r  fe e d in g , which dropped to  the low est 
p o in t the hour b e fo re  fe ed in g *  On the o ther hand when 
they were fe d  8 times a day there was a more constant con­
cen tra tio n  o f  v o la t i l e  f a t t y  acids during the twenty fou r 
hour p e r io d . A c e t ic  a c id  was produced more than the other 
acids when the animals were fe d  2 tim es, but p rop ion ic  
acid  predominated when they were fe d  8 tim es a day.
B utyric ac id  a ls o  in creased  to  a le s s e r  ex ten t when fe d  8 
times a day. The r e s u lt  o f  the work o f Knox and Ward 
(1961) showed that fe ed in g  ruminants s e v e ra l times a day 
produced the same e f f e c t  as fe ed in g  p e l l e t s .  These 
s im ila r  a f fe c t s  are the s ig n i f ic a n t  in c rease  in  v o l a t i l e  
f a t t y  ac id  con cen tra tion  and increased  p rop ion ic  and b u ty r ic  
a c id  p roduction  to ge th er  w ith  in creased  weight ga in  and 
in creased  e f f ic ie n c y  w ith  which d ig e s t ib le  energy is  
converted  to  4% fa t  co rre c ted  m ilk .
The r e s u lt  o f  the work o f  Pa lm qu ist,Smith and 
Ronning (1964) showed that when cows a re  fe d  roughage at 
6 a.m. and 6 p.m. and Concentrates a t 2 a.m. and 2 p.m. 
the m ilk  f a t  percen tage decreased s ig n i f i c a n t ly .  The 
same th ing happened when the roughage and concen trates
33
UNIVERSITY OF IBADAN LIBRARY
irare fe d  at 6 a.m. and 6 p.m. The decrease , however, was 
s ig n i f ic a n t ly  le s s  when the concen trates were fe d  separa­
t e ly  from the hay than when they were fe d  at the same tim e. 
They p os tu la ted  the theory  th a t fe ed in g  hay p e l l e t s  and 
gra in  at separate times p rov id es  a more even supply o f  
rumen ferm en tation  products fo r  m ilk  f a t  s yn th es is .
V o la t i le  f a t t y  ac id  production  in  the rumen is  
a f fe c te d  by the type o f  carbohydrate in  the fe e d .  Shaw 
e t  a l . (1959) rep orted  that cows fe d  ra tio n s  made up 
p r im a r ily  o f  cooked high sta rch  feeds produced m ilk  w ith  
low f a t  con ten t. A ra t io n  composed p r im a r ily  o f  bread 
e f fe c t e d  a decrease o f  more than 30% in  the fa t  content o f 
m ilk and a low le v e l  o f b u ty r ic  acid  in  the m ilk  f a t  but 
had l i t t l e  e f f e c t  on the iod in e  number o f th e  m ilk  f a t .  
There was a s im ila r  e f f e c t  when feeds composed m ainly o f  
cooked r i c e ,  cooked p o ta to  meal, bread and molasses were 
fe d . The decrease o f m ilk  f a t  was worsened by adding 
skim m ilk  to  the r a t io n . The decrease o f  m ilk  fa t  can be 
preven ted  by fe ed in g  low energy in ta k e . Th is r e s u lt  
supports the e a r l ie r  work o f  Balch e t a l .  (1955 ).
Johnson, D eh ority , Conrad, and Davis (1962) observed a 
s ig n i f ic a n t  d if fe r e n c e  between the d i g e s t i b i l i t i e s  o f  the
34
UNIVERSITY OF IBADAN LIBRARY
d ried  and undried samples o f mixed fo ra g e s . The undried 
samples were about 7% more d ig e s t ib le  than th e d r ie d  ones. 
Bowden and Church (1962) rep orted  that the d i g e s t i b i l i t y  
o f oven dry samples o f  T a l l  fescu e d i f f e r e d  from fre sh  
fro zen  samples, oven dry samples being b e t te r  d ig es ted .
But these two samples produced e s s e n t ia l ly  the same molar 
percen tages and t o ta l  amount o f  v o la t i l e  fa t t y  a c id s .
F isher and E l l i o t  (1966) rep o rted  that the in fu s ion  o f 
g lucose re s u lte d  in  redu ction s in  f a t  y i e ld  and percen t 
f a t .  In fu s ion  o f p rop ion ate  a lso  decreased m ilk  f a t ,  but 
to  a le s s e r  e x te n t. Richards and Reid (1953 ); Ademosun 
(1970 ); W aite e t  a l (1964 ); Armstrong (1964 ); Ademosun e t 
a l . (1967) in  th e ir  in v e s t ig a t io n s  observed that pastu re 
grasses became more u npa latab le  and less  d ig e s t ib le  as they 
matured. With in c reas in g  age the amounts o f c e l l  w a ll 
con stitu en ts  ( l i g n in ,  c e l lu lo s e ,  h em ice llu lo se ) in creased  
p ro g r e s s iv e ly  and p e c t in s , sugars, crude p ro te in  and eth er 
ex tra c t  decreased. L ign in  was com p lete ly  u nd igested , 
w h ile  sugars were almost com p lete ly  d ig e s te d  in  the 
herbage a t the th ree  stages o f  growth (v e g e ta t iv e ,  boot to  
e a r ly  head, and f u l l  b loom ). The grazing animals u su a lly
35
UNIVERSITY OF IBADAN LIBRARY
s e le c t  l e a f i e r  and more h igh ly  d ig e s t ib le  p o rtion s  o f  the 
p la n t, but hand-fed or s t a l l - f e d  s tee rs  consumed the 
herbage cut and o f fe r e d  to  them.
S a liv a  production  a ls o  a f fe c t s  rumen d ig e s t io n .
W ilson (1964) in  h is work on d ig e s t io n  in  the ruminant 
reported  that s e c t io n  o f  p a ro t id  ducts and nerves decrea­
sed the in take o f  lucerne c h a ff  d ie t  o f  hay, but had no 
e f f e c t  on the in take o f straw  or m ille d  lu cerne hay. 
A r t i f i c i a l  s a l iv a  increased  fo od  in take to  15% below the 
i n i t i a l  in ta k e . The passage o f  food  and ra te  o f  c e l lu lo s e  
d ig e s t io n  were a lso  decreased , but the d i g e s t i b i l i t y  o f 
dry matter was s l i g h t l y  in creased . A fte r  s e c t io n  o f  the 
nerve and duct to  the l e f t  p a ro t id  gland th ere  was an 
in crease o f  64% in  the s e c re t io n  o f the r ig h t  p a ro t id  gland. 
A fte r  s e c t io n  o f  one or both ducts and nerves th ere  was an 
in crease in  the s e c re t io n  o f  re s id u a l s a l iv a .  McDougall 
(1948) showed the importance o f s a l iv a  in  rum ination.
The type and number o f  m icro-organism s in  the f o r e ­
stomach and the type o f end products a f f e c t  the ra te  o f  
d ig e s t io n . Bowden and Church (1962) rep orted  th at the 
d ig e s t iv e  c a p a c it ie s  o f the rumen liq u o r  c o l le c t e d  from the
36
UNIVERSITY OF IBADAN LIBRARY
same s te e r  on d i f f e r e n t  days d i f f e r e d  con s id erab ly . 
Montgomery, S chu ltz and B&umg&rdt' (1963) rep o rted  that 
" in  v i t r o " c e l lu lo s e  d ig e s t io n  showed that th ere  i s  ve ry  
l i t t l e  d i f fe r e n c e  in  the a b i l i t y  o f  the m icro-organism s 
taken from the rumen o f  cows o f  va ry in g  hay in ta k e , to  
d ig e s t  c e l lu lo s e .  The m icro-organism s need some fa t t y  
acids fo r  e f f i c i e n t  work. Wegner and Foster (1960) 
reported  that some o f  the m icro-organism s is o la t e d  from the 
rumen f a i l e d  to  grow on subcu ltu re in  the b asa l medium 
unless i t  was enriched  w ith  rumen f lu id  or a m ixture o f 
f a t t y  acids commonly found in  the rumen. Gray and P ilg r im  
(1952) rep o rted  th a t the ra te  o f  production  o f  v o la t i l e  
f a t t y  acids by the micro f l o r a  was ra p id  at f i r s t ;  60% o f 
the t o t a l  v o la t i l e  fa t t y  acids was formed in  the f i r s t  
quarter o f  the ferm en tation  p e r io d ; and th e r e a fte r  d e c lin ed  
to  a lower but f a i r l y  steady l e v e l .  They a lso  need some 
c a ta ly s ts  fo r  e f f i c i e n t  fu n c tio n : fo r  example V e il lo m e lla  
gazogenes and sp ec ies  o f  the genus P ro p io n i- bacterium .
Gray e t  a l .  (1962) found that p la n t n itrogen  was 
ra p id ly  a ttacked  and the m icro-organism s grew ra p id ly . 
D if fe r e n t  d ie ts  gave r is e  t o  d i f f e r e n t  p rop o rtion  o f  
p ro to zo a l-n itro g e n  and b a c te r ia l-n it r o g e n  in  m ic ro b ia l-
37
UNIVERSITY OF IBADAN LIBRARY
n itrogen  f r a c t io n .  In th e ir  e a r ly  experim ent Gray e t  a l .
1958) found that 63-82% o f  the t o ta l  n itro g en  was presen t 
as m ic ro b ia l-n itro g en , 11-27% as p la n t-n itro g e n , and 
5-10% as so lu b le  n itro g en . Gray e t  a l .  (1958) c a lcu la te d  
•the qu an tity  o f  n itrogen  reaching the abomasum and duodenum 
to be equ iva len t to  n ea r ly  100% o f  the d ie ta ry -n itro g e n  fo r  
sheep fe d  wheaten hay (N = l. l% ),  but on ly  about 65% fo r  
animals fe d  on a m ixture o f  wheaten hay and lu cerne hay
N=1.8%), and as l i t t l e  as 48% fo r  those fe d  on lu cerne 
hay alone (N=2.9%). An amount in  excess o f the d ie ta ry  
n itrogen  was found to  reach the abomasun in  the sheep fe d  
on a d ie t  o f wheaten hay and wheat straw , very  low in  
n itrogen  (0 .7% ). In a sheep fe d  on lu cerne hay, the con­
ce n tra t io n  o f  ammonia in  the rumen f lu id  was probab ly never 
le s s  than 20 mg. n itro gen  per 100 m i l l i l i t e r ,  and fo r  8
hours a f t e r  fe ed in g  i t  was much g re a te r , reach ing a
♦
maximum va lu e o f  more than 50 mg. n itrogen  per 100 
m i l l i l i t e r .  In the sheep fe d  on wheaten hay the concen­
tra t io n  o f ammonia remained fo r  the g rea te r  p a rt o f  the 
day a t 5-6 mg. n itrogen  per 100 m i l l i l i t e r  rumen f lu id ,  
and on ly  rose  above th is  va lu e to  about 12 mg. per 100
38
UNIVERSITY OF IBADAN LIBRARY
m i l l i l i t e r  fo r  3-4 hours a ft e r  fe e d in g . The ex tra  sources 
o f n itrogen  are the s a liv a ry -n itr o g e n  and the g a s t r ic  ju ic e -  
n itro g en . Badawy, Cam pbell, F e l l ,  Cuthbertson and Markie 
(1958) rep orted  th a t r e la t iv e  to  l ig n in ,  the ra t io s  ( t o t a l  
n itrogen  and non -prote in  n itrogen ) in d ica ted  an in c rease  
o f  n itrogen  in  the abomasum, but the in crease  was much 
g rea te r  in  the proxim al h a lf  o f  the sm all in te s t in e  than 
in  the d is ta l h a l f .  When the in t e s t in e  was d iv id ed  in to  
fou r p a r ts , p ro te in  n itro gen , and n on -p ro te in -n itrogen  
concen tra tions in creased  con s id erab ly  in  the f i r s t  quarter 
o f  the sm all in te s t in e  and decreased p ro g re s s iv e ly  in  the 
other q u a rte rs . L ign in  ra t io s  in d ica te d  that the non- 
p ro te in -n itro g e n  con tr ib u ted  a g re a te r  p rop ortion  to  the 
in crease  in  the sm all in te s t in e  than d id  p ro te in -n itro g e n , 
though the la t t e r  a lso  rose . This con s id erab le  r is e  in  
n itrogen  con cen tra tion  in  the f i r s t  quarter o f  the sm all 
in te s t in e  was not found in  l iv in g  sheep f i t t e d  w ith  perma­
nent cannulas, or w ith  an e s te r io r iz e d  f lo w  o f  the sm all 
in te s t in e  when the cannulas were lo c a ted  w ith in  the f i r s t  
few  fe e t  from the p y lo ru s . A comparison o f  the h is to lo g y  
o f  the mucosa o f the sm all in te s t in e  o f  sheep shot in  the 
fr o n ta l reg ion  w ith  a humane k i l l e r  and then b led , w ith
39
UNIVERSITY OF IBADAN LIBRARY
ecimens removed from sheep under pen tobarb itone anaesthe­
s ia  revea led  that the mucosa remained r e la t i v e ly  in ta c t  
--Then removed under th is  anaesthesia , on the other hand 
there was a very  marked shedding o f  th e ep ith e liu m  in  the 
animals that had been sh ort and bled*. Th is d i f fe r e n c e  
n igh t be expected to  account fo r  p a rt o f  the observed r is e  
in  n itro gen .
The p o s s ib i l i t y  o f  fe ed in g  cows p r o t e in - fr e e  feeds 
fo r  m ilk  production  was c a r r ie d  out by V irtan en  (1966 ); 
P u r if ie d  carbohydrates were fed  along w ith  la b e l le d  urea 
and ammonium su lphate. He es ta b lish ed  the fa c t  that 
syn thesis o f b a c te r ia l  p ro te in  in  the rumen o f la c ta t in g  
cows fe d  p u r i f ie d  carbohydrates, w ith  urea and ammonium 
sulphate as the s o le  source o f  n itro gen , cou ld  be in creased , 
through the fe e d  adap ta tion , to  a l e v e l  adequate not on ly  
fo r  maintenance o f the cow, but a lso  fo r  a r e la t i v e ly  high 
m ilk p rodu ction . The com position o f  the m ilk  was s im ila r  
to  that o f  normal m ilk  r ich  in  fa t  and p ro te in . In th e ir  
work, Salsbury e t  a l .  (1961) rep orted  that a ra t io n  o f 
c e l lu lo s e ,  s ta rch , and urea was found to  be the
sim p lest combination capable o f m ain ta in ing the c e l lu lo s e
40
UNIVERSITY OF IBADAN LIBRARY
d ig e s t in g  a b i l i t y  o f rumen in g es ta  fo r  th ree days.
C e llu lo s e  p lus a p u r i f ie d  soyabean p ro te in  was more e f f e c ­
t i v e  than c e l lu lo s e  p lus u rea. When the ra t io n  con s is ted  
o f  on ly c e l lu lo s e ,  s ta rch , and u rea, a source o f  amino 
acids was requ ired  to  m aintain c e l lu lo s e  d ig e s t io n  f o r  
more than th ree days. W ith th is  r a t io n , no d e f ic ie n c y  o f  
v a le r ic  or is o v a le r ic  ac id  was demonstrated, and yeast 
e x tra c t  was the most e f f e c t i v e  a d d it iv e .
2.2 Absorption  in  th e Ruminant
Kameoka and Morimoto (1959) rep o rted  that 61.7 - 
85 .-4% organ ic  m atter was absorbed in  the rumen, reticu lu m , 
and omasum o f  g oa ts . The absorption  o f  d ig e s t ib le  p ro te in  
in  th e forestom ach ranges from 20 -• 52.1%, w h ile  about
65.7 to  96.9% o f  th e n itro gen  f r e e  e x tra c t  was absorbed 
from the forestom ach. About 33 -  64% o f water p resen t in  
the r e t ic u la r  con ten t was absorbed through the w a ll o f  the 
omasum (Gray, 1954 a; b ) .
Many in v e s t ig a to r s ,  p a r t ic u la r ly  those in  the tempe- - 
ra te  r e g io n s , have worked on the end products o f  d ig e s t io n  
in  the ruminants, and the absorption  and metabolism o f  such 
products . Some o f the in v e s t ig a t io n s  were c a r r ie d  out on 
in ta c t  anim als, w h ile  other workers found the " in  v i t r o 11 
method more conven ien t.
41
UNIVERSITY OF IBADAN LIBRARY
John, B arnett and Reid (1957 ), S tan ley , M orita  and 
Tayama (1964) c a r r ie d  out in v e s t ig a t io n s  on d i f f e r e n t  
roughage le v e ls .  They found that a c e t ic  a c id  was the major 
acid  produced, s in ce  i t  formed over h a lf  o f the t o t a l  acids 
produced in  the rumen. John e t a l .  (1957) noted that rumen 
liqu ors  con ta in in g  the same su bstra te  produced id e n t ic a l  
Y .F .A . and that the potency o f  rumen liq u o r  v a r ie s  through­
out the season. A c e t ic  a c id  was a lso  th e  major a c id  produ­
ced in  th e ir  work. P rop ion ic  ac id  became the major a c id  
produced in  th e ir  " in  v i t r o " procedure as the season 
advanced. B u tyric  and v a le r ic  acids gave a curve that 
fo llo w e d  p a r e l l e l  course throughout the season. Th eir 
fin d in gs  were supported by the re s u lt  o f  D onefer, L lo yd , 
and Crampton (1963) who used sheep in  th e ir  experim ent.
On a molar percen tage b a s is , a c e t ic  was the major acid  
produced, w h ile  the production  o f p rop ion ic  ac id  was next 
to  th at o f  a c e t ic  a c id , and b u ty r ic  a c id  had the low est 
p ercen tage.
S tew art, S tew art and Schu ltz  (1958) rep o rted  that the 
v o la t i l e  f a t t y  a c id  concen tra tions in creased  a f t e r  fe ed in g  
in  a l l  cases. The average v o l a t i l e  f a t t y  ac id  concentra-
42
UNIVERSITY OF IBADAN LIBRARY
-ions by w eight in  th e ir  experim ent were 5.2% fo r  v a le r ic  
acid , 16.5% fo r  b u ty r ic  a c id , 18.3% fo r  p ro p io n ic  a c id , and 
60% fo r  a c e t ic  a c id . The r e la t i v e  p roportion s o f  the 
v o la t i l e  f a t t y  acids in  the rumen remained constan t. The 
t o ta l  q u a n t it ie s  o f  v o la t i l e  f a t t y  a c id  in creased  abruptly  
a ft e r  fe e d in g , but by 8 hours a f t e r  fe ed in g , the t o t a l  
q u a n tit ie s  decreased . The peak in  t o t a l  production  ra te  
was in  some cases reached w ith in  one hour a f t e r  fe ed in g . 
Their work a lso  showed th at th ere  is  no p r e fe r e n t ia l  absorp­
t io n  o f  the va riou s v o l a t i l e  f a t t y  acids from the norm ally 
fu n ction in g  rumen, s in ce  absorp tion  is  p ro p o r tio n a l to  
concen tra tion  o f v o l a t i l e  f a t t y  a c id s .
In in v e s t ig a t io n s  o f D onefer, L loyd  and Crampton(1963) 
a c e t ic  to  p rop ion ic  acids r a t io s  o f 2 .4  to  2 .6 were 
ob ta ined . These were not s ig n i f ic a n t .  S tan ley , M orita  
and Ueyama (1964) ob ta ined  a c e t ic  to  p rop ion ic  a c id  r a t io  
that ranged between 2.1 and 2.74.
Raymond and Terry  (1966) using an " in  v i t r o " method 
reported  that fib ro u s  fe ed s  o f  low d i g e s t i b i l i t y  gave an 
a c e t ic  to  p rop ion ic  a c id  r a t io  g rea te r  than 7 i2 . As 
in c reas in g  amounts o f  carbohydrates are g iven , the rad io
43
UNIVERSITY OF IBADAN LIBRARY
-ends to  narrow reaching almost u n ity  on a m ain ly concen­
tra te  d ie t .  The in v e s t ig a t io n  o f  Brown, S tu l l  and S co tt 
1962) showed th a t low  rouphage d ie t  caused a s ig n i f ic a n t  
increase and the high rouphage d ie t  decreased the h igher 
fa t t y  a c id s . The molar r a t io s  o f any o f  th e  v o l a t i l e  f a t t y  
acid  in  the rumen were not s ig n i f ic a n t ly  a lte r e d  on the 
high rouphage d ie t .  Sutton (1968) in fu sed  monosaccharides 
and observed in creases in  the con cen tra tion  o f the v o la t i l e  
f a t t y  a c id  and decrease in  the pH. The ra te  o f  change in  
the molar p rop ortion s  o f th e v o l a t i l e  f a t t y  acids was 
g rea te s t  in  the f i r s t  fou r hours and decreased th e r e a fte r .
Naga and E l-S h az ly  (1969) rep o rted  that the v o l a t i l e  
f a t t y  a c id  con cen tra tion  in  the b u ffa lo  fed  concen tra te  
plus straw  was s ig n i f ic a n t ly  h igher than in  the b u lls .
Raymond, and T e rry  (1966) in  v e ry  ex ten s iv e  t e s ts  
observed a wide range o f  pH values 11 in  v i v o 11. The pH 
ranges from 5.5 -  7 .0 . They are th e r e fo r e  o f  the op in ion  
that " in  v i t r o "  experim ents should be c a rr ie d  out at pH 
between 5,5 and 8 ,0 .
John, B arnett and Reid  (1957) in  th e ir  work on fre sh  
grass rep orted  a c e t ic  a c id  as the major a c id  produced,
44
UNIVERSITY OF IBADAN LIBRARY
r>_t a O th e  season advanced, p rop ion ic  a c id  was the major 
product. B u tyric and v a la r ic  ac ids gave a curve that 
fo llo w ed  more or le s s  p a r a l le l  course throughout the season. 
The potency o f  rumen liq u o r  v a r ied  throughout the season.
In animals fe d  roughages on ly 61.9 -  73.2% o f 
d ig e s t ib le  ether ex tra c t  was absorbed from the forestom ach, 
but lower values were ob ta ined  when concen tra tes p lus hay 
-*as fe d ,  (Kameoka and Morimoto, 1959). On re ten t io n  times 
o f  fe e d , Combe and Kay (1965) observed that in  the sm all 
and la rg e  in te s t in e s  the re ten t io n  tim es were in v e rs e ly  
r e la te d  to  the dry m atter in tak e  o f  a p a r t ic u la r  fe e d  and 
fa e c a l ou tput, Conrad e t  a l .  (1958) working w ith  4-7 
month o ld  ca lves  measured the b lood  f lo w  o f the forestom ach 
and rep orted  that about 63 gm. o f  a c e t ic  ac id  and 25 gm. o f 
p rop ion ic  a c id  were absorbed fo r  each pound o f  dry fe ed  
consumed during a 24 hour p e r io d . Johnston, K es le r  and 
McCarthy (1961) a lso  working w ith  ca lves  rep orted  that 51% 
o f the v o l a t i l e  f a t t y  ac id  is  absorbed in  th e reticu lum , 
w h ile  83% is  absorbed in  the omasum. C alves can absorb 
fa t t y  acids ra p id ly  i f  they are in troduced to  roughage 
very  e a r ly  in  l i f e  (Su tton  e t  a l . ,  1953; G odfrey,
45
UNIVERSITY OF IBADAN LIBRARY
: ; * 1  a; b ; S i jp e s t e i jn  and E lsden, 1952) in  th e ir  research  
with Qheep noted that the convers ion  o f  c e l lu lo s e  to  
rrop ion ic  a c id  proceeded in  p a rt v ia  su cc in ic  a c id , 
i .c c in a te  accumulated fo r  a short time a f t e r  fe e d in g , 
suggesting that a la rg e  amount o f  succinate was produced 
suring d ig e s t io n . Added su cc ina te is  ra p id ly  absorbed 
from the rumen, a t the same tim e th ere  was an in c rease  
in  the con cen tra tion  o f  p rop ion ic  ac id  on ly . Some o f  the 
v o la t i l e  f a t t y  acids produced a rs  con verted  to  -other 
acids -
Johnston e t  a l .  , (1961) working w ith  ca lves  in je c te d  
14
Na-butyrate-C in to  th e omasum and found that the
14
su tyra te  C was ra p id ly  absorbed from the omasum to  the 
b lood o f the omasal v e in , but 50% o f  the recovered  la b e l 
in  the omasal b lood  was in  the form o f  la c t ic  a c id . This 
in d ica ted  on unknown pathway fo r  the con vertion  o f bu ty­
ra te  to  la c ta te  by omasal ep ith e liu m . Lu ick (1960) used 
c a t t l e  and observed that bu tyra te  is  converted  t o j? " ' 
phydroxy b u ty r ic  ac id  by rumen ep ith e liu m . Gray e t  a l .  
(1952) suggested th a t a con s id erab le  p a rt o f  the h igher 
f a t t y  acids in  the rumen f lu id  may be produced by
46
UNIVERSITY OF IBADAN LIBRARY
secondary rea c tion s  from both a c e t ic  and p rop ion ic  ac ids . 
This v^s supported by th e ir  observa tion  that at the end 
o f  ferm en tation  some o f  the carbon o r ig in a l ly  presen t in  
the carboxyl group o f a c e t ic  ac id  was d is tr ib u te d  among 
a l l  the h igher f a t t y  a c id s , w h ile  pa rt o f the carboxy l 
carbon o f  the p rop ion ic  ac id  appeared in  v a le r ic  but not 
in  b u ty r ic  a c id . This in d ica ted  syn thesis o f  h igher acids 
by condensation o f  the lower ones w ith  two carbon comp­
ounds in  equilibrium w ith  a c e t ic  a c id . Joyner e t a l .  (1963) 
in  the r e s u lt  o f  th e ir  s tu d ies  observed the ra p id  
absorption  o f la b e l le d  bu tyra te  through the omasal w a ll 
and saw evidence o f  i t s  con vertion  to  another v o la t i l e  
f a t t y  a c id . The bu tyra te  is  found as phydroxy
b u ty r ic  ac id  in  the b lood  and is  in  c lo s e  a sso c ia tio n  
w ith  b lood  la c ta t e .
Gray (1948) in  h is  work on absorp tion  o f acids
rep orted  that between 10 and 14% o f  the a c e t ic  a c id  and
■ *
about 47% o f  the p rop ion ic  ac id  in troduced was absorbed 
w ith in  6 hours. The amounts absorbed were not a lte r e d  
by the in c lu s ion  o f  in organ ic  phosphate in  the m ixture.
In an e a r ly  work on the absorption  o f  acids in  th e
47
UNIVERSITY OF IBADAN LIBRARY
ruminant, Gray (1947) rep o rted  that when sodium s a lt  o f  
acetiqr) b u ty r ic ,  and p rop ion ic  acids are fe d  and th e 
animals a te  lucerne th ere  was a more ra p id  absorp tion  o f 
p rop ion ic  a c id  than o f  the o ther a c id s . On the b as is  o f 
r e la t iv e  ra te s  o f absorp tion  o f these ac ids at concentra­
tion s  in  which they were found to  occur in  the normal 
rumen during the fe rm en ta tion  o f  wheaten hay c h a f f ,  i t  
was concluded th at a much g rea te r  p rop ortion  o f p rop ion ic  
ac id  is  formed than is  in d ica ted  by an a lys is  o f the acids 
found in  th e rumen (G ray, 1947; 1961). Montogomery e t  a l . 
(1963) rep o rted  that th ere was a s l ig h t  decrease in  b lood  
urea, su ggesting that the ac id  absorbed in to  the b lood  
stream was b e in g  n eu tra liz ed  by the u rea, which would 
prevent a drop in  the b lood  pH. B a rc ro ft , McAnally and 
P h ilip so n  (1944) in  a ve ry  e a r ly  work on absorp tion  o f 
acids observed  th a t the con cen tra tion  o f  v o l a t i l e  fa t t y  
acids o f the b lood  d ra in in g  the rumen is  con s id erab ly  
h igher than th a t o f  p e r ip h e ra l b lood in  which l i t t l e  
v o la t i l e  f a t t y  ac id  is  p re sen t. V o la t i l e  fa t t y  ac ids in  
s ig n if ic a n t  amount i s  presen t in  b lood  d ra in in g  the omasum 
and the caecum, but is  absent from the b lood  d ra in in g  the
48
UNIVERSITY OF IBADAN LIBRARY
aromasum, the sm all in t e s t in e ,  and th e  empty rumen, and 
w a t e r ( f i l l e d  rumen. Badawy (1958 a; b ) rep orted  that the 
apparent absorption  o f  the v o la t i l e  f a t t y  acids was o f the 
order o f  18 gm (exp ressed  as a c e t ic  a c id ) in  the omasum 
and 4 gm in  the abomasum in  24 hours. Dehydration took 
p la ce  in  the omasum. I t  appeared to  occur to  the g re a te s t  
ex ten t in  the d ig e s ta  between the laminae at the deepest 
p o in t w ith in  the g rea te r  cu rvatu re, w ith  a tendency to  
fu rth er  dehydration  towards the abomasal o r i f i c e .  The 
con cen tra tion  o f  n itro gen  in  terms c f the markers used was 
le s s  in  the omasum than in  the reticu lum , in d ica tin g  that 
absorp tion  occured in  the omasum. The con cen tra tion  o f  
v o la t i l e  f a t t y  a c id s , decreased p ro g r e s s iv e ly  through the 
deeper zones o f  the omasum and from the reticu lum  to  the 
abomasum, in d ic a t in g  absorp tion  during the time spent in  
the omasum. I t  was ca lcu la te d  to  be o f  the order o f 77%
o f th a t en terin g  the organ, Rogerson (1958) observed a
♦
la rg e  degree o f 'ap p a ren t' absorption  o f  both n u tr ien ts  
and water took p la ce  from the omasum. Absorption  o f  
n u tr ien ts  was almost completed by th e  tim e the caecum was 
reached. Apart from a sm all amount o f absorp tion  from the
49
UNIVERSITY OF IBADAN LIBRARY
liBCffli, most o f the dehydration occured in  the term ina l 
: where a s ig n i f ic a n t  amount o f  so lu b le  ash was a lso
absorbed.
V o la t i l e  fa t t y  acids absorption  is  a f fe c t e d  by the 
ra^en pH, w h ile  the pH is  a ls o  a f fe c te d  by fe ed  and 
v o la t i l e  f a t t y  acid  con cen tra tion s . Emery and Brown 
1961) fe d  sodium and potassium b icarbonate  to  cows and 
observed th a t the sodium b icarbonate in creased  the rumen 
pH. Sutton e t  a l .  (1963) in  th e ir  in v e s t ig a t io n  o f the 
absorp tive  a b i l i t y  o f  the rumen observed that the absorp­
t io n  ra te  o f  v o l a t i l e  fa t t y  acids decreased as th e ir  chain 
len gth  decreased at acid  pH values fo r  ca lves  fe d  s ta r te r  
or m ilk . A t a lk a lin e  pH a decrease w ith  decreas in g  chain 
length  was in d ica te d . Gray (1948) rep orted  that a t  ac id  
rea c t io n s , a c e t ic  and p rop ion ic  acids are absorbed r e a d ily ,  
but absorp tion  d id  not occur to  any s ig n i f ic a n t  ex ten t at 
pH o f  7 .5 . A c e t ic  a c id  was not absorbed from the rumen 
when in troduced as a s l i g h t ly  a lk a lin e  pH o f 7.5 so lu t io n  
o f sodium a ce ta te . Rook e t  a l .  (1963) observed that 
a c e t ic  ac id  depressed the pH o f the rumen liq u o r  s l i g h t ly .  
Armstrong and B lax ter (1957 a; b ) rep orted  that a m ixture
50
UNIVERSITY OF IBADAN
LIBRARY
propionic and butyric acids in the molar ratio of 3:2 
-— used into the sheep caused a more rapid absorption of 
nu-yric acid than propionic acid. Later the reverse 
recurred. This change was associated with a rise in the 
pH of the rumen. Barcroft et al, (1944) reported that 
<rben judged by the concentration found in the blood . 
leaving the rumen, the rate of absorption of the sodium 
ralts of acetic, propionic and butyric acids, shows that 
acetate is more rapidly absorbed, propionate less so, 
while butyrate is slowly absorbed. The quantity of 
rlatile fatty acids calculated as acetic acid absorbed 
err an hour from the reticulum and rumen together is 
estimated to vary from 1 to 5 gm. Bensadoun et al. (1952) 
reported that there was essentially no glucose absorption 
from the gastro intestinal tract. Appreciable amount of 
1 _mic acid (4.7 to 13.4 gm/day) were absorbed. The total 
r.antities of volatile fatty acids absorbed per day ranged 
from 73 to 89 gm/day. Gray and Pilgrim (1951) observed 
that there was considerable increase in the concentration 
:f acid in acid rumen after feeding. By the end of the 
uiy, the concentration had returned to its original value.
51
UNIVERSITY OF IBADAN LIBRARY
Gray et al, (1952) reported that propionic acid increases 
and acetic or butyric acid decreases for some hours after 
feeding, after which these changes are reversed and the 
mixture gradually returns to its original composition, 
Waldern et al, (1963) reported that the greatest absorp­
tion of acids occurred between 3 and 9 hours after feeding, 
when the concentration of the volatile fatty acids in the 
rumen was maximal.
2.3 SYNTHESIS OF FAT IN THE RUMINANT
The pathways of conversion of volatile fatty acids to 
fat in the milk or depot fat were investigated by many 
workers. Popjack and Beakmans (1950; 1953) noted that in 
female rabbits cholesterol is synthesised in the liver, 
intestines and overies. The source of plasma cholesterol 
is the liver. Fatty acids are synthesised in the lungs
and along the en♦tire gastro intestinal tract. Acetate
is used for the synthesis of fatty acids to a greater 
extent in the lungs. Folley and French (1949; 1950) also 
reported fatty acid synthesis from acetate in the lung of 
the goat. Phospholipin fatty acids and glyceride fatty 
acids in the lungs and intestine are not at equilibrum,
52
UNIVERSITY OF IBADAN LIBRARY
the C1^ being more in the former.- In the liver the two 
types of fatty acids appear to come to equilibrum rapidly. 
There is the possibility that the fat precursors in the 
liver and intestines are not identical. Cholesterol is 
formed in the free form and esterified later. The two 
workers on further work with rabbits (1950) reported that 
non-lactating mammae of pregnant rabbits synthesise 
cholesterol and fatty acids. The foetus synthesized its 
own fatty acids and cholesterol, but also absorbs lipids 
from the maternal circulation. The mammae of lactating 
rabbits synthesise long and short chain fatty acids and 
cholesterol from acetate and carbohydrates. In 6 hours at 
least 30 - 70% of short-chain acids originate from acetate, 
or 25% from carbohydrates. Long chain fatty acids are 
however synthesised to a lesser extent from acetate and 
carbohydrate in the mammary gland. About 65-95% of the 
glycerol part of fat, derived from carbohydrate, was 
newly formed in the mammary gland in 6 hours. It was 
concluded that the glycerol part of fat is more rapidly 
metabolised by the animal than the fatty acid part.
About 20% of the body's acetate used for acetylation of
53
UNIVERSITY OF IBADAN LIBRARY
£-aminobenzoic acid was derived from glucose in fully fed 
lactating rabbits. Chemical degradation of octanoic acid 
from milk and mammary gland fat and the acetyl group of 
^»-acetamidobenzoic acid showed that the conversion of 
glucose to fatty acids proceeds by the overall reactions
thus, glucose ------^ pyrurate ■ ■ - ■ fatty acid.
Continuing their research Popjak et al, (1952) concluded 
that glucose is the carbohydrate precursor of glycerol in 
the udder. This is supported by the work of Luick (1960). 
The acetate carbon entered glucose by way of the citric 
acid cycle followed by glycolytic process in reverse. The 
citric acid cycle provides a path for the entry of 
acetate carbon into pyruvate, and hence by the reversal 
of the glycolytic cycle, acetate carbon can find its way 
into glucose. It is likely that the breakdown of glucose 
to glycerol occurs within the udder itself (Luick, 1960). 
Glycerol could be formed from glucose at the triosephos- 
phate stage of the glycolytic breakdown. Luick (1960) 
used labelled glucose and observed that 68% of milk fat 
glycerol is derived from plasma glucose. Their result 
showed that 2 pathways might be involved, one of which is
54
UNIVERSITY OF IBADAN LIBRARY
the synthesis of glycerol from glucose in the udder and the 
other the synthesis of plasma lipid glycerol from glucose, 
presumably in the liver, and its subsequent absorption into 
the udder. There is no free glycerol in the blood of 
cattle so that glycerol as such cannot be considered an 
important precursor of milk fat glycerol. The trials 
indicated that milk fat is synthesised within the mammary 
gland from glycerol and free fatty acids. The bulk of the 
acetate produced in the rumen seems to pass unchanged 
through the liver into the general circulation, (Luick, 
I960). This is supported by Joyner at al, (1963).
Propinate is thought to give most of its C to the 
synthesis of glucose. Butyrate is oxidised to ̂ -hydroxy 
butyrate (BHBA) by the rumen epithelium and perhaps by the 
liver. Butyrate cannot give more than 13% of the C needed 
for the synthesis of short chain fatty acids. The mammary 
gland absorbs large quantities of triglycerides from the 
blood. Micro-organisms in the rumen produce transisomers 
of the dietary fatty acids, and large quantities of short 
chain fatty acids, especially acetate, propionate and 
butyrate synthesised from non lipid dietary precursors.
55
UNIVERSITY OF IBADAN LIBRARY
Rook et al. (1963) observed that in growing heifers infu­
sion of butyric acid increased blood BH3A, acetone and 
aceto acetic acid.
Cowie et al. (1951) used labelled acetic acid to 
perfuse the cow’s udder and they observed that about 40% 
of the labelled C was found in the udder fat and some of 
the labelled C acetate was incorporated into fatty acid 
fractions of milk triglycerides. This experiment also 
showed that short chain acids are not formed directly by 
degradation of long chain acids. Some of the labelled C 
was absorbed into the cholesterol molecule. This showed 
that cholesterol is synthesised in the udder of the cow 
and the goat. Balman and Folley (1951) observed the effect 
of insulin on fat synthesis by lactating mammary gland 
slices of rats, mice, rabbits and sheep. They suggested 
that the stimulating effect of insulin on fat synthesis by 
mammary tissue may be due, partly, to the stimulation of 
the formation of glycerol from glucose. Mammary gland can 
synthesise and secrete glycerides, then the supply of 
glycerol might be a critical, rate-limiting factor in 
fat synthesis by this tissue. It is also possible that the
56
UNIVERSITY OF IBADAN LIBRARY
insulin effect is related to the utilization of glucose as 
an energy source for fat synthesis.
Luick (1961) also infused labelled glycerol, acetate, 
glucose, propionate and butyrate into the udder of cows.
The result indicated that glycerol is synthesised in the 
udder from glucose, but not from acetate, propionate or 
butyrate. The newly formed glycerol is incorporated into 
milk fat.- This strongly implies that one pathway of milk 
fat synthesis involves its in situ synthesis in the mamma­
ry gland from pools of free fatty acids and glycerol.- 
Folley and French (1949) working with rats, mice, rabbits, 
guinea pigs, lactating goats and cows observed the Respi­
ratory quotient (R. Q) of the mammary slices in the presen­
ce of carbohydrates. In the presence of glucose the R.Q. 
of tissue from the mouse, rat, guinea pig and 
rabbit was well above unit, but that of the tissue of 
ruminants - cows, goats, was less then unity. This result 
did not support the theory that the lower fatty acids of 
the ruminant milk fat are synthesised from carbohydrates 
in the udder.- The result with rat showed that under 
anaerobic conditions the rat mammary gland slices in the
57
UNIVERSITY OF IBADAN LIBRARY
presence of glucose produce quite considerable amount of 
acid. It indicated that glycolysis is not the only process 
whereby the acid is produced. The mammary tissue of rat 
therefore exhibits a marked Pasteur effect. On further 
work with R.Q those workers reported that in the rat there 
exists some mechanism of fat synthesis in the mammary 
gland. The initiation of lactation is under endocrine 
control, so that there is likely to be a close relation­
ship between the lactogenic hormone or hormone complex 
and changes in the mammary gland metabolism occurring 
after parturition. Folley and French (1950) observed the 
metabolism of acetate by mammary gland slices of sheep, 
goat, cow, rat and rabbit, and observed that ruminant 
mammary tissue in early or late lactation was almost 
inert to glucose. The tissues from lactating rumminants 
greatly utilise acetate, and glucose stimulates the use of 
acetate by mammary slices from rat, rabbit and sheep.
Miller and Allen (1955)'fed sodium acetate to lactating 
cows, and their result suggested that there is a minimum 
level of acetate required for production of milk of normal 
fat content, and that feeding of acetate up to this level
58
UNIVERSITY OF IBADAN LIBRARY
will cause recovery from the diet-depressed milk fat. 
Additional amounts above this level will not cause further 
increases. Van Soest and Allen (1959) in their studies 
with cows observed that when ground and restricted rough- 
age was fed to lactating cows and goats there was a 
decrease in arterial blood acetic acid. It appeared that 
the peripheral tissues as well as the mammary gland were 
utilizing less acetic acid under conditions of milk fat 
depression. The feeding of Na-acetate tended to increase 
low milk fat, and the feeding of Na-propionate tended to 
lower it further. This showed that acetic acid is not the 
only acid involved. In their investigation they observed 
that hydroxy butyric acid is a precursor of milk fat. The 
propionate is converted to succinate, then to oxaloacetate. 
This condenses with acetyl-CoA and is diverted from aceto- 
acetate formation toward oxidation in the Kreb's cycle.
This reaction leads to non synthesis of milk fat and 
causes a lowered utilization of acetate. Schmidt and 
Schultz (1958) fed Na-propionate to lactating cows and 
observed a non-significant fall in milk fat content. The 
propionate did not affect milk production. When the
59
UNIVERSITY OF IBADAN LIBRARY
blood glucose and Ketone bodies are normal, propionate 
feeding had no appreciable effect. Terner (1951) carried 
out his investigation to ascertain the operation of the 
citric acid cycle in the udder. He used slices from rats, 
rabbits, goats and sheep and used pyruvate and glucose, 
and acids as substrates. Small amounts of citric acid 
accumulated when depleted mammary gland slices were in­
cubated with fumarate and pyruvate. Fumarate reversed the 
inhibition of respiration caused by malonate. These 
observations suggest that the citric acid cycle is opera­
tive in the mammary gland. He also observed that pyruvate 
is oxidised more completely in the presence of dinitro 
phenol ( DNP) than in its absence. Dinitro phenol appears 
to affect carbohydrate metabolism in two ways, one of which 
is by influencing the glycolytic breakdown of glucose to 
pyruvate, and the other by influencing the metabolic fate 
of pyruvate. Pyruvate is metabolished by mammary tissue 
by oxidation via the Kreb’s cycle and by synthetic react­
ions. About 2 mol of pyruvate appear to be utilized in 
synthetic reaction for every mol of pyruvate oxidised.
60
UNIVERSITY OF IBADAN LIBRARY
2.4 STRUCTURE AND COMPOSITION OF MILK FAT
Milk fat is not consistent in composition. Hensen 
and Shorland (1951; 1952) analysed butterfat and reported 
that based solely on the melting-point-evidence of branched 
chain fatty acids, presented by Cason (1948), one of the 
two C17 fatty acids isolated (M.P. 54,4°) appears to be 
the iso acid (15 methyl-hexadecanoic acid) while the other 
(M.P. 39.8°) appears to be the ante-iso-acid (14 methyl-
hexadecanoic acid). These two Q17 methyl branched chain 
fatty acids are isomeric with normal heptadecanoic acid.
A Q20 saturated acid fraction containing at least three 
and possibly four methyl groups was isolated from butter 
fat* This acid has a low solidifying point and very low 
melting point of -7°C.
Carolyn Boatman, Decoteau, and Hammond (1961) 
observed that the amount of trisaturated glyceride varied 
from 21.5 to 32.0% by weight. They found that there was 
no preferential selection or exclusion of any of the major 
saturated fatty acids from the trisaturated glycerides.
The relation among the melting point of a fatty acid and 
the melting point and amount of trisaturated glyceride,
61
UNIVERSITY OF IBADAN LIBRARY
whi»ch has been found to hold for many fats, does not hold 
for milk fat. The heat of fusion of the last tri9lyceride 
in the fat to melt changes from sample to sample.
Smith and Lowry (1962) separated the lipids in milk, 
and found the major phospholipids in milk to be 
Phosphatidyl cholines (PC)
Phosphatidyl ethanolamines (PE) 
and Sphingomyelins.
Patton et al. (1964) obtained the same classes of phosph­
olipids, mainly cephalins, lecithin, and sphingomyelin, in 
similar proportions with much the same total fatty acid 
composition in milk, skim milk, cream, and butter milk.
Virtanen (1966) reported that when vegetable oil was
fed, the unsaturated fatty acids which occur in lesser
amounts especially C 16 and C14 acids, were higher in the 
fat of the test milk than in the fat of the normal milk.
The amount of branched chain fatty acids was increased in 
the fat of the test milk.
Laura Evans and Stuart Patton (1962) observed that the 
high density lipoproteins had a strong binding capacity for 
cholesterol and phospholipids and that low density lipo­
62
UNIVERSITY OF IBADAN LIBRARY
proteins showed a great affinity for cholesterol palmi- 
tate and tripalmitin. Palmitin and linoleic acids were 
bound almost entirely by serum lipoproteins. Cholesterol 
exchanged between high and low density lypoproteins , but 
the rate of transfer is in the direction of the high 
density lipoproteins. Cholesteryl palmitate moved only 
from low to high density lipoproteins. Tripalmitin and 
phospholipid did not transfer in either direction. Palmi­
tin and linoleic acids transfered from both lipoprotein 
groups to the serum proteins. Brown et. al, (1962) in
their analysis observed that cottonseed oil depressed the
acids of milk fat from C 6 through C14, but increased the 
r 18 acids. Smiths and Jack (1954 a; b; c.) in their 
analysis of milk fat established the presence of conju­
gated and non-conjugated polyethanoid constitutents. The 
small values of conjugated trienoic constitutents were 
relatively constant and also the trace amounts of tetra- 
enoic systems agree with the result of other workers. The 
non-conjugated dienoic acids fluctuated less and non- 
conjugated trienoic and tetraenoic acids were observed. 
Polyethenoid constituents were concentrated mainly in the
63
UNIVERSITY OF IBADAN LIBRARY
c 1&- c20 fraction. Relatively more of the conjugated
components formed urea complexes. There is likely to be
a non-conjugated pentaenoic constituent. The C 18 to C12 
monoethenoid fractions have treans isomers whose approxi­
mate concentration ranged from 14 - 27% of the monoethenoid 
methyl esters. The unsaturated bond of decenoic acid 
occurs between the 9th and 10th carbons. The conjugated 
double bonds are principally cis-trans. The fatty acids 
of milk fat with shorter carbon chains than 10 do not 
contain double bonds.
Zaletel, Bird, Cannon, Wise and Kempthorne Bartley 
(1951) observed that the lactation trends in the majority 
of animals appear to be characterized by the production 
of fats with a high iodine value at the peak of milk 
production followed by decline in the iodine number to 
the 4th or 5th month of lactation and later a slight 
increase in iodine value to the end of lactation. The 
changes in iodine value were associated largely with chan­
ges in estimated oleic acid content of the milk fat. The 
percentage of linoleic acid decreased slightly in a linear 
manner during the lactation period. Pasture grazing during
64
UNIVERSITY OF IBADAN LIBRARY
periods in which the effect of lactations was at a minimum
increased the iodine value by an average of five units.
This level was maintained when the cows were on pasture,
but when the pasture herbage was removed from the diet,
the iodine value dropped rapidly to levels considered to
be normal. Pasture feeding had little effect on the lino-
leic acid content of the milk fat. Hensen and Shorland
(1952) noted a regular increase in the content of C 6 - C1 4
saturated acids, and total saturated acids, beginning in
July up to November, and afterwards a slow decline to the
end of the season. The unsaturated acids varied in the
opposite direction to that of the C 6 - C14 constituents.
The butyric acid content declined throughout the season.
Palmitic acid showed little change, but when expressed as
a percentage of the total saturated acids it showed a
tendency to increase throughout the season. The variat- 
ions in content.  of C18 unsaturated fatty acids reflect the 
influence of the changing plane of nutrition throughout 
the year.
65
UNIVERSITY OF IBADAN LIBRARY
2.5 MEASUREMENT OF RUMINANT FEEDING STUFF
Basically chemical analysis shows that food is 
composed of the same elements which go to form the animal 
body, and its products. The amount and proportion of the 
elements in each food vary greatly. However, these
elements are built together to form compounds which are 
similar in kind and can be classified. The dry matter of 
all foodstuffs can be divided into organic and in-organic 
groups.
The ruminant feeds are evaluated by their chemical 
compositions or by "in vivo" or "in vitro" digestibility 
methods.
Chemical analyses involve the estimation of water, 
ash, crude fibre, crude protein, organic matter, dry 
matter, ether extract and nitrogen-free-extract. The 
Weende Station investigators were the first to establish 
a system of analysis over a century ago. This is known 
as the "Proximate Analysis". Most of the nutrients 
analysed are more or less uniform, but the crude fibre 
part of plants consist of a mixture of variable cabohy- 
drates. Despite its short-comings, these methods of
66
UNIVERSITY OF IBADAN LIBRARY
analysis still form the basis of most analytical procedures 
in use today, although it is now being widely improved or 
modified (Van Soet 1966; 1967; Adenosun et al. 1967; 
Ademosun 1970).
Ruminants can digest about 5Q% of the crude fibre of 
most feeds. There are differences in the breakdown of 
crude fibre from different sources. The polysaccharides 
of mature plants are less digestible than those of young 
growing plants. The crude fibre of growing pasture grasst 
fresh or dried, is more digestible than that of hay. The 
difference is due to chemical and physical structure, and 
also to the presence of certain substances like lignin 
which as the plant matures get deposited in the cell wall. 
Intact fibre prevents the action of the digestive enzymes 
on other useful nutrients in the stems, leaves, seeds and 
every cell. Cell walls are ruptured by cellulose decompo­
sing organisms as well as the movements of digestion. The 
amount of crude fibre present in the feeds of ruminants 
and the nature of the crude fibre determine the level of 
digestibility of the nutrients present in the feeds.
The end products of carbohydrate digestion in the
67
UNIVERSITY OF IBADAN LIBRARY
rumen are volatile fatty acids (V.F.A's) and gases. Some
of these acids are acetic, propionic, iso and n-butyric
acids. Gases like ammonia, CO , 00 and higher V.F.A’s
are also produced from microbial actions on proteins and
nitrogenous compounds. Valeric and isovaleric acids and
other higher V.F.A's and combustible gases like CH4 are 
produced by this microbial fermentation of carbohydrates.
"In vitro" digestibility analysis offers a practica­
ble method of examining the potential nutritive value of 
various feeds, and indicates those which may justify furth­
er animal evaluation. Among commercial varieties of cocks­
foot, the early "stemmy" varieties were in general more 
digestible than the late "leafy" ones, while with any par­
ticular maturity type, the stemmy varieties tended to be 
more digestible than the leafy. This indicated that the 
generally held view that leafiness is associated with high 
nutritive value is not necessarily correct. Raymond, and 
Terry (1966) in their work on various animal feeds observed 
that in cocksfoot, immature stem and leaf sheath are at 
least as digestible as leaf. Only as the plant matures 
does the stem become less digestible than leaf. At
68
UNIVERSITY OF IBADAN LIBRARY
maturity a leafy variety might be expected to be the more 
digestible. Alexander and Mary McGowan (1961) described 
a method for the "in vitro" determination of digestibility 
of herbage. In this procedure two stage digestion deve­
loped by Tilley and Terry was used. The rumen liquor 
stage ended after forty eight hours. The pH of the 
medium was adjusted to 1.2 and pepsin solution added to 
digest the remaining protein. The hyflo supercel filter 
aid used along with fibre glass filter paper quickened the 
filtration. Digestible dry matter content of the samples 
gave a coefficient of correlation of r = + 0.97 with the 
"in vivo" figures. Armstrong, Alexander, and Mary 
McGowan (1964) modified their former method by adding 
ammonium sulphate to the rumen liquor buffer mixture.
Barns (1965) in his own "in vitro" experiment calcula­
ted the energy intake, the relative intake, and the nut­
ritive value index.
Fina, Teresa, and Bartley (1958) observed that the 
rumen liquor decomposed completely in less than 48 hours 
500 mg. of cellulose. They reported that anaerobic condi­
tions must prevail throughout the trials in order to
69
UNIVERSITY OF IBADAN LIBRARY
obtain maximum cellulose digestion. Protozoal activity 
was sustained for twenty four hours, but after thirty 
eight hours this activity was greatly reduced. The rumen 
temperature and pH vary and they affect the rate of decomp­
osition of the cellulose,
McDougall (1948) reported that saliva lubricates the 
feed and aids the process of mastication. In the ruminant 
it forms a fluid medium for transporting food back to the 
mouth for remastication and downwards through the stomach 
to the small intestine. It forms also a buffered medium 
in which the micro-organisms of the rumen can flourish. 
There are four salivary glands but the parotid produces 
quite a lot. The dry matter in gm. per 100 ml saliva was 
1.28 while the ash content was 0.97. Sodium formed the 
largest part of the ash followed by phosphorus and 
chlorine, potassium and nitrogen are present in small 
amounts while calcium and magnesium are in traces. Carbon 
dioxide is also present in saliva. Saliva is slightly 
alkaline, its pH at room temperature ranges from 3.05 - 
8.46, but this may decline to between 7.96 - 8.26 with 
rise in temperature. This is the reason why artificial
70
UNIVERSITY OF IBADAN LIBRARY
saliva solution is added to the medium in "in vitro" 
digestibility studies.
Extensive grazing is the chief form of land use in the 
dry pastural tropics. These lands are usually sparsely po­
pulated, rainfall is variable and pasture yields are low.
The patterns of growth of pastures have the main feature of 
laternate poor growth with good and abundant growth periods. 
Where conditions are good, pasture yields in the tropics 
and also the output in terms of animal production compare 
favourably with those of temperate countries. Live weight 
gain recorded with cattle fattened on Pangola grass pastu­
res in Jamaica were as high as expected from temperate 
pastures.
The amount of herbage eaten by grazing animals is 
estimated from data from their faeces output together with 
estimates of the digestibility. Grazing animals choose 
the younger and presumably the more digestible components 
of the pasture. This shows that the pasture harvested 
mechanically is not likely to be of the same digestibility 
as that selected by the animal.
Direct and indirect methods have therefore been
71
UNIVERSITY OF IBADAN LIBRARY
developed for predicting herbage digestibility The direct 
method for determining herbage digestibility includes the
daily measurement of feed intake and faces out put.- This 
method is good for stall-fed animals, but leads to a lot 
of error when applied to grazing animals. Many investiga­
tors have therefore evolved some indirect methods for 
estimating the digestibility of herbage by grazing animals. 
Some of these workers are Forbes and Gerrigus (1948; 1950) 
Raymond (1951); Lancaster (1949); and Reid et al, (1952).
Markers have been used by nutritionist in trials 
involving omnivora and carnivora, A marker is substance 
consumed as a part of the meal in a digestibility trial
and is also given as a part of the meal after the end of
the experiment.- Some of the makersr that are in use are 
iron oxide, bone black and chromic oxide. Other substances 
used as index in digestibility trials are lignin, crude 
fibre and methoxyl and various dyes.
Marker substances are not suitable for use with her­
bivores, because the colouring substance from the first 
and second feedings are mixed either in the rumen or in the 
caecum* This causes no sharp division between feedings.
72
UNIVERSITY OF IBADAN LIBRARY
In order to avoid quantitative collection of faeces and 
quantitative records of feed intake, index substances are 
used. Index substances are substances that may be consumed 
by, or administered to an animal, but are entirely inert 
in the digestive tract, and so are completely and regularly 
excreted uniformly mixed with the faeces.
Index methods;
Nitrogen as faecal index;
This method involves the estimation of nitrogen in 
the feed and faeces. Lancaster (1954), Raymond and co­
workers (1948, 1954) Reid (1952) and Gallup and Briggs 
(1948) Kennedy, Carter, and Lancaster (1959) used this 
method. There have been differences in the digestibility 
predicted by different workers due to analytical methods, 
differences in animals and the types of herbage. Green- 
Halgh and Corbett (1960), GreenHalgh, Corbett and Me 
Donald (1960), Minson (1958) and Raymond and co-workers 
(1956) also estimated digestibility of the forages used in 
their experiment from faecal nitrogen. Use of nitrogen as 
an index is prefered to chromogen because nitrogen is 
easier to determine. Lancaster (1949) showed that
73
UNIVERSITY OF IBADAN LIBRARY
Metabolic faecal nitrogen is excreted in amounts directly 
proportional to the dry matter intake of the animal, its 
concentration in the faeces will be proportional to dry 
matter digestibility. GreenHalgh and Corbett (1960) and 
GreenHalghet al. (1960b) observed that Spring and Summer 
trials showed the same differences a.s the digestibility 
and faecal nitrogen relationship. Faecal nitrogen diffe­
red in value for the first and aftermath growths.
Plant chromogen as Faecal Index;
The chromogen in the feed and faeces were analysed, 
and equations formulated to determine the digestibility 
of the feed. Plant chromogen as faecal index has been used 
by Raymond et al. (1954 a; b), Reid et al. (1952), Kane 
and Jacobson (1954), Kane et al. (1953), GreenHalgh and 
Corbett (1960a), GreenHalgh, Corbett and McDonald (1960). 
The handicap in chromogen experiments is that the equa­
tions were not more precise than nitrogen equations. In 
fact incomplete extractions leading to high recoveries and 
the extracts increasing in optical density cause a lot of 
problem.
74
UNIVERSITY OF IBADAN LIBRARY
Chromic Oxide:
Chromic oxide appears to be the most generally satis­
factory marker of dry matter yet tested. Difficulties in 
its use are probably due more to inadequate mixing with 
digesta than to its physical properties. It has been used 
successfully in digestibility trials by Corbett, GreenHalgh, 
Gwym and Walker (1958), Christian and Coup (1954), Coup 
and Lancaster (1952), Balch et al. (1957), Moore (1958), 
Olubajo (1969). It has been used on ruminants and non­
ruminants .
Faecal chromic oxide concentrations are more variable 
in grazing than in hand fed animals. Corbett et al.
(1958) observed that even when a marker is well mixed 
with the contents of the alimentary tract, variable 
excretion would occur if feed constituents of different 
digestibilities become stratified in passage through the 
gut or absorption varied at different times of the day. 
Variable marker excretion by ruminants arises usually 
from uneven clearance from the four-chambered stomach.
Uneven excretion may also arise from the rapid passage of 
a portion of the dose before thorough mixing with digesta.
75
UNIVERSITY OF IBADAN LIBRARY
Identification of faeces of grazing animals in 
hgestibility trials:
The experimental animals used in digestibility trials 
are fed polystyrene particles of different colours. These 
ensure a rapid and good identification of faeces voided by 
each animal. In some cases the polystyrene is ground into 
powderor cut i11̂ 0 cubes of variable sizes. Mins on, Taylor, 
-.Ider, Raymond and Rudman (1960) and Corbett et al. (1960) 
also used coloured particles in their investigations.
Lignin and methoxyl groups have been used successfully 
: • many investigators in digestibility studies (Ely, Kane, 
iacobson and Moore, 1953; Richards and Reid, 1952;
Anthony and Reid, 1958).
2.6 MEASUREMENT OF VOLATILE FATTY ACIDS
Fatty acids of compounds of plant and animal origin 
have been determined in the past by fractional distilla­
tion and by displacement of the lower homologues from 
substances like charcoal (Holman and Hagdahl, 1948; Clarke, 
1928; 1943). James and Martin (1952) were pioneers in 
investigations involving gas - liquid chromatographic 
separation of volatile fatty acids. Since then chromo­
cographic separation of short and long chain volatile fatty
76
UNIVERSITY OF IBADAN LIBRARY
idds, and methyl esters of saturated and unsaturated 
raids, and other volatile compounds and gases in different 
feeds and animal products like silage, cheese, milk, fat, 
fetter fat, tissue fluids, blood plasma and blood serum 
have been carried out by many investigators (Storry and 
lillard, 1965; Bills, Khatri and Day, 1963; Anderson and 
-lollenbach, 1965; Jennings, 1957; James and Martin, 1965; 
Deman, 1946; James and Web, 1957; Mobbitt, Gillian Mick- 
innon, 1963). The method of James and Martin has been 
codified by many workers (Storry and Millard, 1965; James, 
1960; Bills, Khatri and Day, 1963; Anderson and Hollenbach, 
1965). Other forms of chromatography like the thin layer, 
paper chromatography and displacement separation techni­
que have also been evolved (Kuramoto, Jezenski and 
Holman, 1957). Chromatographic methods may be used to 
fractionate a natural product, isolate its components, 
characterize, and to a limited extent, classify the origi­
nal mixture as well as its constituents components.
Choosing a chromatographic technique to be employed for the 
separation of a compound depends on the amounts to be 
separated, and the physical state of the sample. No
77
UNIVERSITY OF IBADAN LIBRARY
single chromatographic method at present is good enough 
for the complete separation of a complex mixture of comp­
ounds. Accurate temperature control of the column and 
often of the detector is necessary when highly reproduci­
ble results are required. Provided the temperature, 
quantity of stationary phase in the column, and the flow 
rate of gas are kept constant, a given acid always emerges 
at the same time. Peaks are recorded by the detector and 
the peak areas measured by triangulation, planimeter, by 
cutting out the peaks and weighing and by a recording inte­
grator .
78
UNIVERSITY OF IBADAN LIBRARY
CHAPTER 3
MATERIALS AIO METHODS
3.1 HISTORY AND MANAGEMENT OF THE EXPERIMENTAL
PLOTS
The experimental plots are located within the low­
land rain forest zone with a mean annual rainfall of 48 
inches. There are two main seasons in the year: one of 
which is the dry season which starts from November or late 
October to February, and the other is the rainy season 
which starts from March to October or November, with a 
short break in August.
The experimental plots are located on the Western 
part of the teaching and research farm. The plots are 
situated on the North Western side of the University of 
Ibadan Campus. Clearing of the site was started in March 
1961, when a few acres were planted with Kyasua grass plus 
centrosema for silage. A few more acres were ploughed in 
1965 to make a total of 12 acres. The 12 acres were 
divided into four randomized blocks of 3 acres each, and 
each was replicated 4 times. Each block contains the 4 
treatments H, J, K and L. Each treatment is § acre in size 
and each is sub-divided into £ acre size plots to faci­
79
UNIVERSITY OF IBADAN LIBRARY
litate effective grazing. This makes a total of 12 sub­
plots per treatment. Each plot was fenced round with barb 
wire and water troughs and salt licks provided in easily 
accessible spots.
After ploughing, tripple super phosphate was applied 
to the soil at the rate of 1 cwt per acre by tractor broad 
caster. The two legumes were planted first, and the grass 
es planted two weeks later. The grasses and legumes were 
planted in rows, and they alternated with one another 
within the rows. Cutting back was carried out at the end 
of every grazing experiment, by a hand slasher, to a 
height between 6” and 8" above the ground. At the onset 
of the rainy season, fertilizer application by hand is 
carried out yearly at the rate of 2 cwt of single super­
phosphate plus 1 cwt of sulphate of ammonia per acre. 
Experimental Design
The four established pastures used in this experi­
ment, designated H, J, K and L are composed as follows: 
Treatment H consists of Cynodon plectostachyus. Pilger
Centrosema pubescens Bentham 
and Stylosanthes gracilis H.B.K.
80
UNIVERSITY OF IBADAN LIBRARY
Plate 1
One of the fistulated cows on the field. '
UNIVERSITY OF IBADAN LIBRARY
-r^atment J Pennisetum purpureum Schum 
Centrosema pubescens 
and Stylosanthes gracilis 
Treatment K Pennisetum purpureum 
Panicum maximum Jacq 
Centrosema pubescens 
and Stylosanthes gracilis 
Treatment L Pennisetum purpureum 
Panicum maximum 
Cynodon plectostachyus 
Centrosema pubescens 
and Stylosanthes gracilis 
These grasses and legumes have been described in 
chapter 1.
3.2 The White Fulani (Zebu) cattle
The live-stock of West Africa were classified by 
Cason (1951) and later by Faulkner and Epstein (1957). 
The possession of hump was used to classify the. live­
stock. Mason and Maule (1960) in their furthest work on
classification of livestock of Eastern and Southern
UNIVERSITY OF IBADAN LIBRARY
Plate 2
Another fistulated cow on the field.
UNIVERSITY OF IBADAN LIBRARY
-_frica also used the presence of hump as their basis of 
classification, while Joshi and Phillips (1953) used the 
presence of horn in their classification of cattle in 
India and Pakistan.
Tse-tse fly affects the belt of the African Continent 
chat lies approximately between latitude 15°N and 15°S, 
covering some 4,500,000 square miles of territory. This 
fly causes trypanosomiasis in cattle, but the Zebu is 
fairly tolerant to this and other diseases like red- 
viter-fever, foot and mouth and anaplasmosis disease.. The 
rrthern States of Nigeria are relatively free from tse- 
cse flies, while the Southern States are within the tse­
tse fly belt.
The White Fulani cattle belongs to the Lyre-horned 
Zebu group also found in Senegal, and the Sudan. It is 
the most widely distributed and most promising cattle in 
Nigeria. This breed possesses a heat resisting mechanism 
that is of prime importance. It has a close glossy coat, 
thick skin with large folds at the dewlap which starts 
from the throat and goes as far as between the front legs. 
The dewlap and sheath give a much greater surface area per
82
UNIVERSITY OF IBADAN LIBRARY
Plate 3
Fistulated steer grazing on the field.
UNIVERSITY OF IBADAN LIBRARY
_T_it of body weight than in European breeds. The White 
T_lani possesses an efficient sweating mechanism which 
helps it to survive the heat of the tropical climate.
5.3 Health of the Animals
All the animals were in good health at the beginn­
ing of the experiment. The veterinarians in the depart- 
rent of veterinary medicine were responsible for keeping 
the animals in good health. The animals were sprayed 
routinely with insecticide against tick, but one of the 
fistulated steers died at the end of the experiment on 
treatment J.
3.4 Plan of the Experiment
Eight White Fulani animals were used in these experi­
ments. Six of them were cows while the remaining two were 
steers. The two steers and two of the six cows were fis­
tulated. The remaining cows were lactating cows. All the 
animals had access to fresh water in troughs and salt licks 
daily. The animals weighed between 286 kg. and 376 kg.
The cattle were divided into two groups of four animals. 
Each group consisted of two intact plus one fistulated cow 
and one fistulated steer. One group was fed treatment H
83
UNIVERSITY OF IBADAN LIBRARY
Plate U
Fistulated steers and cows in the field
UNIVERSITY OF IBADAN LIBRARY
at 4 weeks, while the other was fed treatment H at 12 
weeks. All the fistulated animals were kept in stalls and 
fed the same forages as their group mates grazing in the 
field. The same procedure was adopted for treatments J,
K and L.
3.5 Feeding of Animals and Sample Collection
During the experimental period, all the animals in 
the stall received 60 lb of fresh herbage daily. Repre­
sentative samples of pasture herbage were cut and chopped 
into bits. 60 lb of the fresh herbage was divided into two 
equal parts, one part fed at 8.30 a.m. and the remaining 
part fed at 4.30 p.m. The residue for each day was coll­
ected, weighed, and 100 gm. (1 lb) representative samples 
taken for chemical analysis. 100 gm (1 lb) representative 
samples of the fresh herbage was also taken for chemical 
analysis. 50 gm. representative samples of fresh her­
bage and residue were also taken for Dry matter analysis.
Each animal in the stall and field was fed 20 gm. 
chromic oxide paper wrapped in duplicating paper. The 
marker was fed at 8.30 a.m. and 4.30 p.m., making a total 
of 40 gm. paper per day (14.2 gm. Cr203 per day). The
84
UNIVERSITY OF IBADAN LIBRARY
Plate 5
Fistulated steer on the field
UNIVERSITY OF IBADAN LIBRARY
paper containing the chromic oxide was lubricated with 
liquid paraffin and administered with a balling gun into 
the oesophagus of the animal. The administration of chro 
mic oxide continued throughout the experimental period. 
For identification of faeces from each grazing animal,
20 gm. polystyrene particles encapsulated in gelatine 
capsules was given at 8.30 a.m. Administration started 
three days to faeces collection and ended two days to the 
end of the experiment.
Faeces Collection
The animals in the stall were not fitted with digest 
ibility bags, but the faeces voided were collected and 
weighed as soon as they are voided. The faeces were then 
kept in polythene bags. The morning collections started 
from 9 a.m. and the evening collections started from 
4 p.m.
The faeces of the animals grazing in the field were 
collected immediately they were voided. Faeces for each 
animal were compounded and weighed, and 100 gm. represen­
tative sample taken for chemical analysis, 100 gm. rep­
resentative samples were also taken for Dry matter deter-
85
UNIVERSITY OF IBADAN LIBRARY
nination. The faeces collection was for six days after a 
seven day preliminary period. Faeces samples not immedia­
tely analysed were kept in the deep freeze at -5°C to 
-8°C.
Drying of Samples and milling
100 gm. representative samples of the fresh feed 
offered to the animals were dried in a Gallenkamp air oven 
at 65°C to 70°C for 48 hrs. The dried samples were milled 
in an 8" Gallenkamp laboratory haromar mill to a fineness 
of 4 mm. diameter mesh. 100 gm.'representative samples 
of the grass residues and faeces voided were also dried 
and milled in like manner. Sub-samples of the grass 
samples were taken and milled in a micro mill to a fine­
ness of 1 mm. diameter. The milled samples were kept in 
well stoppered Killner jars until ready for analysis.
86
UNIVERSITY OF IBADAN LIBRARY
CHAPTER 4
BOTANICAL ANALYSIS
4.3. INTRODUCTION
Grazing animals influence the botanical composition 
of pastures, their yield and chemical composition. Fre­
quency of cutting pasture and climatological factors and 
topography of the land also affect botanical composition 
of pasture. When pasture is cut more frequently, the 
production is reduced and due to exposure of soil to rain 
and sunlight, the growth of other species of grasses or 
legumes may be encouraged (Akinola et al. 1971; Tuley,
1968; Chheda et al., 1971; Smith, 1964; Patterson, 1933.)
In grazing trials therefore it is necessary to carry out 
botanical analysis in order to know the changes in the 
pasture composition due to grazing and trampling, and the 
contribution of each component to the performance of the 
animal.
Methods of botanical analysis have been developed, 
but no one method is very accurate (Brown, 1954; Pasto, 
Allison and Washko, 1957; and Van Keuren and Ahlgren, 1957) 
Botanical analysis of pastures may be done by visual
87
UNIVERSITY OF IBADAN LIBRARY
estimation of herbage as it is on the field, or by visual 
estimation of cut herbage samples in the laboratory or by 
hand separation of the cut herbage into the different 
species making it up. The last method is by far the best 
in that it is free from bias.
4.2 METHOD OF ANALYSIS
The botanical analysis of the pasture treatments was 
carried out in October to December 1969, and in December 
1970 and January 1971. Eight samples were taken per plot 
during the experimental period. The samples were taken to 
the laboratory in cellophane bags and hand-separated into 
individual species. Each component was dried separately 
in tins in the oven at 100°C for 48 hours and the dry 
weight recorded. Each species was then calculated on dry 
matter basis,
4.3 RESULTS AND DISCUSSION
Table 4.1 shows the results of the botanical analyses 
for the last three months of 1969. The table showed that 
for treatment H, Giant star grass contributed about three 
quarters of the feed intake of the animals. Centrosema 
made up about 10 percent of the composition and weed
88
UNIVERSITY OF IBADAN LIBRARY
growth made up just over 5 percent. STYLOSANTHES was not 
present at all in the grass samples. The absenso of 
Stylosanthes throughout the experimental periods in 1969, 
1970, and 1971 could be that it could not compete very 
well with the other species of grasses grown. The: frequ­
ency of cutting and the treonpling effect of the grazing 
animals may be another factor which led to its complete 
eradication. The seeds produced by Stylosanthes also need 
some scarification before they can germinate well but new 
scarified seeds were not planted every year, so that poor 
and slow rate of germination together with the depth to 
which they were buried did not favour their regrowth.
Gaint Star Grass population remained fairly constant 
for the three months. The Centrosema population decreased 
from October onwards. The drop in population from October 
to November was more than that from November to December. 
The weed population rose sharply from October to November, 
but rose only slightly from November to December.
89
UNIVERSITY OF IBADAN LIBRARY
TABLE 4.1
MEAN DRY MATTER BOTANICAL COMPOSITION OF TREATMENT SWARDS
TREATMENT H TREATMENT J TREATMENT K TREATMENT L
G. Star Centro- Stylosan- Weed E Cen tro- Stylo- Weed E G Centro- Stylo- Weed E G G  Centro- Sty lo- Weed
sema. thes. grass sema. santhes g r a s s  g r a s s  s e r n a . san- a r a s s  ^ ar 9rass sema. 
1969 thes.
grass S E .
O ct. 72.88 24.35 0 2.78 78.25 20.08 0 1.67 47.29 40.98 10.97 0 0.94 42.43 21.22 24.X  10.41 0 1.14
Nov. 7 2 .X 20.83 0 6.87 79.60 16.31 0 4.10 48.33 35.83 9.17 0 6.67 33 16 26.70 29.82 9.60 0 0.73
Dec. 72.08 20.10 0 7.82 78.81 16.84 0 4.35 46.52 37.60 8*.68 0 8 .X 1? 75 27.52 X .2 5  8.00 0 1.48
Mean 72.42 21.77 0 5.82 78.89 17.74 0 3.37 4 7 .X  X . 14 9.55 0 4 94 \6 11 25.15 X .2 9  9.34 0 1.12
1970
Dec. 71.97 21.20 0 6.83 77.56 17.00 0 5.44 47.86 X .24 9 .X 0 4.70 33 12 27.50 2 8 .X  8.50 0 2 .X
1971
Jan. 70.00 22.50 0 7.50 75.60 18.X 0 6 .X 45.95 40.00 9.00 0 5.05 13 X  24.15 X .0 0  10.00 0 2.65
Mean 70.99 21.85 0 7.17 76.58 17.60 0 5.82 46.90 39.12 9.10 0 4.88 13 16 25.83 29.44 9.25 0 2.33
90
UNIVERSITY OF IBADAN LIBRARY
There seems to be a trend that as the population of 
the legume Centrosema decreases in the sward, the weed pop­
ulation increases.
In treatment J, Elephant Grass also contributed the 
major part of the animal intake. Centrosema made up just 
under 20% of the population while the weed population was 
under 4%, The range of the population percentage of the 
Elephant Grass was between 73.25% and 79.60% which is 
narrow. The range for Centrosema was from 16.31% to 20.08% 
which is wider than the one for grass. The range for the 
weed population during the three months was from 1.67% to 
4.35%. The weed population increased from October to 
December. The increase was sharp from October to November.
A similar trend observed in Treatment H was also observed 
in Treatment J* The weed population increased as the 
legume population decreased.
In Treatment K, Elephant Grass made up under half of 
the total sward population. Guinea Grass also made up an 
appreciable amount of the sward population. The two grasses 
made up 85.52% of the total sample. Both grasses contri­
buted more to the animal feed than the single grass in
91
UNIVERSITY OF IBADAN LIBRARY
treatment H or J* The centroseraa population decreased 
appreciably in this sward, since it made up under 10% of 
the total population. It decreased progressively from 
October to December. The weed population also increased 
sharply from October to November, but the increase from 
November to December was not sharp. The weed population 
ranged from under 1% in October to over 8% in December.
In Treatment L, Elephant grass also contributed most 
to the animal feed than the remaining two grasses, although 
its contribution was less than in Treatment K. Guinea 
grass was more in the sward than Giant Star grass. The 
three grasses made up 89.55% of the total sward population* 
Centrosema accounted for gust over 9% of the total popu­
lation, while weed was gust over 1%. Elephant grass popu­
lation decreased sharply from October to November, and 
decreased gust slightly from November to December. Giant 
Star and Guinea grasses populations on the other hand 
increased sharply from October to November, but there­
after increased slightly. The weed population showed very 
little change, while Centrosema population decreased 
steadily. An observation here is that the more grass in
92
UNIVERSITY OF IBADAN LIBRARY
the sward the less weed is found, and the decrease in 
legume population is gradual.
In December 1970 and January 1971, botanical analyses 
of the swards showed similar trends. In Treatments H and 
J however, Giant Star Grass population was less, Centro- 
serna population remained the same while the weed popula­
tion increased. In Treatment K the two grasses together 
formed the largest component of the Sward than in 1969, 
but the increase was small, and the weed population also 
decreased slightly than the 1969 value. The three grasses 
in Treatment L were about 1% less than the 1969 value and 
the weed population increased by about the same value in 
1970/1971.
The inability of Stylosanthes gracilis to remain 
permanently in pastures used mainly for grazing has been 
shown by the investigations of Okorie, Hill and Mcllroy 
(1965), Adegbola (1965), Foster (1961), Nwosu (1961), and 
Miller et al. (1964).
93
UNIVERSITY OF IBADAN LIBRARY
CHAPTER 5
MICROBIOLOGY
5.1 INTRODUCTION
The ruminants are noted for the large number of micro 
flora present in the rumen. The bacteria and protozoa are 
responsible for fermenting some part of the ruminant feed 
which are not normally digested by the digestive enzymes. 
However, the population growth and predominant species of 
the microbes, rate of fermentation, and type of end pro­
duct of fermentation of the feed, are affected by many 
factors, some of which are, the pH of the medium, type of 
feed, enzymes, vitamins, essential mineralSjamino acids, 
and fatty acids (Bryant and Doetsch, 1954b; Wegner and 
Foster, 1963; and El-Shazly, 1952a; Scott and Dehority, 
1965; Bryant, Robinson and Chu, 1959; Salisbury et al.. 
1961). The rumen bacteria function at pH between 5.5 and 
7.0 anaerobically, although wider pH values (5.5-8.5) have 
been reported (Raymond and Terry, 1966). The optimum 
termperature for their function ranges from 38 - 40°C, 
and they also need some amount of fermentation products
<
94
UNIVERSITY OF IBADAN LIBRARY
(Wegner and Foster, 1960). Naga, and El-Shazly (1969) 
collected rumen samples from water buffalo and Zebu cattle 
before feeding, on two successive days. In their micros­
copic examination they found the protozoa belonging to the 
genius Entodinium to be predominant under all conditions. 
There was a sharp drop in the total number of protozoa in 
the rumen liquor in water buffalo when sweet Sudan was fed. 
The relative concentration of Entodinium was also reduced 
in favour of Isotricha and Budiplodinium. Almost similar 
number of ciliate protozoa were found in the bulls and 
buffaloes - fed on berseem, but when concentrate and straw 
were fed, the number in bulls were double those in buffa­
loes. Both bulls and buffaloes had similar genera of 
protozoa, but their relative concentrations and sizes 
were different. Large Oliqotricha were abundant in 
buffaloes.
5.2 METHOD OF ANALYSIS
Rumen bacterial and protozoal populations have been 
counted by Culture counts (Kistner, Gouws and Gilchrist, 
1962; and Claypool, Jacobson and Wiseman, 1961). In this 
procedure a special habitat similar to the rumen medium
95
UNIVERSITY OF IBADAN LIBRARY
was’-ised. Liquid or solid media may be used, certain pre­
cautions should be taken during dilution and counting: 
such precautions are to avoid oxygen and unfavourable pH 
and temperature. The other method is the Direct Counts, 
which takes into account the total number of bacteria 
present, the total dead and living bacteria, and the 
number of individual species present. It is the most re­
liable method. It is a quick and easy method also. 
Treatment H at 4 and 12 weeks was fed to three fistulated 
ruminants and rumen samples taken from them for bacterial 
and protozoa counts.
The Direct Counts method was adopted in this work. 
Since rumen bacteria are many, the rumen liquor was dilu­
ted, and the cells killed and stained to render them more 
visible. Good staining solutions have been developed by 
Hobson and Mann (1955; 1957), Moir (1951), and Hungate 
(1957). The actual counting for bacterial population was 
done with NEUBAUER COUNTING CHAMBER, although other 
counting chambers specially designed for bacterial counts 
have been developed (Ubrner, 1962).
Direct Counts for the protozoal population was done
96
UNIVERSITY OF IBADAN LIBRARY
using a counting cell covered with cover slip. Counting 
procedures have been described by Warner (1962 a; b),
Purser and Moir (1959), and Boyne Eodie and Raitt (1957). 
Microscopic examination was carried out to identify mor­
phological types. Details of the Analytical procedures can 
be found in Appendix V.
5.3 RESULTS AND DISCUSSION
Table 5.1 showed the protozoa and bacterial populat­
ion during the experimental period in 1969. The table 
showed that bacteria formed the greater component of rumen 
microflora. The protozoafjere many also, but from the 
result theyfcrmedless than one million in cattle. The 
population varied a lot and many dead protozoa were visi­
ble, On two occasions no living protozoa could be found 
in the ruminal fluid of the stall-fed steer. There were 
more protozoa in the goat ruminal fluid when the goat was 
kept in the stall than when it was grazing in the field.
The steer contained relatively more protozoa in the 
liquor than the cow, The liquor contained far less 
amount of protozoa before feeding in both steer and cow, 
while the bacterial population was more in the cow than the 
steer.
97
UNIVERSITY OF IBADAN LIBRARY
TABLE 5.1
RESULT
Ruminal Protozoan and Bacterial Counts
Stage of
Date Feed growth Animal Inwks Stall Pgrmo tofozoa pe 
r
p3 earc tegmr ioaf  
content content
2/9/69 H 12 Steer 114 t t 247,400 1 6 5 0 , 0 9 0 , 0Q0
9/9/69 H 4 Goat M 1,560,000 1 , 4 0 0 , 0 0 0 ,0 0 0
16/9/69 H 12 Steer 114 t f 220,000 1 , 2 5 0 , 0 0 0 ,0 0 0
23/9/69 H 12 Steer 114 Grazir g 90,000 1 , 7 0 0 , 0 0 0 ,0 0 0
23/9/69 H 4 Goat I t 78,000 1,2 0 0,0 0 0 ,0 0 0
30/9/69 H 12 Steer 114 Stall Dead prot
oz8o4,a000 3 , 0 0 0 , 0 0 0 , 000
3/10/69 H 12 Steer f t Dead prot -
ozoa
66,000 3,2 0 0,000,000 
6/10/69 H 12 Steer 114 t t 120,000 6 , 5 0 0 , 0 0 0 ,0 0 0  
14/10/69 H 12 Steer 114 t t 118,000 12 ,2 5 0 , 0 0 0 ,0 0 0  
22/10/69 H 4 Goat t t 3,080,000 6 ,5 0 0 , 0 0 0 ,0 0 0  
4/11/69 H 4 Cow 49 t t 340,000 7 ,7 5 0 , 0 0 0 ,0 0 0  
11/11/69 H 4 Cow 49 t t 180,000 10,,200,000,000 
18/11/69 H 12 Steer 114 t t 72,000 7 ,5 0 0 , 0 0 0 ,0 0 0
18/12/69 H 4 Before feed
Cow 49 t t 4,000 10 ,2 0 0 , 0 0 0 ,0 0 0
18/12/69 H 12 Before feed
Steer 114 Less -thant t 2,000 3 ,5 5 0 , 0 0 0 ,0 0 0
18/12/69 H 4 Before feed
Steer 198 Less thant t 2,000 4,,5 5 0 , 0 0 0 ,0 0 0
98
UNIVERSITY OF IBADAN LIBRARY
The number of bacteria present in the liquor taken 
from the steer when there were living protozoa did not 
vary much whether the steer was stall-fed or grazing. 
When all the visible protozoa were dead, the bacterial 
population increased rapidly to about three times the 
former population. The cow and steer contained more 
bacteria in their liquor when the protozoal population 
decreased, but in the goat, the greater the number of 
protozoa the greater was the bacterial population. The 
cows liquors contained more bacteria per gm of content 
than the Steer. The difference may be due to the fact 
that the Cows were fed the four week old forage.
Some of the bacteria seen under the microscope were 
rodshaped. They may belong to the genera Bacteroides 
and Clostridium. The members of these genera digest 
cellulose and sugars like glucose, cellobiose, maltose, 
sucrose, and starch.
Some roundish or cocci forms of bacteria were also 
identified. Some of them were in aggregation while 
others stood singly. They are likely to belong to the 
genus Ruminococcus. Ruminococcus species have been
99
UNIVERSITY OF IBADAN LIBRARY
isolated by Sijpestex jn (1951); Hungate (1957); and Synge 
(1953). The cocci forms of bacteria axe also celluloly­
tic .
The protozoa recognised were mostly ciliates which 
moved about the medium in fresh samples and a few flage­
llates. The flagellates were fewer in number, and the 
cilia in ciliates were all over or just in some parts of 
the body.
Both types of protozoa were easily visible from 
direct illumination. The ciliate protozoa recognised 
are probably members of the genera Isotricha. Entodinium, 
Sudiplodinium and Dasytricha. These have been identified 
by many investigators (Naga and El-Shazly, 1969; Clarke, 
1964aj 1964b.) Most of them contained particles inside 
them, and these stained well with iodine solution. These
are starch grains stored in their protoplasm. The proto-
■ *
zoa also contained nuclei and contractile vacuoles.
The variation in protozoal and bacterial population, 
and the occurence of dead protozoa showed that the dige­
stibility of a forage by "in vitro" procedure is affected 
to a large extent by the microflora. A check on the
100
UNIVERSITY OF IBADAN LIBRARY
MICROBIOLOGY OF RUMEN LIQUOR
PLATE SHOWtNG THE TYPES OF BACTERIA AND PROTOZOA 
FOUND IN ^THE RUMEN LIQUOR OF WHITE FULANI CATTLE.
UNIVERSITY OF IBADAN LIBRARY
microbiology also affords a measure of the health of the 
ruminant.
101
UNIVERSITY OF IBADAN LIBRARY
CHAPTER 6
CHEMICAL COMPOSITION OF TREATMENTS 
H, J, K, ATO L, AT 4 AND 12 WEEKS
6.1 INTRODUCTION
The nutritive value of a forage or pasture herbage 
may be estimated from its chemical composition. Chemical 
analyses show the amount of nutrients in the forages.
Some of these nutrients are well defined (protein or 
nitrogen, minerals, glucose, starch, lignin, vitamins, 
cell-wall, N.F.E) while some are of mixed composition 
(crude fibre). These analyses shov/ the extent at which 
a particular nutrient is present, the seasonal variation 
of each nutrient and whether a feed has toxic or inhibi­
tory substances.
The Nutritive values of some tropical forages have 
been calculated from their chemical composition (Oyenuga, 
1957; 1959a, lSfc£b;l 960a, J96Cfo;Ademosun, 1970; Miller, 1963; 
Ademosun, et al., 1967; Miller et al«, 1964; Patterson, 
1933; Okorie et al •, 1965) while those of temperate 
forages have also been carried out by many workers 
(Forbes et al,, 1950; Ely et al., 1953; Richards et al.,
102
UNIVERSITY OF IBADAN LIBRARY
1952; Anthony et al., 1958.)
Chemical composition of forages has the disadvantage 
in that it does not show the availability of the nutrients 
to cattle.
The nutritive value of pasture forages can also be 
estimated from results of grazing trials (Smith et alt, 
1955; Richards et al., 1952; Topps, 1962; Olubajo, 1969; 
Olubajo et al., 1971; Raymond, 1954; Lancaster, 1954; 
GreenHalgh, 1960a, 3960b) This method is more reliable in 
that it shows the actual amount of a forage nutrient that 
is available to the animal#
6.2 ANALYTICAL METHODS
Sample collection and pretreatments for chemical 
analyses are described under chapter 3# The chemical ana­
lyses were carried out according to the official methods 
of analysis of the A.O.A.C. (1964). Determinations were 
carried out in duplicates and the results expressed on 
dry matter basis. All the reagents used were of the analy­
tical grade.
Moisture: 2 gm duplicate samples of milled material
were dried at 105°C in an electric oven to constant
103
UNIVERSITY OF IBADAN LIBRARY
weight. The difference between the weights before 
and after drying gave the residual moisture content.
Dry matter content was calculated from the results.
Total ash; The dried duplicate samples from the mois­
ture determination were ignited at 600°c in a muffle 
furnace for two hours or until the colour was whitish. 
Organic natter: This was calculated as the difference 
between the weight of dry matter and the weight of 
total ash.
Ether extract: This was determined by using petroleum 
ether, (B.P. 40-60°C) to extract the ether extract in 
the milled samples. Soxhlet Extraction apparatus was 
used, and each extraction lasted 6-7 hrs.
Crude fibre: The duplicate residues from the ether ext­
raction were used. The fat free residues were boiled 
with 1.25% HgSO^ for 30 minutes followed by boiling 
with 1.25% NaOH for another 30 minutes. Each residue was 
filtered, washed, dried and weighed. The dried and 
weighed residues were ignited in a muffle furnace at 
600°C for 2 hrs, cooled and weighed. Crude fibre was 
calculated as the weight of dried material minus weight 
of ash.
104
UNIVERSITY OF IBADAN LIBRARY
Crude protein was determined by the Kjeldahl method;. 
Crude protein was calculated by multiplying total 
nitrogen content by the factor 6.25.
Nitrogen-free-extract (N.F.E). This represents the 
soluble carbohydrates in the feed. It was calculated 
as the difference between 100 and the sum of moisture, 
total ash, crude protein, ether extract and crude 
fibre.
6.3 RESULTS
The summary of the results is shown in table 6.1. 
Details of the results can be seen in Appendix VI. The 
mean monthly rainfall figures for the years 1967-1971 are 
shown in figure 6, while mean daily variations of treat­
ment nutrients during the experimental periods are shown 
in figures 6.2-6.5.
105
UNIVERSITY OF IBADAN LIBRARY
The results of the chemical composition of treatments, 
H, J, K and L cut at 4 and 12 weeks are shown in Table 6,1. 
Crude Fibre
When all the forages were cut at four weeks, forage 
H had the highest crude fibre content, while forage J had 
the lowest crude fibre content. The difference between the 
highest and the lowest values being 2.84%. The difference 
between H and K was 1.65% and the difference between H and 
Lwas 2.80%. Forage K was 1.15% more than L, while forage 
L was 0.04% higher than forage J.
When all the forages were cut at twelve weeks forage 
H also had the highest crude fibre content, followed by J. 
Forage L had the lowest crude fibre content. The diffe­
rence between forages H and Jwas0«75%, between H and K was 
2.76%, between H and L was 3.51%. The difference between 
forage J and Kwas 2.01%, between J and L was 2.76%, and 
between K and L was 0.75%.
Comparing the crude fibre content at the two stages 
of growth, forages, H, K and L contained higher levels at 
four weeks than at twelve weeks. Forage J was the only 
forage containing higher level of crude fibre at twelve
106
UNIVERSITY OF IBADAN LIBRARY
TABLE 6.1
MEAN CHEMICAL COMPOSITION OF TREATMENTS 
H, J, K, AND L, CUT AT 4 AND 12 WEEKS
(% Dry Matter)
Feed T R E A T M E N T S Time of 
Constituent S(awmepelH J K L k
isn)g 
Dry Matter 90.9 93.4 93.3 tm 4
39.8 92.6 94.7 - 12
Organic 83.3 82.9 83.9 90.0 4
liotXtfcii 82.3 81.3 82.9 7.5 12
Crude 9.5 9.0 3.3 4
jrx.c>x<ixjn 10.9
9.8 8.6 7.2 9.9 12
Crude 35.3 32.5 33.7 32.5 4
34.5 33.8 31.8 31.0 12
Ether 1.1 1.1 1.1 1.0 4
♦ 1.1 1.1 1.1 1.1 12
Ash 7.5 10.3 10.0 9.7 4
7.4 11.4 12.1 11.6 12
N.F.E. 46.6 47.2 47.0 45.9 4
47.2 45.1 47.8 46.5 12
107
UNIVERSITY OF IBADAN LIBRARY
weeks than at four weeks. Forage K contained 0.81% more 
crude fibre at four weeks, while forage K contained 1.92% 
more crude fibre when four weeks, and forage L contained 
1.52% more crude fibre when four weeks. Forage J con­
tained 1.28% less crude fibre when four weeks.
However, analysis of variance for the crude fibre 
content of the four forages at the two stages of growth 
showed no significant differences between the forages and 
time of cutting (f9?0.05). All the forages except J 
contained higher crude fibre levels at four weeks than 12 
weeks. One of the reasons for this may be due to leaf to 
stem ratio. At maturity many pastures plants produce a 
lot of leaves.
The treatments were cut at 4 and 12 weeks and a lot 
of chemical changes went on within the herbage during the 
4 weeks interval. Pasture herbages increase in crude 
fibre content up to a point before the bvalue falls. This 
fall after a peak has been shown by Oyenuga 1958; 1960; 
said Ademosun 1970. The treatments except J must have 
reached the crude fibre peak production before 12 weeks. 
The crude fibre content at 12 weeks may be taken to be a
108
UNIVERSITY OF IBADAN LIBRARY
decline as was shown by these workers. The lower crude 
fibre content at 12 weeks does not indicate better nutri­
tive value or digestibility.
Another reason for the high crude fibre content at 
four weeks of growth may be because sampling was carried 
out while the forages were only a little height above 
ground. Therefore it was possible that a few old stumps 
have been sampled along with the young growing forages. 
Crude Protein
Table 6.1 also showed that crude protein contents of 
all the forages except H were higher at 4 weeks than at 12 
weeks. Considering all the forages at 4 weeks, forage L 
contained the highest level of crude protein, followed by 
H and then J and lastly K. Forage L exceeded forage K by 
2.69%, it was also higher in crude protein than forages J 
and H by 1.90% and 1.40% respectively. H was slightly 
higher in crude protein than J by 0.56% and more than K 
by 1.29%. Forage K was only lower in crude protein than 
forage J by 0,73%.
At 12 weeks, forage L again contained the highest 
level of crude protein, followed by H and J and lastly K,
109
UNIVERSITY OF IBADAN LIBRARY
Forage L exceeded K in crude protein by 2.67%, it was 
higher than J by 1.27% and H by as little as 0.06%.
Forage H contained more crude protein (1.21%) than J and 
more than K by 2.61%. J contains more crude protein 
(1.40%) than K.
There were no significant differences between cutting 
intervals, but there were significant differences among 
treatments K and L, (Appendix VI).
Organic Matter
When the treatments were 4 and 12 weeks the organic 
matter content of all the treatments except L were above 
80%, (Table 6.1.) Treatment K was consistently higher in 
organic matter than the rest at the two stages of growth. 
Treatment K was higher in organic matter than treatment L 
by as much as 3.88%, while it was higher than treatment 
J by only 0.94% and higher than treatment H by a still 
lower value of 0,54%. Treatment H was higher in organic 
matter than treatment J by only 0.40%, and higher than L 
by 3.34%. Treatment J was higher in organic matter than 
treatment L by 2.94%.
110
UNIVERSITY OF IBADAN LIBRARY
1
At 12 weeks treatment K was higher in organic matter 
content than treatment L, and the amount this time was 
even higher, 5,44%, than at 4 weeks. Treatment K was 
higher than treatment J by 1,69% a value also higher than 
that of the early stage, while it was higher than treat­
ment H by 0,69% a value also higher than that of the 
early state. Treatment H was higher in organic matter 
content than treatment J and L by just 1% and 4,75% res­
pectively, Treatment J was higher than Treatment L ih 
organic matter by 3.75%.
Analysis of variance showed significant differences 
among treatments at 5% level and between sampling periods 
at 5% level.
Dry matter
At 4 weeks the dry matter content of all the treat­
ments except K was higher than at 12 weeks. The differen­
ce in each case was however not significant-.
Ash
Ash content exhibited greater variation in treatments K 
and L at both stages of growth than in treatments H and J. 
Treatment H contained about the same ash content at both
111
UNIVERSITY OF IBADAN LIBRARY
stages of growth, while the ash content increased with 
increase in maturity in treatments J, K, and L treatment 
K having the greatest increase with increase in maturity. 
The increases were not significant.
Ether Extract
This was the same for all the treatments at both 
stages of growth.
Nitrogen free extract (N.F.E)*
The level of N.F.E* increased with maturity in all 
the treatments except treatment J, The increases were not 
significant, so also was the decrease in treatment J.
Figure 6.1 showed the monthly variations in rainfall 
(inches) for the years 1967-71. The total rainfall in 
1967, 1968, 1969, 1970, 1971 was 32.87 ins, 79.4 ins,
41.7 ins, 55.3 ins, 48.2 ins, respectively, 1967 was the 
driest year since the amount of precipitation for each 
month was low. There was a small peak in June and the 
major peak was in September, The rainfall figure for 
September was only lower than that for 1969. January and 
December were the driest months, and the break in rainfall 
was always in August. The two rainfall peaks for every
112
UNIVERSITY OF IBADAN LIBRARY
FIG. 6.1 MONTHLY VARIATIONS IN RAINFALL (iNS)FOR THE YEARS 
u 1967 ANO 1968 , 19 69 1970 AND 1971.
13
12
11
10
9
a
7
6
5
4
3
2
0
RAINFALL IN INCHES
UNIVERSITY OF IBADAN LIB
ARY
FIG-6*1 MONTHLY VARIATIONS RAINFALL (jNS) FOR THE YEARS
1969 ANO 1970 
u
13
11
10
9
RAWFAU IN INCHES
UNIVERSITY OF IBADAN LIBRARY
FIG. 6*1 MONTHLY VARIATIONS IN RAINFALL (iN S) FOR THE YEAR
1971 1 I i | | I »— 1---
7  7
_  J--
-1 —
t—
RAINFALL IN INCHES
UNIVERSITY OF IBADAN LIBRARY
year were at June and. September. There were however three 
rainfall peaks in 1969 and 1971.
Figure 6.2 showed the mean daily crude fibre variation 
of all treatments at 4 and 12 weeks for experimental period. 
The crude fibre content of all the treatments at 4 weeks 
except treatment J rose for a few days before falling. The 
fall was not continuous but broken by occasional rises 
during the experimental period. The levels at the end of 
the experiment were lower than those at the beginning of 
experiment. The crude fibre level however dropped after 
the first day in treatment J. The level then rose from 
the third day till the end of the sampling period. At 
12 weeks all the treatments except treatment J increased 
in crude fibre level for a few days before the levels 
started to fall. In this case the crude fibre levels were 
still higher at the end of the experiment than the levels 
at the beginning. Treatment J had a fall in curde fibre 
content the second day it was cut, but rose the third day 
and fell again before rising to very high level at the end 
of the sampling period. Treatments H and J cut during the 
dry months showed increases in crude fibre contents of
113
UNIVERSITY OF IBADAN LIBRARY
1
FIG-6-2 MEAN DAILY CRUDE FIBRE VARIATION OF EACH TREATMENT
AT 4 AND 12 W EEKS FOR EXPERIMENTAL PERIOD
’ ' l • ' i i ! l '  I i L-J__!
x — -  x H 
® ----- a J
X -----X K
• —t- • l
1 2 3 4 5 6
EXPERIMENTAL 12 WEEKSPERIOD (D AYS.)
U CRUDE FIBRE (•/.)NIVERSITY OF IBADAN LIBRARY
treatments K and L rose for a few days and dropped as the 
experiment progressed.
Figure 6.3 showed the mean daily crude protein varia­
tion of each treatment at 4 and 12 weeks during the experi­
mental period. At 4 weeks, the crude protein content of 
treatments H and K increased for the first few days before 
falling, but the levels in treatments J and L fell from 
the first day for a few days before rising again. The 
protein content of treatment L even rose above the initial 
level at the end of the experiment* At 12 weeks all the 
treatments except treatment K contained lower crude pro­
tein levels, and the levels continued to decrease till 
the end of the experiment. The crude protein level of 
treatment K increased for a few days before declining.
The rainfall in March and April may be the cause of increa­
sed crude protein contents of treatments K and L at 4 
weeks, but at 12 weeks only treatment K showed an increase 
in crude protein for a few days before declining.
Figure 6.4 showed the mean daily organic matter varia­
tion of each treatment at 4 and 12 weeks during the sampling
114
UNIVERSITY OF IBADAN LIBRARY
FIG 6- 3 MEAN DAILY CRUDE PROTEIN VARIATION OF EACH TREATMENT
AT U AND 12 WEEKS FOR EXPERIMENTAL PERIOD
X  ----------  X H
0 —--------  3 J
X ------------X  K
15
• ---------  •  L
6 /
/ /
1 5  6 1 2 1 5  6
4 W EEKS 12 WEEKS
EXPERIMENTAL PERIOD Q ) A Y s }
CRUDE PROTEIN (•/.)
UNIVERSITY OF IBADAN LIBR
RY
period. At both stages of growth, treatment L contained 
the lowest level of organic matter and it exhibited the 
greatest variation daring the experimental period. All 
the treatments showed a downward trend, with occasional 
increases, in organic matter level. At 12 weeks the 
organic matter level rose at the end of the experiment 
to the original level. At both stages of growth treat­
ments H, J, and K contained more organic natter than 
treatment L, but treatment K had the highest level even 
though there had been some rains.
Figure 6.5 shows the mean daily dry matter variation 
for each treatment at 4 and 12 weeks. All the treatments 
at both stages of growth showed decrease in the dry matter 
content from first to the last day of sampling. There 
were some increases in dry matter content, but.these 
inter-mittent peaks were lower than the level at the 
first day. However at 12 weeks the dry matter content of 
treatments J and L rose above the initial level before the 
end of the sampling period in J and at the last day of 
sampling in L. Treatments J and K exhibited less varia­
tions during the sampling period, v/hile treatments H and
115
UNIVERSITY OF IBADAN LIBRARY
FIG- 6-4 MEAN DALY ORGANIC MATTER VARIATION OF EACH TREATMENT
AT 4 AND 12 W E E K S  FOR EXPERIMENTAL PERIOO
X ----------- X  H
•  ----------  a  j
X --------------X  K
• ----  • l
85
U ORGANIC MATTER (*/•)NIVERSITY OF IBADAN LIBRARY
L exhibited greater variations at 4 weeks. Treatments 
L and H contained less dry matter than treatments J and 
K, At 12 weeks, treatments K and L showed less variation 
than treatments H and J. Treatments J and K contained 
higher levels of dry matter than H and L,
The dry matter content of J at 4 weeks was the high­
est and from the rainfall data it will be seen that there 
was no rainfall throughout January 1970 when the experi­
ment was carried out. The dry matter level fell as the 
rains started to fall, thus treatment K had lower content 
of dry matter than J, while treatment L had still lower 
level of dry matter than treatment K. There was no rain­
fall in December 1966 when Treatment H was sampled, but 
it contained lower dry matter contents at both stages of 
growth than treatment J, and K,
6.4 DISCUSSION
The chemical analyses of the treatments showed that 
the constituents of each treatment did not vary much at 
both stages of growth. The dry matter, organic matter and 
N.F.E. showed very little variation at any particular 
growth period and at the two stages of growth. The
116
UNIVERSITY OF IBADAN LIBRARY
FIG -6 5 MEAN DAILY DRY MATTER VARIATION OF EACH TREATMENT
AT 4 AND 12 W E E K S  EXPERIM ENTAL PERIOD
X ---------  X H
® --------- o  J
X ---------X K
• --------  •  L
96
95
1 2  3 4 5 6
12 WE E KS
PERIOD (D A Y S)
U DRY MATTER (% JNIVERSITY OF IBADAN LIBRARY
reason for the close chemical composition may be due in 
part, to the fact that the experiments were carried out 
during the late rains and dry season when there was not 
enough precipitation (table 6.1 and fig 6.1). There were 
many very hot and dry days, and the growth of pasture 
herbage was not maximal (figures 6.2-6.5).
The constituents that showed some variation were the 
crude protein, ash and ether extracts. The usual trend 
is that the older the plant, the lower the protein content, 
and the higher the crude fibre and ash contents. Invest­
igations of Oyenuga (1957, 1953, 1959, 1960); Patterson 
(1933); Woodman et al. (1934); Milford et al, , (1965a);
VanSoest (1966, 1967); Tilley and Terry (1964, 1966);
•>
Whyte et al. (1959); Todd (1956); and Ademosun (1970); 
Ademosun et al. (1967); and Okorie et al. (1965) 
revealed similar variations with increase in maturity.
The fall in the amounts of nutrients in the treatments 
during the experimental period (Appendix VI) is a normal 
process with forages. When pasture forages are cut and 
when the mature shoots are dying out, new shoots grow to 
replace those that have been cut as well as the dead shoots.
117
UNIVERSITY OF IBADAN LIBRARY
The tender regrowths are succulent and contain more water 
than the mature herbage, so they contain less dry matter. 
The shock of frequent cutting, particularly when the 
former shock received due to cutting has not been over­
come, leads to less forage production and a decline in 
the amounts of the various constituents.
These data show that the pasture forages under 
investigation contained adequate crude protein levels 
to meet the maintenance requirements of grazing cattle. 
This result is supported by an earlier work by Oyenuga 
(1957, 1960), Since the levels in all cases were higher 
than 7%, which many investigators including William, 
Davies and Skidmore (1966) in temperate regions regard 
to be the lowest limit, the forages may be said to have
good nutritive value, Milford and Minson (1965a) obser-
■#
ved that low crude protein content of tropical grasses 
lead to low productivity of tropical cattle. The crude 
protein content is however low for grass/legume 
mixtures. Higher values have been recorded by Oyenuga 
(1960), and Patterson (1933), The grasses contained 
higher crude protein levels at the young growing stages
118
UNIVERSITY OF IBADAN LIBRARY
than at maturity. Pasture plants have passed the stage 
of active growth and are in the reproductive stage before 
they are twelve weeks. By this time also many of the 
leaves and stems are dead and dry. Minson and Milford 
(1965b) observed drastic falls in the crude protein 
levels of some tropical forages they investigated. There 
were cases where the falls in tropical pastures went 
drastically low and remained between 1% and 3%, particu­
larly during the dry season. The high nitrogen content 
of these pastures during the dry season might be due to 
the presence of centrosema which featured in all the 
mixtures. This legume is known to be draught resistant. 
It could also explain the higher level of crude protein 
in mixture H at 12 weeks than at 4 weeks.
Comparing the organic matter contents at the two 
stages of growth, it is clear that forage K offered the 
highest organic matter (O.M.) at both periods, although 
the amount offered at the mature stage was slightly 
lower. All the other forages too offered lower amounts 
at maturity. The organic matter contents of the other 
forages were consistently lower at the late stage of
119
UNIVERSITY OF IBADAN LIBRARY
growth than at the early stage of growth. Sorae tropical 
pasture forages offer lower amounts of organic matter at 
their late stages of growth because of high total ash 
content usually encountered at these stages of growth.
120
UNIVERSITY OF IBADAN LIBRARY
CHAPTER 7
VOLATILE FATTY ACID PRODUCTION IN THE 
WHITE FULAI'II (ZEBU) CATTLE.
7.1 INTRODUCTION
The performance of the grazing animal depends on its 
health, nutritional status, climatological effects and 
breed. The proper function of the digestive system of the 
animal depends on the number and type of microflora in the 
fore-stomachs and the medium in which they operate. The 
efficiency of utilization of a feed can therefore be judged 
by the amount and variation of the volatile fatty acids in 
the rumen, their absorption and transport within the rumi­
nant body and their utilization for energy, growth, and 
milk fat and depot fat synthesis.
7.2 COLLECTION OF SAMPLES
The animals used, treatments, and experimental design 
have been described in chapter 3. Rumen liquor and blood 
samples were collected from each of the fistulated animals 
during the last five days of each experiment.
About 300 ml rumen liquor were collected from each 
animal by suction through a perforated transparent rubber 
tubing inserted through the fistula into the ventral part
12l
UNIVERSITY OF IBADAN LIBRARY
Plate 6
Rumen liquor sampling in the stall
UNIVERSITY OF IBADAN LIBRARY
of the rumen. The liquor poured directly into clean glass 
bottles. The bottles were well stoppered after collection. 
Sampling was started one hour before feeding, and continued 
hourly up to eight hours after feeding. The samples not 
immediately analysed in the laboratory were stored at 
-5°C until required for analysis.
Blood samples
About 30 ml blood samples from each of the fistulated 
animals were collected. Sampling was also started one hour 
before feeding and then hourly up to eight hours after 
feeding. The blood samples were drawn from the jugular 
vein. The well stoppered bottles containing the whole 
blood were kept in a cold room for twenty four hours to 
allow for a good separation of serum from the blood cells. 
The separated serum was centrifuged and decanted off and 
analysed in the laboratory. Samples not immediately analy­
sed were stored below - 5°C until needed. The sodium salt 
obtained by titrating the distillate against 0.01N NaOH was 
evaporated in a rotary evaporator to 2 ml, under vaccum.
3 ml 0.1N H^SC^ was added to release the acids. The clear 
liquid was poured into clean well stoppered bottle. The 
samples were kept at 0°C until needed for chromatography<
3.0 j?.l of each sample was injected into a Pye Chromatogra­
ph using hydrogen fla^e ionization detector. The operating
122
UNIVERSITY OF IBADAN LIBRARY
condition was as for rumen liquor.
7.3 ANALYTICAL PROCEDURE
About 50 ml of the rumen samples were squeezed through 
fine cloth. 5 ml of the squeezed sample plus 5 ml Q.1N 
HgSO^ saturated with Mg 30^ were distilled in a Markham 
Still. 350 ml distillate were collected and titrated 
against 0.01N NaOH to obtain the total steam volatile 
fatty acids.
For the estimation of the individual volatile fatty 
acids a Pye Chromatograph using hydrogen flame ionization 
detector was used. 25 ml of each of the squeezed liquor 
were poured into centrifuge tube and 5 ml of 25% Orthopho- 
sphoric acid in 5N H^O^, were added to each liquor. It 
was left for at least 30 minutes and then centrifuged at 
2,500 r.p.m. for 10 minutes. The supernatant was poured 
into a small bottle and well stoppered, 3 yi.l. of this 
was injected into a column packed with polyethylene glycol 
20M (P.S.G. 20M) with phosphoric acid on celite 100-120 
mesh. The working temperature was 125°C. Argon was the 
eluant gas and the attenuation was 1 x 500. Each peak 
was measured by triangulation and its area calculated in 
inches. The corrected peak area was used to calculate the 
milli equivalent percent of ech acid. The column had a 
recovery rate ranging from 97-106%.
123
UNIVERSITY OF IBADAN LIBRARY
7.4 RESULTS
Ruminal volatile fatty acids (V.F-.A-.) production
Table 7.1 shows the results of treatments H, J, K and 
L at 4 and 12 weeks, fed to Zebu cattle and sampled one 
hour before feeding and hourly after feeding up to 2 hours. 
Analytical data for treatment H at 12 weeks are missing 
because most of the bottles used for storing the rumen 
liquor got broken and the samples were lost.
Ruminal pH
On the average, the pH of the rumen liquor produced 
by each treatment at the two stages of growth was over 7. 
There was no steady rise or fall in pH in all the forages. 
For treatment H at 4 weeks the pH fell very slightly to 
lower levels one and two hours after feeding. At 12 weeks 
of growth the pH level also fell one hour after feeding, 
but rose only very slightly 2 hours after feeding. Treat­
ment J at 4 weeks had a lower pH level one hour after 
feeding, but rose again 2 hours after feeding, at 12 weeks 
the pH level fell at one and two hours after feeding-;
With treatment K the pH level rose one hour after feeding 
but dropped very little 2 hours after feeding. At 12 
weeks the pH level rose one hour after feeding and 
continued to rise two hours after feeding. Treatment L
124
UNIVERSITY OF IBADAN LIBRARY
at 4 weeks gave a rise in pH level one hour after feeding 
but dropped to lower level 2 hours after feeding. At 12 
weeks the pH fell one hour after feeding but rose again 
two hours after feeding.
Total volatile fatty acids (V.F.A.)
The total volatile fatty acids (V.F.A*s) produced in 
the rumen from the 4 week treatment H rose one hour after 
feeding, but dropped 2 hours after feeding,. The high 
level also coincided with the higher pH level after feeding. 
At 12 weeks the peak for the total volatile fatty acids in 
the rumen occured one hour after feeding. For treatment 
J at 4 weeks the total V.F.A. rose one hour after feeding 
but dropped again two hours after feeding. The pH level 
dropped to lower level after feeding but rose again two 
hours after feeding.. At 12 weeks the total V.F.A. rose to 
higher level after feeding and it dropped to lower level 
two hours after feeding. The highest total V.F.A. level 
coincided with the highest pH level in some cases.
Treatment K at 4 weeks produced more V.F.A. at one 
hour than at two hours. This higher V.F.A. content also 
coincided with the higher pH level. At 12 weeks treatment 
K gave a higher V.F.A. content one hour after feedipg than 
at two hours after feeding, but the pH level was lower at 
this time.
1 2 5
UNIVERSITY OF IBADAN LIBRARY
Treatment L produced more volatile fatty acids one 
hour after feeding when the treatment was 4 weeks. At this 
time also the pH was higher than two hours after feeding.
At 12 weeks the V.F.A. produced was higher one hour after 
feeding than at two hours, but the pH was lower than at 
two hours after feeding.
It was observed that the higher total V.F.A.. produc­
tion before feeding than after feeding was not consistent.. 
Individual V.F.A.1s
The separation of the volatile fatty acids chromato- 
graphically showed that in all the treatments and at both 
stages of growth, acetic acid accounted for well over 70% 
of the total V.F.A. in the rumen. Propionic acid came 
next with just under 20% while Butyric acid formed the 
lowest amount, being under 10% in most cases except in 
treatment L at 12 weeks, when the mean was 11.6%.
With treatment H at 4 weeks there was not much 
variation in the acetic acid content before feeding and 
one and two hours after feeding. The peak production of 
acetic acid occured one hour after feeding. The propionic 
acid peak however, occured two hours after feeding. At 12 
weeks the peak for acetic acid was also at one hour after 
feeding; propionic and butyric acids also showed their 
peak levels at two hours after feeding.
1 2 6
UNIVERSITY OF IBADAN LIBRARY
Treatment J at 4 weeks produced the highest amount of 
acetic acid one hour after feeding and the highest propio­
nic and butyric acids two hours after feeding. Similarly, 
at 12 weeks the peak production of propionic and butyric 
acids occured two hours after feeding..
Treatment K produced the highest amount of acetic 
acid two hours after feeding. The acetic acid level 
dropped after feeding when the treatment was 4 weeks, but 
increased only very slightly after feeding when it was 12 
weeks.
Treatment L at 4 weeks produced acetic acid peak one 
hour after feeding. This coincided with the peaks for pH 
and total V.F.A, at this particular stage of growth. 
Propionic acid level was lowest one hour after feeding 
while butyric acid content was highest one hour after 
feeding. At 12 weeks the acetic acid peak was at 2 hours 
after feeding, the propionic acid peak was at 2 hours after 
feeding and the butyric acid peak was at one hour after 
feeding.
Just as the pH level and the total V*F.A* content of 
the rumen liquor, the prefeeding acetic, propionic and 
butyric acid levels did not show any clear relationship 
with the levels after feeding. In some cases the
1 2 7
UNIVERSITY OF IBADAN LIBRARY
prefeeding levels were higher, and in other cases lower 
than the post feeding levels. There was a tendency however, 
for the various levels to come close to the prefeeding 
levels two hours after feeding.
Acetic acid to Propionic acid (A/P) ratio
The acetic to propionic acid ratio is of great impor­
tance in ruminal V.F.A. studies because it shows at a 
glance the type of feed being digested and absorbed, and 
the metabolic processes that may follow the absorption of 
the V.F.A.. produced. All the treatments gave a ratio above 
4 at the two stages of growth, except L at 12 weeks before 
feeding which gave 3.37. Treatment J gave the highest 
ratio of over 5 at both stages of growth. The ratio tends 
to be slightly higher at 4 weeks than at 12 weeks of growth.
1 2 8
UNIVERSITY OF IBADAN LIBRARY
TABLE 7 .1
R u m i n a l  t o t a l  V . F . A . ,  i n d i v i d u a l  V . F . A . ,  a n d  
a c e t i c  t o  p r o p i o n i c  a c i d  r a t i o  ( A / P )  o f  t r e a t m e n t s  ( H )  
a t  4  a n d  1 2  w e e k s  o f  g r o w t h  f e d  t o  Z e b u  c a t t l e .
S t a g e  o f  T i m e  o f  PH T o t a l I n d i v i d u a l  
g r o w t h S a m p l - ' o f V . F . A . V . F .  A .  M e q  % A / P
o f i n g . l i q u o r M e q /  A c e t i c P r o p i ­ B u t y ­
F o r a g e I X  m l A c i d o n i c r i c
( w e e k s ) r u m e n  A c i d A c i d
l i q u o r
H B e f o r e
4 f e e d i n g 7 . 3 7 7 . 2 9 7 8 . 2 9 1 4 . 2 7 7 . 0 4 5 . 5 1
H o u r s
o f
S a m p l ­
i n g .
1 7 . X 7 . 3 3 7 8 . 7 2 1 5 . 2 4 6 . 0 4 5 . 1 7
2 7 . 2 1 7 . 2 2 7 7 . 7 5 1 6 . 0 6 6 . 1 9 4 . 8 4
M e a n 7 . 2 9 7 . 2 8 7 8 . 3 9 1 5 . 1 9 6 . 4 2 5 . 1 6
1 2 B e f o r e
f e e d i n g 7 . 1 3 7 . 4 2 7 2 . 4 3 2 0 . 4 4 7 . 1 3 3 . 5 4
H o u r s
o f
S a m p l ­
i n g .
1 6 . 9 9 7 . 5 7 7 7 . 3 6 1 6 . 3 3 6 . 3 1 4 . 7 4
2 7 . 0 3 7 . 0 9 7 5 . X 1 7 . 6 9 7 . 3 1 4 . 2 4
M e a n 7 . 0 5 7 . 3 6 7 4 . 9 3 1 8 . 1 5 6 . 9 2 4 . 1 3
129
UNIVERSITY OF IBADAN LIBRARY
TABLE 7 .1
Ruminol V . F . A . , P ^  , A cetic/P ro p io n ic ratio (A/P)
of treatments (J) at different stages of growth fed to
Zebu ca tt le .
S t a g e  o f T i m e  o f  PH T o t a l I n d i v i d u a l
g r o w t h S a m p l ­ o f V . F . A .  V . F . A .  M e q  % A / P
o f i n g . l i q u o r M e  q /  A c e t i c P r o p i ­ B u t y ­
F o r o g e 1 0 0  m l A c i d o n i c r i c
( w e e k s ) r u m e n  A c i d A c i d
l i q u o r
J B e f o r e
4 f e e d i n g 7 . 0 5 1 4 . 8 2 7 7 . 9 7 1 4 . 2 0 7 . 8 3 5 . 4 9
H o u r s
a f t e r
f e e d i n g
1 6 . 9 8 1 5 . 1 2 8 0 . 3 0 1 3 . 3 6 6 . 3 4 6 . 0 1
2 7 . 1 0 1 4 . 4 8 7 9 . 2 9 1 4 . 1 9 6  5 2 5 . 5 9
M e a n 7 . 0 3 1 4 . 8 1 7 9 . 1 9 1 3 . 9 2 6 . 9 0 5 . 7 0
1 2 B e f o r e
f e e d i n g 7 . 3 0 1 3 . 8 5 7 7 . 7 6 1 4 . 1 0 8 . 1 4 5 . 5 1
H o u r s
a f t e r
f e e d i n g
1 7 . 2 5 1 4 . 6 3 7 9 . 9 4 1 2 . 3 6 7 . 2 0 6 . 2 2
2 7 . 0 8 1 2 . 9 2 7 3 . 7 3 1 5 . 1 9 1 1 . 0 8 4 . 8 5
M e a n 7 . 2 1 1 3 . 8 0 7 7 . 1 4 14.05 9 . 8 1 5 . 5 3
UNIVERSITY OF IBADAN LIBRARY
TABLE 7.1
Ruminal V . F . A . , P ^ ,  A cetic/lV o p io n ic  ratio (A/P)
of treatment (K) at 4 and 12 weeks of growth fed to
Zebu ca tt le .
S t a t e  o f  T i m e  o f  pH T o t a l I n d i v i d u a l  
g r o w t h S a m p l - o f V . F . A . V  , F . A .  M e q  % A / P
o f i n g . l i q u o r M e q /  A c e t i c P r o p i ­ B u t y ­
F o r a g e 1 0 0  m l A c i d o n i c r i c
( w e e k s ) r u m e n  A c i d A c i d
l i q u o r
K B e f o r e
4 f e e d i n g 7 6 1 8 0 6 7 9 . 5 9 1 7  8 6 8 5 5 6 . 7 1
------------------------------- --------
- -
H o u r s
a f t e r
f e e d i n g
1 7 . 8 6 7 . 9 4 7 5 . 5 4 1 4 . 6 1 9 . 8 5 5 . 1 7
2 7 , 7 8 7 . 2 7 7 9 , 7 3 1 4 . 0 3 6 . 2 4 5 . 6 8
M e a n 7 . 7 5 7 . 7 6 7 8 . 2 9 1 5 . 5 0 8 . 2 1 5 . 8 5
1 2 B e f o r e
f e e d i n g 7 . 3 1 9 . 0 1 7 7 . 5 8 1 7 . 5 2 4 . 9 0 4 . 4 3
H o u r s
a f t e r
f e e d i n g
1 7 . 6 0 8 . 1 1 7 8 . 6 0 1 6 . 8 2 4 . 5 8 4 . 6 7
2 8 . 1 8 7 . 9 2 7 9 . 6 4 1 6 . 1 2 4 . 2 4 4 . 9 4
1
M e a n 7 . 7 0 8 . 3 5 7 8 . 6 1 1 6 . 8 2 4 . 5 7 4 . 6 8
UNIVERSITY OF IBADAN LIBRARY
TABLE 7 .1
Ruminol V . F .A . , P M ,  A cetic/P rop ion ic ratio (A/P)
of treatment (L) at 4 and 12 weeks of growth fed to
Zebu ca tt le .
S t a g e  o f  T i m e  o f  PH T o t a l I n d i v i d u a l
g r o w t h  S a m p l ­ o f V . F . A • V .  F .  A .  M e q  % A / P
o f i n g . l i q u o r M e q / A c e t i c P r o p i ­ B u t y ­
F o r a g e I X  m l A c i d o n i c r i c
( w e e k s ) r u m e n A c i d A c i d
l i q u o r
L B e f o r e
4 f e e d i n g 7 . 3 8 9 . 3 6 7 6 . 8 8 1 6 . 9 7 6 . 3 5 4 . 5 2
H o u r s
a f t e r
f e e d i n g
1 7 . 5 0 7 . 8 7 7 6 . 9 8 1 3 . 4 4 7 . 5 8 5 . 8 8
2 7 . 3 5 7 . 5 7 7 7 . 2 7 1 6 . 8 6 5 . 8 7 4 . 5 8
M e a n 7 . 4 1 8 . 2 7 7 7 . 6 4 1 5 . 7 6 6 . 6 0 4 . 9 9
1 2 B e f o r e
f e e d i n g 8 . 1 5 1 0 . 8 9 6 3 . 8 1 1 8 . 9 1 1 7 . 2 8 3.37
H o u r s
a f t e r
f e e d i n g
1 7 . X 8 . 3 1 7 6 . 0 6 1 3 . 4 9 1 0 . 4 9 5 . 6 4
2 8 . 1 0 8 . 1 2 7 8 . 6 9 1 4 . 2 4 7 . 0 7 5 . 5 3
M e a n 7 . 8 5 9 . 1 1 7 2 . 8 5 1 5 . 5 5 1 1 . 6 0 4 . 8 5
________ ______
UNIVERSITY OF IBADAN LIBRARY
Table 7.2 showed the results of pH, total V.F.A., the 
i-ravidua1 acids, and the acetic acid to propionic acid 
ritic ox the rumen liquor when treatments H, J, K and L 
ire fed to Zebu cattle at 4 and 12 weeks of growth.
Ire sampling period was extended to 4 hours after feeding.
Treatment H at 4 weeks gave an almost constant pH level 
rowever, fell by a few units one hour after feeding from 
the prefeeding level and also at 4 hours after feeding.
There were two small peaks, one at one hour after feeding 
arc the other at 3 hours after feeding. The total V*F.A. 
rose after feeding reaching a peak two hours after feeding, 
The level thereafter fell to 7.02 raeq.% at 3 hours after 
feeding but rose to 7.18 raeq. % 4 hours after feeding.
At 12 weeks treatment H produced a pH peak at 4 hours 
rarer feeding. The pH level dropped from the prefeeding 
level but started to rise two hours after feeding. The 
rrtal V.F.A. content also dropped after feeding, but 
iTarred to rise 2 hours after feeding till it reached a 
leak 4 hours after feeding.
Treatment J at 4 weeks produced a fairly uniform pH 
level throught the sampling period. The highest level was 
i■ 5 hours after feeding. The level fell from the prefeed- 
_-r level but rose again two hours after feeding. The
UNIVERSITY OF IBADAN LIBRARY
total V.F.A. content of the rumen liquor dropped one hour 
after feeding and continued to drop up till 4 hours after 
feeding. The highest level was at one hour after feeding.
At 12 weeks the pH level also remained fairly steady 
throughout the sampling period. However, the pH rose by 
small units and the highest pH level was at 3 hours after 
feeding. The total V.F.A. content dropped from the pre­
feeding level of 13.24 meq. % to 15.31 meq.% one hour after 
feeding. It rose by a small unit two hours after feeding 
but dropped again to the lowest level 3 hours after feeding. 
The level rose to a peak: at 4 hours after feeding.
Treatment K at 4 weeks produced the highest pH level 
4 hours after feeding. The pH level dropped from the pre­
feeding level of 7.05 to 6.92 one hour after feeding. It 
rose 2 hours after feeding and remained at the level 3 
hours after feeding, but rose to the peak 4 hours after 
feeding. The total V.F.A. content also dropped to lower 
level after feeding, but rose two hours after feeding, 
dropped again 3 hours after feeding and reached the peak 
4 hours after feeding. At 12 weeks there was a slight drop 
one hour after feeding, it dropped again 2 hours after 
feeding but rose steadily till it reached a peak 4 hours 
after feeding. The total V.F.A. rose after feeding, but 
dropped to lower level 3 hours after feeding and latter
131
UNIVERSITY OF IBADAN LIBRARY
rose to a peak 4 hours after feeding. The highest pH level 
and the total V.F.A. peak occured at the same time, at the 
two stages of growth..
Treatment L at 4 weeks produced rumen liquor pH that 
remained constant from one hour before feeding till 2 hours 
after feeding. The pH level then rose 3 hours after feed­
ing till it reached its peak 4 hours after feeding. The 
total V.F.A. content rose after feeding till it reached 
a peak 4 hours after feeding. The pH peak and the total 
V.F.A. peak coincided.
At 12 weeks the pH remained constant till one hour 
after feeding but rose steadily till it reached a peak 4 
hours after feeding. The total V.F.A. also rose after 
feeding but fell to lower level and rose again till it 
reached a peak 4 hours after feeding. The peaks for the 
pH and total V.F.A. also occured at the same time. 
Individual V.F.A.
Acetic acid formed over 70% of the separated V.F.A.s 
in all the treatments and at the two stages of growth.
For treatment H at 4 weeks the acetic acid content 
dropped to lower level one hour after feeding and continued 
to drop but rose a bit 4 hours after feeding. The level 
was however still lower than the the level one hour after
132
UNIVERSITY OF IBADAN LIBRARY
feeding. Propionic acid content also dropped to lower 
level one hour after feeding but rose to a peak 3 hours 
after feeding and dropped again 4 hours after feeding,
3utyric acid content rose after feeding reaching a peak 2 
hours after feeding but dropped thereafter till 4 hours 
after feeding. The content was still higher at 4 hours 
than at the prefeeding stage.
At 12 weeks the acetic acid content dropped to lower 
level one hour after feeding but rose to a peak 2 hours 
after feeding and it dropped again. The propionic acid 
content rose after feeding but dropped to loxver level 2 
hours after feeding. It rose from then onwards till it 
reached a peak 3 hours after feeding. Butyric acid also 
rose after feeding and reached a peak 4 hours after feeding.
Acetic acid was the major acid produced when treatment 
J was fed at 4 weeks of growth. Propionic acid was next to 
it in production while butyric acid had the lowest produc­
tion. At 12 weeks of growth acetic acid also formed the 
greater part of the total volatile fatty acids produced in 
the rumen. Propionic acid came next while butyric acid 
came least in production..
Treatments K and L also produced more acetic acid than 
propionic and butyric acids. The individual V.F.A. produc­
tion was similar at both stages of growth.
133
UNIVERSITY OF IBADAN LIBRARY
A/P ratio
The acetic to propionic acid ratio did not fall below 
3. Treatments H and J had the highest ratio at both stages 
of growth, while treatmentsK and L had lower ratios at both 
stages of growth.
134
UNIVERSITY OF IBADAN LIBRARY
TABLE 7 .2
RuminolPH, Total V .F .A .  and individual V . F .A . ,
Acetic/^ropionic (A/P) ratio of treatment (J) at 4
and- 12 weeks of growth fed to Zebu cattle
Stoge cf Time of PH Total Individual .
growth Sampl­ of V.F.A. V. F.A.Molar %
of ing. liquor meq/100 Acetic Propi­ Buty A/P
=oroge ml Acid onic ric
-ee« e « rumen Acid Aridliquor
J Before * 
4 feeding 7.27 11.90 77.56 17.16 5.28 4.52
Hours
after
feeding
1 7.12 8.54 79.20 14.73 6.07 5.38
2 7.23 8.24 80.97 12.97 6.06 6.24
3 7.47 7.75 81.93 13.24 4.83 6.19
4 7.22 7.45 79.44 14.65 5.91 5.42
Mean 7.26 8.78 79.82 14.55 5.63 5.55
12 Before
feeding 6.85 18.24 79.00 16.18 4.82 4.88
Hours
after
feeding
1 6.93 15.31 78.61 14.02 7.37 5.61
2 6.88 15.36 79.76 15.86 4.38 5.03
3 6.98 13.02 80.39 15.34 4.27 5.24
4 6.90 15.46 78.27 17.05 4.68 4.59
Mean 6.91 15.48 79.21 15.69 5.10 5.07
135
UNIVERSITY OF IBADAN LIBRARY
TABLE 7.2
R u m in a lT o ta l V .F .A . and individual V .F .A .,
and Acetic/frropionic (AJY) acid ratio of treotrre-* -
at 4 and 12 weeks of growth fad to Zecj cattle
Stage of Time of PH Total
growth Sampl­ of V.F.A. V .- fT 'a . Mo*ar *
of ing. liquor meryHOO Acetic A/P
Forage ml Acid onic ric
(weeks) rumen Acid Acid
liquor
H Before
4 feeding 7.46 6.09 82.51 14.24 3.25 5.79
Hours
after
feeding
1 7.43 6.88 78.79 12.61 8.60 6.24
2 7.42 8.65 76.96 13.84 9.20 5.56
3 7.43 7.02 73.82 18.53 7.65 3.98
4 7.35 7.18 75.98 17.02 7.00 4.46
Mean 7.42 7.16 77.61 15.25 7.14 5.21
12 Before
feeding 7.10 7.51 80.16 14.24 5.60 5.62
Hours . 
after 
feeding 
1 6-80 6.80 77.34 15.13 7.53 5.11
2 6.90 7.06 79.08 14.70 6.22 5.37
3 7.05 7.22 75.75 16.84 7.41 4.49
4 7.20 7.81 75.54 16.45 8.01 4.59
Mean 7.01 7.28 77.57 15.47 6.95 5.04
UNIVERSITY OF IBADAN LIBRARY
TABLE 7 .2
Ruminal V . F . A . ,  p H f Acetic/Propionic (A/P) ratio
of treatment (K) at 4 and 12 weeks of growth-fed to
Zebu cattle
Stage of Time of pH Total Individilal
growth Sampl­ of V.F.A. V.F.A. V\olar % A/P
of ing. liquor Meq/100 Acetic Propi­ Buty­
Forage ml Acid onic ric
(weeks) rumen Acid Acid
liquor
K Before
4 feeding 7.05 7.82 68.20 16.69 15.11 4.09
Hours
after
feeding
1 6.92 7.77 78.93 16.13 4.94 4.89
2 7.00 9.00 77.70 16.62 5.68 4.68
3 7.00 8.61 77.89 15.90 6.21 4.90
4 7.25 9.41 76.40 17.64 5.96 4.33
Mean 7.04 8.52 75.82 16.60 7.58 4.58
12 Before
feeding 6.95 7.62 74.01 13.34 12.65 5.55
Hours
after
feeding
1 6.90 7.72 78.34 11.61 10.05 6.75
2 6.80 8.01 67.35 18.49 14.16 3.64
3 7.20 7.92 77.09 17.02 5.89 4.53
/
/  * 7.40 9.11 57.92 19.99; 12.09 3.40
Mem 7.05 I J i  72.94 • ’6.09 10.97 4.77
k  -
UNIVERSITY OF IBADAN LIBR
RY
TABLE 7 .2
RuminolpH^total V . F. A .,  and individual V .F .A .
Acetic/Propionic (A/P) ratio of treatment (L) at 4
and 12 weeks of growth fed to Zebu cattle
Stage of Time of pH Individual 
growth Sampl­ of V. F. A. Molar % A/P
of ing. liquor Acetic Propi­ Buty­
Forage Acid onic ric
(weeks) Acid Acid
L Before
4 feeding 6.73 7.78 76.25 16.81 6.94 4.54
Hours
after
feeding
1 6.73 8.66 77.45 16.39 6.16 4.74
2 6.73 9.16 76.85 16.86 6.29 4.56
3 7.00 9.61 77.04 16.30 6.66 4.72
4 7.13 10.20 75.21 16.77 8.02 4.48
Mean 6.86 9.08 76.56 16.63 6.81 4.61
12 Before
feeding 7.15 6.43 79.57 13.38 7.05 5.95
Hours
after
feeding
1 7.15 8.61 78.60 16.01 5.39 4.91
2 7.20 6.63 70.04 20.08 9.88 3.49
3 7.35 7.72 71.21 18.25 10.54 3.90
4 7.40 9.11 76.68 15.33 7.99 5.00
Mean 7.25 7.70 75.22 16.61 8.17 4.65
UNIVERSITY OF IBADAN LIBRARY
1 §■
■2 > S  2 -
7.4 pH Values and total V.F.A.
In table 7.3, the pH for J at 4 weeks reached its 
maximum 4 hours after feeding, while the total V.F.A. 
reached its peak production at 1 hour after feeding. The 
greatest amount of acetic acid was produced 2 hours after 
feeding. The mean of the acetic acid to propionic acid 
was 5.42.
The pH of 7.57 and acetic to propionic acid ration of 
5.42 are high. These are expected because the feed was not 
supplemented and it was fibrous.
At 12 weeks the pH reached its maximum at 6 hours 
after feeding, and the total V.F.A. reached its maximum 
production 1 hour after feeding. Acetic acid production 
reached its highest at 4 hours after feeding. The acetic 
acid to propionic acid ratio was not as high as at 4 weeks.
In treatment L the pH reached its maximum 1 hour after 
feeding, while the total V.F.A. reached its maximum produc­
tion also 1 hour after feeding. The acetic acid reached 
its highest production 2 hours after feeding. The acetic 
to propionic acid ratio was 5.37.
When treatment L was 12 weeks the pH reached its 
highest at 1 hour and 6 hours after feeding* The total 
V.F.A. reached its peak at 1 hour after feeding, while the
136
UNIVERSITY OF IBADAN LIBRARY
acetic acid production was at its highest 4 hours after 
feeding. The acetic to propionic acid ratio of 4.78 was 
lower than the value at 4 weeks.-
137
UNIVERSITY OF IBADAN LIBRARY
TABLE 7 .3
Ruminal V .F .A . ,P H  / Acetic/Propionic (A/P) ratio of
treatment (J) at different stages of growth fed to Zebu~
Cattle.
Stage of Time of pH Total Individu al Acetic
growth Sampl­ of V.F.A. V. F. A. Mol ar % Propi­
of ing. liquor Meq/ Acetic Propi­ Buty­ onic
Forage 100 ml onic ric Ratio
(weeks) rumen
liquor Acid Acid Acid
J Before
4 feeding 7.43 12.29 79.58 15.32 5.09 5.19
Hours
after
feeding
1 7.10 13.51 77.32 16.13 6.55 4.79
2 7.45 10.19 80.24 14.40 5.36 5.57
4 7.83 10.64 79.55 14.33 6.12 5.55
6 7.48 11.26 79.94 13.87 6.19 5.76
8 8.13 10.33 80.04 14.08 5.88 5.68
Mean 7.57 11.37 79.45 14.69 5.87 5.42
12 Before
feeding 7.15 11.61 78.21 16.75 5.05 4.67
Hours
after
feeding
1 6.83 13.70 75.10 18.85 6.05 3.98
2 7.10 13.41 74.40 15.33 10.27 4.85
4 7.38 12.62 77.89 16.53 5.59 4.71
6 7.45 11.94 76.98 18.66 4.36 4.13
8 7.43 10.96 75.64 19.50 4.87 3.85
1 . Mean 7.22 12.37 76.37 17.60 6.03 4.34
UNIVERSITY OF IBADAN LIB
ARY
TABLE 7 .3
Ruminol pH totol V . F .A . ,  Individual V . F . A ., Acetic/
Propionic (A/P) ratio of treatment (L) ot 4 and 12 w e lcs
of growth fed to Zebu Cattie.
Stage of Time of PH Total Individual Acetic
growth Sampl­ of V.F.A. V. F. A. Molar % Propi­
of ing. liquor Mecy' Acetic Propi­ Buty­ onic
Forage 100 ml onic ric Ratio
(weeks) rumen
• liquor Acid Acid \cid
L Before
4 feeding 7.10 7.92 83.19 14.84 1.97 5.61
Hours
after
feeding
1 7.24 6.81 82.18 15.43 2.39
2 7.16 6.57 83.82 13.79 2.39 6.07
4 7.15 5.77 83.01 14.54 2.41 5.69
6 7.08 5.67 81.43 14.08 4.49 5.78
8 7.29 5.54 73.39 19.56 7.05 3.75
Mean 7.17 6.38 81.17 15.38 3.45 5-37
12 Before
feeding 7.52 8.17 70.91 14.74 14.35 * *
Hours
after
feeding
1 7.60 6.83 75.48 16.70 7.82 4-5"
2 7.58 6.43 75.39 16.91 7.70 i  4t
4 7.57 6.24 76.66 15.41 7.93 4 .IT
6 7.60 5.25 76.42 15.31 8.27 4 .f*
8 7.80 5.54 77.43 15.66 6.91 4.«ft
Mean 7.61 6.41 75.38 15.79 8.83 4.71
UNIVERSITY OF IBADAN LIBRARY
Tables 7,4, 7.5 and 7.6 showed the pH, total V.F.A. 
in rumen and blood, individual V.F.A. and acetic to pro­
pionic acid ratio of treatments H, J, K and' L fed at 4,
8 and 12 weeks of growth. The sampling was carried out 
one hour before feeding and hourly after feeding up to 8 
hours after feeding.
Table 7.4 and figures 7,11, 7.12, 7.13, 7.14 and 
7.15 showed the pH, total V.F.A. in rumen liquor and blood 
serum and the individual V,F.A. in the rumen liquor, when 
H was 4 weeks and 8 weeks respectively. At 4 weeks, 
treatment H had a pH range between 6.93 and 7.42. The 
pH fell from the prefeeding level to a lower level one 
hour after feeding. The highest pH level was at 2 hours 
after feeding. This was also illustrated in figure 7.11. 
The total V.F.A. dropped from the prefeeding level of 7.07 
meq. percent to 4.69 neq. percent. The peak V.F.A. produc­
tion was at 4 hours after feeding. This is illustrated in
figure 7.12. The acetic acid peak was at 8 hours after 
although
feeding,/' there was a minor peak 5 hours after feeding. 
Propionic acid peak was at 4 hours after feeding, and this 
acid varied between 16.54 molar percent to 22.74 molar 
percent. Butyric acid varied from 0.78 molar percent 2 
hours after feeding to 4.32 molar percent 3 hours after 
feeding. Acetic to propionic acid ratio was gust over 4.
139
UNIVERSITY OF IBAD
N LIBRARY
EFFECT OF TIME OF SAMPLING AFTER FEEDING 
PASTURE FORAGE (H) AT DIFFERENT STAGES 
OF GROWTH TO ZEBU CATTLE ON RUMINAL PH
* ------ U WKS
o-------- o 8 WKS
FIG-7 - II TIME OF SAMPLING (hrs) AFTER FEEDING
UNIVERSITY OF IBADAN LIBRARYH d
EFFECT OF TIME OF SAMPLING AFTER  
FEEDING PASTURE FORAGES (H ) ON THE 
TOTAL VOLATILE FATTY ACID PRODUCTION 
BY ZEBU CATTLE.
*------ *  A WKS
100 o------ © 8 WKS.
9-5-
0 Before 1 2 3 A 5 6 7 8
F IG .7-12 TIME OF SAMPLING (hrs.) AFTER FEEDING.
UN TOTAL V. F. A. Meq.IVERSITY OF IBADAN LIBRARY
E FFE C T OF TIME OF SAMPLING AFTER FEEDING 
PASTURE FORAGES ( H ) ON THE TOTAL BLOOD 
VOLATILE FATTY ACID PRODUCTION (M eq. %>) 
BY ZEBU C A TTLE.
x -------M  WKS
0 -------08 W KS
0 Before 1 2 3 A 5 6 7
F IG .7 - 13 TIME OF SAMPLING(hrs)AFTER FEEDING
U total V F A Meq o.NIVERSITY OF IBADAN LIBRARY
EFFECT OF TIME OF SAM PLING AFTER FEEDING 
PASTURE FORAGES (H ) AT 8 WKS. OF AGE TO 
ZEBU CATTLE ON ACETLC AND PROPIONIC ACIDS.
(MOLAR % )
F IG .7 .1 4  TIME OF SAMPLING (h rs .) A FTER  FEEDING.
ACETIC AND PROPIONIC ACIDS 
UN MOLAR %IVERSITY OF IBADAN LIBRARY
EFFECT OF TIME OF SAMPLING AFTER FEEDING 
PASTURE FORAGES (H )  AT A WKS. OF AGE TO 
ZEBU CATTLE ON ACETIC AND PROPIONIC ACIDS 
(MOLAR % )
*  ACETIC ACID
UNIVERSITY OF IBADAN LIBRARY
The total V.F.A. in blood serum did not vary much.
The level dropped a bit from the prefeeding value to a 
lower level one hour after feeding, then it rose from then 
onwards reaching a peak 3 hours after feeding. The 
level fell 4 hours after feeding, but rose to 4.37 meq 
percent and remained at this level till 8 hours after 
feeding. This is illustrated in figure 7.13.
At 8 weeks of growth treatment H produced rumen liquor 
with almost uniform pH. The pH remained at just over 8.
It varied from 8.00 to 8.70. The pH fell one hour after 
feeding but rose afterwards till it reached a peak 6 hours 
after feeding. This is illustrated in figure 7,11, The 
peak for the total V.F.A. was at 4 hours after feeding, 
figure 7.12, The total V.F.A, varied from 5.72 meq percent 
to 8.85 meq. percent. Acetic acid varied from 76.78 molar 
percent to 80.69 molar percent. The highest acetic acid 
production was at 2 hours after feeding. Propionic acid 
varied from 12.50 molar percent to 16.15 molar percent.
The peak production of propionic acid was at 7 hours after 
feeding. Butyric acid varied from 4.7 molar percent to 
7.24 molar percent. The maximum butyric acid production 
was at 1 hour after feeding. Acetic to propionic acid 
ratio was 5.25. These two acids are illustrated in figures 
7.15 and 7.14.
140
UNIVERSITY OF IBADAN LIBRARY
The total V.F.A. in blood serum remained at just over 
4 up to 4 hours after feeding. Its level dropped from 5 
hours after feeding to 7 hours after feeding. By 8 hours 
after feeding the level rose almost to the prefeeding 
level. The graphical presentation of the total V.F.A. in 
blood serum is seen in figure 7,13.
Table 7.5 showed the pH, total V.F.A., individual 
V.F.A. Acetic to propionic acid ratio, and total V.F.A. in 
blood serum, when treatment J 'was fed at 4, 8 and 12 weeks 
of growth. The pH variation over 9 hours of sampling, and 
the total V.F.A, in rumen and blood serum acetic to 
propionic acid ratio, over the same sampling periods are 
also illustrated in figures 7.16, 7.17, 7.18, 7.19, 7.20 
and 7.21 respectively. At 4 weeks of growth the pH 
remained at just over 7. There was a fall in pH level 
after feeding and it rose till it reached a peak 4 hours 
after feeding. At 8 weeks of growth the pH rose after 
feeding but dropped after one hour. There was a rise from 
3 hours onwards till it reached the peak 6 hours after 
feeding. At 12 weeks of growth the pH remained at just 
over 7. The pH increased after feeding but the highest 
level was at 8 hours after feeding.
141
UNIVERSITY OF IBADAN LIBRARY
EFFECT OF TIME OF SAMPLING AFTER FEEDING
PASTURE FORAGES (J ) AT DIFFERENT STAGES OF
GROWTH TO ZEBU CATTLE ON RUMINAL PH
X-- x a W K S
o------® 8 WKS
F I G . 7.16 TIME OF SAMPLING (hrs) AFTER FEEDING
UNIVERSITY OF IBADAN LIBRARY
EFFECT OF TIME OF SAMPLING AFTER FEEDING
PASTURE FORAGES (J ) ON THE TOTAL VOLATILE
FATTY ACID PRODUCTION BY ZEBU CATTLE.
x--------x A WKS
FIG.7.17 TIME OF SAMPLING (hrs) AFTER FEEDING
UNIVERSITY OF IBADAN LIBRARY
EFFECT OF TIME OF SAMPLING AFTER FEEDING 
PASTURE FORAGES (J ) AT A WKS. OF AGE TO 
ZEBU CATTLE ON ACETIC AND PROPIONIC ACLDS 
(MOLAR °/o)
ACETIC AND PROPIONIC ACIDS 
U MOLAR %NIVERSITY OF IBADAN LIBRARY
EFFECT OF TIME OF SAMPLING AFTER FEEDING
PASTURE FORAGE ( J ) AT 8 WKS. OF AGE TO
ZEBU CATTLE ON ACETIC AND PROPIONIC ACIDS
( MOLA-R °/o)
F I G . 7 .1 9  j (ME OF SAMPLING (h rs .) AFTER FEEDING.
ACETIC AND PROPIONIC ACIDS 
U MOLAR °/oNIVERSITY OF IBADAN LIBRARY
EFFECT OF TIME OF SAMPLING AFTER FEEDING 
PASTURE FORAGES (J )  AT 12WKS- OF AGE TO ZEBU 
CATTLE ON ACETIC AND PROPIONIC ACIDS (MOLAR 7«)
X ------ACETIC ACID
90 0 — - PROPIONIC ACID
80
12WKS
75
70
60
50
AO
30
25
20
15
10
7. TIME OF SAMPLING (hrs) AFTER FEEDING
UNIVERSITY OF IBADAN LIBRARY
EFFECT OF TIME OF SAMPLING AFTER 
FEEDING PASTURE FORAGES (J )  ON THE 
TOTAL BLOOD VOLATILE FATTY ACID 
PRODUCTION BY ZEBU CATTLE.
5-6- *  A wks.
54-
52-
5 0 -
4 8 -
4 6 -
A A-
A2-
A0-
3-8“
3-6-
34-
32-
30 -
----------- -----------1---------- 1---------- 1---------- 1---------- 1---------- 1---------- 1---------- T -
0  .Before 1 2 3 A 5 6 7 81 .
FIG.7. 21 TIME OF SAMPLING (hrs.) AFTER FEEDING.
U TOTAL V .F A .M e q .  N IN BLOOD SERUM.IVERSITY OF IBADAN LIBRARY
At 4 weeks the total V.F.A. increased after feeding 
- 3  a maximum of 14.13 meq percent one hour after feeding.
The total V.F.A. content dropped afterwards and came close 
to the prefeeding level at 8 hours after feeding. At 8 
-.reeks the total V.F.A. dropped a bit from the prefeeding 
level. There was a further drop two hours after feeding 
but increased rapidly to a peak of 7.76 meq percent at 3 
hours after feeding. At 12 weeks the total V.F.A. dropped 
from the prefeeding level of 13.89 meq percent to 10.39 meq 
percent one hour after feeding. It increased till it 
reached a peak of 12.34 meq percent 4 hours after feeding.
The amount dropped thereafter and continued to drop even 
at 8 hours after feeding.
Acetic acid peak, when treatment J was 4 weeks was at 
6 hours after feeding. There was not much variation in 
the acetic acid content throughout the sampling period.
It varied between 77.91 molar percent to 79.05 molar 
percent. At 8 weeks the peak was at 2 hours after feeding, 
while the variation was between 77.74 molar percent and 
81.55 molar percent. At 12 weeks the variation was from 
77.38 molar percent to 30,17 molar percent. The peak was 
also at 6 hours after feeding.
142
i
UNIVERSITY OF IBADAN LIBRARY
At 4 weeks of growth the propionic acid content varied 
between 15.27 to 17.12 molar percent. There was a sharp 
rise after feeding to a peak one hour after feeding. The 
content rose and fell afterwards and did not vary much 
from the prefeeding level at 8 hours after feeding. At 8 
weeks of growth the propionic acid peak was also at one 
hour after feeding. The level fell afterwards and came 
close to the prefeeding level 8 hours after feeding.
At 12 weeks of growth propionic acid peak was at 7 hours 
after feeding. The variation was from 14.93 to 17,78 
molar percent.
Butyric acid content when treatment J was at 4 weeks 
varied from 4.97 molar percent to 6.01 molar percent.
The peak of 6.01 molar percent was at 4 hours after feeding. 
The level fell to nearly the prefeeding level. At 8 weeks 
butyric acid content varied from 4.23 to 7.60 molar percent. 
The peak of 7.60 molar percent was at 6 hours after feeding. 
At 12 weeks butyric acid content varied between 4.16 and 
6.07 molar percent at 2 hours after feeding. The amount 
dropped till it cane close to the prefeeding amount.
The acetic to propionic ratio varied from 4.55 to 
5.06. The mean was 4.89 when treatment J was 4 weeks.
The ratio also varied from 4.72 to 6,39 when the treatment
143
UNIVERSITY OF IBADAN LIBRARY
was 8 weeks. The mean was 5.48. At 12 weeks the variation 
was from 4.36 to 5.37. The mean was 4.77. The ratios for 
the treatment at 4 and 12 weeks ware close while the ratio 
when the treatment was 8 weeks was higher.
The total V.F.A* in blood serum did not show much 
variation throughout the sampling period. The amount 
dropped after feeding and thereafter rose and fell.
At 3 weeks the amount also fell after feeding but rose and 
fell slightly. The amount at 8 hours after feeding was 
the same as when the feed was at 4 weeks. The means for 
both growth periods are close. At 12 weeks the total 
V.F.A. in blood serum remained fairly constant till 3 
hours after feeding before it started to fluctuate.
The mean vas 4.23 meq/100 ml.
Table 7.6, and figures 7.22, 7.23, 7.24 and 7.25 
showed the effect of time of sampling on the pH, total 
V.F.A., individual V.F.A., acetic to propionic acid ratio 
and the total V.F.A. in blood serum by Zebu cattle fed 
treatment K at 4, 8 and 12 weeks.
When treatment K was 4 weeks and fed to Zebu cattle 
the pH of the rumen liquor vas above 7 but below 8. The 
variation was not much since the range was between 7.19 
and 7.55 during the sampling period. The highest was
144
UNIVERSITY OF IBADAN LIBRARY
EFFECT OF TWE OF SAMRJNG AFTER FEEDING 
PASTURE FORAGES (K) AT DEFERENT STAGES OF 
GROWTH TO ZEBU CATTLE ON RUMINAL PH
4W KS
8WKS-
12WKS
UNIVERSITY OF IBADAN LIBRARY
EFFECT OF TIME OF SAMPLING AFTER FEEDING 
PASTURE FORAGE (K ) AT A WKS. OF AGE TO
ZEBU CATTLE ON ACETIC AND PROPIOWC ACIDS 
(M OLAR •/.)
F IG .7 .23  j|M E  OF SAMPLING (h rs .)  AFTER FEEDING.
U ACETIC AND PROPIONIC ACIDS. N MOLAR ( #/ . )IVERSITY OF IBADAN LIBRARY
EFFECT OF TIME OF SAMPLING AFTER FEEDING 
PASTURE FORAGES (K) ON THE TOTAL VOLATILE 
FATTY ACID PRODUCTION BY ZEBU CATTLE.
* ----- « 4 WKS.
* ---0 8 WKS.
*  ---*12 WKS.
F IG «7*24  t im e  OF SAMPLING (hrs.) AFTER FEEDING-
UN TOTAL V F . A . Meq. 7.IVERSITY OF IBADAN LIBRARY
EFFECT OF TIME OF SAMPLING AFTER FEEDING 
PASTURE FORAGES (K ) ON THE TOTAL BLOOD 
VOLATILE FATTY ACID PRODUCTION (M e q .° /.)
BY ZEBU CATTLE.
FIG.7.25 TIME OF SAMPLING (hrs.)AFTER FEED/ ING.
U TOTAL V F A Meq. % N IN BLOOD SERUM.IVERSITY OF IBADAN LIBRARY
-.55 and it was at 6 hours after feeding. At 8 weeks 
tie pH was higher throughout the sampling periods. The 
-H was above 7 but below 9. The peak was at 7 hours after 
feeding and the pH range was between 7.90 and 8.85. At 
12 weeks the pH range was from 7.10 to 7.90. The peak of 
7.90 was at 6 hours after feeding. In all the three stages 
cf growth the pH rose after feeding.
The total V.F.A. content of the rumen liquor when 
treatment K was 4 weeks dropped to lower level after feed­
ing. The V.F.A. content showed some alternate increases 
and falls throughout the sampling period. The range was 
from 6.60 meq percent to 8.06 meq percent was at 6 hours 
after feeding. At 8 weeks the total V-.F.A. content was 
lower than at 4 weeks.. The level also fell to lower level 
after feeding but the peak of 6.83 meq. percent was at 4 
weeks after feeding.. The range was from 3.99 meq. percent 
to 6.83 meq. percent.. At 12 weeks the total V.F.A. content 
of the rumen liquor also dropped by small amounts after 
feeding. The total V.F.A. produced however, was greater 
than that produced at 4 or 8 weeks. The amount continued 
to fall until it rose to a smaller peak at 4 hours after 
feeding after which the level fell again but rose to the 
larger peak 6 hours after feeding.
145
UNIVERSITY OF IBADAN LIBRARY
Separation into individual V.F.A. by GLC
The chromatographic separation of the V.F.A. in the 
rumen liquor into the individual V.F.A. showed acetic acid 
rs the major acid in all the three stages of growth. At 
weeks of growth the acetic acid content dropped to lower 
level after feeding. It rose to the peak 7 hours after 
feeding. The level then dropped again. On the average it 
formed 67.17 molar percent of the total V.F.A. separated. 
The range was from 62.57 molar percent to 80.40 molar 
percent. On the other hand propionic acid content increa­
sed after feeding until it got to the peak of 22.57 molar 
percent 4 hours after feeding. The level then dropped.
The lowest amount of 14.68 molar percent coincided with 
the acetic acid peak. The mean propionic acid during the 
sampling period was 20.08 molar percent.
Butyric acid content was the smallest in all cases.
It rose immediately after feeding but fell 2 hours after 
feeding and remained almost constant until 5 hours after 
feeding, when the peak production of 15.10 molar percent 
was obtained. The amount dropped sharply after 5 hours. 
The mean butyric acid content over the sampling period 
was 12.75 molar percent.
146
UNIVERSITY OF IBADAN LIBRARY
At 8 weeks the acetic acid content rose immediately 
after feeding but rose and fell alternately afterwards.
The peak was at 1 hour after feeding. The range was from 
78.11 molar percent to 82.33 molar percent. The average 
was 79.82 molar percent.. The acetic acid content was 
higher at 8 weeks than at 4 weeks.
Propionic acid level dropped immediately after feed* 
ing, but rose steadily afterwards till it got to a peak 6 
hours after feeding. Propionic acid content was lower at 
8 weeks than at 4 weeks. The average amount was 14.23 
molar percent and the range was from 12,48 molar percent 
to 15.59 molar percent.
Butyric acid range was between 5.18 molar percent and 
7.46 molar percent. The amount was lower than at 4 weeks. 
The peak was at 8 hours after feeding, and the mean was 
5.95 molar percent.
At 12 weeks the acetic acid content rose up to two 
hours after feeding, before the level then dropped to lower 
levels and continued so until the end of sampling period. 
The peak was at 2 hours after feeding. The average of 
78.20 molar percent was greater than the value at 4 weeks 
but lower than the value at 8 weeks..
147
UNIVERSITY OF IBADAN LIBRARY
Propionic acid level dropped immediately after feeding 
and continued to drop but rose sharply to a peak 4 hours 
after feeding and the level dropped again. The range was 
from 12.59 molar percent to 15.24 molar percent. The average 
was 13.97 molar percent, a value less than that at 4 or 8 
weeks.
Butyric acid level fell after feeding and continued so 
until 2 hours after feeding. After 2 hours the level rose 
till it reached a smaller peak 5 hours after feeding. The 
level fell after this period but rose to the larger peak 
8 hours after feeding. The range was from 5.30 molar per­
cent to 9.87 molar percent. The mean was 7.83 molar percent 
and this value was less than that at 4 weeks but more than 
the value at 8 weeks.
Acetic to propionic acid ratio range when treatment K 
was 4 weeks old was from 2.77 to 5.48. The mean was 3.43..
At 8 weeks the range was from 5.06 to 6.60 and the mean was 
5.64. At 12 weeks the ratio varied from 4.97 to 6.26, 
while the mean was 5.62. This value was less than the 
value at 8 weeks but greater than the value at 4 weeks.
Blood V.F.A.
The total V.F.A. in blood serum dropped immediately 
after feeding, but rose to a peak 2 hours after feeding.
148
UNIVERSITY OF IBADAN LIBRARY
The level showed some alternate rises and falls after 2 hours. 
Ine amount remained constant as from 7 hours after feeding. 
The range was from 4.37 to 4.92 meq percent, and the mean 
was 4.68 meq percent.
At 8 weeks the total V.F.A. in the blood serum was 
lower than the amount during 4 weeks of growth. The peak 
was at 2 hours after feeding and it remained at this level 
till 3 hours after feeding. The level dropped after 3 
hours and remained constant up till 6 hours after which it 
rose sharply till it reached the second peak 8 hours after 
feeding. The mean was 3.89 meq percent and the range was 
from 3.28 meq percent to 4.37 meq percent. The lower 
V.F.A. level of the blood serum may be as a result of the 
lower V.F.A. level of the rumen liquor when treatment K was 
8 weeks.
At 12 weeks the total V.F.A. in blood serum remained 
fairly constant until 4 hours after feeding before falling. 
The mean was 3.93 meq/100 ml.
Table 7.7, figures 7.26, 7.27, 7.28, and 7.29 showed 
the effect of sampling on the pH, total V.F.A., individual 
V.F.A., Acetic to propionic acid ratio and total V.F.A. in 
blood serum by Zebu cattle fed treatment L at 4, 8 and 12 
weeks of growth.
149
UNIVERSITY OF IBADAN LIBRARY
EFFECT OF TIME OF SAMPLING AFTER FEEDING 
PASTURE FORAGES (L) AT DIFFERENT STAGES 
OF GROWTH TO ZEBU CATTLE ON RUMINAL PH
X — 4WKS.
0 -----8WKS-
A — 12WKS
FIG-7 .2 6  TIME OF SAMPLING (hrs) AFTER FEEDNG
UNIVERSITY OF IBADAN LIBRARY
E F F E C T  O F TIM E O F SA M P LIN G  A FTE R
U TOTAL V .F .A . M eq.NIVERSITY OF IBADAN LIBRARY
EFFECT OF TIME OF SAMPLING AFTER FEEDING 
PASTURE FORAGES (L ) AT AWKS OF AGE TO 
ZEBU C A TTLE  ON ACETIC AND PROPIONIC 
ACIDS (M O LA R 0/.)
50 - 
AO -
------1------ 1---- 1------1------1------1------1------1------1-------
0 Bie<5f*ore 1 2 3 A 5 6 7 8
FIG .7 .2 8  TIME OF SAMPLING (hrs) AFTER FEEDING
UN A C ETIC  AND PROPIONIC ACIDS  MOLAR %IVERSITY OF IBADAN LIBRARY
EFFECT OF TIME OF SAMPLING AFTER FEEDING 
RfcSTURE FORAGES (L ) ON THE TOTAL BLOOD 
VOLATILE FATTY ACID PRODUCTION (Meq)*/»)
BY ZEBU CATTLE.
4  2- 
4 1- 
4  0-
T “ “T- ~r
BEFORE 1 3 4 7 8
FIG.7 .2 9  TIME OF SAMPLING (hrs) AFTER FEEDING
UN
TOTAL IVV. F EA. M«q% N BLOOD SERUMRSITY OF IBADAN LIBRARY
At 4 weeks the pH of the rumen liquor dropped immedia­
tely after feeding and continued to drop slowly, until it 
rose to a minor peak 3 hours after feeding. The level 
dropped 4 hours after feeding but rose to the major peak
5 hours after feeding. The - pH later dropped until the.
end of sampling period. The range was from 6.96 to 7.31 
and the mean was 7.17.
The total V.F.A. dropped after feeding but afterwards 
showed alternate rises and falls throughout the sampling 
period. The major peak was at 4 hours after feeding.
The range was from 7.71 to 8.51 meq percent, and the 
mean was 8.21 meq. percent.
Separation into individual V.F.A, by GLC
Separation of the acids by GLC showed that acetic 
acid made up over 60?? of the total acids separated. The 
range was from 60.94 molar percent to 79.11 molar percent. 
The acetic acid content rose after feeding but rose and 
fell a number of times afterwards till it reached the 
highest level 8 hours after feeding. The mean was 73,06 
molar percent.
Propionic acid came next in quantity. The level of 
this acid in the rumen liquor fell after feeding but rose 
sind fell a few times before it got to the peak 5 hours after 
feeding. The range was from 16.83 molar percent to 22.54 
molar percent.
150
UNIVERSITY OF IBADAN LIBRARY
3utyric acid formed the smallest proportion of the 
-.F.A. separated. The level of this acid rose after 
feeding and continued to rise slowly until it rose very 
sharply to a peak 7 hours after feeding and it immediately 
fall sharply also one hour after. The range was from 
„D6 molar percent to 17.32 molar percent, and the mean 
6.99 molar percent.
Acetic to propionic acid ratio varied between 2.80 
and 4.70, while the mean was 3.71.
Hood V.F.A.
The total V.F.A. in blood serum fell after feeding 
: rose to a peak 3 hours after feeding. The V.F.A. 
content then dropped by very small amounts until the end 
of sampling. The variation was from 4*37 meq percent to 
5.10 meq percent, while the mean was 4*80 meq. percent.
At 8 weeks pH of treatment L remained high throughout 
the sampling period. The pH was above 8 but below 9.
The peak was attained 1 hour after feeding. It later 
dropped by small units. The range was from 8.0 to 8.85. 
The mean was 8.48, and the pH was higher than that at 4 
weeks.
Total V.F.A. rose after feeding and it rose slowly to 
a peak 4. hours after feeding.. The level dropped sharply
151
UNIVERSITY OF IBADAN LIBRARY
i_r*:r t -ours, but the range was from 4.05 meq. percent to
fw:" aier percent, and the mean was 5.43 meq. percent.
-- i peaks for 4 and 8 weeks treatment were obtained at 4 
after feeding. But the total V.F.A. content of the 
— —,--g liquor was lower when the feed was 8 weeks. 
la. — visual V.F.A.
,-cetic acid formed over 70 percent of the total 
.... separated by GLC. The range was from 75.43 molar 
■ LTcent to 78.50 molar percent. The variation was small, 
tie mean was 76.65 molar percent and the highest amount 
rat obtained 8 hours after feeding.
Propionic acid came next in production. The propionic 
eta a level fell by small amount after feeding. The amount 
regained fairly constant until 5 hours after feeding when 
at reached a minor peak, but the level fell at 6 hours 
after feeding but rose sharply to the major peak 7 hours 
after feeding. The mean was 14.23 molar percent.
Propionic acid level at 8 weeks was smaller than the level 
at 4 weeks.
3utyric acid showed a lot of variation at 8 weeks.
Tie level rose after feeding but continued to rise and 
fall throughout the sampling period. The peak was attained 
3 hours after feeding. The range was from 7.11 molar
152
UNIVERSITY OF IBADAN LIBRARY
:: ;r.t to 10.36 molar percent. The mean was 9.12 molar 
arrert, a level higher than that at 4 weeks.
Acetic to propionic acid ratio remained fairly con- 
.- The ratio was above 5 but below 6 except for the
: 7 hours after feeding. The range was from 4.73 to
.76.
lisoc V.P.A.
Total V.F.A., in blood serum at 8 weeks did not vary 
-r.-- also. The level of V.F.A. remained fairly constant 
--ic ghout. There was however a peak 4 hours after feeding 
ifxcr which the level dropped sharply to the prefeeding 
level. The peak was reached one hour later than at 4 weeks. 
If Weeks
At 12 weeks treatment L produced rumen liquor with 
fairly constant pH.. The pH range was from 6.98 to 7.20, 
rat the peak was at 8 hours after feeding. The pH level 
dropped after feeding, and the mean was 7.05. The total 
'.F.A. dropped immediately after feeding but rose again 2 
hours after feeding. The V.F.A. content rose and fell a 
nunber of times during the sampling period. The range was 
from 6.97 meq percent to 8.32 meq percent, while the peak
153
UNIVERSITY OF IBADAN LIBRARY
production was at 2 hours after feeding. The total V.F.A. 
content of the rumen liquor at 12 weeks was higher than at
8 weeks.
Individual V.F.A.
Chromatographic separation of the fatty acid showed 
acetic acid as the major acid, since it formed over 70% of 
the total acids separated. The acetic acid level increased 
after feeding and rose to a minor peak 4 hours after feed­
ing. The major peak was at 7 hours after feeding, but the 
range was from 76.15 molar percent to 79.02 molar percent, 
while the mean was 76.55 molar percent.
Propionic acid came next in quantity and this acid 
also increased after feeding. Its level however dropped 
after one hour and came close to the prefeeding level at 
the end of the sampling period. The peak production was 
at one hour after feeding, and the range was from 13.98 
molar percent to 16.42 molar percent. The mean was 14.96 
molar percent.
Butyric acid level dropped after feeding but rose to 
a minor peak 3 hours after feeding, before the level then 
dropped sharply one hour after but rose sharply also to 
the major peak 5 hours after feeding. The level then 
dropped till the end of sampling, and the range was from
154
UNIVERSITY OF IBADAN LIBRARY
6.38 molar percent to 12.3-5 molar percent. The mean was 
8.48 molar percent.
A/P
Acetic to propionic acid ratio varied between 4.66 
and 5.65, and the mean was 5.13. • The highest ratio was 
at 7 hours after feeding. The ratios for 8 and 12 weeks 
treatments were quite close.
Blood V.P.A.
The level of blood V.F.A. remained about the same 
throughout the experimental period. The mean was 4.47 
meq/100 ml.’
155
UNIVERSITY OF IBADAN LIBRARY
TABLE 7 .4
Effect o f time of sampling on the pH^Toto l V . F . A . ,  individual V . F .  A .
Acctic/Wopionic acid ratio and Total V . F . A .  in blood serum by Zebu cottle
fed treatments (H) at two stages of growth.
Tim e o f c lipping  Tim e o f sampling pH To ta l V . F . A .  Ind iv idua l V . F . A .  o f rumen liq u o r M o la r % A /P ------ To ta l V . ~ T T  A .
forage (weeks) o f Mea per 100 ml Aceti c Propionic Buty ric in  blood serum 
1 i quor Rumen liq uo r Acid Acid A cid mec/100 ml
H Before
4 feeding 7 .4 2 7 .0 7 79 .61 1 7 .2 9 3 .1 0 4 .6 0 4 .2 8
Hours a fte r feeding 
1 7 .0 5 4 .6 9 7 9 .6 5 1 9 .2 7 1 .0 8 4 .6 1 4 .1 9
2 7 .3 8 4 .8 2 7 7 .6 2 2 1 .6 0 0 .7 8 3 .5 9 4 .2 8
3 7 .1 5 3 .9 0 7 7 .4 8 1 8 .2 0 4 .3 2 4 .2 6 4 .7 4
4 7 .0 0 5 .3 8 7 6 .2 3 2 2 .7 4 1 .0 3 3 .3 5 4 .1 9
5 6 .9 6 5 .0 8 8 1 ,4 6 1 7 .0 3 1.51 4 .7 8 4 .3 7
6 7 .1 6 4 .7 5 8 0 .1 5 18.11 1 .7 4 4 .4 3 4 .3 7
7 7 .2 6 5 .0 8 79 .81 1 8 .4 3 1 .7 6 .  4 .3 3 4 .3 7
8 6 .9 3 4 .4 2 8 1 .7 3 1 6 .5 4 1 .7 3 4 .9 4 4 .3 7
Mean* 7 .1 5 5 .0 2 7 9 .3 0 1 8 .8 0 1 .8 9 4 .3 2 4 .3 7
8 Before feeding 7 .7 0 8 .6 0 7 5 .0 9 1 7 .7 8 7 .1 3 4 .2 2 4 .2 8
Hours a fte r feeding  
1 8 .2 7 8 .2 0 7 6 .7 8 1 5 .9 8 7 .2 4 4 .8 0 4 .1 9
2 8 .0 0 7 .6 2 8 0 .6 9 1 2 .5 0 6 .8 1 6 .4 6 4 .1 9
3 8 .3 3 7 .6 1 7 9 .81 1 5 .1 0 5 .7 1 5 .2 4 4 .4 6
4 8 .2 0 8 .8 5 7 8 .7 6 1 5 .2 8 5 .9 6 5 .1 5 4 .1 0
5 8 .1 7 7 .2 1 8 0 .6 2 1 4 .6 8 4 .7 0 5 .4 9 3 .7 4
6 8 .7 0 5 .8 7 7 8 .7 6 1 5 .8 7 5 .3 8 4 .9 6 3 .7 4
7 8 .3 0 5 .7 2 7 8 .0 7 1 6 .1 5 5 .7 8 4 .8 3 3 .4 6
8 8 .0 0 5 .7 9 8 0 .3 5 1 3 .1 0 6 .5 5 6 .1 3 4 .0 1
Mean* 8 .1 9 7 .2 7 7 8 .7 0 1 5 .1 6 6 .1 4 5 .2 5 4 .0 2
*Each is the mean o f 18 determ inations.
1 5 6
UNIVERSITY OF IBADAN LIBRARY
TABLE 7.5
Effect o f time o f sampling on the P H |  Total V .  F .  A . ,  individual V .  F .  A 
Acetic/Propionic ocid ratio and Total V . F . A .  in blood serum by Zebu ca ttl• 
fed treatments (J) ot three stages o f growth.
Time of clipping I Time of Sampling pH Total V .  F .  A . Individu al V . F . A .  o f rumen liquor M olar % Total V . F .  A . 
forage (weeks) of Meq per 100 ml Acetic Propionic Butyric V P in blood serum 
liquor Rumen liquor Acid Acid Acid meq/100 m l.
J
4 Before feeding 7 .3 9 11.21 7 9 .28 15 .23 5 .4 4 5.21 5 .3 7
H rs. after feeding 
1 7 .4 4 14.13 77.91 17.12 4 .9 7 4 .5 5 4 .5 5
2 7 .51 11.60 7 8 .82 15.79 5 .3 8 4 .9 9 4 .2 0
3 7 .6 3 11.39 7 7 .9 2 16.98 5 .1 0 4 .5 9 3 .6 5
4 7 .7 8 10.80 78.71 15.27 6.01 5 .0 6 4 .4 4
5 7 .5 6 10.66 78 .50 16 .14 5 .3 5 4 .8 6 3.91
6 7 .4 2 10.69 7 9 .05 15.71 5 .5 4 5 .0 3 3 .9 2
7 7 .4 9 10.55 7 8 .22 16.35 5 .4 2 4 .7 8 4 .01
8 7 .6 8 10.60 7 8 .67 15.93 5 .1 2 4 .9 4 3 .8 3
Mean 7 .5 4 11.29 7 8 .5 6 16.06 5 .3 7 4 .8 9 4.21
8 Before feeding 7 .5 0 6 .85 7 9 .75 14.65 5-59 . 5 .4 4 4 .9 2
H rs . after feeding 
1 7 .9 0 6 .2 7 7 8 .3 9 16.53 5 .0 8 4 .7 2 4 .5 5
2 7 .6 3 5 .7 9 81 .55 14.22 4 .2 3 5 .7 3 "4 .7 4
5 7 .8 3 7 .7 6 81 .3 3 13 .49 5 .1 7 6 .0 3 4 .6 4
4 7 .8 3 6 .0 5 7 9 .42 14.88 6 .6 9 5 .3 4 4 .2 8
5 8 .0 3 4 .7 4 7 7 .74 15.52 6 .7 4 5 .01 4 .3 7
6 8 .0 7 6 .0 5 7 9 .8 9 12.50 7 .6 0 6 .3 9 4 .1 9
7 7 .9 7 5 .9 7 78 .28 15.50 6.21 5 .0 5 4 .1 9
8 7 .9 3 5 .9 0 7 9 .38 14.12 6 .4 9 5 .6 2 3 .8 3
Mean 7 .8 5 6 .1 5 7 9 .5 3 14.60 5 .8 7 5 .4 8 4.41
12 Before feeding 7 .1 5 13.99 79 .00 16.40 4 .6 0 4 .8 2 4 .6 2
H rs. after feeding 
1 7 .2 0 10.39 78 .3 0 16.34 5 .3 6 4 .7 9 4 .2 0
2 7 .3 6 10.86 77 .3 8 16.55 6 .0 7 4 .6 8 4 .2 0
3 7 .3 6 12.03 7 8 .7 7 15.88 5 .3 5 4 .9 6 4 .1 0
4 7 .4 5 12.34 7 8 .8 7 16.64 4 .4 9 7 .7 4 3 .98
5 7 .3 8 10.92 7 8 .7 3 17.11 4 .1 6 4 .6 0 4 .2 0
6 7 .3 7 9.81 80 .1 7 14.93 4 .8 9 5 .3 7 3 .9 6
7 7 .4 2 9 .4 8 7 7 .4 4 17.78 4 .7 8 4 .3 6 4 .41
8 7 .5 4 9 .1 7 7 8 .3 9 16.91 4 .7 0 4 .6 4 4 .4 2
Mean 7 .3 6 10.98 7 8 .5 6 16.50 5 .0 4 4 .7 7 4 .2 3
1 5 7
UNIVERSITY OF IBADAN LIBRARY
TABLE 7.6
Effect of time of somplinq on the P H , Total V . F . A .,  individual V . F . A .
Acetic/Vropionic acid ratio and Total V .F .A .  in blood serum by Zebu cattle
fed treatments (K) ot three stages of growth.
Time of clipping ‘ Time of sampling pH Total V . F .  A . Individual V . F .A .  o f rumen liquor M olar % A /P Total V . F .  A 
forage (weeks) of Meq per 100 ml Acetic Propionic Butyric in blood meq/ 
liquor Rumen liquor Acid Acid Acid 100 ml.
K
4 Before feeding 7 .1 8 6 .8 3 65 .05 20.21 14.75 3 .2 2 5 .2 8
H rs. a fter feeding 
1 7 .2 2 6 .6 0 6 3 .17 2 1 .0 2 14 .56 3 .0 6 4 .9 2
2 7 .1 9 7 .0 8 6 4 .42 2 1 .0 2 14 .56 3 .0 6 4 .9 2
3 7 .2 6 6 .7 9 6 4 .14 2 1 .0 4 14.82 3 .0 5 4 .5 5
4 7 .3 4 7 .2 7 6 2 .5 7 2 2 .5 7 14 .86 2 .7 7 4 .7 4
5 7 .3 9 7 .0 4 6 4 .09 20.81 15.10 8 .0 8 4 .4 6
6 7 .5 5 . 8 .0 6 7 4 .6 6 18 .32 7 .0 2 4 .0 8 4 .7 4
7 7 .3 7 7 .3 9 80 .4 0 14.68 4 .9 2 5 .4 8 4 .5 5
8 7 .2 7 6 .8 8 66 .02 2 1 .05 12 .92 3 .1 4 4 .5 5
Mean 7.31 7 .1 0 6 7 .1 7 20 .08 12.75 3 .4 3 4 .6 8
8 Before feeding 8 .3 5 5 .6 8 8 0 .8 6 13.84 5 .2 9 5 .2 9 3 .8 3
H rs. a fter feeding 
1 8 .4 5 4 .8 6 8 2 .33 12.48 5 .1 8 6 .6 0 3 .83
2 7 .9 0 6.61 7 8 .80 14.99 6.21 5 .2 6 4 .3 7
3 8 .7 5 6 .7 8 7 8 .95 14.85 6 .2 0 5 .3 2 4 .3 7
4 8 .0 5 6 .8 3 78 .69 15 .07 6 .2 5 5 .2 2 3 .28
5 8 .7 5 5 .5 7 8 0 .8 4 13.38 5 .7 8 6 .0 4 3 .28
6 8 .6 5 5 .1 7 7 8 .95 15.59 5 .4 6 5 .0 6 3 .28
7 8 .8 5 4 .2 7 80 .8 4 13.44 5 .7 2 6.01 3 .8 3
8 8 .5 0 3 .9 9 78.11 14.43 7 .4 6 5.41 4 .3 7
I Mean 8 .4 7 5 .5 3 8 9 .8 2 14.23 5 .9 5 5 .6 4 3 .89
12 Before feeding 7 .0 0 9 .1 0 7 9 .2 7 14.85 5 .8 8 5 .3 4 4 .7 3
H rs. a fter feeding 
1 7 .4 8 9 .0 6 80.71 13.83 5 .4 6 5 ,8 4 4 .7 4
2 7 .1 0 8 .5 6 8 1 .19 13.51 5 .3 0 6.01 4 .8 3
3 7 .4 5 8 .3 2 7 8 .8 6 12.59 8 .5 5 6 .2 6 4 .5 5
4 7 .6 0 8.91 75.81 15 .24 8 .9 5 4 .9 7 4 .3 2
5 7 .8 5 8 .0 7 75.71 15.19 9 .1 0 4 .9 8 3 .8 3
6 7 .9 0 9 .0 6 7 8 .1 0 13.23 8 .6 7 5 .9 0 3 .28
8 7 .5 0 7 .5 3 7 6 .3 4 13.79 9 .8 7 5 .5 4 3 .83
Mean 7 .5 3 8.51 78 .2 0 13 .97 7 .8 3 5 .6 2 3 .9 3
1 5 8
UNIVERSITY OF IBADAN LIBRARY
TABLE 7.7
Effect o f time o f sampling on the PH,--Total V .  F .  A . ,  individual V  .F  .A .
Acetic/Propionic ocid ratio and Total V . F . A .  in blood serum by Ze bu cattle
fed treatments (L) at three stages of growth.
Tim e o f c lipp ing  Tim e o f sampling p H Tota l V . F . A .  Ind iv idua l V . F . A .  o f rumen liq u o r M ola r % To ta l V .  F .  A . 
forage (weeks) o f Meq per 100 ml A cetic Propionic Buty ric A /P in blood serum 
liq uo r Rumen liq uo r Acid Acid Acid meq/100 ml
L
4 Before feeding 7 .2 4 8 .4 8 7 4 .4 9 19 .79 5 .7 2 3 .7 6 5 .2 8
H rs . a fte r feeding  
1 7 .0 2 8 .0 5 7 5 .3 7 1 8 .8 3 5 .8 0 4 .0 0 4 .9 2
2 6 .9 6 8 .4 3 7 2 .5 6 20 .71 6 .7 3 3 .5 0 4 .7 4
3 7 .2 6 8 .3 2 7 1 .7 3 2 1 .9 9 6 .2 8 3 .2 6 5 .1 0
4 7 1 2 8 .51 7 5 .2 6 1 9 .1 2 5 .6 2 3 .9 4 4 .9 2
5 7 .31 8 .0 9 7 1 .8 0 2 2 .5 4 5 .6 6 3 .1 9 4 .3 7
6 7 ,1 9 8 .4 2 7 6 . X 18.01 5 .7 0 4 .2 4 4 .7 4
7 7 .2 4 7 .71 6 0 .9 4 2 1 .7 4 1 7 .3 2 2 .8 0 4 .6 4
8 7 .1 5 7 .8 9  * 79 .11 1 6 .8 3 4 .0 6 4 .7 0 4 .4 6
Mean 7 .1 7 8 .2 1 7 3 .0 6 1 9 .9 8 6 .9 9 3 .71 4 .8 0
8 Before feeding 8 ,7 3 4 .9 7 7 6 .9 7 13.91 9 .1 2 5 .5 3 4 .3 7
Hours a fte r feeding 
1 8 .8 5 5 .4 7 7 6 .2 5 1 3 .4 2 1 0 .3 3 5 .6 8 4 .3 7
2 8 .6 0 5 .4 1 7 6 .9 8 1 3 .5 2 9 .5 0 5 .6 9 4 .3 8
3 8 .8 0 5 .5 2 7 5 .9 7 1 3 .6 7 10.3*6 5 .5 6 4 .3 8
4 8 .2 5 6 .6 7 7 5 .4 3 1 4 .7 3 9 .8 4 5 .1 2 5 .4 7
5 8 .4 0 6 .3 4 7 6 .5 2 1 4 .9 3 8.5*5 5 .1 3 4 .3 8
6 8 .4 3 5 .5 8 7 7 .1 2 1 3 .3 9 9 .4 9 5 .7 6 4 .3 8
7  • 8 .0 0 4 .8 7 7 6 .1 2 1 6 .08 7 .8 0 4 .7 3 4 .3 7
8 8 .2 5 4 .0 5 7 8 .5 0 1 4 .3 9 7 .1 1 5 .4 6 4 .3 7
Mean 8 .4 8 5 .4 3 7 6 .6 5 1 4 .2 3 9 .1 2 5 .4 1 4 .5 0
12 Before feeding 7 .0 7 8 .9 6 7 4 .7 0 1 5 .3 6 9 .9 5 4 .9 0 4 .8 0
H rs . a fte r feeding  
1 7 .0 5 6 .9 7 7 6 .5 0 1 6 .4 2 • 7 .0 8 4 .6 6 4 .3 7
2 7 .0 0 8 .3 2 7 6 .1 5 1 4 .5 7 9 .2 9 5 .2 3 4 .5 0
3 7 .0 0 7 .5 2 7 4 .5 9 1 4 .7 9 1 0 .6 2 5 .0 4 4 .3 7
4 7 .0 8 7 .3 8 7 8 .8 8 1 4 .7 4 6 .3 8 5 .3 5 4 .7 4
5 6 .9 8 7 .7 2 7 3 .6 0 14 .05 12 .35 5 .2 4 4 .3 7
6 7 .0 7 8 .1 2 7 7 .7 6 1 5 .7 4 1 5 .7 4 4 ,9 4 4 .3 7
7 7 .0 0 8 .0 2 7 9 .0 2 1 3 .98 7 .0 0 5 .6 5 4 .4 6
8 7 .2 0 7 .8 2 7 7 .7 9 1 5 .0 3 7 .1 8  1 5 .1 8 4 .3 8
Mean 7 .0 5 7 .8 7 7 6 .5 5 1 4 .9 6 8 .4 8 5 .1 3 4 .4 7
1 5 9
UNIVERSITY OF IBADAN LIBRARY
TABLE 7.8
Ruminal V.F.A.t pH, and blood V.F.A, of treatments 
H, J, K, and L at 4 weeks of ago fed to Zebu cattle.*
H J K L
pH of Rumen liquor 7.15 7.54 7.31 7 .1 7
Total V.F.A. of Rumen 
liquor Meq % 5.02 11.29 7.10 8*21
Individual
V.F.A. of Acetic 
Rumen Acid 79.30 78.56 67.17 73.06
liquor
molar % Propio­
nic 
Acid 18.80 16.06 20.08 19.95
Butyric
Acid 1.90 5.38 12.75 6.99
Acetic/Propionic 
Ratio (A/P) 4.32 4.89 3.43 3.71
Total V.F.A. 
in blood serum 
Meq % 4.37 4.21 4.68 4.80
* Each figure is the mean of 18 determinations.
160
UNIVERSITY OF IBADAN LIBRARY
1 •
TABLE 7.8 continued
Tuninal V.F.A., pH, Acetic/Propionic Ratio, (A/P) 
and blood V.F.A. ox treatments H, J, K and L at 8 
weeks of age fed to Zebu cattle*
------
H J V K L
tr-r ox Rumen liquor 8.19 7.85 8.47 8.48
Total V.F.A. of Rumen 
loc-or Meq. % 7.27 6.15 5.53 5.43
Individual
.F.A. of Acetic 78.70 79.53 79.82 76.46
loosen
liquor
♦blar % Propio­
nic 
Acid 15.16 14.60 14.23 13.94
Butyric
Acid 6.14 5.87 5.95 9.60
--cetic/Propionic 
Ratio (A/P) 5.25 5.48 5.64 5.50
Tino tball oVo.dF .sAe.r um
Xeq. % 4.02 4.41 3.89 4*50
* Each figure is the mean Of 18 determinations.
161
UNIVERSITY OF IBADAN LIBRARY
TABLE 7.8 continued
Ruminal V.F.A., pH, Acetic/Propionic Ratio (A/P) 
of1 treatments H, J, K and L at 12 Weeks' of age 
fed to Zebu Cattle*
1 J* K* L*
pH of Rumen liquor 7.36 7.53 7.05
Total V.F.A. of Rumen 
liquor Meq. % 10.98 8.51 7.87
Individual i
VR.uFm.eAn.  of AAccietdic 78.56 78.20 75.13
liquor
Molar % Propio­
nic 
Acid 16.50 13.97 14.80
Butyric
Acid 5.04 7.83 10.07
Acetic/Propionic 
Ratio (A/P) 4.77 5.62 5.13
* Each figure is the mean of 18 determinations.
162
UNIVERSITY OF IBADAN LIBRARY
TABLE 7.9
Ruminal V .F .A .,  P **, Acetic/Propionic ratio, (A/P) 
and blood V .F .A . of treatments H ,J ,K  and L at 
different stages of growth fed to Zebu cattle.
Forage PH Individual Rumen liquor Total Total
stage of V . F. A . Molar % A /P V .F .A . V .F .A . 
of liquor Actic Propionic Butyric M e t/  in blood 
growth Acid Acid Acid 100 ml serum 
(weeks) Meq %
V
H
4 7.15 79.30 18.80 1.90 4.32 5.02 4.37
8 8.19 78.70 15.16 6.14 5.25 7.27 4.02
J
4 7.54 78.56 16.06 5.37 4.89 11.29 4.21
8 7.85 79.53 14.60 5.87 5.48 6,15 4.41
12 7.36 78.56 16.50 5.04 4.77 10,98 4.23
K___________________ .________ ___________
4 7.31 67.17 20.08 12.75 3.43 7,10 4.68
8 8.47 79.82 14.23 5.95 5.64 , 5.53 3.89
12 7.53 78.20 18.97 7.83 5.62 8.51 6.93
L
4 7.17 73.06 19.95 6.99 3.71 8.21 4.80
8 8.48 76.46 13,94 9,60 5.50 5.43 4.50
12 7.65 75.13 14.80 10.07 5.13 7.87 4.47
163
UNIVERSITY OF IBADAN LIBRARY
Tables 7.8 said 7.9 showed the summary of ruminal pH, 
V.F.A., acetic to propionic acid ratio and blood serum 
V.F.A. of treatments H, J, K and L at 4, 8 and 12 weeks of 
growth fed to Zebu cattle.
Separation of blood serum V.F.A. by GLC showed that 
acetic acid was the only detectable acid in the blood 
serum under the operating conditions. The acetic acid 
content was however very low.
Discussion and Summary 
PH levels
The pH of the rumen liquor of the Zebu cattle was 
above 7 but below 8 in most cases. Whether at 4 weeks, 8 
or 12 weeks of growth the pH remained high. These high 
pH values below 8 are seen in tables 2, 3, 4, 5, 6-9, 10-11, 
and 12-15. However the pH was below 7 in tables 6-9 when 
L was 4 weeks and treatment J was 12 weeks.
The pH levels for all the treatments were high when 
the treatments were 8 weeks. In most cases the pH levels 
were higher than the values at 4 or 12 weeks. In most 
cases the pH levels were higher than 8, and high values are 
seen in tables 12-15.
The pH levels showed a tendency to rise or fall to 
the prefeeding level. This tendency is shown in tables
164
UNIVERSITY OF IBADAN LIBRARY
2-7, table 8 when the treatment was 4 weeks, table 9 when 
then treatment was 12 weeks, tables 10, 11, and 13, 14 and 
15, and table 12 when the treatment was 8 weeks.
High pH levels are characteristic of fibrous and 
unsupplemented feeds.
The pH values recorded by Steward, Stewart and Schultz 
(1958) did not rise up to 7. They worked with four rations 
one of which was solely alfalfa hay. This and the supple­
mented feeds produced rumen liquor with pH less than 7. 
Raymond and Terry (1966) discovered that there is a wide 
range of pH values "in vivo’1. The pH range was said to be 
between 5.5 and 8.0, depending on the feed. In this 
experiment the pH of over 8 was recorded in some cases. 
Total V.F.A.
The total V.F.A. content of the rumen liquor of Zebu 
cattle fed H, K and L was between 7 and 10 meq per 10O ml, 
while the content of the liquor when J was fed was between 
13 and 15 meq per 100 ml. This is shown in table 7.
In some cases the total V.F.A. content of the rumen liquor 
showed little difference between the treatments at 4 and 
12 weeks. .This little difference is shown in tables 7, 7.6 
and 7.7, There were times when the total V.F.A. content 
of the rumen liquor was higher at 4 than at 12 weeks as is
165
UNIVERSITY OF IBADAN LIBRARY
shown in table 7, and more at 12 weeks than at 4 weeks as 
is shown in table 7.6.
In table 7, the total V.F.A. was lowest when the 
treatments were 8 weeks. However, in table 7.4 the total 
V.F.A. content was lower at 4 than at 8 weeks. There was 
a tendency here also for the total V.F.A* content of the 
rumen liquor to rise or fall to the prefeeding level.
This was shown in table 7.7 when the feed was 8 weeks; 
table 7.6 when the feed was 4 weeks, and table 7.5 when 
the treatment was 4 weeks.
Stewart, Steward and Schultz (1958) reported increases 
in total V.F.A. production after feeding for each of the 
four rations used in their experiment. In these experiments, 
the total V.F.A. content of the rumen liquor did not show 
such a regular pattern. In some cases the amount increased, 
while the level dropped in others. After 6 hours the level 
dropped appreciably (Stewart et ajL.,1958). This was also 
observed in the present work. The level dropped six hours 
after feeding, but in a few cases the peaks occured after 
six hours. The reason for some inconsistencies in the 
pH and total V.F.A. levels in the present work may be due 
to the feeding habits of the animals. The time interval 
from the field to the laboratory may also be one of the 
causes, since the microflora continuedto ferment actively.
166
UNIVERSITY OF IBADAN LIBRARY
Individual V.F.A
Whether the feed is supplemented or not acetic acid 
formed the major proportion of the acids in the rumen 
liquor. The only difference was that the acid increased 
in proportion if the feed was fibrous and of low digestibi­
lity and was unsupplemented. The acetic acid levels in 
these studies were over 70 molar % and even in certain 
cases went up to over 80 molar %. Propionic acid came 
next in quantity and butyric acid made up the lowest.
Acetic acid to propionic acid ratio (A/P)
The ratio of acetic acid to propionic acid was high. 
The ratio ranged between 3 and 6 on the average, but the 
highest of 5.64 was obtained for treatment K when 8 weeks. 
The ratio was higher for the treatments when 8 and 12 
weeks. The high ratio is peculiar to fibrous and unsupple­
mented feeds. When the acetic acid content rises and 
propionic and butyric acid levels decrease, the ratio 
increases. This was what was observed in these studies.
A wide A/P ratio means high concentration of acetic acid 
and low concentration of propionic acid. The indication 
is that such feed would favour fat deposition either in 
milk or in the body; in order xvords such rations are 
lipogenic. Whereas a narrow ratio means higher concentra-
167
UNIVERSITY OF IBADAN LIBRARY
tion of propionic acid and such ration is glucogenic and 
may favour tissue protein synthesis. That is the signici- 
cance of this ratio. These treatments with A/P ratio of 
more than 4 can favour more fat deposition in the milk.
Blood V.F.A,
Total bllod serum V.F.A. did not vary much. The almost 
constant V.F.A. content of the blood tend to show that the 
liver may be converting excess V.F.A* to other substances 
and the liver regulates the amount that enters the blood 
stream.
Chromoatographic separation of the V.F.A. in the 
blood serum showed acetic acid as the only acid detectable 
to a large extent under the operating conditions. The 
very small amount of acetic acid, and the minute amounts 
of the other acids may be an indication that small amounts 
of digested and absorbed volatile fatty acids are used in 
the synthesis of milk and body fats. To give a clearer 
view, tracer techniques need to be employed so that the 
lebelled carbon atom in the feed or substance infused may 
be traced within the animal.
168
UNIVERSITY OF IBADAN LIBRARY
CHAPTER 8
MILK CONSTITUENTS
8.1 INTRODUCTION
Milk is a very important food to both young and old 
all over the world. There are established dairy farms 
owned by priva.te and government agencies in advance 
countries, and these farms own high yielding Holstein or 
Freisian cows which produce good quality milk for sale as 
fresh milk or as dairy products like butter, cream and 
cheese. A lot of research has been carried out in Europe 
and A-merica on the nutritional aspects, health, breeds, 
production and quality of the dairy animals.
In Nigeria, little is known, and little work has been 
done on the selection, breeding, nutrition, health, manage­
ment, production and quality of the dairy animals. The 
Government dairy farms and some University faculties of 
Agriculture have tried to improve milk production by 
importing high yielding cows from Europe or America and 
by crossing the imported breeds with the local White 
Fulani cattle.
169
UNIVERSITY OF IBADAN LIBRARY
This chapter therefore deals with the effect of feed 
and the volatile fatty acid production in the rumen, on 
the milk composition of the White Fulani cows.
8.2 MILK COMPOSITION
Milk fat and protein are the two constituents that 
show a lot of variation (Table 8.2).
Percent
Water 87.25
Dry Matter 12.75
Fat 3.8
Protein 3.5
Sugar 4.8
Ash 0.65
Total 12.75 100.00
Detailed composition (Ling, 1946; Jenness and Patton, 
1959; Kon and Cowie, 1961; and Ling, Kon and Porter, 1961) 
showed that water content of milk is over 80%. Water 
helps to hold in solution the soluble constituents of the 
milk, and the percentage of water varied from 84.0 to 
89.0%. Milk composition according to Jenness and Patton 
(1959) is shown in table 8.1
170
UNIVERSITY OF IBADAN LIBRARY
TABLE 8.1
Cow’s Milk Constituents according to Jenness 
and Patton (1959).
Milk
Waler pits Water Protelins Suears CGOa,ses Minerrals NonSolu­ Proteinble '2 ’ °2Vitamins N, Mg, Nitro­ gen
Triglyce­ Carote Thiamine 
Lv, ic­ Glu­ Ca,
 Ribofla- tose cose Na, K, Urea,
rides noids vine 3) Ammo­  ( sC i' - 'tA  >Phospho- Vita­ Niacin ra­tes , nia 
lipides Crea­mins A, Pyrido-
Cerebro- D, E Clp, tine xx ne
sides and K. Pantothe­ Bicar­ uric
Sterols nic acid Casein p,Y) Enzymes bonates acid
Biotin, B lactoglobulin Catalase Sulpha­ Adenine
Folic & lactalbumin Peroxi­ tes Guanine
acid Albumin dase Traces 
Choline, Pseudoglobulin Xanthine of Rb, 
Vitamin oxidase Li, Ba, Phospha­ Sr. ,
B12 tases Mu, Al,Inositol,
Ascorbic Aldolases
Zn, 
Lypases Cu, Co, F
B,e,
acid. Proteases
Carbonic- V
anhydrase
171
UNIVERSITY OF IBADAN LIBRARY
Milk Fat:
Milk fat is also called butter fat. It is commercial­
ly the most valuable constituent of the milk. The flavour 
of milk and other dairy products is due to its fat content. 
Pure fat extracted from milk, cream, or butter is a 
mixture. It melts between 28-33°C and sets between 24- 
19°C. The heterogenous nature of milk fat is shown in its 
specific gravity, 0.936-0.946 at 15°C and refractive index, 
1.459-1.462 at 15°C.- It is soluble in ethyl alcohol and 
readily soluble in hot amyl alcohol.
The Jersey gives an average of 4.5-5.0% fat,
Holstein’s give 3.5%. It will seldom go below 2.5% or 
above 6.0%. Butter contains 80-85% of milk fat. Cheddar 
cheese contains 30-40% fat. Ice cream contains 8-20% of 
milk fat, while condensed milk contains 8.0% milk fat, and 
dry milk contains 27.0% fat.
The indigenous livestock of Eastern and Southern 
Africa as well as West African Zebu breeds give milk fat 
that ranges from 3.4% to well above 6%, (Mason and Maule, 
1960). The Kanana Zebu breed gives 4.73% fat and 9.25% 
S.I-J.F. The Red Butana Zebu gives 5.5% fat; the Abyssinian
172
UNIVERSITY OF IBADAN LIBRARY
(Ethiopian) shorthorned Zebu gives 3.4% .to 6.5%; the 
Gasara (small Somalia Zebu) gives 5.5%; the Garre Zebu 
gives 5.4% and the Kenya Boron Zebu gives 5-6.8%.
TABLE 8.2
The Composition of milk of Various Species 
according to Eckles et al (1943)
Species Water Fat Protein Lactose Ash
% % % % %
Human 88.30 3.11 1.9 7.18 0.21
Cow 87.25 3.80 3.50 4.80 0.65
Goat 87.88 3.82 3.21 4.54 0.55
Sheep 80.82 6.86 6.52 4.91 0.89
Mare 90.70 1.20 2.00 5.70 0.40
Lactose or milk sugar:
Lactose is formed exclusively in the milk of mammals 
from glucose (Folley, 1956). Milk from various breeds of 
cattle contain variable amount of lactose. Jersey gives 
5%, Holstein gives 4.6% xvhile the human milk is about 6.3%. 
Lactose is in the true solution in the serum. On crystal-
173
UNIVERSITY OF IBADAN LIBRARY
lization from water it forms hard, gritty crystals
C1X  Ho/ -0 XX .HW 0. By the action of lactase in the intestines<Cr
and mineral acids, lactose is hydrolysed to glucose and
galactose, C
+ acid glucose galactose
Aqueous solution of lactose reduces Fehling’s solution and 
ammoniacal silver nitrate solution. After hydrolysis, the 
reducing power is doubled. Under slightly acid condition 
it is oxidised to formic acid and laevulinic acids. 
Oxidation with concentrated HNO^ gives oxalic acid and 
carbonic acid. When heated between 110~130°C, lactose 
hydrate crystals lose their water of crystallization.
Above 150°C they turn yellow, and at 175°C they turn brown 
forming lacto caramel.
Lactose is used in the preparation of infant and 
invalid foods. It is the only sourse of galactose for 
human and animals in the brain and nerves. The chief 
source of lactose is whey.
Bacteria in the milk can decompose lactose to lactic 
acid at 37°C. The acid gives the milk its sour taste.
H20 bacteria
174
UNIVERSITY OF IBADAN LIBRARY
The activity of the micro organisms is stopped at an 
acidity of 1%.
12 22°11 bacteria 2C6, H,12_ 06A C H H2 °
37°c
20,o- H,1 2 O,o  bacteria 4CH„5CHOHCooH
------------- ^
37°C lactic acid
When lactic acid concentration increases, the casein which 
is normally united with calcium is withdrawn and unites 
with lactic acid to form calcium lactate. Some of the 
colloidal calcium phosphate is converted to soluble 
calcium phosphate►
Mineral matter or Ash content of Milk:
When milk is dired first, and then the residue ashed 
in a furnace, a white powder is obtained. This is the ash. 
It forms about 0.7-0.76%, but the total mineral salts in 
milk will exceed this figure. This ash contains a lot of 
metallic elements as those found in the animal body. 
Potassium (k), Sodium (Na), Calcium (Ca), Magnessium (Mg), 
Chlorin (Cl), Phosphorus (P), and Sulphur (S) are present 
in relatively large amounts. Iron (Fe), Copper (Cu),
Zinc (Zn), Alluminum (Al), Manganese (Mn) and Iodine (I2 )
175
UNIVERSITY OF IBADAN LIBRARY
are present in small amounts, while silicon, boron, tita­
nium, vanadium, rubidium, lithium and strontium are present 
in traces.
Much of the nutritive properties of milk are due to 
its minerals. It is richer in calcium than lime water.
Milk can therefore correct calcium poor cereal diets of 
man and animals and it is a very important source of 
calcium in human nutrition.
All the mineral elements in milk are essential for 
nutrition, but the iron and iodine are very low.
Other constituents of milk
Phospholipids These are lecithin and cholesterol. 
Pigments are also present. The carotenoids are fat soluble, 
and the carotene is responsible for its yellow colour.
It is absent in the milk of goat, ewe and camel, so they 
produce white or colourless milk. The carotene is not 
synthesized in the cow but finds its way from the feed into 
the milk via the blood.
The water soluble pigment is the riboflavin and it is 
found in the serum. It is about 0.05-0.1% and occurs in 
the milk of most mammals. There is some relationship bet-
176
UNIVERSITY OF IBADAN LIBRARY
ween the riboflavin content of milk and high protein feeds.
Enzymes of milk
Enzymes of milk are normal constituents of milk. 
Galactase is a proteolytic enzyme for cheese ripening, 
while lipase is a fat splitting enzyme that causes rancidi­
ty in butter. Catalase, an oxidising enzyme, and reductase, 
a reducing enzyme are also present. Raw milk contains 
phosphatase which is inactivated by pasteurization.
Vitamins
The vitamins present are vitamin A, vitamin in the 
form of thiamine hydrochloride, 3^ or G (riboflavin), 
nicotinic acid (nicotinamide), (pyridoxin), Pantothenic 
acid, vitamin C (ascorbic acid), D and vitamin E (alpha 
tocopherol).
Gases:
These make up 7-lO?3 by volume of milk. Carbon dioxide 
is present as it comes from the udder, but nitrogen and 
oxygen are taken up by the milk during milking.
Factors affecting the composition of milk;
Many factors affect the yeild and composition of milk. 
These are the type of feed given to the animal, the age of
177
UNIVERSITY OF IBADAN LIBRARY
the animal, its breed, the time of milking,the stage of 
lactation, disease prevailing at the time, the season of 
the year and hormonal control.
8.3 ANALYTICAL METHOD
During the experimental period, the cows were milked 
in the morning and evening. Samples were taken from the 
cows in the morning during the last three days of the 
experiment. The samples of milk were taken to the labora­
tory for milk fat, lactose, ash, solid matter and protein 
analyses. The milk samples were stored at 1° to 2°C to 
prevent them from getting sour and from separating out. 
Milk Fat
The milk fat content was determined according to the 
Gerber method. This method is quick and accurate. It 
involves the use of sulphuric acid specially made for milk 
testing and amyl alcohol.
Milk Lactose
This was determined colorimetrically. The method of 
Barnett and Tawab (1957) was adopted.
Water content was determined by drying to constant 
weight in an oven at 65°C. The dry matter was calculated
178
UNIVERSITY OF IBADAN LIBRARY
from the residue left in the dish after drying. Milk ash 
was calculated after ashing the dry residue, and the milk 
protein was determined by the Kjeldahl method, and the 
result multiplied by 6.38.
179
UNIVERSITY OF IBADAN LIBRARY
RESULTS
Tables S.21 and 8,22 showed the milk constituents of 
the milk samples taken from cows fed treatments H, J, K and 
L at four weeks. The water content of each milk sample 
was over 80%. The range was between 83.08% and 85.98%, 
and this variation in water content was small. The fat 
content was also fairly high. The differences in the fat 
contents of all the milk samples were very small since the 
range was between 5.91% and 6.73%.
Milk protein varied from 3.70% to 4.38%, while lactose 
varied from 4.14gm % to 5.09gm %. Milk ash varied from 
0.68% to 0.83 and total solids varied from 14.02% to 
16.92%. The solid-not-fat content varied from 8.11% to 
10.38%.
Treatment H produced milk with more protein, total 
solids and solid-not-fat. It also produced milk with the 
least water content compared with treatments J, K and L.
Tables 8.31 and 8.32 showed the milk constituents 
of cows milk when the cows were fed treatments H, J, K and 
L at 12 weeks. Water formed the major part of the milk in 
each case. It made up over 82% of each milk sample. The
180
UNIVERSITY OF IBADAN LIBRARY
TABLE 8.21
Comparison of milk constituents of cows fed H t J,
K and L when four (4 weeks)
(%)
Milk H J K L
Constituent Cow Cow Cow Cow Cow Cow Cow Cow
195 183 195 183 195 236 322 236
Water 83.08 85.06 64.60 85.53 84.60 85.98 85.62 84.86
Fat 6.54 6.14 6.70 6.58 6.73 5.91 6.13 5.99
Protein 4.38 3.98 3.84 3.94 3.71 3.70 3.94 4.02
Lactose 4.14 4.94 4.86 4.81 5.07 5.09 5.07 4.90
Ash 0.69 0.74 0.83 0.78 0.72 0.68 0.69 0.69
Total solids 16.92 14.94 15.40 14.47 15.40 14.02 14.38 15.14
Solid-not- 
Fat (s.n.f.) 10.38 8.80 8.70 7.89 8.67 8.11 8.25 9.15
181
UNIVERSITY OF IBADAN LIBRARY
TABLE 8.22
HMe, anJ,  %K  mialnkd  Lc onats t4i tuweeenktss of cows fed treatments
Milk
Constituent H J K L
Water 84.07 85.07 85.29 85.24
Fat 6.34 6.64 6.32 6.06
Protein 4.18 3.89 3.71 3.98
Lactose 4.54 4.84 5.08 4.99
Total solids 15.93 14.94 14.71 14.76
Ash 0.72 0.81 0.70 0.69
S.N.F. . 9.59 8.30 8.39 8.70
182
UNIVERSITY OF IBADAN LIBRARY
range was from 82.44% to 88.19%. Treatments L produced
milk samples containing the least amount of water. The fat
content varied more than for the samples taken when the
treatments were four weeks, The range was from 4,l3e3a%s tto
7.91%. Treatment K produced milk samples with the/butter- 
fat content while treatment L produced milk with the 
highest butterfat content. The protein content did not 
vary much since it made up between 3,29% and 4,67% of the 
milk. Treatment L produced milk with the highest milk 
protein content. The lactose varied from 4,43% to 5,47gm 
%, while milk ash varied from 0.68% to 0,83%, Since most 
of the milk samples contained more water than those- obtained 
when the treatments were four weeks, the total solids and 
solid-not-fat contents were also low. The total solids 
varied from 11.81% to 17.56%, while solid-not-fat varied 
from 6.67% to 9.65%. Treatment L produced milk with the 
greatest amount of solids-not-fat and total solids.
183
UNIVERSITY OF IBADAN LIBRARY
TABLE 8.31
Comparison of milk constituents of cows fed treat­
ments H,Jt K and L at twelve weeks (12 wks.} '
(*)
Milk H J - L✓
Constituent fCow Cow Cow Cow Cow Cow Cow Cow
AD11 220 AD11 256 AD11 256 282 258
Water 86.21 81.10 85.96 86.18 88.19 85.79 84.84 82.44
Fat 6.28 6.18 7.37 6.50 4.33 5.97 6.30 7.91
Protein 3.36 4.11 3.29 3.63 3.39 3.46 4.65 4.67
Lactose 4.69 4.59 4.59 4.45 4.62 5.47 4.92 4.43
Ash 0.70 0.79 0.74 0.71 0.83 0.71 0.82 0.68
Total solids 13.79 12.90 14.04 13.82 11.81 14.21 15.16 17.56
Solid-not
Fat 7.51 6.72 6.67 7.32 7.48 8.24 8.86 9.65
184
UNIVERSITY OF IBADAN LIBRARY
TABLE 8,32
Mean % milk constituents of cows fed treatments
H, J, K and L at 12 weeks"
Milk
Constituent H J K L
Water 88.66 86.07 86.99 83.64
Fat 6.23 6.94 5.15 7.11
Protein 3.74 3.49 3.43 4.66
Lactose 4.64 4.52 5.05 4.68
Ash 0.75 0.73 0.77 0.75
Total solids 13.35 13.93 13.01 16.36
S.N.F, 7.12 7.00 7.86 9.26
185
UNIVERSITY OF IBADAN LIBRARY
Tables 8.41 and 8.42 showed the milk constituents of 
cows fed treatments H, J, K and L simultaneously when they 
were four weeks. The water content of the milk samples 
varied from 85.28% to 88.43%. These milk samples contained 
more water than the samples of the previous experiment.
The fat content also showed more variation this time. It 
ranged between 3.70% and 6.51%. Treatment L produced milk 
with more butterfat content. The milk protein remained 
fairly constant in all the samples. It varied from 3.06% 
to 3.83%. The milk protein content was lower than that 
obtained in the previous experiment. Milk lactose varied 
from 3.84% to 6.40%, and the milk ash varied from 0.62% to 
0.68%. The ash content was lower this time. Total solids 
and solid-not-fat contents were low too. Total solids 
varied between 11.72% and 14.72% while solid-not-fat varied 
between 5.71% and 14.72% while solid-not-fat varied between 
5.71% and 8.47%
186
UNIVERSITY OF IBADAN LIBRARY
TABLE 8.41
Comparison o f milk constituents o f cows fed H / J ,  K  and L at four 
weeks (4 wks.)
(%)
M ilk H J K L
C o nstitue n t Cow  Cow Cow Cow Cow Cow Cow  Cow Cow Cow Cow Cow
A D I 1 195 118 69 142 183 A D I 1 118 195 69 142 183
•
W a te r 8 2 .2 8 8 6 .3 3 8 6 .0 6 8 7 .8 2 8 7 .2 3 8 5 .2 8 8 8 .4 3 8 8 .2 9 8 6 .8 8 8 5 .9 6 8 6 .2 3 8 5 .9 2
Fa t 3 .7 0 5 .2 0 6 .0 2 5 .4 1 5 .9 0 6 .5 1 3 .7 0 6 .0 0 4 .6 6 6 .3 7 5 .4 9 6 .1 6
Pro te in 3 .0 6 3 .6 5 3 .5 5 3 .2 1 3 .3 9 3 .6 9 3 .1 1 3 .6 1 3 .3 9 3 .5 3 3 .4 4 3 .8 3
Lactose 5 .6 1 5 .7 1 3 .8 4 5 .1 6 5 .8 9 4 .6 2 5 .2 0 4 .6 9 4 .0 6 6 .4 0 4 .8 2 4 .6 7
Ash 0 .6 7 0 .6 7 0 .6 6 0 .6 4 0 .6 7 0 .6 2 0 .6 7 0 .6 8 0 .6 5 0 .6 8 0 .7 0 0 .6 8
To ta l so lids 1 1 .7 2 1 3 .6 7 1 3 .9 4 1 2 .1 8 1 2 .7 7 1 4 .7 2 1 1 .5 7 11 .71 1 3 .1 2 1 4 .0 4 1 3 .7 7 1 4 .0 8
S o lid -n o t Fa t ( s .n . f ) 8 .0 2 8 .4 7 7 .9 2 6 .7 7 6 .8 7 8 .2 1 7 .8 7 5 .7 1 8 .4 6 7 .6 7 8 .2 8 7 .9 2
T A B L E  8 .4 2
Mean %  m ilk  constituents o f cows fed treatm ents 
H , J ,  K and L at 4 w ks.
M ilk H J K L
C o nstituents
W a te r 8 4 .8 9 8 6 .7 8 8 7 .8 7 8 6 .0 4
Fa t 4 .9 7 5 .9 4 4 .7 9 6 .0 1
Pro te in 3 .4 2 3 .4 3 3 .3 4 3 .6 0
Lactose 5 .0 5 5 .2 2 4 .6 5 5 .3 0
Ash 0 .6 7 0 .6 4 0 .6 7 0 .6 9
To ta l so lids 13.11 1 3 .2 2 1 2 .1 3 1 3 .9 6
S . N . F . 8 .1 4 7 .2 8 7 .3 5 7 .9 6
187
UNIVERSITY OF IBADAN LIBRARY
Tables 8.51 and 8.52 showed the milk constituents of 
cows fed treatments H, J, K and L when eight weeks. Water 
formed over 80% of the milk samples. The water content 
varied between 83% and 87.62%. The butterfat content 
varied between 4.44% and 7.37%. Treatment L produced milk 
with the greatest butterfat content, and the lowest milk 
protein content. The milk protein varied from 2.97% to 
3.88%, while milk lactose varied from 3.48% to 5.94%. 
Treatment L produced more lactose than the rest. The ash 
content varied from 0.50% to 0.73% and Treatment J produced 
more ash. Total solids varied from 12.38% to 16.68% and t 
treatment L produced more total solids and solids-not-fat. 
The solids-not-fat varied between 6.87% and 11.18%.
188
UNIVERSITY OF IBADAN LIBRARY
TABLE 8.51
Comparison of m ilk constituents of cows fad treatments H, J, K f and 
L at eight weeks (8 wks)
(%)
M ilk H J K L
Constituent’s Cow  Cow Cow Cow Caw Cow Cow  Cow Cow Cow Cow Cow
A D I  1 118 195 69 142 183 A D 1 1 118 195 6 ? 142 183
Water 87 .62 85 .76 87.20 86.11 87 .03 86 .26 86.30 85.48 86.42 84.53 86.25 83 .32
Fat 4 .77 7 .37 6.48 5 .44 5 .44 5 .63 4.68 6 .97 4 .77  •“ 7.00 5.83 5 .50
Protein 3 .73 3.41 3.54 3 .72 3.58 3.88 3.10 3 .50 3.43 3.63 3.66 2 .97
Lactose 4 .06 3.48 3.58 3.98 3 .83 3.79 5.40 5 .37 5.31 5.52 5.94 5 .49
Ash 0 .67 0 .69 0 .68 0 .6 6 0 ,73 0.71 0 .63 0 .5 6 0 .50 0.61 0 .52 0 .59
Total solids 12.38 14.24 12.80 13.89 12.97 13.74 13.70 14.52 13.58 15.47 13.75 16.68
Solids-not Fat (s.n.r) 7.61 6.87 8 .36 7 .05 7 .53 8.11 9 .02 7 .55 8.81 8.47 7.92 11.18
TABLE 8 .52
M ean %  m ilk constituents of cows fed treatments 
H, J, K , and L ot 8 wks.
M ilk H J K L
Constituent
Water 86 .86 86.47 86 .07 84.70
Fat 5.53 5.85 5 .47 6.11
Protein 3.56 3.73 3.34 3.42
Lactose 3.71 3.87 3.36 5 .65
Ash 0 .67 0.70 0 .56 0 .5>
Total solids 13.14 13.53 1 ) 9 3 15 30
S . N . F . 7.61 7.56 < M 9 19
189
UNIVERSITY OF IBADAN LIBRARY
Table 8.61 showed the comparison of milk produced by 
Zebu cattle fed treatments H, J, IC and L when four weeks* 
The milk produced by the Nigerian Zebu contained more 
total solids than the other breeds listed in the table.
The milk also contained more butterfat-. Milk protein, 
lactose and ash contents were very similar.
Table 8.62 also exhibited the same trends noted in 
table 8.61 except that the differences in butterfat and 
total solids were not as marked as in table 8.61. The 
lactose content was more in the Nigerian Zebu than in the 
other breeds.
Table 8.63 showed that the eight week old treatments 
produced less milk ash in the Nigerian Zebu than the other 
breeds compared with it. The milk contained more butter­
fat and in some cases more lactose than the other breeds.
In Table 8.64 treatment L stood out as a good forage 
producing good quality milk. The milk produced from it 
contained less water and more of the other constituents. 
The prominent feature again is the high butterfat content 
of the Zebu milk.
190
UNIVERSITY OF IBADAN LIBRARY
TABLE 8.61
Milk composition of different breeds compared with
the Nigerian Zebu Cows
Breed Treat­ Age of Water Fat Pro­ Lac- 1 Ashtein tose Totalment forage solids
Nigerian 4
Zebu H wks. 84.07 6.34 4.18 4.54 0.71 15.93
Nigerian 4
Zebu J wks. 85.07 6.64 3.89 4 • 84 0.81 14.94
Nigerian 4
Zebu K wks. 85.29 6.27 3.71 5.08 0.70 14.71
Nigerian 4
Zebu L wks. 85.24 6.06 3.98 4.99 0.69 14.76
Indian t ’
Cows * 86.48 4.83 2.78 4.56 0.74 13.52
Holstein 88.07 3.45 3.15 4.65 0.68 11.93
Guernsey 85.45 4.98 3.84 4.98 0.75 14.55
Jersey 85.43 5.14 3.80 4.87 0.76 14.57
>
Ayrshire 87.28 3.85 3.32 4.90 0.65 12.72
Shorthorn 87.19 3.80 3.32 4.99 0.70 12.81
i
191
UNIVERSITY OF IBADAN LIBRARY
TABLE 8.62
Milk composition of different breeds compared with
the Nigerian Zebu Cows
(%)
Breed t Treat­ Age of Water Fat Pro­ Lac­ Ash Total * ment forage tein tose solids |
Nigerian 4
Zebu H wks. 86.89 4.97 3.42 5.05 0.67 13.11
Nigerian 4 ' 
Zebu J wks. 86.78 5.94 3.43 5.33 0.64 13.22
Nigerian 4
Zebu K wks. 87.87 4.79 3.37 4.65 0.67 12.13 j
Nigerian 4
Zebu L wks. 86.04 6.01 3.60 5.30 0.69 13.96 j
S
Indian
Cows 86.48 4.83 2.78 4.56 0.74 13.52 ;>
Holstein 88.07 3.45 3.15 4.65 0.63 11.93 j
. . . »
Guernsey 85.45 4.98 3.84 4.98 0.75 14.55 Inj
Jersey 85.43 5.14 3.80 4.87 0.76 14.57 ;
Ayrshire 87.28 3.85 3.32 4.90 0.65 12.75
Shorthorn 87.19 3,80 3.32 4.99 0.70 12.81 !j
192
UNIVERSITY OF IBADAN LIBRARY
TABLE 8,63
Milk composition of different breeds compared with
the Nigerian Zebu Cows
(%)
Breed Treat­ Age of Water Fat Pro­ Lac­tein Ash Totalment forage tose solids
Nigerian 8
Zebu H wks. 86.86 5.53 3.56 3.71 0.68 13.14
Nigerian 8
Zebu J wks. 86.48 5.97 3.73 3.87 0.70 13.52
Nigerian 8
Zebu K wks. 86.07 5.47 3.34 5.36 0.56 13.93
Nigerian 8
Zebu L wks. 84.70 6.11 3.42 5.65 0.57 13.30
Indian
Cows 86.48 4.83 2.78 4.56 0.74 13.52
Holstein 88.07 3.45 3.15 4.65 0.68 11.93
Guersey 85.45 4.98 3. 84 4.98 0.75 14.55 |
Jersey 85.43 5.14 3.80 4.87 0.76 14.57 j
Ayrshire 87.28 3.85 3.32 4.90 0.65 12.72 |
Shorthorr 87.19 3.80 3.32 4.99 0.70 12.81 |
193
UNIVERSITY OF IBADAN LIBRARY
TABLE 8.64
Milk compesition of different breeds compared with
the Nigerian Zetm Cows (%) _  .
Breed Treat­ Age of Water Fat Pro­ Lac­ Ash Total
ment forage tein tose solids
Nigerian 12
Zebu H wks. 86.66 6.23 3.74 4.64 0.74 13.34
Nigerian 12
Zebu J wks. 86.07 6.93 3.49 4.52 0.72 13.93
Nigerian 12
Zebu K wks. 86.99 5.15 3.42 5.04 0.77 13.01^
Nigerian 12
Zebu L wks. 83.64 7.10 4.66 4.68 0.75 16.36
Indian
Cows 86.48 4.83 2.78 4.56 0.74 13.52
Holstein 88.07 3.45 3.15 4.65 0.68 11.93
Guernsey 85.45 4.98 3.84 4.98 0.75 14.55
Jersey 85.43 5.14 3.80 4.87 0.76 14.57
Ayrshire 87.28 3.85 3.32 4.90 0.65 12.72
Shorthorn 87.19 3.80 3.32 4.99 0.70 12.81
194
UNIVERSITY OF IBADAN LIBRARY
Table 8.7 showed the live-weight changes of the cows 
and steers used in this experiment. When H at 4 weeks was 
fed to the animals, all the animals lost weight. Cow 94 
lost more weight than the other animals. On the average 
4.31 kilograms were lost. When treatment J was fed, one of 
the animals did not gain or lose v/eight while one gained 
some weight, the rest lost weight.- On the whole 4.14 
kilograms were lost. All the animals lost weight when fed 
treatment K too and on the whole they lost 6.64 kilograms. 
All animals gained weight when fed treatment L and the 
gain on the whole was 4.14 kilograms.
When the treatments were twelve weeks and fed to the 
animals all the animals on treatment H lost weight and the 
loss was of the same magnitude as when the treatment was 
four weeks. With treatment J one animal did not gain or 
lose v/eight and on the average less v/eight, 1.49 kilograms, 
v/as lost this time. All the animals also lost v/eight on 
treatment K but the loss was less than when the treatment 
was four weeks. No animal lost weight on treatment L and 
the gain was more than v/hen the treatment v/as four weeks.
195
UNIVERSITY OF IBADAN LIBRARY
RESULT
TA B LE  8 .7
Live  weight chonge* o f Zebu cattle during the experiment
TR EA TM EN T H . 1 3 - l f i / lV #
Animal In itia l Live  Final Live  L ive  weight L ive  weight 
N o . weight weight gain or lass per day gain or loss per week
lb . kg. lb . ____ ____________ kfc_________ lb . kg. kg.
195 822 372.86 810 367.41 -12 -5 .4 4 -3 .9 7
4 *eefc« 183 800 362.88 790 358.34 -10 -4 .5 4 -3 .31
4 ##c^> 198 758 343.83 746 338.38 -12 -5 .4 4 -3 .9 7
4 94 800 362.88 782 354.71 -18 -8 .1 6 -5 .9 6
Met«t 795 360.61 782 354.71 -13 -5 .9 0 -4.31
I f  week* A D I 1 632 286.67 630 285.77 -2 -0.91 -0 .6 6
I f  n h I>i 220 830 376.49 822 372.86 -8
- -3 .6 3 -2 .6 5
I f  week* 114 906 410.96 878 398.26 -28 -12 .70 -9 .2 7
I f  week* 194 764 346.55 750 340.20 -14 -6 .3 5 -4 .6 4
Me mu 783 355.17 770 349.27 -13 -5 .9 0 -4.31
196
UNIVERSITY OF IBADAN LIBRARY
RESULT
TA B LE  8.7 continued  
L iv e  weight change* o f Zebu cattle during the experiment
lit**** <>( Animal In itia l L ive  Fina l L iv e  L iv e  weight L iv e  weight 
N o . weight weight gain or lass per day gain or loss per week 
lb . _____________________ Isa*__________ lb . kg . lb . kg. kg.
4 wmmht 195 760 3 4 4 .7 3 760 34 4 .7 3 0 0 0
4 w m Ii i  183 732 3 3 2 .0 3 740 3 3 5 .6 6 8 3 .6 3 2 .6 5
4 198 760 3 4 4 .7 3 764 33 8 .3 8 -14 - 6 .3 5 - 4 .6 4
4 w m Ii i 94 080 366.51 780 353.81 -28 -1 2 .7 0 - 9 .2 7
Mmm 765 3 47 .00 7 5 6 .5 343 .15 - 1 2 .5 - 5 .6 7 - 4 ,1 4
I j  weeks A D I 1 600 171.16 592 26 8 .5 3 -8 - 3 .6 3 - 2 .6 5
I J 256 642 291.21 634 2 87 .58 -8 - 3 .6 3 - 2 .6 5
I J  weeks1 114 832 3 77 .39 830 376.40 -2 -0 .9 1 - 0 .6 6
12 weeksl 194 674 3 0 5 .7 2 674 30 5 .7 2 0 0 0
Mean 687 31 1 .6 2 6 8 2 .5 309 .58 - 4 .5 - 2 .0 4 -1 .4 9
198
UNIVERSITY OF IBADAN LIBRARY
RESULT
TA B LE  8.7 cont inued  
Live  weight changes of Zebu cattle during the experiment ̂  
____________  TR E A TM E N T K 2-7/3/70
Stage of Animal In itia l Live  Final Live  Live  weight L ive  weight 
Growth N o . weight weight gain or loss per day gain or loss per week
lb . kg. lb . kg. lb . kg. kg-
4 weeks 195 744 351.08 762 345.64 -12 - 5 .4 i -3 .9 7
4 weeks 236 656 297.56 642 291.21 -14 -6 .3 i5 -4 .6 4
4 weeks 198 856 388.28 818 371.04 -38 - 1 4 .f>2 -10 .60
4 weeks 94 822 372.86 806 365.60 -16 - 7 .2 6 -5 .2 9
Mean 777 352.44 757 343.37 -20 -9.1 -6 .6 4
12 weeks A D I 1 612 277.60 602 273.07 -10 -5 .5 4 -3.31
12 weeks 256 638 289.39 636 288.49 -2 -0 .9 1 -0 .6 6
12 weeks 194 732 332.03 712 322.96 -20 -9.1 -6 .6 4
Mean 6 6 0 .7 299.69 647 293.48 -1 0 .7 -4 .8 5 - .3 4 5
1 9 9
UNIVERSITY OF IBADAN LIBRARY
R E S U LT
TA BLE  8 .7  c o n t i n u e d
Live weight chonges of Zebu c° n le  durin9 the experiment 
TREA TM EN T l  2-7/3/10_____________
Stage o f Animal In itia l Live Final Live  L iv i b weight Live  weight 
Growth N o . weight weight gain or loss per day gain or loss per week
lb- ka . lb. ka.__________ lb . kg. . _J5Jh______________
4 weeks 322 482 1 1 .7S 8.611 218.63 508 230.43 26
---------------------------—
4 weeks 236 632 640 290.30 8 3.63 2 .65286.67
4 weeks 198 672 304.82 674 305.72 2
0.91 0 .6 6
4 weeks 94 808 822 372.86 14 6 .35 4 .64366.51
Mean 648.5 294.16 636 288.49 12.5
5 .67 4 .14
12 weeks 282 644 19.05 13.91292.12 686 311.17 42
12 weeks 258 668 303.00 700 317.52 2
0.91 0 .6 6
12 weeks 194 744 337.48 746 338.38 2
0.91 0 .6 6
Mean 685.3 310.85 710.7 322.37 15.3
6 .94 5 .07
2 0 0
UNIVERSITY OF IBADAN LIBRARY
/ -
Treatment L stood out as a good forage for our Zebu cattle 
in that all the animals gained weight. This may be due to 
the fact that treatment L consists of a combination of all 
the grasses and legumes, it comprised of grass/legume in 
H, J and K. Treatment L offered more C.P., and these 
levels (fig. 6.1) at four and twelve weeks may be adequate 
for maintenance and growth requirements of the animals.
The other treatments offered submaintenance nutrients and 
therefore caused loss in weight.
8.5 DISCUSSION AND CONCLUSION
Looking through the results of this experiment, it is 
observed that the Nigerian Zebu cows produce more butterfat 
(5-7%) than the Indian Zebu (4.83%) or the European breeds. 
The Jersey cows produce high butterfat (5.14%) but the 
Nigerian Zebu exceeds this limit. The Zebu cows of Eastern 
and Southern Africa produce high butterfat which falls in 
line with the Nigerian Zebu. Examples are the Red Butana 
Zebu which produces 5.5% fat, the Abyssinia (Ethiopia) 
shorthorned Zebu which produces 6-6.5% fat, the Gasara 
(Small Somalia) Zebu which produces 5.5% fat and the Kenya 
Boran Zebu which produces 5% to 6.8% fat, (Mason et_ al. ,
201
UNIVERSITY OF IBADAN LIBRARY
1960). The Inidan cows which live under similar tropical 
conditions like the Nigerian Zebu produce lower milk fat, 
although the fat content is higher than most European cows 
(except Jersey), and American cows (Mahaderan, 1958;
Eckles et al., 1943). In some investigations carried out 
by Olaloku (1968), Adeneye, Oyenuga and Olaloku (1970), 
and Olaloku, Egbuiwe and Oyenuga (1971) high milk fat 
contents were recorded for the White Fulani Cows.
The milk protein in the Zebu used in this experiment 
is between 3.34% and 4.66%. Most of the cows produced 
less than 4% protein. Similar results have been recorded 
by Adeneye et aJ. (1970). Since the Indian cows produce 
less than 3% milk protein and the other breeds of cows 
produce over 3% but less than 4% milk protein, it may be 
said that the Zebu cows used in these experiments produced 
high quality milk. Protein is a very important nutrient 
needed by man and animal. Milk protein is a very good 
source of human protein, so its production in large 
quantities is therefore necessary to avoid malnutrition.
202
UNIVERSITY OF IBADAN LIBRARY
These cows produced higher milk lactose and total 
solids than the other breeds under comparison. The other 
breeds produce over 4% but under 5% lactose, but these 
cows produced (except in two cases) between 4% and 6% and 
lactose. The lactose level is however higher than that 
recorded by Adeneye et al. (1970). Milk is the only 
source of lactose, so the production of higher quantity 
of lactose by the Nigerian Zebu cows puts the breed in a 
favourable position. Lactose may play important role in 
nutritional studies in the future, and a good source may 
be of commercial importance in the future, The total 
solids did not at any one time fall as low as 11.92% which 
is the figure for Holstein cows. The value in these 
experiments were between 13% and 16%, Similar results 
have been recorded by Adeneye et al. (197); and Olaloku 
et al. (1971). This showed that these cows secrete more 
dry matter than the other breeds. The quantity of the 
milk (in lb.) may be less than those of the European or 
American breeds, but the quality is surely better.
The ash content is less than 1.0% in all cases. The 
other breeds produce less than 1% milk ash also. The
203
UNIVERSITY OF IBADAN LIBRARY
greatest variation in the milk analysed occured here.
The ash content varied from 0.56% to 0.81%. Definitely 
the ash content is above average.
The four feeds are quite good for the production of 
high quality milk. For greater milk production, high 
milkers should be selected and bred, so that their projeny 
may produce more milk under better animal husbandry.
Treatment L under all conditions appeared to be the 
best for high quality milk since the cows on this treatment 
produced the highest total solids, lowest water, highest 
fat, protein, lactose and ash in most cases.
Table 8.8 shows the summary of mean milk yield and 
chemical constituents.
The cows in advanced stages of lactation on treatments 
H and J at 4 weeks produced less milk per day and less 
butter fat per day. The S.N.F. content too was lower for 
the cows in advanced stages of lactation. The crude fibre 
and crude protein content of treatment H at 4 weeks were 
higher than those for treatment J at the same stage of 
growth. The cows in advanced stages of lactation on 
treatments K and L produced more milk per day, more butter-
204
UNIVERSITY OF IBADAN LIBRARY
fat, and more S.N.F. Treatment K however contained higher 
crude fibre and lower crude protein at 4 weeks while treat­
ment L contained lower crude fibre and higher crude protein 
at 4 weeks,
The cow in advanced stage of lactation on treatment 
H at 12 weeks produced less milk per day, more butter fat, 
and more solid-not-fat. The crude fibre was lower and 
crude protein was higher in treatment H at 12 weeks than 
at 4 weeks. On the average the lower crude fibre and 
higher crude protein treatment H produced less milk per 
day, less butterfat and less S.N.F. Treatment J at 12 
weeks contained more crude fibre and less crude protein 
than at 4 weeks. This treatment increased milk production 
per day, and the butterfat content, but the S.N.F. content 
v/as lower than at weeks.
Treatment K at 12 weeks decreased milk yield per day, 
and it also decreased butter fat, and S.N.F. contents.
The crude fibre and crude protein were lower than at 4 
weeks.
Treatment L contained less crude fibre and crude 
protein at 12 than at 4 weeks. At 12 weeks the cows
UNIVERSITY OF IBADAN LIBRARY
produced more milk per day, more butterfat and more S.N.F.
Comparing all the treatments at 4 and 12 weeks, the 
milk production per day for cows on treatment H was consis­
tently higher than those of the others. Production per 
day of the cows on J, IC and L followed in that order down­
wards .
Brown, Stull, and Stott, (1962) reported that low 
rouphage diet plus cotton seed oil significantly depres­
sed total milk production, 4% fat corrected milk (FCM), 
percent fat and the average daily fat production. On the 
low and high roughage diets the addition of fat did not 
significantly alter the protein or lactose content of the 
milk. Joseph'Edwards (1950) compared milk production and 
butter fat in two breeds of cows. He observed that from 
the 45th day of lactation the rates of milk production for 
both breeds of cows fell at a very regular rate. About 
the 7th month of lactation the rate of fall becomes more 
rapid. In the early stages of lactation, the rate of 
secretion is twice as great as in the last stages. The 
fat content rises from 5.8% at the start of lactation to 
6.51 at the end. Banicoat, Logan, and Grant, (1949)
206
UNIVERSITY OF IBADAN LIBRARY
observed a decrease in milk fat of one ewe on six consecu­
tive days.
Johnson, Fourt, Hibbs, and Ross, (1961) reported the 
lowest solids-not-fat (S.N.F.) content during the second 
month of lactation for both Hosteins and Jersey cows.
The fat content was lowest the third month of lactation 
for the Holsteins, and during the second month for the 
Jerseys. There was less variation in solids-not-fat than 
in milk fat for both breeds of cows. The relationship 
between fat and solids-not-fat was not linear, but there was 
a gradual yet irregular decrease in both fat and solids- 
not-fat content with age for both breeds. Nickerson (1961) 
in his own work on milk constituents reported that most 
individual constituents of milk change positively with 
changes in total solids. Some constituents show no 
significant correlation to changes in total solids of 
milk. Table 8.8 showed that treatment L at 12 weeks which 
produced milk with the highest total solids also produced 
milk with the highest butter fat and high S.N.F. Fat has 
a higher correlation with total nitrogen than with any 
other constituent measured, but table 8.8 showed that the
207
UNIVERSITY OF IBADAN LIBRARY
treatment with the highest protein does not necessarily 
produce milk with the highest butter fat. The treatment 
with the lowest crude protein however produced milk with 
the lowest butter fat content.
Casein, Lactalbumin, and lactoglobulin increase as 
the total nitrogen content of the milk increase, but at 
respectively slower rates. Total nitrogen is highly 
correlated to fat and total solids, therefore casein 
should show a similar high correlation.
208
UNIVERSITY OF IBADAN LIBRARY
TABLE 8.8
Summory of Mean Y ie ld  ond Chemical composition of milk 
(%)
Treatment Cow Days In M ilk M ilk Butter Total
wks. No Lactation Production Production fat S . N . F , solids C . F . C . P
lb . per day 
lb .
195 198 2 ,9 2 5 14.8 6 .5 4 10.38 16.92
4 6 .3 4 9 .5 9 15.93 35 .33 9 .34
u 183 207 2 ,139 10.3 6 .1 4 8 .8 0 14.94
12 A D I 1 227 2 ,135 9 .4 6 .2 8 7.51 13.79
6 .2 3 7 .1 2 13.35 34.52 9.11
220 170 1,786 10.5 6 .1 8 6 .7 2 12.90
195 233 3 ,2 3 6 13.9 6 .7 0 8 .7 0 15.40
4 6 .6 4 8 .3 0 14.94 32.49 N VN
i 183 242 2 ,259 9 .3 6 .58 7 .8 9 14.47
256 185 986 5 .3 6 .5 0 7 .3 2 13.82
12 6 .9 4 7 .0 0 13.93 33.77 N Ml
A D I 1 205 2 ,3 3 2 11.3 7 .3 7 6 .6 7 14.04
195 275 3 ,468 12.8 6 .7 3 8 .6 7 15.40
4 6 .32 8 .3 9 14.71 33.67 1 M
Y 236 107 670 6 .2 5.91 8.11 14.02
256 227 1,191 5 .2 5 .9 7 8 .2 4 14.21
12 5 .1 5 7 .8 6 13.01 31.76 M O
A D I 1 247 2 ,4 0 6 9 .8 4 .3 3 7 .48 11.81
322 107 524 5 .0 6 .1 3 8 .2 5 14.38
4 6 .0 6 8 .7 0 14.78 23.53 10 94
i 236 156 858 5 .5 5 .9 9 9 .1 5 15.4
282 169 1,070 6 .3 6 .3 0 8 .8 6 15.16
12 7.11 9 .2 6 16.36 31.01 V * '
258 147 965 6 .5 7.91 9 .6 5 17.56
1
2 0 9
UNIVERSITY OF IBADAN LIBRARY
CHAPTER 9
Ammonia nitrogen and urea nitrogen 
produced in the rumen liquor and 
blood serum of the Zebu cattle on 
treatments H,J,K and L cut at dif­
ferent stages of growth.
9,1 INTRODUCTION
The ruminants are able to digest most of the fibrous 
parts of their feeds (cellulose, hemicellulose) and in some 
cases the simple carbohydrates due to the activities of the 
numerous microorganisms in the rumen, and the accompaying 
forestomachs. Other feed components utilized by the rumi­
nants only are the non-protein nitrogen of the feeds. The 
mixed rumen organisms have great power to decompose amino 
acids to ammonia, and other products like carbon dioxide. 
This power is increased greatly when the amount of soluble 
protein in the feed is increased.
El-shazly (1952) in his work on degradation of pro­
tein in the rumen of the sheep noted that volatile fatty 
acids, ammonia and carbon dioxide were the end products of 
amino acids decomposition.
Owen, Smith, and Wright (1943) used urea as a 
partial protein substitute in the feeding of dairy 
cattle. They found blood meal and urea to be equally 
good. The milk yield fell appreciably when no urea or
210
UNIVERSITY OF IBADAN LIBRARY
blood meal was fed and the yield did not come up to the 
original level when urea or blood meal was re-introduced, 
McDonald (1952; 1954) fed casein, gelatine, and zein to 
sheep and measured the ammonia nitrogen formed. Ammonia 
nitrogen formed from casein represented about 20% of the 
total nitrogen added. Amide nitrogen consists of 9.3% 
of the total nitrogen of casein, and the rise in 
ammonia is not due solely to removal of amide groups.
This shows that deamination and deamidation reactions 
were responsible for the formation of ammonia. Similar 
results were obtained from gelatine which contains only 
a trace of amide nitrogen. Direct addition of zein to 
the rumen unlike the former two did not produce any change 
in the concentration of ammonia nitrogen in the rumen.
This was because zein was very insoluble in aqueous media 
and was resistant to proteolysis. However zein was 
digested to a considerable extent in the rumen, and this 
showed that its rate of digestion was too slow to allow 
an accumulation of ammonia. Casein is a readily attacked 
protein and its hydrolysis produces ammonia and other non­
protein nitrogen. The rise in residual nitrogen was 
of brief duration and after two hours the amount decreased 
and the level of ammonia nitrogen continued to rise for 
four hours after feeding. In the presence of readily
- 211
UNIVERSITY OF IBADAN LIBRARY
MTWWP V W m
212
UNIVERSITY OF IBADAN LIBRARY
available sources of energy (glucose and starch) the 
organisms use the ammonia as a source of nitrogen for 
growth. When the growth rate of the microbes declined, 
the rate of ammonia production may exceed the rate of 
uptake and the concentration of ammonia rises slowly to 
the prefeeding stage. When non-protein nitrogen were fed 
at low concentrations ammonia accumulated rapidly in the 
rumen after feeding and this reflects the high activity 
of the micro-organisms. Amino acids do not accumulate in 
the medium and this shows that the rate of uptake of the 
amino acids by the microbes from the medium exceeds the 
rate of proteolysis by the proteases produced by them, 
or the microbes may in addition deaminate free amino acids.
The gastric reservoirs in ruminants are capable of 
absorbing numerous substances, notably urea and ammonia.
On the other hand, urea is a substance that diffuses very 
easily. It might reasonably be assumed that, when a large 
quantity of urea is introduced, the baterial population 
of the fore-stomachs would not be able to utilize it all 
immediately, therefore most of the urea and ammonium salts 
would pass into the blood to be eliminated by the kidneys.
McDonald (1948); Dinning (1945); Bouckaert ..and 
Oyaert (1952); Chalmers (1954); Annicolas (1956); and
213
UNIVERSITY OF IBADAN LIBRARY
Lewis (1957); demonstrated the absorption of ammonia.
The absorption of ammonia is increased by increase of 
pH in the rumen (Bouckaert and Oyaert, 1952).
In general, ammonia is found in only small quanti­
ties in the peripheral blood because the liver converts 
ammonia to urea (Le Bars, 1957). Labouche (1960) observed 
that blood ureas were higher in N'damas than in Zebus, and 
that blood ureas are higher in old animals than in young 
cows, but seasonal variations, linked with the nature of 
the food can be observed, whatever the age.
The urea in the blood is not excreted solely by the 
kidneys; a considerable quantity is returned to the gastric 
reservoirs, either in the saliva or directly through the 
epithelium of the rumen. Somers (1961) estimated that 
under normal conditions, urea represented 60-70% of total 
nitrogen in sheep saliva, which contained no ammonia.
When 3gm urea was given intra - arterially to sheep which 
had been fasting for 24 hours, the salivary content 
remained high for six hours, and fluctuations therein did 
not run parallel to fluctuations of the urea in the blood. 
Under normal conditions, it has been observed that 
fluctuations in the salivary content of urea in the course 
of the twenty four hours are dependent on blood levels
214
UNIVERSITY OF IBADAN LIBRARY
which themselves are a function of the ammonia content 
of the rumen. Two phases are evident in the twenty four 
hour salivary nitrogen cycle. The first is an immediate 
response to the act of feeding, in which there is increase 
both in the volume of saliva secreted and in the nitrogen 
content of the saliva. The second phase is the intensity 
of the fermentation processes in the rumen and masticac- 
tion which stimulates salivary secretion.
There appears to be competition between kidneys and 
salivary glands in connection with excretion of blood urea. 
The rumen may also play some role in urea excretion. When 
there is increased need of nitrogen, salivary excretion is 
increased and urinary excretion reduced. Schmidt-Nielsen 
(1957) have shown that in the camel receiving a ration with 
a normal nitrogen content, about 40% of the urea filtered 
out in the glomerulus is excreted in the urine, but this 
percentage falls to a mere 1-2% when the feed is poor in 
nitrogen. A comparable phenomenon has been observed in 
the sheep.
Schaadt and Johnson (1969) in their feeding experi­
ments found that when urea was fed to sheep along with 
corn silage, the pH decreased after feeding and did not 
increase until four hours after feeding. The total 
volatile fatty acids produced increased rapidly during
215
UNIVERSITY OF IBADAN LIBRARY
the first hour after feeding and only slightly more to 
a maximum at two hours after which they declined. Somers 
(1961) investigated a few of the factors that affect the 
nitrogen fractions in the parotid saliva of sheep. The 
concentration of ammonia nitrogen in the rumen fluid 
increased at a relatively rapid rate reaching a maximum 
of 24 mg/lOOml 4 hours after feeding. It declined to the 
prefeeding level at the 24 hr. sampling period. The rise 
in the concentration of blood urea nitrogen is an indica­
tion that part of the ammonia produced in the rumen was 
absorbed, metabolised to urea in the liver and the urea 
discharged into the systemic circulation. The rise was 
progressive and continued until it reached the maximum 
concentration of 27mg/100ml of blood at 8fhr. after feed­
ing, The concentration of urea nitrogen in blood and 
saliva increased and did so for the next 7 hours. But 
the rate of increase in the concentration of urea nitrogen 
in the saliva exceeded that in the blood. This showed 
that the salivary urea nitrogen secretion rate was limited 
by the blood urea nitrogen level. Urea nitrogen in blood 
continued to rise for a further two hours before reaching 
the maximum concentration. The concentration of urea 
nitrogen and total nitrogen in the saliva started to fall 
after the seventh (7th) hour.
216
UNIVERSITY OF IBADAN LIBRARY
Lewis (1957) sampled the blood from the jugular vein 
and the blood from the carotid artery of the sheep. The 
ammonia lost from the rumen was proportional to the con­
centrations of ammonia in the rumen liquor. The rate of 
increase in the ammonia of portal vein was not as great 
as that of the rumen liquor. Blood urea level was rela­
tively constant in all cases but was clearly dependent on 
the diet of the animal. As rumen ammonia increased there 
was a greater return of nitrogen to the rumen via the 
saliva. There were no significant differences between 
the concentrations of urea in venous and arterial blood.
The concentrations of rumen ammonia varied considerably 
during twenty four hours. Rapid changes in rumen ammonia 
concentrations produced by variations in the diet are 
paralleled by equally rapid changes in blood urea level. 
Considerable ammonia passes along the portal vein which 
results in a higher blood urea six to seven hours after 
feeding.
9.2 DETERMINATION OF UREA AMD AMMONIA
Different methods were employed by different workers 
to determine urea in blood and ammonia in the rumen liquor. 
In most cases the en2yme urease in buffer solution was 
used in these determinations (Howell, 1939a;b). Pearson
217
UNIVERSITY OF IBADAN LIBRARY
*Mfc NITROGEN CYCLE IN NATURE
217 ®
UN *****IVERSITY OF IBADAN LIBRARY
tAo#acyi*
and Smith (1943) compared three different methods of urea 
analyses and obtained good and similar results. Conway 
and Cooke (1939) used a titrimetical method in their 
ammonia determinations. Donald Van Slyke (1927) used 
urease and measured the urea in the blood by the ammonia 
concentration and by the carbon-dioxide produced from the 
ammonium carbonate formed by the action of urease on the 
urea. Lebiboff and Kahn (1929) used a colorimetric 
method for their urea determination. Other people who 
used colorimetric methods for urea and ammonia determina­
tions were Fawcett and Scott (1960) and Chaney and 
Marbach (1962).
9.3 ANALYTICAL PROCEDURE
The blood urea concentrations and rumen ammonia were 
determined using the methods of Fawcett and Scott (1960) 
and Chaney and Marbach (1962). The optical density was 
read at 625jum and the concentration in mg. per 100ml rumen 
liquor or 100ml blood calculated from standard curves 
prepared from ammonium sulphate solutions for ammonia 
and from urea solutions for urea.
9.4 RESULTS
Table 9.1 showed the ammonia nitrogen expressed in mg. 
per 100ml rumen liquor produced by the Zebu cattle. The
218
UNIVERSITY OF IBADAN LIBRARY
treatments were at four weeks of growth when cut and fed 
to the animals. The ammonia level before feeding was 
fairly high. The level was higher than that present one 
or two hours after feeding in case of treatments H and K. 
But the level increased after feeding in treatments J and 
L. The increase in both treatments remained almost con­
stant for the two hours after feeding. The greatest amount 
of ammonia production was by treatment L, and the least 
was by treatment K.
Table 9.2 showed the ammonia nitrogen produced by 
Zebu cattle fed treatments K and L at 12 weeks. The ammo- 
nial levels of the two rumen liquors were not very high.
The levels increased after feeding, although the increase 
was small in the case of treatment K while it was abrupt 
in case of treatment L. Treatment L also gave the great­
est ammonia production at this stage of growth.
219
UNIVERSITY OF IBADAN LIBRARY
TABLE 9.1
Ammonia nitrogen (mg/lOOml rumen liquor) produced by
Zebu cattle fed four treatments cut at 4 weeks.
Time of 
Sampling H J K K
Before feeding 16.80 17.75 12.69 19.89
Hours after 
feeding 1 15.20 20.00 9.21 26.58
2 12.85 19.25 10.52 26.64
Mean 14.95 19.00 10.81 24.37
Each is the mean of 20 determinations
TABLE 9.2
Ammonia nitrogen (mg/lOOml rumen liquor) produced by 
Zebu cattle fed two treatments cut at 12 weeks
Time of
Sampling K L
Before feeding 10.52 8.60
Hours after feeding
1 10.75 15.60
2 11.15 14.53
Mean 10.81 12.91
Each is the mean of 10 determinations
220
UNIVERSITY OF IBADAN LIBRARY
In table 9.3 the level of ammonia in the rumen liquor 
increased one hour after feeding only when treatment J was 
fed. All the other treatments caused a decrease in the 
ammonial level of the rumen liquor after feeding. The 
level started to rise in the case of treatments H and K 
three hours after feeding and got to the maximum four 
hours after feeding. The peak however was reached two 
hours after feeding in the case of treatments J and L.
On the average treatment H produced more ammonia than the 
rest and treatment K produced the least.
Table 9.4 showed the ruminal ammonia production by 
Zebu cattle sampled hourly up to eight hours after feed­
ing. All the treatments caused a decrease in the rumen 
liquor ammonia level. In treatments H and J the rumen 
ammonia level did not rise to the pre-feeding level 
throughout the sampling periods. But treatments K and L 
produced rumen ammonia levels higher than the prefeeding 
levels. Treatment K produced a peak production five hours 
after feeding while treatment L produced a peak level 
four hours after feeding. On the average there was little 
difference in ammonia production by treatments H,J and 
K. Treatment L produced the least amount of ammonia.
221
UNIVERSITY OF IBADAN LIBRARY
TABLE 9.3
Ammonia nitrogen (mg/lOOml ruman liquor) produced by
Zebu cattle fed four treatments cut at 4 weeks.
i
Time of 
Sampling H J K L
Before
Feeding 17.90 17.75 14.80 15.55
Hours after 
f eeding 
1 17.30 20.10 9.65 12.50
2 14.50 20.25 1 8.50 20.00
3 18.15 9.69 14.00 16.20
4 24.60 19.00 20.50 17.20
Mean 18.49 17.34 13.91 16.29
Each is the mean of four determinations
222
UNIVERSITY OF IBADAN LIBRARY
- - y - \
TABLE 9.4
Ammonia nitrogen (mg/lOOml rumen liquor) produced by 
Zebu cattle fed treatments H, J, K, and L at 4 week's.
Time of ----------- !
Sampling FT J K L
Before
feeding 21.48 21.63 14.56 13.83
Hours after 
feeding 
1 16.68 17.97 11.58 13.59
2 11.70 18.72 12.79 15.87
3 13.68 13.27 16.02 16.08
4 17.08 11.32 13.75 17.25
5 17.08 16.42 19.65 13.08
6 16.37 15.84 17.60 11.48
7 12.52 17.43 15.77 10.73
8 15.96 11.28 17.75 13.01
Mean 15.84 15.99 15.50 13.88
Each figure is the mean of six determinations
224
UNIVERSITY OF IBADAN LIBRARY
Table 9.5 showed the data for ammonia produced in the 
rumen liquor by Zebu cattle when the treatments were eight 
weeks. Both treatments caused an increase in the ruminal 
level one hour after feeding, and both reached th^ir 
peak production one hour after feeding. The levels then 
dropped slowly till they reached almost the prefeeding 
levels eight hours after feeding. On the average the dif­
ference in ammonia level was small. There was a lot of 
fluctuations during the sampling periods. The levels 
varied from 10.75 mg/lOOml rumen liquor to 19.58 mg/lOOml 
for treatment H and they varied from 12.69 mg/lOOml rumen 
liquor to 21.45 mg/lOOml rumen liquor for treatment J.
225
UNIVERSITY OF IBADAN LIBRARY
TABLE 9.5
Ammonia nitrogen (mg/lOOml rumen liquor) produced
by Zebu cattle red H and J  at 8 weeks
Time of 
Sampling H J
Before
feeding 14.75 16.92
Hours after 
feeding
1 19.58 21.45
2 17.05 14.65
3 19.45 15.27
4 12.15 12.69
5 9.93 15.00
6 10.75 17.17
7 14.02 16.10
Mean 14.46 15.79
226
UNIVERSITY OF IBADAN LIBRARY
Table 9.6 showed the ruminal ammonia production when 
the treatments were twelve weeks. With treatment J the 
ruminal ammonia level increased after feeding and conti­
nued to increase till it reached a peak four hours after 
feeding. The level was maintained for the next one hour 
before it started to fall, but the level was still higher 
than the prefeeding level. With treatment L the ruminal 
ammonia level decreased after feeding and did not rise 
to the prefeeding level throughout the sampling period. 
The level rose to a peak three hours after feeding and 
the level showed alternate rises and falls throughout the 
sampling period.
On the average, treatment L produced significantly 
more ruminal ammonia than treatment J. The fluctuations 
in the levels were high. With treatment J the levels 
varied from 9mg/100ml rumen liquor to 20mg/100ml rumen 
liquor, while with treatment L the levels varied from 
20mg/l00ml rumen liquor to 31mg/100ml rumen liquor.
227
UNIVERSITY OF IBADAN LIBRARY
TABLE 9.6
Time of 
Sampling J L
Before
feeding 9.00 31.60
Hours after 
feeding 
1 14.00 21.75
2 16.50 26.00
3 18.30 28.70
4 20.20 27.10
5 20.20 26.80
6 18.00 27.10
7 16.20 25.70
8 16.20 20.25
Mean - 16.54 26.11
Each is the mean of duplicate samples.
228
UNIVERSITY OF IBADAN LIBRARY
Table 9.7 showed urea nitrogen produced by Zebu 
cattle fed treatments H and J cut at four weeks. The 
sampling was carried out up to four hours after feeding. 
After feeding the urea level in blood serum increased in 
both cases. The peak blood serum level was reached one 
hour after feeding with treatment H, but the peak was 
reached four hours after feeding with treatment J. The 
blood urea level in both cases reached almost the same 
level four hours after feeding. The fluctuations in the 
urea levels were not as great as fluctuations in ammonia 
levels in the rumen liquor.
Table 9.8 showed the sampling of blood up to eight 
hours after feeding. Treatments H, J and L produced the 
highest level of urea seven hours after feeding. Treat­
ment K produced the peak urea five hours after feeding. 
The fluctuations in all cases were not much within the 
sampling periods.
229
UNIVERSITY OF IBADAN LIBRARY
TABLE 9.7
Urea nitrogen (mg/lQQml blood serum) produced by
Zebu cattle fed two treatment cut at 4 weeks
Time of 
Sampling H7 J
Before
feeding 17.50 15.88
Hours after 
feeding 
1 20.58 16.25
2 17.20 15.50
3 20.00 15.90
4 18.63 18.65
Mean 18.78 16.44
Each is the mean of four determinations.
230
UNIVERSITY OF IBADAN LIBRARY
TABLE 9.8
Urea nitrogen (mg/100ml blood serum) produced by
Zebu cattle fed four treatments cut at 4 weeks
Time of 
Sampling K J K L
Before
feeding 21.00 20.78 22.18 15.83
Hours after 
feeding 
1 22.96 17.70 21.73 16.98
2 23.26 19.54 22.10 17.29
3 24.20 18.54 22.39 17.97
4 22.90 18.74 22.38 18.86
5 24.33 20.29 24.27 21.95
6 23.88 20.80 23.83 21.09
7 25.55 21.51 22.87 23.11
8 21.81 18.77 17.67 16.77
Mean 23.32 19.63 22.16 18.87
Each is the mean of 12 determinations.
231
UNIVERSITY OF IBADAN LIBRARY
Table 9.9 showed the urea levels of the Zebu cattle
blood when the treatments were 8 weeks. The fluctuations 
in the urea levels did not vary much for treatments H and 
J, but there were wide fluctuations in the blood urea 
levels for treatments K and L. On the average the urea 
production from treatments H and J were similar, treatments 
K and L produced less blood urea.
9.5 DISCUSSION AND CONCLUSION
Since the ammonia released into the rumen liquor 
reached the peak at different times, it may be that the 
microbial activities varied a lot within the rumen. The 
microbial population may also be a factor. The more they 
are the more rapid the ammonia production. Ammonia is 
absorbed into the blood system and some of it changed to 
urea in the liver. The rate of absorption will also 
depend on the amount in the rumen liquor.
The fibrous feeds are expected to take longer time 
for digestion and absorption. The resuts indicate very 
little difference in the rate of ammonia production for 
the feeds clipped when four, eight or twelve weeks. The 
herbage was as fibrous at four weeks as at twelve weeks.
Urea is the diamide of carbonic acid, and it is the 
principal end product of nitrogen metabolism in mammals.
232
UNIVERSITY OF IBADAN LIBRARY
TABLE 9.9
Urea nitrogen (mg/lOOml blood, serum) produced by
Zebu cattle fed four treatments cut at 8 weeks
Time of 
Sampling H J K L
Before
feeding 18.70 20.82 23.22 19.25
Hours after 
feeding 
1 18.19 19.76 23.70 18.25
2 21.30 20.53 26.85 22.40
3 21.32 19.95 15.95 19.94
4. 20.91 21.77 10.45 14.55
5 22.25 22.99 18.63 11.03
6 23.72 25.51 8.89 13.13
7 23.80 25.61 19.98 8.89
8 18.60 19.71 12.45 8.40
Mean 20.98 21.85 17.79 15.09
Each is the mean of 12 determinations
233
UNIVERSITY OF IBADAN LIBRARY
The ammonia produced from the microbial breakdown of pro­
tein and non-protein compounds is used partly by the micro­
flora for their growth, and some are absorbed into the 
blood stream. A lot of the absorbed ammonia is quickly 
converted to urea by the liver and is excreted as such.
Some of the ammonia is also used in the synthesis of non- 
essential amino acids by amination, and some of the urea 
reenters the rumen through the saliva. When the micro 
organisms are not synthesising microbial protein, the 
ammonia produced tend to accumulate and a lot is absorbed; 
converted to urea and lost to the body. Urea can safely 
replace a part of the protein in selected rations for 
beef, dairy and growing cattle. But ammonia produced 
from urea is toxic so it can only be used to a certain 
extent.
Ruminal ammonia level in this experiment rose in 
some cases to 26mg/100ml rumen liquor, a value higher than 
what Somers (1961) recorded in his sheep experiment.
Blood serum urea levels also showed almost the same 
pattern as ruminal ammonia levels. The rises or falls 
indicate that part of the ammonia produced in the rumen 
was absorbed, converted to urea in the liver and excreted 
into the blood. The highest level in this experiment
234
UNIVERSITY OF IBADAN LIBRARY
was just over 27mg/100ml blood serum, a value quite close 
to that obtained by Somers (1961). Somers work indicated 
however that it was possible to get an increase in blood 
urea level and the peak production after eight hours 
after feeding.
235
UNIVERSITY OF IBADAN LIBRARY
CHAPTER 10
l,ln vitro1* determination of digestibility coefficient of 
treatments according to Tilley and Terry, modified by
Alexander.
10.1 INTRODUCTION
In animal nutritional studies it is not always possi­
ble to get enough animals to complete a stastically sound 
experiment. A lot of information is needed concerning the 
digestion, absorption and the metabolism of different 
feeds. It is not possible to increase the number of ani­
mals in a head as one wishes because a cow can only produce 
a calf in one to one and a half years. The heifer calf 
has to grow up to two years or more before it is ready 
for reproduction. Research workers on ruminants have 
therefore devised a technique whereby a lot of information 
is obtained within a short time from experiments carried 
out under conditions controlled in such a way as to simu­
late what obtains in the animal.
One of such techniques is the "in vitro" technique 
where feeds are digested in tubes using rumen liquor 
withdrawn from the donor animal. A lot of information 
has been obtained in the past, and a lot is being 
obtained presently.
UNIVERSITY OF IBADAN LIBRARY
The ruminants such as cattle, sheep and goats are 
needed for beef and milk production. The present output 
of these animals in Nigeria is very low. One of the 
factors causing low yield is feed utilization. We want 
to know the feed value of a feed and how much of it is 
used for a particular function. The nutritive value of 
a treatment is a function of chemical composition and 
digestibility. The type of the end product produced 
during digestion is therefore very important.
Factors which influence the extent of "in vitro" 
digestibility of a treatment are many. Some of these are 
concentration of the feed, the freshness of the feed, 
its fineness, the composition and buffering capacity of 
the medium, the amount and preparation of the rumen 
fluid inoculum and the diet of the donor animal.
The "in vitro" determination of digestibility is of 
considerable use in predicting the value of dried grasses 
as sources of energy for ruminants. The determination of 
digestibility has the added advantage of providing a 
measure of the faecal energy loss which is not only the 
major determinant of the energy per unit of food, but 
also of great importance as a factor controlling voluntary 
feed intake by ruminants.
237
UNIVERSITY OF IBADAN LIBRARY
Thera is increasing interest shown in beef and dairy
oroduction in Nigeria, but there is little information 
available on indigenous pasture. This has therefore 
necessitated the use of rapid methods for pasture evalua­
tion. The "in vivo" digestibility trials, though give 
the actual digestibility by the use of animals, requires 
a considerable use of time, requires large quantities of 
uniform treatment, and the collection of large number of 
samples from treatmentsand faeces. Collection of faecal 
samples requires a lot of care in order to avoid conta­
mination.
However "in vitro" methods are capable of handling 
large numbers of samples in a short period of days. In 
"in vivo" experiments only one treatment digestibility 
can be carried out and completed in a 3 - 4 week experi­
mental period.-
10.2 RUMEN LIQUOR
Rumen liquor for inoculation was obtained from a 
fistulated steer. The liquor was immediately stored in 
a thermos flask and taken to the laboratory. The liquor 
was strained through thin cloth and then used for in­
oculation. 10ml of rumen liquor was used for each grass 
sample. The pH of the liquor was measured before use.
238
UNIVERSITY OF IBADAN LIBRARY
10.3 ANALYTICAL PROCEDURE
Large boiling tubes (20cm x 3 cm) were washed and 
dried at 100°C in the oven. The tubes were cooled and 
duplicate samples, 0.5gm, were weighed. The samples were 
kept in a water bath at 39°C until needed. 640 ml 
artificial saliva buffer solution was poured into a flask 
and kept in the water bath, and CQ2 was passed through it 
until it was saturated and clear (15 minutes). The pH was 
adjusted to between 6.7 - 6.9, before 160 ml rumen liquor 
was added, and 16 ml (NH4)2 S04 solution was also added. 
C02 was passed through t he mixture again and the tempera­
ture kept at 39°C.50 ml of this mixture was added into 
each tube and left in the water bath at 39°C. Each tube 
was shaken gently by swirling, and C02 passed through to 
displace any gas in the tube. The tubes were left in the 
bath for 24 hours.
After 24 hours the pH of each tube was read and 
adjusted to pH 6.9 by adding N Na2C03. The tubes were 
left for another 24 hours. Then 1.5 ml followed by 2.5 ml 
HCl (20% v/v) was run down the side of each tube as it 
sits in the bath. The tubes were not disturbed at this 
time to avoid frothing. The pH of the solution was 
adjusted to 1.2.
239
UNIVERSITY OF IBADAN LIBRARY
Iml of aqueous pepsin solution (1.2g/5ml) was added 
to each tube and left to digest for 48 hours. CO2 was 
passed through the tubes after pepsin addition.
After 48 hours the contents of each tube was filtered, 
using fine celite as filter aid, through whatman filter 
paper 541 under suction. The residue was washed several 
tines with hot water, dried at 100°C overnight, weighed, 
ignited at 480°C and weighed again.
Calculation 
"in vitro"
Digestibility = O.M in 0.5gm sample - (O.M. in
of organic residue - O.M. in control)
— -------------------------------------------------------------------------------  x  100
Matter • O.M in 0.5 gm sample.
O.M. = Organic Matter.
10,4 RESULTS
Table 10.1 showed that in 1967 treatment H had the 
lowest digestibility at one week. The digestibility 
increased at two weeks and then rose to the highest value 
at t hree weeks before declining at four weeks. The 
digestibilities at three and four weeks were higher than 
those at one and two weeks.
In 1968 treatment H showed a higher digestibility 
than in the previous year. The digestibility was greater
240
UNIVERSITY OF IBADAN LIBRARY
at one week than at two weeks. The treatment was most 
digestible at three weeks. The digestibility fell to 
nearly the same level as was in the previous year when four 
weeks old. Treatment H showed the greatest digestibility 
at three weeks during the two years. The means for both 
years were 57.74%, 53.49%, 60.05% and 52.87% at one, two, 
three and four weeks respectively.
Treatment J also had the lowest digestibility during 
the first week of growth in 1967. The digestibility 
increased by about 4% in the second week but dropped by a 
few units the third week before reaching the highest 
digestibility at four weeks.
However in 1968 treatment J had almost the same 
digestibility at one, three and four weeks. It was least 
digestible at two weeks. The average for both years 
showed that the treatment was more digestible at four 
weeks, and the digestibilities at two and three weeks 
were very close, while the value for one week was the lowest. 
Treatment K was most digestible in its first week of growth 
in 1967. It dropped by about 3% in the second week and 
rose slightly the third week but it dropped again in the 
fourth week. The lowest digestibility was obtained 
during the second week.
241
UNIVERSITY OF IBADAN LIBRARY
In 1968 the digestibility was fairly good in the 
first week. The value was higher than in the previous 
year. This value was higher than that of the second 
week. Treatment K was more digestible in the second week 
than in the previous year. The treatment was most 
digestible in the third week. The digestibility fell 
by almost 4% in the fourth week. The digestibilities 
were higher at the four stages of growth during the second 
year. The means for both years showed the third week to 
be the period with the highest digestibilityt59.23%, 
57.38%, 55.02%, and 36.78% were the digestibilities for 
the first, second, and fourth weeks respectively.
In 1967 treatment L had almost the same digestibili­
ties during the four stages of growth. The least was in 
the third week while the highest was in the fourth week. 
There was little difference between the first and second 
week,
In 1968 the digestibilities were higher in every 
case except in the fourth week. The highest digestibility 
was obtained in the first week and this declined gradually 
from then on till it fell to 51.11% in the fourth week. 
This value was lower than that of the previous year.
UNIVERSITY OF IBADAN LIBRARY
The mean values also showed the treatment to be most 
digestible in the first week with the digestibility 
declining till the fourth week.
243
UNIVERSITY OF IBADAN LIBRARY
TABLE 10.1
lonparison of "in vitro*1 Organic Matter digestibilities
of treatments H, J, K, and L at four stages o 1 growth
with Zebu cattle.
Stages of growth (weeks)
Treatment 1 2 3 4
H
1967 42.52 46.15 56.51 52.72
1968 62.96 60.83 63.59 53.02
Mean 57.74 53.49 60.05 52.87 56.04
J
1967 51.71 55.40 54.84 57.62
1968 60,76 58.67 60*66 60.16
Mean 56.24 57.04 57.75 58.89 57.48
K
1967 55.56 52.02 53.93 52.74
1968 59.19 58.01 64,53 60.82
Mean 57.38 55.02 59.23 56.78 57.10
L
1967 51.53 51.80 50.95 52.29
1968 60.54 58.25 56.32 51.11
Mean 56.04 55.03 53,64 51.70 54.10
244
UNIVERSITY OF IBADAN LIBRARY
Comparing the means of the four treatments, treat­
ments H and K had the same digestibilities at one week, 
and treatments J and L also had about the same digestibi­
lities at one week. Treatment H however was the most 
digestible of them all at one week. When two weeks old, 
treatment J had the highest digestibility, while treat­
ments K and L were identical in their digestibilities. 
Treatment H was the least digestible of the treatment at 
this time of growth. At three weeks treatment H had the 
highest digestibility followed closely by treatment K. 
Treatment J was next to treatment K in digestibility, 
and the least digestible was treatment L. At four weeks 
treatment L was the least digestible followed by treatment 
H with slightly higher digestibility, but treatment J 
was the most digestible followed by treatment K.
The mean digestibilities of the four treatments over 
the four periods of growth did not vary much. Treatment 
L was the least digestible in all cases and it had a mean 
of 54.10% while treatments J and K were almost identical. 
Treatment H was lower in value by about 1%. Except for 
treatment J, all the treatments were less digestible at 
four weeks than at one week. The difference was about 1%
245
UNIVERSITY OF IBADAN LIBRARY
for treatment K but the difference was about 5% for 
treatments H and L.
The lower digestibility at four weeks may be due to 
increased crude fibre, cellulose, lignin and other less 
digestible cell wall constituents in the fodders. When 
plants grow the crude fibre, lignin and cell wall consti­
tuents increase. This increase with maturity was also 
reported by Oyenuga (1958 1960), Ademosun et a.lA (1967),
Ademosun (1970), Tilley and Terry (1964), Maynard and 
Loosli (1962), VanSoest (1966, 1967).
Tables 10.2 and 10.3 showed the chemical composition 
of some grasses planted as sole plants and clipped at 4 
and 8 weeks. Their "in vitro" digestibilities are also 
shown. At four weeks all the grasses contained over 90% 
dry matter (D.M.). Paspalum scrobilatum had the highest 
D.M. content followed very closely by Chloris gayana.
The variation in D.M. % among the grasses was very narrow, 
being from 90.68% to 93.66%. The organic matter (O.M.) 
content too was fairly high for every grass. Each grass 
contained over 80% organic matter and the amount varied 
from 80.25% to 86.90%. Setaria sphacelata contained the
246
UNIVERSITY OF IBADAN LIBRARY
lowest amount of D.M. and O.M. while Chloris gayana
had the highest organic matter content. There was much 
variation in the ash content of the grasses. The lowest 
amount, 5.7%, was found in Andropogon tectorum while the 
highest amount 10.44%, was produced by Setaria sphacelata.
All the grasses except Paspalum Scrobi latum contained 
over 8% crude protein (C.P.). IB8 Giant Star grass con­
tained the highest amount of C.P., 14.73%, whilst Paspalum 
scrobilatum contained just 7.57% C.P. Setaria sphacelata 
and Andropogon gayanus also contained fairly good amount 
of C.P.
At this tender age the crude fibre (C.F.) content of 
all the grasses was about 30%. This is typical of tropi­
cal grasses. Digitaria decumbens was the most fibrous 
with 35.9%C.F. followed very closely by Setaria sphacelata. 
The C.F. content varied from 30.51% to 35.90%.
The ether extractives were above 1% in all the grasses. 
188 Giant Star contained fairly high ether extracts and it 
is followed by Andropogon gayanus and Setaria sphacelata.
The Nitrogen free extracts (N.F.E.) varied widely. The 
lowest amounts were found in Setaria sphacelata and IB8 
Giant Star, but Chloris gayana and Paspalum scrobilatum 
contained the highest amounts of N.F.E.
247
UNIVERSITY OF IBADAN LIBRARY
It is interesting to note that these grasses showed 
a Tendency to produce high protein along with high crude 
fibre content. Setaria sphacelata, Andropogon gayanus, 
and IB8 Giant Star grasses contained high protein and high 
crude fibre contents, Paspalum scrobilatum also contained 
the lowest amount of crude fibre and crude protein.
At 8 weeks the grasses contained higher amounts of 
dry matter, the variation however was very small. The 
variation was from 93.17% to 94.98%. The organic matter 
content was also higher in all the grasses than at 4 weeks. 
The ash content decreased slightly at this sta.ge of growth 
than at 4 weeks except IB8 Giant Star grass which showed 
an increament in ash content.
The crude protein content, ether extracts, and the 
crude fibre contents also decreased. IB8 Giant Star still 
maintained the lead in having the highest amount of protein 
and fat, followed by Setaria sphacelata and Andropogon 
gayanus. The crude fibre content of Melinus minutiflora 
increased at 8 weeks and it had the highest amount of 
crude fibre at this stage of growth, but IB8 Giant Star 
contained the lowest amount of crude fibre.
Nitrogen free extract varied very widely this time.
The range was from 40.44% to 58.76%. Paspalum scr obi la. turn
248 -
UNIVERSITY OF IBADAN LIBRARY
contained the highest amount of N.F.E. , whilst IB8 Giaoit 
Star grass contained the lowest amount of N.F.E.
The "in vitro" digestibility of organic matter of 
these grasses at 4 weeks showed that Setaria sphacelata, 
Andropogon gayanus and Melinus minutiflora have very low 
digestibilities. They all gave less than 50% digesti­
bilities. Setaria sphacelata was the least digestible. 
Andropogon tectorum, Chloris gayana, ^igitaria decumbens 
and Paspalum scrobilatum gave digestibilities above 50%. 
IB8 Giant Star showed a very good degree of digestibility 
since it was the only grass having a digestibility of 
over 60% at this stage of growth.
At 8 weeks, the "in vitro" digestibilities increased, 
and the increase was appreciable in the case of Setaria 
sphacelata, Digitaria decumbens, Andropogon gayanus and 
Melinus minutiflora. The digestibility of Paspalum 
scrobilatum decreased at 8 weeks, whereas IB8 Giant Star 
showed the same digestibility as at 4 weeks; it also had 
the highest digestibility at 8 weeks. The very wide 
variation in digestibility shown at 4 weeks was reduced 
greatly at 8 weeks. All the grasses had over 50% digesti­
bility and IB8 Giant Star was the only one having digesti­
bility above 60%.
249
UNIVERSITY OF IBADAN LIBRARY
TABLE 10.2
Chemical composition and " in  v itro " d igestib ility  of organic matter of single stand 
grasses at 4  weeks planted on Un iversity  o f Ibadan Farm
( %  Dry matter )
4 weeks
Total C. Ether " In V itro "  
Fodder D . M . O . M . Ash Protein C . F . Extract N . F .  E . D ig . %
Setaria 
sohacelata 90 .68 80 .25 10.44 11.70 35.29 2 .00 40 .57 4 3 .0 7
Andropogon
tectorum 91 .19 85 .49 5 .7 0 9 .3 0 3 3 .73 1.60 49 .67 52 .84
Chloris
gayana 9 3 .5 6 86 .90 6 .6 8 8 .7 7 31 .65 1 .25 51.65 50 .54
Digitaria
decumbens 9 0 .9 7 82.41 8 .5 5 9 .71 35 .90 1.10 44 .74 5 1 .86
Paspalum 
scrobi latum 9 3 .6 6 8 5 .1 7 8 .4 8 7 .5 7 30.51 1 .56 51.88 54 .50
IB8
G . Star 90 .9 0 81 .09 9 .8 7 14.73 3 2 .06 2 .68 40 .66 62 .68
Andropogon
gayanus 9 1 .8 3 8 5 .7 2 6 .10 10.00 34 .46 2 .00 47 .44 44 .89
Mel inus 
m ir.utiflora 9 2 .48 8 6 .1 2 6.41 9.11 33 .04 1.75 49 .69 45.71
Each figure is the mean of duplicate samples
250
UNIVERSITY OF IBADAN LIBRARY
TABLE 10.3
Chemical corr; sition  and " in  v itro " d ig e stib ility j l  •*§»»!'
o f single stanc grasses a? 8 weeks planted on U nlvnM ii, -I M•• • t..
Farm .
—
( %  Dry Matter)
8 weeks
Total C . Ethe r " In V itro "  
Fodder D .M . O . M . Ash Protein C . F . Extract N . F ,  E . D ig . %
Setaria
sphGCeicta 9 3 .1 7 8 3 .7 3 9 .4 4 9 .9 5 29.39 1 .96 49 .26 5 0 .13
Andropogon
tectorum 94.01 88 .65 5 .3 5 8 .1 2 2 7 .37 1 .00 57 .16 54 .00
Chloris
gayanc 9 4 .98 90.01 4.91 7 .5 0 28.81 0 .9 9 57.79 52.51
Digitaria t
decumbens 9 3 .9 4 85 .8 3 8.11 8 .0 0 28 .59 0 .7 5 54.55 57 .65
Paspal um 1
scrobilotum ! 9 3 .2 2 86.01 7 .2 0 6.91 26 .29 0 .8 4 58|,76 51 .73
” 1!--------------1
198
G . Star 2.41 40 .44. ----9-4 .1 5■  - -  - i! 8 2 .2 3 11.91 12.08 2 3 .1 6 62 .57r—  —  -----------------
1
Andropogor
gayanus 9 3 .3 2 88 .15 5 .6 2 8 .8 4 27 .49 1 .86 5 6 .1 9 56 .78
Melinus
m inuftflorc 94.31 8 8 .80 5.51 8.21 3 5 .4 7 1 .16  j 49 45 50.61
Ecch figure is the mean o f duplicate samples.
UNIVERSITY OF IBADAN LIBRARY
10.5 DISCUSSION
In an early investigation by French (1940), Zebu and 
Ayrshire cattle were fed hay and green grass. The digest­
ibility of organic matter for hay was 60.45% for Zebu and 
55.91% for Ayrshire. When green grass was fed the digesti 
bility coefficient of organic matter for the Zebu was 
48.85% and 49.34% for Ayrshire. The higher diges td&-- 
lities of the feeds used in this experiment may be due 
to the legumes planted along with the grasses. Some of 
the results here showed that the digestibility of grasses 
or grass legume/mixtures will not necessarily be high 
when they are very young.
Of all the eight grasses analysed only Digitaria 
decumbens, and IB8 Giant Star grass showed higher digesti­
bility coefficients in their early stages of growth.
Todd (1956) in his work on tropical grasses obtained 
63.46% as the digestibility coefficient of organic matter 
for Chloris gayana in its early flowering stage, while the 
digestibility fell to 55.34% in the early dry season. 
Pennisetum clandestinium also had a higher digestibility 
coefficient of organic matter (72.68%) during the younger 
stage of growth and a lower digestibility, 59.10% when it 
was older.
252
UNIVERSITY OF IBADAN LIBRARY
Woodman, Evans and Norman (1934) in their investiga­
tions on the nutritive value of lucerne, obtained highest 
digestibility at the earliest stage of growth. This is 
similar to the digestibility of grass. At this stage also 
the dry matter of lucerne was richest in starch equivalent 
and digestible protein.
Todd (1956) investigated the digestibility and 
nutritive value of Chloris gayana (Rhodes grass) and 
Pennisetum clandestine::! (Kikuyu grass) at medium altitudes 
in the tropics. Chloris gayana was found to be more 
digestible in the early flowering stage than in the early 
dry season. Pennisetum clandestinum was more digestible 
at the vegetative young growth stage than at the high 
vegetative stage. Okorie, Hill and Mcllroy (1965) 
obtained higher digestibility coefficients with the dwarf 
sheep and Nidama cattle during the first year than in the 
second year of grazing tropical grass/legume pasture. 
French (1960) compared the digestive powers of Zebu and 
high grade European cattle (Ayrshire) using different 
feeds. The digestibility coefficients obtained for both 
animals in most cases were very close. He obtained no 
significant difference'between the average digestibility 
coefficients in the Zebu and the Ayrshire crosses.
253
UNIVERSITY OF IBADAN LIBRARY
CHAPTER 11
DIGESTIBILITY TRIALS
11.1 INTRODUCTION
The urgent need for a method or methods for assessing 
the digestibility of tropical pastures has been felt in 
recent times. Some work has been carried out on many of 
the local species of grasses and legumes of which little 
or nothing was known about their digestibilities. Some 
investigators assessed the'nutritive value of pasture 
forages by the live weight gains of grazing animals 
(Stobbs, 1969a, b; c; d) or by their chemical composition 
(Long et ad., 1969; Schneider et al., 1951; Raymond et al., 
I960;) or by "in vitro" digestibility studies (Raymond e_t 
al., 1966; Barns, 1965; Stewart et al., 1958; Sutton, 1968).
Faeces voided by grazing or stall fed animals can be 
collected attaching collection bags to harnesses fitted 
on to the animals. Many animals do not like being har­
nessed because of discomfort. This method is very good, 
particularly with male animals, in that there is no con­
tamination by urine, feed or soil. Digestibility of pasture 
herbage by grazing animals can also be carried out without 
harnesses, but by the administration of markers such as 
chromic oxide (Cr203). This substance has been used in
254
UNIVERSITY OF IBADAN LIBRARY
digestibility trials all over the world for ruminants as 
well as non-ruminants like pigs and poultry. There are 
at times diurnal variations and uneven voiding of the 
marker due to feed and method of administration (Moore, 
1958; Corbett _et al, , 1958).
Digestibility trials using Cr203 as indicator involves 
the measurement of amount of 0 ^ 0 3  in the faeces voided, 
and the amount of the oxide administered every day during 
the preliminary and collection periods.
Collection of grass samples and faeces and their 
chemical analyses have been described in chaper 3.
11.2 DETERMINATION OF CHROMIC OXIDE IN FAECES
Coup and Lancaster (1952) used arsenious acid and 
Postassium permanganate along with other oxidising agents 
in their chromix oxide recovery determinations. Christian 
and Coup (1954) used Postassium bromate and phosphoric 
acid along with other oxidising agents in their chromic 
oxide recovery determinations. A modified form of the 
method of Christian and Coup (1954) was used to estimate 
the chromix oxide in the faeces (C.A..B. 1962)
11.3 ANALYTICAL PROCEDURE
The proximate analysis of the feeds and faeces were
255
UNIVERSITY OF IBADAN LIBRARY
carried out according to the method of the A.O.A.C. (1964). 
Chromic oxide recovery was carried out using the modified 
method of Christian and Coup (1954). This method was 
modified a little in that ferrous ethylene di-ammonium 
sulphate was used instead of ferrous ammonium sulphate. 
Digestibility coefficient for each animal was calculated 
as:
D = 100 X (Wt. of D.M. in herbage eaten) - (Wt. of D.M. in
________________________________ faeces voided)
(Wt. of1 D.M. in herbage eaten)
Wohr eroer gaD.n ic=  mPaetrtceern taign e thdei gheesrtbiabgiel.ity of dry matter 
Ib of faeces D.M. or O.M. voided by animal 
under grazing condition = gm Cr203 fed per day
453.6 x gm O 2O3 voided per day
D.M, or O.M. of herbage consumed in
the field = wt of faeces voided x 100
100 - percentage digestibility
% Recovery = gm 0:203 voided,< 
gm O 2O3 consumed.
256
UNIVERSITY OF IBADAN LIBRARY
11.4 RESULTS
The digestibility coefficients of treatments H,J,K,
and L at 4 weeks by Zebu cattle are shown in table 11.1.
With treatment H, ether extract was the least digestible 
of the nutrients. At this stage the crude fibre was highly 
digestible, being only slightly less digestible than the 
crude protein. It was more digestible than the nitrogen 
free extracts. The first two rows (Appendix XI) showed 
the mean digestibility values for the samples taken during 
the first six days of the experiment, while the last two 
rows showed the mean values for the last six days of the 
experiment. The first two readings were higher in most 
cases than the last two readings and the difference was 
sharp in the case of dry matter digestibility. The result 
showed that the digestibility of a treatment can change 
from day to day during the experimental period, lasting 
for more than three days. The digestibilities in this 
case dropped after 1he sixth day.
Treatment J did not show as much variation in digesti­
bility as treatment H. The ether extract was also the least 
digestible in this case. The crude fibre and the crude 
protein were digested to almost the same extent. The crude
257
UNIVERSITY OF IBADAN LIBRARY
TABLE 1L.1
Mean Digestibility coefficients of four treatments
cut at 4 weeks by Zebu cattle
Treatment D.M. O.M. C.F. C.P. E.E. ATsohtal n .f ;e .
H; 61.1 60.4 67.9 69.3 21.2 , 57.8 55.2
J 55.0 58.1 57.0 56.7 21.3 40.5 56.8
K 43.6 47.5 52.1 42.3 10.5 26.7 42.2
L 51.6 55.2 57.6 58.6 9.0 23.2 54.0
258
UNIVERSITY OF IBADAN LIBRARY
fibre had almost the same digestibility as nitrogen free 
extract. Ether extracts and total ash had the lowest 
digestibilities. All ithe nutrients in treatment J except 
N.F.E. were less digestible than those in treatment H.
The tendency for the digestibility to fall as the experi­
ment (Appendix X])progressed was shown, although less 
clearly in this treatment.
Treatment K had very low dry matter digestibility, 
particularly during the last six days of the experiment, 
when there was a sharp drop. The crude fibre was more 
digestible than the crude protein and nitrogen free 
extract. The digestibility of the nutrients dropped 
aftert he first six days, while total ash and ether extract 
were the least digestible of the nutrients.
In treatment L the ether extract had the lowest 
digestibility. The crude fibre was more digestible than 
the nitrogen free extracts and organic matter. The 
digestibility of the nutrients fell after the first six 
days of the experiment.
Comparing the four treatments at 4 weeks, treatment 
H had the highest dry matter and organic matter digesti­
bility coefficients*followed by treatment J, while 
treatment K had the lowest digestibility. Treatments H
259
UNIVERSITY OF IBADAN LIBRARY
and L had the highest crude fibre digestibility coeffici­
ents followed by treatment J and lastly by treatment K.
The crude protein digestibility was very high in treatment 
H followed by treatments L and J while K had a lover value of 
42.3%. Treatment L was least digestible as to ether 
extract constituent. Treatment H had the highest total 
ash digestibility followed by treatments J, K and L in 
that order respectively.
Generally, treatment H showed the highest digesti­
bility of each nutrient.
Table 11.2 showed the digestibility coefficients of 
the four treatments at twelve weeks of growth. With treat­
ment H, the ether extract had the lowest digestibility 
coefficient, but the crude fibre was digested to a 
greater extent than nitrogen free extract. Ether extract 
and total ash had the lowest digestibilities, although the 
crude protein was digested to a fairly good extent in 
treatments H and L. The digestibility of each nutrient 
dropped after the first six days (Appendix XI).
Treatment J also had the ether extract having the 
lowest digestibility. The crude fibre was more digesti­
ble than the crude protein and nitrogen free extract.
260
UNIVERSITY OF IBADAN LIBRARY
The digestibility of each nutrient decreased during the 
last six days of the experiment.
The ether extract had the lowest digestibility in 
treatment K. The crude fibre was more digestible than 
crude protein or nitrogen free extract, and as the case 
with treatments H and J, ether extract and total ash 
were the least digestible. The digestibility of each 
nutrient decreased during the last six days of the 
experiment.
The ether extract of treatment L was the least digest- 
ble just as was the case with the other treatments. The 
organic matter, crude fibre, crude protein and nitrogen 
free extract had very close digestibilities. The nutrients 
in most cases had lower digestibilities during the last 
six days of the experiment.
Considering the four treatments at twelve weeks, 
treatments H and L seemed to be the better of the treat­
ments since some of their nutrients were digested to a 
greater extent than those in J and K with treatment K 
having the least digested nutrients.
Comparing the four treatments at both stages of 
growth it was clear that they all showed very low dry
261
UNIVERSITY OF IBADAN LIBRARY
TABLE 11.2
Mean Digestibility coefficients of four treatments cut
at l2 weeks by Zebu  cattle
Treatment D.M. O.M. C.F. C.P. E.E. ATsothal N.F.E.
H 55.3 55.2 62.8 62.9 33.5 37.5 51.1
J 51.0 53.5 59.7 47.9 13.4 40.3 50.7
K 46.1 49.9 53.8 39.3 34.5 38.0 43.9
L 57.9 58.2 58.7 61.2 27.3 52.5 58.8
262
UNIVERSITY OF IBADAN LIBRARY
natter digestibilities. Treatment K showed the lowest 
digestibility at both stages of growth. The organic 
matter digestibility remained very close to D.M. digest- 
ility. The crude fibre digestibility increased at 
twelve weeks except for treatment H which had a decrease 
in digestibility. The crude protein and N.F.E. digesti­
bilities also decreased at twelve weeks except for treat­
ment L which showed an increase in its digestibility. 
Chromic Oxide Recovery
Recovery of from faeces organic matter for the
digestibility trials is given in table 11.3.
263
UNIVERSITY OF IBADAN LIBRARY
TABLE 11.3
Mean % recovery of Cr203 from faeces organic matter 
of Zebu cattle
Treatment wee4ks we1e2ks
H 97.57 + 7.29 99.31 + 4.7
J 97.63 + 4.02 98*83 + 2.88
K 99.84 + 4.34 99.31 + 0.02
L 95.69 + 2.06 94.09 + 0.72
For treatment H at 4 weeks, (Table 11.3,) the mean 
recovery was 97*57 + 7.29, while the range for this 
treatment was from 92.20% to 101.18%. At 12 weeks the 
mean for this treatment was 99.31 + 4.7, while the range 
was from 97*16% to 103.22%. The variations in these 
cases were not large* For treatment J the ranges at 4 
and 12 weeks were also small. The range at 4 weeks was 
from 94.66% to 100.21%. The mean was 97.63 + 4.02%, 
whereas at 12 weeks the range was from 96.92% to 100.27% 
and the mean was 98.83 + 2.88%. Treatments K and L did
264
UNIVERSITY OF IBADAN LIBRARY
not show much variation. The means for both were 99.84 + 
4.34%, 99.31 + 0.02, 95.69 + 2.06, and 94.09 + 0.72%.
Corbett, GreenHalgh, Gwynn and Walker (1958) observed 
variation in Chromic Oxide recovery of the same grass 
cut at different times of the year. They also did not 
get any variation in chromic oxide recovery of more than 
10%. Olubajo (1969; 1970) obtained good Cr203 recovery 
in his digestibility trials.
11.6 CORRELATION AND REGRESSION EQUATIONS
Correlation and regression equations for dry matter 
digestibility trials of stall-fed and grazing animals 
using faecal nitrogen as the index are shown in appendix 
XI.
The correlation between faecal nitrogen and dry 
matter digestibility in these trials was very low. The 
correlation for treatment H at 4 weeks was 0.4. When the 
regression equation was used to calculate the digestibi­
lity of the treatment by the grazing animals the mean 
value was very high. A correlation of 0.5 was obtained 
for treatment H at 12 weeks, and the regression equation 
when applied this time also gave very high mean digesti­
bility. Treatment J at both stages of growth gave
265
UNIVERSITY OF IBADAN LIBRARY
negative correlations between faecal nitrogen and dry 
matter digestibility. The regression equations used in 
both cases gave digestibility values less than those for 
the stall-fed animals.
Treatment K gave a very good correlation between 
faecal nitrogen and dry matter digestibility at 4 weeks. 
The regression equation gave very good digestibility 
value for the grazing animals. Whereas the 12 weeks cut 
gave a negative correlation and the regression equation 
produced lower digestibility value for the grazing 
cattle.
Treatment L gave a very low positive correlation at 
4 weeks and the equation used produced digestibility 
value almost the same for the two groups of animals. 
There was also a positive correlation for the 12 week 
cut and the regression equation produced almost similar 
digestibility value for the grazing animals..
266
UNIVERSITY OF IBADAN LIBRARY
Regression equations from percent digestibility of 
organic matter of stall fed animals during the experi­
mental period.
Treatment Weeks Regression equation CCooerfrfeilcaiteinotn
H 4 Y = 62 X - 8.21 + 6.93 r = 0.4
12 Y + 102.9X-78.08 hk 11.98 r s 0.5
4 Y s 54.94 - 0.01 X + 0.65 r = -0.05
12 Y = 94.47 - 29 X + 2.53 r = -2.23
K 4 Y = 109 X - 105.92 + 7.66 r s 0.71
12 Y s 48.16 - 1.5 X + 0.18 r =r 0.47
4 Y = 47.61 + 2.77 X + 0.74 r - 0.11
12 Y 40.39 + 12 X + 0.45 r = 0.55
X = % nitrogen in fa.eces organic matter from 
gazed herbage.
Faecal nitrogen has been used successfully by various
workers, Topps (1962), GreenHalgh and Corbett (1960a; 
1960b) as an index to predict the dry matter digestibi­
lity of treatments. Others have met with difficulties 
in obtaining good correlation for most of the feeds.
267
UNIVERSITY OF IBADAN LIBRARY
The correlations obtained for the treatments in these
trials showed that faecal nitrogen can be used to predict
digestibility, but that it does not give good correlation
all the time. It can be used along with other indi ces
like lignin, methoxyl groups, to predict the digestibility
of treatments by grazing animals (Sullivan, 1959;
Richards and Reid, 1952).
11.7 IDnI StChUeSsSeI OeNxperiments faecal nitrogen or crude protein 
was more for the grazing animals than for the stall-fed 
animals, Topps (1962) obtained significantly more 
digestible crude protein in herbage grazed by cattle than 
that collected by hand. GreenHalgh £t ah (1960b) observed 
that single sward regressions were considerably more pre­
cise than those which combine results from many treat­
ment types. Grazing animals may have lower O.M. digesti­
bility than the stall-fed animals if they consume more 
of the treatment, since high forage intake depresses 
digestibility. This may be the cause of the lower 
organic matter digestibility shown by some grazing 
animals in some of the treatments. Other causes may be 
the health of the animals or intestinal infestations.
268
UNIVERSITY OF IBADAN LIBRARY
These observations were also expressed by Minson (1958), 
and Raymond, Minson and Harris (1956).
Differences in the equation for the faecal nitrogen 
used for predicting digestibility of the treatments, and 
the different digestibilities obtained can be attributed 
to analytical methods used or to differences in animals 
used, or to the type of herbage. In these experiments 
the two groups were used for all the treatments, so that 
the differences in herbage were likely to be the major 
cause of different digestibilities obtained.
French (1940) used Zebu cattle as well as Zebu x 
Ayrshire crosses in his digestibility trials. The green 
grass he fed the animals gave very low digestibility 
values for each of the nutrients as compared with the 
values of the present work. Dry matter digestibility 
was the lowest except for N.F.E. for the Zebu cattle. 
Ether extract was t he least digestible nutrient. Ether 
extract and total ash were the least digestible nutrients 
in the present trial. The increased digestibility of 
each nutrient in the present work may be due to the 
presence of the legume centrosema.
269
UNIVERSITY OF IBADAN LIBRARY
Okorie, Hill and Mcllroy (1965) grazed grass legume 
mixture with N ’dama cattle, and they obtained fairly high 
digestibility coefficient for each nutrient. Crude pro­
tein was the most digestible while ether extract was the 
least digestible nutrient. The second year digestibility 
coefficients were lower than the first year values. The 
fall in digestibility coefficients was noticed in each 
of the trials during the experimental period of the 
present trial.
The crude fibre of the treatments were digested to 
greater extent than some of the nutrients in the feed, 
particularly the nitrogen free extract and crude protein 
in some cases. ' Nitrogen free extract is supposed to be 
highly digestible but its digestibility has not been as 
high as that of crude fibre, in some cases since the crude 
fibre was digested very well at four weeks and also at 
the advanced stage of twelve weeks, it seems that the 
Zebu cattle possess a good ability to digest crude fibre. 
These four mixtures have proved that there are some 
selected tropical pasture treatments that can be very 
digestible.
270
UNIVERSITY OF IBADAN LIBRARY
Analyses of variance for the nutrients in the 
treatments H,J, K and L cut at 4 weeks (Appendix XI) 
showed that there were significant differences between 
the treatments (PTO.05) for the dry matter, organic 
matter and ash contents. The difference in crude fibre 
contents were very low. There were significant differences 
between days of cutting the samples for organic matter 
and ash contents. There were no significant differences 
for N.F.E., crude protein and ether extracts.
The analysis of variance for t he dry matter content 
of fresh pastures showed significant differences among 
the treatments.
271
UNIVERSITY OF IBADAN LIBRARY
/
APPENDIX V
Microbiology of the rumen liquor
It is possible to count all the bacteria present in 
the liquor, or to count only the viable bacteria, or the 
numbers of the individual species present. In this experi­
ment all the bacteria present were counted.
Collection of Specimen for the Total Bacterial Count
The liquor was collected through a permanent fistula, 
using rubber tubing with special valves and connected to 
a thermos flask. Slight pressure was exerted using a 
metal syringe to draw out the liquor. The liquor was 
taken to the laboratory and 200 ml to 300 ml of it mixed 
in a blendor or a shaker with small quantity of surface 
active agent such as Tween 80. This prevent clumping and 
so encourages good separation of the organisms from the 
food particles. C02 was bubbled through the liquor and 
then filtered through muslin.
1 - 2 ml of the liquor was diluted with Cysteine 
hydrochloride and sodium carbonate and then strained with 
Resazyrin and Fuchsin, safranin or Gentian violet. The 
sample was pured into a tube and autoclaved. The sample
272
UNIVERSITY OF IBADAN LIBRARY
was cooled at 45® - 50°C and. then CO2 bubbled through to 
replace any oxygen present and to adjust the pH.
Counting the Bacteria
The diluted specimen was shaken and a portion of 
it dropped on the Neubauer Counting Chamber, preventing 
overflow of the fluid into the Channels. The cover slip
was placed on carefully avoiding air spaces. The chamber
O was left on the bench for 2-3 minutes to settle properly. 
The chamber was mounted and focussed on the microscope.
All the bacteria on the four corner squares and the centre 
of the central ruled area were counted. All the bacteria 
on the treble lines were also counted. For quick calcula­
tion it is enough to multiply the number of cells counted 
by 5 x 101.
Total Count of Protozoa
A portion of the fluid in the flask was diluted with 
Cysteine hydrochloride, sodium carbonate and then stained 
with Resazyrin. The solution was poured into a tube and 
autoclaved. It was then cooled to 45°C - 50°C. CO2 was 
bubbled through it to replace the oxygen present.
273
UNIVERSITY OF IBADAN LIBRARY
o
The specimen was diluted for easy counting and l-2ml 
of the diluted specimen was taken and 1-2 ml of Grams 
iodine were added to kill or immobilize the protozoa. The 
iodine solution will also stain the protozoa for easy 
recognition. It was mixed thoroughly and left for five 
minutes. It was shaken again and only 0.01ml of it was 
mounted for counting. Counting was started from the upper 
left corner of the cover slip. The counting was done 
horizontally until the right corner was reached. Counting 
continued until the bottom line of the cover slip was 
reached. The number of protozoa counted was multiplied 
by the dilution factors.
The sizes of the protozoa varied from 20 - 200 
and they had highly and specialized internal structures 
which were readily shown by the iodine stain.
274
UNIVERSITY OF IBADAN LIBRARY
APPENDIX VI
Analysis of variance for Dry Matter (D.M.) content
o£ treatments H, J , K and L cut at 4 weeks ' ' "
Source D.F. S.S. M.S. F. *0.05
Total 23 86.76
Replication 5 3.23 0.646 0.7 N.S. 2.90
Variety 3 69.86 23.29 25.51** 3.29
Error 15 13.70 0.913
Analysis of variance for Organic Matter (O.M.) 
content of' treatment's H, j', K and L cut at '4' weeks
** =•■ Significant at 1% level 
N.S. = Not significant
275
UNIVERSITY OF IBADAN LIBRARY
Analysis of variance for organic matter contents of
treatments H, J , K and L cut at 4 and 12 weeks
Source D.F. S.S* M.S. F.. F0.05
Total 7 31.34
Block 3 4.65 1.55 22.1** 9.28
Varieties 1 26.49 26.49 378.4** 10.13
Error 3 0.20 0.07
** = Significant at 5% level
N.S. = Not significant
276
UNIVERSITY OF IBADAN LIBRARY
treatments H, J, K and L cut at 4 and Weeks
Source D.F. S.S. M.S. F. F0.05
Total 7 14.62
Block 3 1.10 0.37 0.37 N.S. 9.28
Variety 1 10.48 10.48 10.48 N.S. 10.13
Error 3 3.04 1.01
Analysis of variance for crude protein levels
of treatments H, J, K and L cut at 4 and 12 weeks
Source D.F, S.S. M.S. F. F0.05
Total 7 9.25
Block 3 0.62 0.21 1 N.S. 9.28
Variety 1- 8.02 8.02 40.1** 10.13
Error 3 0.61 0.20
** = Significant at 5% letrel 
NiS. = Not significant
m
UNIVERSITY OF IBADAN LIBRARY
Analysis of variance for crude fibre (C.F.) content of
treatments H, J , K and L cut at 4 weeks
Source D.F. S.S. M.S. F., p0.05
Total 23 83.35
Block 5 13.32 2.66 1.06 N.S. 2.9
Variety 3 32.22 10.74 4.26* 3.29
Error 15 37.81 2.52
Aonfa ltyrseiast meonf tsv aHr,i anJc, e K foarn d cLrude protein (C.P.) contentcut at 4 weeks ..  ". ..
Source D.F. S.S. M.S. F. F0.05
Total 23 81.35
Block 5 3.20 0.64 0.18 N.S. 2.9
Variety 3 23.42 7.81 2.14 N.S. 3.29
Error 15 54.73 3.65
* = Significant at 5% level 
N.S. = Not significant
278
UNIVERSITY OF IBADAN LIBRARY
Analysis of variance for Nitrogen free extracts
4( Nw.eFe.kEs.) content of 'treatments H, j, K, and L cut at 
Source D.F. s . s . M.S, F. r0.05
Total 23 148.08
Block 5 53.20 10,64 1.7 N.S, 2.9
Variety 3 1,84 0.613 0.09 N.S, 3.29
Error 15 93.04 6,20
N.S. Not significant
279
UNIVERSITY OF IBADAN LIBRARY
APPENDIX VI
Chemical Composition o f Pasture treatments cut at 4  and 12
weeks < »f~growth. (Dry matter~%T
4  Weeks 12 Weeks
Ether Ether
Treatment D . M . O . M . Ash C . F . C . P . Extract Is Treatment D . M . O .  M . Ash C . F . C . P . Extract N .  F .  E .
H 9 2 .0 5 8 4 . X 7 .0 5 3 2 .9 4 10 .22 0 .8 7 4 f .92 H 9 2 .2 5 8 3 . X 8.01 3 1 .3 6 10.68 1.02 18.93
8 8 .8 4 8 0 .9 6 7 .8 8 37.81 11.15 1 .15 4: .01 8 8 .3 5 81 .6 7 6 . X 3 5 .4 3 10.90 1 .13 15.86
91.51 84 .8 0 6.71 3 5 .5 7 10.52 1 .13 4 .07 9 0 .4 5 84 .10 6 .7 2 36 .0 2 9 .9 2 1.08 46 .26
89 .90 8 2 .7 3 7 .1 8 37.01 8 .1 3 0 .9 3 4 ..75 8 9 .3 2 81 .90 7 .4 3 3 5 .3 7 10.29 1 .13 45.78
91.71 8 4 . X 7.71 3 3 .5 6 7 .3 9 1.10 5(1.24 8 8 . X X . 1 7 8 .1 7 3 3 .8 7 7 .7 5 1.11 4 8 .5 6
Mean 9 0 .9 3 83.31 7 .5 0 3 5 .33 9 .5 4 1 .05 4 :..58 Mean 8 9 .7 6 82 .25 7 .4 0 34 .5 2 9 .81 1.10 47.17
J 9 4 .2 8 83.21 10.09 31 .90 9 .51 1 .05 4 r.4 5 J 9 3 .1 5 82 .59 11.31 3 3 .93 9 .8 9 1.12 43.75
9 4 .2 5 8 4 .5 3 9 .7 2 2 9 .63 9 .2 8 1.08 50 .29 9 2 .8 9 X . 7 7 12.12 3 0 .95 9 .6 6 1.01 46 .2 6
9 3 .0 4 82 .28 10.03 3 3 .34 9 .1 7 1.11 4 6 .35 9 1 .7 6 81 .09 11.29 34 .58 7 .3 9 1.08 45 .63
92 .6 5 8 3 .4 2 9 .2 2 32 .90 9 .6 8 1.08 4 7 .1 2 9 3 . X X . 3 5 13.53 32 .19 7 .4 6 1.11 45.71
9 3 .1 2 8 1 .75 11.37 3 3 .43 8 .4 6 0 .9 9 4 5 .75 9 0 .5 3 81 .34 9 .1 9 33 .82 ll 95 1 .16 46.88
92 .8 5 8 2 .2 6 11.05 3 3 .72 7 .7 8 1 .07 4 6 . X 93.21 81 .2 7 1 1 .X 37 .16 I) .'} 1.14 4 2 .X
Mean 9 3 .3 7 82.91 10.25 32 .49 8 .9 8 1 .06 4 7 .2 2 Mean 9 2 .5 7 81 .25 11.44 33.77 8 ,6 0 1,10 45.09
UNIVERSITY OF IB -nA mDAN LIBRARY
0 ,  M . 0 .  M. EtherAsh C. F . EtherC P. Extracts N . F .  E . Treatment D. M. O . M . Ash C . C. P . Extract N .  F .  E
„  K VJ,| ! 14.10 9.11 34 .38 5 .2 8 1 .12 50.11 K 95.06 82 .95 12.11 31. 29 5 .4 2 1.05 5 0 .1 3
v 1 nil __ I4_j24 10.03 i34 .8 4 8 23 1.04 45 .86 95.01 8 3 .06 12.00 31. 70 7 .3 7 1 .02 47.91
n .a f j —83.26 10.28 32 .7 4 9 .8 2 1 .06 46.10 94 .86 83 .6 2 12.88 32. >0 8 .6 4 1 .09 4 4 .89
_ 9? ,97 64 .36 9 .80 33 .90 8 .48 1.10 46.72 94 .64 83 .20 11.83 32. 18 7 .8 6 1 .10 46 .8 3
93 ,89 83 .13 __10.76 32 .63 8 .8 5 1.13 46 .63 93 .84 81.81 11.99 32.: 20 7 .4 6 1 .03 4 7 .3 2
J92 .93 84.00 9 .7 7 33 .58 8 .8 2 1.11
Mean 46 .72 94.78
82 .99 12.04 30,; 50 6 .4 7 1 .10 49 .89
93 .28 83.85 9 .9 6 33 .68 8 .25 1 .09 47 .02 Mean 94 .70 8 2 .9 4 12.14 31.; 76 7 .20 1 .07 4 7 .8 3
__________
88 .94 80 .39________ 8 .5 5 3 2 .17 12.31 1.08 54 .44 L 89 .32 78 .95 10.37 29„^19 12.25  1 1.21 46 .6 8
9 0 .09 _ _81 .84 8 .2 0 33.41 9 .3 4 0 .8 8 4 8 .1 7 88 .89 77 .59 11.30 30.810 9 .8 6 1 .06 4 6 .9 8
,9 0 .4 9 81 .84 8 .6 5 35 .53 7 .0 2 0 .7 8 4 8 .0 2 8 9 .2 8 7 8 .3 6 10.92 3 2 .; 1 7 .8 5 0 .9 6 4 8 .0 6
J 9 .3 9 ____ __ 8 0 .72 1 0 .6 8 j 32 .10 11.25 0 .9 2 45 .0 5 8 8 .60 76.61 11.99 30.8 4 9 .6 3 0 .9 7 4 6 .57
,B9_.43___ 78.95 10.68 32 .10 11.25 1 .16 44.81 8 8 .6 6 7 6 .7 7 11.89 3 2 .C5 10.37 1 .13 4 4 .5 6
,67.44 _  76 .09 11.35 29 .84 14.49 1 .06 4 3 .2 6 8 9 .5 8 76 .6 9 12.89 30.256 9 .2 7 1.12 4 6 .0 6
8 9 .30 79 .97 9 .6 9 32 .53 10.94 0 .9 8 4 5 .8 6 Mean 8 9 .0 6 7 7 .5 0 11 .56 31 .C 1 9 .8 7 1.08 46 .48
-----------
Eoch f l , u r .  „  A .  msan o f
UNIVERSITY OF IBADAN LIBRARY
Analysis of variance for Dry Matter (D.M.) content
of fresh pastures H J ,  K t and L cut at 4 weeks
Source D.F. S.S. M.S . F. K0.05
Total 23 1881.56
Block 5 306.79 61.16 0.97 N.S. 2.9
Variety 3 632.90 210.97 3.36 N.S. 3.29
Error 15 941.87 62.79
i
N.S. = Not significant
UNIVERSITY OF IBADAN LIBRARY
APPENDIX VII
Rumen liquor Sampling
Rumen liquor was obtained by suction through a rubber 
tubing fitted with special valves. The pressure was 
applied by using a metal syringe fitted to one end of the 
rubber tubing. The perforated end of the rubber tubing 
was dipped into different parts of the rumen, and the 
rumen liquor brought up went down straight into a thermos 
flask fitted into another end of the rubber tubing. This 
devise was used to prevent loss of temperature. The liquor 
was carried in the stoppered falsk to the laboratory 
immediately for the various analyses.
Removal of protein and carbohydrate
The rumen liquor was strained through two layers of 
thin cloth to remove most of the food residues and 
bacteria and other materials. 5 ml of the strained 
liquor in duplicate was poured into a beaker or centri­
fuge tube, and an equal volume of normal sulphuric acid 
(N H2S04 ) saturated with magnesium sulphate (MgS04) was 
added to precipitate the carbohydrates and proteins pre­
sent in the fluid. The mixture was shaken gently and
UNIVERSITY OF IBADAN LIBRARY
o
allowed to stand for ten minutes (10 mins). It was then
centrifuged for ten minutes (10 mins) alt 2,500 r.p.m.
The supernatant was decanted and centrifuged again at
3.500 r.p.m. for ten minutes (10 mins.) to further remove 
the proteins and carbohydrates in the liquor. The very 
cloudy supernatants were filtered through Whatman No.4, 
or 41, or 541 filter paper before centrifuging at 3,500 
r.p.m. 3 ji.I. of the supernatant were injected into the 
column and the samples not needed immediately were kept 
in the refrigerator (below 0°C) until needed.
When the samples gave poor separations and poor base 
line, 25% ortho-phosphoric acid in 5N sulphuric acid was 
used. 1 ml per every 5ml of rumen liquor was added and 
left for 30 minutes before centrifuging only once at
1.500 r.p.m. for ten minutes.
Barium hydroxide Ba(0H)2^, zinc sulphate (ZnS04), 
sodium sulphate (Na2S04) may also be used to saturate the 
normal sulphuric acid and used to precipitate proteins 
and carbohydrates in rumen liquor.
282
UNIVERSITY OF IBADAN LIBRARY
Centrifuge
Any good centrifuge calibrated above 4,000 r.p.m. 
will serve the purpose. For this work a dual purpose MSE 
centrifuge calibrated from L,000 to 6,500 r.p.m. was used. 
There was an automatic timer to the centrifuge. The high 
centrifugal force applied was used to separate t he colloi­
dal particles in the liquor. Not all the colloidal 
particles will come down in the first centrifugation, but 
the remaining precipitate will come-down during the second 
centrifugation.
Chromatograph
One of the Pye Series 104 Chromatographs was used. 
Model 24 which is a dual flame ionisation detector 
programmed chromatograph was used. This model provides 
routine and research analytical facilities over a wide 
range of sensitivity. The analyser oven enables the 
coiled column to be held at t he controlled operating 
temperature of 125°C,
Calibration graphs for Argon, hydrogen and compressed 
air were prepared according to the instructions in the 
manual. The hydrogen flow rate was 31.6ml/min, Argon was
283
UNIVERSITY OF IBADAN LIBRARY
61.5ml/min. and compressed air was 923.1ml/min. The 
column was purged at t he end of each days run by passing 
through the column the carrier gas (Argon) overnight at 
125°C.
Preparation of standard V.F.A. solutions
Acetic Acid:-. 99.6% acetic was used. The weight per ml
is 1.048.
Molecular weight is 60.05 and equivalent weight is 60.05.
IN solution of 99.6% contains 60.05 = 57.3ml/litre
1.048
IN solution of 100% Acetic acid contains 100 x 37.3ml/litre
99.6
This comes to 57. ml/litre.
57,3ml/litre is equivalent to 60.05 gm
IM/litre = 60.05 ml/litre of 99.6% Acetic acid
IM/50 ml = 60.05 x 50 = 3.0025 ml 
1000
2M/50 ml of 100% acetic acid = 57.5 x 50 x 2 = 5.75ml
Propionic acid: 99% propionic acid was used. The weight 
per ml is 0.0003. Molecular weight is 74.08 and the 
equivalent weight is 74.08.
284
UNIVERSITY OF IBADAN LIBRARY
31 Normal Solution = 74*.6 ml/litre
0.993
100% Propionic acid = 100 x 74.6 = 75.4 ml/litre
W
IM/50ml = 3*77ml 
2M/50ml = 7.54ml
Iso-Butyric Acid:- 99% iso butyric acid was used
Wei^bt/ml = 0*947. Molecular weight = 88.11 and equiva­
lent weight = 88 ill.
IN solution = 88.11 = 93.04 ml/litre 
6.947
100% iso butyric acid = 100 x 93.04 = 93.98 ml/litre
99
1MO1/50 ml * 93.98 x 50 * 4.70 ml
im r
2M/50 ml = 9.40 ml
N-Butyric Acid:- 99.7% n-butyric acid was used*
Weight/ml = 0.957. Molecular weight = 88.11 and equiva­
lent weight = 88.11.
IN solution = 08787.1517 = 0.92 ml/litre
100% n-butyric acid = 100 x 92.07 = 93.0 ml/litre
9977
lMdl/50 ml = 93.0 x 50 = 4.65 ml 
1000
285
UNIVERSITY OF IBADAN LIBRARY
Fatty acid mixture:- Acetic, propionic and n-butyric 
acids were mixed in molar proportions of 2; 1: 1 respec­
tively. The volume was made up to 100 ml with distilled 
water. A known volume, 0,3 p.l., of this standard fatty 
acid mixture was injected into the coiled column using 
PEG 20M as the packing material. The working temperature 
was 125°C and Argon was the carrier gas. Nine runs of 
this standard solution were made and the estimated standard 
error, and recovery were calculated. Acetic acid had a 
recovery rate of 98.77%, propionic acid had a recovery of 
98.13%, 97.99% for n-Butyric acid and 106,91% for n-Valeric 
acid. The iso acids were only present in trace amounts 
and were disregarded in this present work. The total 
V.F.A. in the samples were determined by steam distilation.
286
UNIVERSITY OF IBAD
N LIBRARY
APPENDIX VII
Analysis of variance for pH levels of treatments
H, J. K and L cut at 4 weeks
Source D.F. S.S. M.S. F. f 0.05
Total 7 0.68
Block 1. 0 0 0 N.S . 6.61
Variety 1 0.65 0.65 108***- 6.61
Error 5 0.03 0.006
Analysis of variance for total V.F.A. production 
of H, J, K and L cut at 4 weeks
Source D.F. S.S. M.S. F. F0.05
Total 7 79.90
Block 1. 0.37 0.37 7.40* 6.61
Variety 1 79.42 72.42 158.*8** 6.61
Error 5 0.11 0.05
* Significant at 5% level 
* *  it ii 1 %  ti;
*** ” it 0.1% »'
N.S. — Not Significant
287
UNIVERSITY OF IBADAN LIBRARY
Analysis of variance for Acetic acid production
of H, J , K and L cut at 4 weeks
Source D.F. S.S. M.S. F, F0.05
Total 7 16.47
Block 1 0.03 0,03 0,01 N.s . 6.61
Variety 1 5,25 5,25 2.34 N.s . 6.61
5 11,19 2,24
Aonf a'ltyrseiatsm eontf' sv'a Hr,i aJn,c eK  foarn d PLr opcuito niatc  waeceikds production 
Source D.F. S.S. M.S. F. F0.05
Total 7 10.90
Block 1. 2.52 2.52 3 v04’̂ I*S. 6.61
Variety 1 4.21 4.21 5.07 N.S 6.61
Error 5 4.17 0.83
N.S. = Not significant
288
UNIVERSITY OF IBADAN LIBRARY
Analysis of variance for Butyric acid production 
of treatments H, J, K and L cut at 4 weeks
Source D.F. S.S. M.S. F. F0.5
Total 7 12.33
Block 1 3.12 3.12 3.15 N.S. 6.61
Variety 1 4.32 4.32 4.36 N.S. 6.61
Error 5 4.89 0.99 •
Analysis of variance for pH levels of Treatments 
H,J, K and L cut at 12 weeks
Source D.F. S.S. M.S. F. f0.05
Total 7 1.56
Block 1 0.19 0.19 3.0 N.S. 6.61
Variety 1 1.06 1.06 17.6* 6.61
Error 5 0.31 0.06
* = Significant at 5% level 
N.S.— Not significant
289
UNIVERSITY OF IBADAN LIBRARY
o
Analysis of variance for total V.F.A. production
of treatments H, J, K and L cut at' 12 weeks'
Source D.F. S.S. M.S. F. **0.05
Total 7 55.08
Block 1 0.90 0.90 7.5* 6.61
Variety 1 53.46 53.46 445.5***: 6.61
Error 5 0.72 0.12
Analysis of variance for Acetic acid production 
of H, J, K and L cut at 12 weeks
Source D.F. S.S. M.S. F. f0.05
Total 7 35.62
Block L 3.02 3,02 0.6 N.S. 6.61
Variety 1 9.55 9.55 2.07 N.S. 6.61
Error 5 23.05 4.61
***•  ==  Sign•i* ficant aHt  5%  le\% »v>el
*** = » *» 0.1% n
N.S. = Not significant
290
UNIVERSITY OF IBADAN LIBRARY
Analysis of variance for Propionic acid production
of treatments H, J, k and L cut at 12 weeks
Source D.F. S.S. M.S. F. *0.05
Total 7 20.22
Block 1 1.75 1.75 3.65 N.S. 6.61
Variety 1 15.94 15.94 33.2** 6.61
Error 5 2.42 0.48
Analysis of variance for Butyric acid production 
of treatments H, J, K and L cut at 12 weeks
Source D.F. S.S. M.S. F. * 0.05
Total 7 42.01.
Block 1 0.17 0.17 0.06 N.S. 6.61
Variety 1 28.21 28.21 10.37* * 6.61
Error 5 13.63 2.72
* = Significant at 5% level
* *  =  » t  » »  i %  II:
N.S. = Not significant
291
UNIVERSITY OF IBADAN LIBRARY
Analysis of variance for total V.F.A. production
from treatments J and L cut at 4 weeks
Source D.F. S.S. M.S. F. F0.05
Total 9 74.14
Block 4 6.18 1.54 2.41N.S. 6.39
Variety 1 65.38 65.38 102.16* 7.71
Error 4 2.58 0.64
Analysis of variance for total V.F.A. production
Source D.F. S.S. M.S. F. F0.05
Total 9 111.24
Block 4. 5.87 1.47 7.74 N.S. 6.39
Variety 1 104.59 104.59 5.50 N.S. 7.71.
Error 4 0.78 0.19
* = Significant at 5% level 
N.S. = Not significant
292
UNIVERSITY OF IBADAN LIBRARY
Analysis of variance for Acetic acid production
from treatments J and L cut at 12 weeks
fS j ou-ui rce1 ' D.F. S.S. M.S. F. F0.05'
Total 9 11.15
Block 4 8.06 2.01 2.76 N.S. 6.39
Treatment 1 0.19 0.19 0.22 N.S. 7.71
Error 4. 2.90 0.72
Analysis of variance for Butyric acid production 
from treatment J and L cut at 12 weeks
Source D.F. S.S. M.S. F. F0,05
Total 9 28.73
Block 4 11.40 2.85 0.9 N.S. 6.39
Treatment 1 5.68 5.68 1.95 N.S. 7.71
Error 4 11.65 2.91 <
N.S. Not significant
293
UNIVERSITY OF IBADAN LIBRARY
Analysis of variance for propionic acid production
from Treatments J and""L "cut at 12 weeks
Analysis of variance for Acetic acid production 
from treatments J and L cut at 4 weeks
Source D.F. S.S. M.S. F. r 0.05
Total 9 81.51
Block 4 34.08 8.52 0.7 N.S. 6.39
Treatment 1 4.54 4.54 0.3 N.S. 7.71
Error 4 42.89 10.72
N.S. w Not significant
294
UNIVERSITY OF IBADAN LIBRARY
Analysis of variance for butyric acid production
from treatments J and L cut at ’4 weeks
Analysis of variance for Propionic acid production 
from treatments J and L cut at 4 weeks
Source D.F, S.S. M.S. F. *0.05
Total 9 27.66
Block 4 10.76 2.7 2.3 N.S. 6.39
Variety 1 2.14 1.14 1.8 N.S. 7.71
Error 4 4.76 1.19
N.S. = Not significant
295
UNIVERSITY OF IBADAN LIBRARY
APPENDIX VII
Analysis of variance for the pH leve of rumen liquor 
produced by animals fed treatments H, J, K and L cut at 
4 and 8 weeks
Source D.F * S.S. M.S. F. F0.05
Total 7 2.19
Block 1 1.83 1.83 18.30* 10.13
Variety 3 0.07 0.02 0.20 N.S. 9.12
Error 3 0.29 0.10
Analysis of variance for the pH level of rumen liquor
K t  r  a  n  i  m- a  1 c  - f - I  +• r  a  a  + r n A  n  +  c  T  T r > u +  a  4*
4, 8, and 12 weeks 
Source D.F. S.S. M.S. F. F0.05
Total 8 2.21
Block 2 1.76 0.88 9.78* 6.94
Variety 2 0.07 0.03 0.03 N.S. 6.96
Error 4 0.38 0.09
* = Significant at 5% level
N.S. = Not significant
296
UNIVERSITY OF IBADAN LIBRARY
Analysis of variance for the total V.F.A. of rumen
liquor produced by animals ied treatments'" J, K, and
L cut at 4, 8 and 12 weeks
Analysis of variance for the total V.F.A. of rumen
liquor produced by animals fed treatments H, J, K and 
L at 4 and 8 weeks.
Source D.F. s . s . M.S. F. F0.05
Total 7 29.22
Block 1 6.55 6.55 1.37 N.S. 10.13
Variety 3 8.38 2.79 0.58 N.S. 9.12
Error 3 14.29 4.76
N.S. = Not significant
297
U
IVERSITY OF IBADAN LIBRARY
Analysis of variance for the Acetic acid content of rumen
liquor produced by animals fed J, K and L cut at 4, 8 and 
12 weeks
Source D.F. S.S. M.S. F. 0.05
Total 8 17.97
Block 2 2.87 1.44 4.00 N.S. 6.94
Variety 2 13.64 6.82 18.44** 6.94
Error 4 1.46 0.36
Analysis of variance for Acetic acid content of 
rumen liquor produced by animals Ĵ ed H, J, K ari5 
L cut a t 4 and £ weeks
Source D.F. S.S. M.S. F. F 0 .0 5
Total 7 135.96
Block 1 34.49 34.49 2 . 6 2 . N .S . 10.13
Variety 3 48 .86 19.29 1 . 4 7 . N .S . 9 .12
Error 4 52.61 13.15
** = Significant at 1% level
N.S. = Not significant
298
UNIVERSITY OF IBADAN LIBRARY
Analysis of variance for the Propionic acid of rumen
liquor produced from treatments" H, J, K and L at 4 and
8 weeks
Source D.F. S.S. M.S. F. *0.05
Total 7 45.96
Block 1 34.86 34.86 16.14* 10.13
Variety 3 4.63 1.54 0.71 N.S. 9.12
Error 3 6.47 2.16
Analysis of variance for Propionic acid of rumen liquor 
produced from treatments J, K and L cut at 4, 8 and
12 weeks
Source D.F. S.S. M.S. F. * 0.05
Total 8 46.13
Block 2 32.27 16.14 4.91 N.S. 6.94
Variety 2 0.68 0.34 0.01 N.S. 6.94
Error 4 13.18 3.29
* = Significant at 5% level
N.S. = Not significant
299
UNIVERSITY OF IBADAN LIBRARY
Analysis of variance for Butyric acid Produced by
animals fed treatments h ) J,"'*K'"and"L cut at 4 and
8 weeks
Source D.F. S.S. M.S. F. F0.05
Total 7 68.99
Block 1 0.00 0.00 0 N.S 10.13
Variety 3 34.44 11.48 0.99 N.S. 9.12
Error 3 34.55 11.52
Analysis of variance for Butyric acid produced by animals
fed treatments J, K and L cut at 4, 8 and 12 weeks
Source D.F. S.S. M.S. F. F0.05
Total 8 47.18
Block 2 3.54 1,51 0.02 N.S. 6.94
Variety 2 19.79 9.89 1.24 N.S. 6.94
Error 4 23.85 7.95
N.S. = Not significant.
300
UNIVERSITY OF IBADAN LIBRARY
APPENDIX VIII
Milk Fat:
The milk fat was determined according to the Gerber 
method which was chosen because it is a quick and accurate 
method.
Reagents used:
h2S04 (for milk testing) S.P. 1.815g. per ml. at 20°C. 
This acid must be colourless. Amyl Alcohol.
Apparatus;
Standard butyrometer 
Standard rubber stopper
Standard pipette to deliver 10.94 ml of milk 
Standard pipette to deliver 10 ml H2S0^
Shaking stand for the butyrometers 
Centrifuge specially made for milk testing 
This centrifuge should go up to 1,100 r.p.m. and the 
diameter is between 18" - 20",
The centrifuge has a timer and heat regulating 
devise which keeps the temperature at 70°C.
301
UNIVERSITY OF IBADAN LIBRARY
Water bath for the butyrometers The water bath has a
standard stand to hold the butyrometers. The tempera 
ture can go as far as 100°C. The water bath has an 
automatic thermometer built in it. This gives the 
temperature as the water is heated.
10 ml H2SO4 specially made for milk testing was 
poured into the Gerber butyrometer from an automatic 
Gerber dispenser. 10,94 ml of warm (30°C) well mixed 
milk was pipetted from a standard pipette into the butyro­
meter. 1 ml amyl alcohol was then added. The butyrometer 
neck was closed with a special stopper and the samples 
were shaken in a protected stand until no white particles 
were seen. The butyrometers containing the samples were 
centrifuged at 1,100 r.p.m, at 70°C for four minutes.- 
They were removed and placed in the water bath maintained 
at 65°C for three minutes. The fat content was read from 
the graduated neck of each butyrometer. The fat content 
is a percentage by weight.
A special key was used for the Cerber butyrometer. 
This was used to push the sample up the tube whenever the 
solution fell below the graduated neck.
302
UNIVERSITY OF IBADAN LIBRARY
Milk Analysis:
There are three methods for milk fat analysis. These 
are the
a. Rose-Gottlieb method which is the determination of 
milk fat by weight.
b. The Gerber method which is good for routine labora­
tory analysis. It is also a quick method. It 
miis naat iroanp.id commercial method for milk fat deter­
c. The Babcock method is another rapid commercial method.
It is a specific method.
Milk Lactose;
This can be determined:
a. By d+ if%f eArsehn)c.e. 100 - (% water, + %. protein, + % fat
b. . By using a lactometer. Lactose will rotate the
plane of polarized light, so it can be determined 
using a polarimeter.
c. . By the Chloramine - T method of Hinton and Macara.
d. . By the reduction of Fehling*s solution.
e. Colorimetrically.
Water content:
This was determined by drying a known weight of 
homogenised milk at 65°C for 24 hours. The difference in 
weight is the water content.
303
UNIVERSITY OF IBADAN LIBRARY
Dry Matter:
The weight of the residue left in the dish after 
drying is the dry matter of t he milk.
Milk Ash:
The dish containing the residue after drying is 
ashed in a muffled furnace at 500°C for 2 hours. The 
difference between the weights before and after ashing is 
the weight of the ash.
Milk Protein:
The total milk protein content is determined by the 
Kjeldahl method. The nitrogen content is multiplied by 
6.38 to give the protein content in milk.
Lactose:
The lactose content of milk was determined colori- 
metrically. Phenol was used as the colouring agent. This 
method needs only a small volume and it is quick. The 
method of Barnett and Tawab (1957) was adopted.
Procedure:
The milk was warmed and well mixed. 0.1 ml of this 
well mixed sample was pipetted using a micro pipette, into 
a 5 ml volumetric flask. This was made up to the mark
304
UNIVERSITY OF IBADAN LIBRARY
with distilled water. 0.5 ml of this solution was pipetted 
into another 5 ml volumetric flask, and made up to the 
mark with distilled water. 0.25 ml of the last solution 
was taken and poured into a 20 ml volumetric flask. 0.5ml 
of 80% phenol (A.R.) plus 6 ml concentrated H2SO4 (A.R.) 
were added respectively. The flask was left for ten 
minutes to allow the reaction to end and the solution to 
develop the colour fully. The flask was cooled to room 
temperature and the optical density read at 490 :pM from 
an SP 500. Duplicate samples of each milk sample were 
determined.
Blank solution was prepared using distilled water 
instead of milk sample.
Standard curve was prepared by plotting the optical 
density against the different standard lactose solutions 
(concentrations) used.
Calculation 
Reading (mg)
from standard x Y1C0O0'C f x 200 =* gra lactose % 
curve
305
UNIVERSITY OF IBADAN LIBRARY
Preparation of Reagents;
1 gm lactose was weighed, dissolved in distilled 
water and poured into a 100 ml volumetric flask. More 
distilled water was added and made to the mark. The solu­
tion was kept in the refrigerator until needed.
80% Phenol:
80 gm phenol crystals were weighed into a 100 ml 
volumetric flask. Warm distilled water was added to reach 
the mark. The phenol solution was stored in the refrigera­
tor until needed.
Sulphric Acid;
Analar grade of sulphric acid was used. Ordinary 
grades are good too, but their use will involve the prepa­
ration of new standard curves each time the stock solution 
finishes.
306
UNIVERSITY OF IBADAN LIBRARY
APPENDIX IX
Urea and Ammonia determinations 
Reagents;
Aqueous sodium hypochlorite
Ammonium sulphate, Urea, and Mercuric iodide
O.IN sodium thiosulphate 
Sulphuric Acid 
Starch solution
Potassium iodate solution, Potassium iodide solution 
Urease tablets to prepare lgm/litre or 1 mg/ml.
Ethylene diaminetetra acetic acid (EDTA) 1% solution
Sodium nitropruside
Phenol, and Chloroform
Sodium hydroxide
Glacial Acetic Acid.
Preparation of solutions 
Aqueous sodium hypochlorite. 1*74N
32gm NaOH(A.R.) were dissolved in 15ml distilled water. 
It was cooled to room termperature and 150gm crushed ice 
were added. The container was immersed in ice blocks
307
UNIVERSITY OF IBADAN LIBRARY
plus crushed ice and a rapid stream of chlorine gas, 
generated from a ĵ ipp 's apparatus containing KMr»04 into 
which concentrated hydrochloric acid was poured, was 
passed into it. This was continued until the total weight 
increased by 21 - 24 gms. Under this condition about 4gm 
of the alkali remained unchanged and the final solution 
was 1.74N. or approximately 2N. The excess alkali present 
will suppress hydrolysis which would have given rise to 
hypochlorous acid.
0.1N Sodium thiosulphate solution:- Na2S203:-
Weigh 6.25gm sodium thiosulphate H2O (A.R.). Dissolve
in deionised or carbon dioxide free water. Transfer to
250 ml standard flask. Add 0.025gm sodium carbonate or
0.0025 gm mercuric iodide or 1 drop of chloroform and make
up to the mark with carbon dioxide free water,
Standadization of Sodium thiosulphate solution with 
potassium iodate : ;
0.IN K103 Solution:- Dry KIO3 at 100 - 120°C and weigh
0.8918 gm dry KIO3. Dissolve in carbon dioxide free water
and transfer to 250 ml volumetric flask. Make up to the
mark. Pipette out 25ml 0.1N KIO3 solution into a 25ml
conical flask, and 10 ml 10% iodate free KI solution and
308
UNIVERSITY OF IBADAN LIBRARY
3ml 2N H2SO4 solution. Titrate the liberated iodine with 
thiosulphate solution with constant stirring. When the 
colour of the liquid is pale yellow, dilute to 200 ml with 
distilled water, add 2 ml of starch solution, and continue 
to titrate until the colour changes from blue to colour­
less. Repeat three times and find the mean.
lml N Na2S203 = 0.03567g KIO3 
.*.lml 0. IN Na2S203 = 0.003567g K103
Starch solution;
Weith lgm starch and make to a paste with a little 
water. Pour with constant stirring into 70ml boiling 
water and boil for 1 minute. Transfer to 100ml flask and 
cool. Add 0.005gm mercuric iodide or 2-3gm KI. 
Standadization of sodium Hypochlorite solution
Pipette out 5ml of the sodium hypochlorite solution 
into 100 ml flask, add some distilled water, shake well 
and make up to the mark. Pipette 25ml of this solution 
into a 250 ml conical flask, add 25ml distilled water, 
followed by 20ml 10% KI solution and 10ml glacial acetic 
acid. Titrate the liberated iodine with standard 0.1N 
sodium thiosulphate solution. Add 2ml starch solution
309
UNIVERSITY OF IBADAN LIBRARY
when the colour is pale yellow, continue to titrate 
until the blue colour disappears. Repeat two times and 
find the mean.
lml N Na2S2C>3 - 0.03546 gm ^
.. lml 0.IN Na2S203 = 0.003546 gm Cl2 
Buffered urease solution
Dissolve 150mg (1 tablet) urease in 100ml of a 10% 
solution of ethylene diaminetetra acetic acid (SDTA). 
Adjust the pH to 6.5. This will keep for one month if 
kept in the refrigerator.
Phenol-sodium nitropruside solution;
Weigh 50gm phenol and 0.25gm sodium nitropruside 
into a beaker. Dissolve in distilled water and pour 
into a litre volumetric flask. Make to the mark. Pour 
into a brown bottle to avoid direct light and keep in the 
dark or in the frigidaire. Take 1 ml of this and dilute 
to 5ml for use.
Sodium hydroxide-sodium phypochlorite solution;
Dissolve 25gm sodium hydroxide plus 2.1gm sodium 
hypochlorite in water. Pour into 1 litre volumetric flask 
and make to the mark. Pour into a brown bottle to protect
310
UNIVERSITY OF IBADAN LIBRARY
it from direct light. Take 1 ml and dilute to 5 ml for 
use. Keep the solution in the refrigerator.
Urea standard solution:
Weigh 1 gm urea and dissolve in 100ml distilled water. 
THis lgm/litre solution gives lmg/ml.
Standard Ammonium sulphate solution:
Weigh 4.7gm ammonium sulphate (A.R.) and dissolve 
in distilled water. Pour into 1 litre volumetric flask 
and make up to the mark with distilled water. This gives 
1 gm ammonium nitrogen per litre or lmg/ml.
Determination of Ammonia in rumen liquor 
Procedure:
The rumen liquor was strained through two layers of 
cloth. 1 ml of this was poured into a 10ml volumetric 
flask or graduated test tube, and made to the mark with 
distilled water. 0.1ml of this solution was taken up in 
a pipette and poured into 50ml standard flask in duplicate. 
5m1 of dilute phenol-sodium ni tropruside solution and 5ml 
dilute sodium hydroxide-sodium hypochlorite solution were 
added respectively, and the volume was made up to 50ml.
The blank was prepared using distilled water instead of
313L
UNIVERSITY OF IBADAN LIBRARY
the rumen in water. Pour into 1 litre volumetric flask 
and make to the mark. Pour into a brown bottle to protect 
it from direct light. Take 1 ml and dilute to 5 ml for 
use. Keep the solution in the refrigerator.
Urea standard solution:
Weigh 1 gm urea and dissolve in 100ml distilled, 
water. This lgm/litre solution gives lmg/ml.
Standard Ammonium sulphate solution:
Weigh 4.7gm ammonium sulphate (A.R.) and dissolve 
in distilled water. Pour into 1 litre volumetric flask 
and make up to the mark with distilled water. This gives 
1 gm ammonium nitrogen per litre or lmg/ml.
Determination of Ammonia in rumen liquor 
Procedure;
The rumen liquor was strained through two layers of 
cloth. 1 ml of this was poured into a 10ml volumetric 
flask or graduated test tube, and made to the mark with 
distilled water. 0.1ml of this solution was taken up in 
a pipette and poured into 50ml standard flask in duplicate. 
5ml of dilute phenol-sodium nitropruside solution and 
5ml dilute sodium hydroxide-sodium hypochlorite solution
312
UNIVERSITY OF IBADAN LIBRARY
were added respectively, and the volume was made up to 
50ml. The blank was prepared using distilled water instead 
of the rumen liquor. The flasks were left for 30 minutes 
for maximum colour development. On some occasions the 
flasks were warmed in a water bath at 37°C for 5 minutes. 
The blue colour that developed was stable for twenty four 
hours. The optical density of each sample in duplicate 
was read from an SP 500 colorimeter at 625 m.y.
A standard curve was prepared using ammonium sulphate 
(A.R.).
Calculation:
mg NH3-N % = Reading of sample x 100 x dilution factor 
Reading of standard
Determination of blood urea
Procedure:
Blood samples from the Jugular vein of the Zebu 
animals were kept in stoppered bottles and left for 24 
hours in a cold room. During this time the blood plasma 
seperated out from the blood cells and other substances 
in the blood. The blood was poured into centrifuge tube 
and centrifuged. The serum was decanted into a clean
313
UNIVERSITY OF IBADAN LIBRARY
bottle. 1ml of each blood sample was diluted to 100ml.
1ml of this dilute blood solution was poured into 50ml 
standard flask and 2ml buffered urease solution was added. 
The flasks with their contents were warmed in a water bath 
at 37°C for 5 minutes. Then 5ml dilute phenol-sodium 
nitropruside plus 5ml dilute sodium hydroxide-sodium 
hypochlorite were added respectively. The flasks were 
left at room temperature for 30 minutes for maximum blue 
colour development and the optical density read on an SP 
500 colorimeter at 625 m.p.
Blank solution was prepared using distilled water 
instead of blood.
A standard curve was prepared using urea.
Calculation:
mg Urea-N% , = Reading of sample x 100 x dilution
in blood Reading of standard factor
314
UNIVERSITY OF IBADAN LIBRARY
APPENDIX X
MIn Vitro*1 Digestibility Experiments 
Boiling tubes
Large Pyrex boiling tubes, 20cm x 3cm were used for 
the experiment. This was to give enough room for shaking. 
Each tube was stoppered with a rubber bung through which 
passed a 6mm glass tubing with 1mm internal diameter bore. 
This tube was connected to another 6mm glass rod by rubber 
tubing. A small hole of about 4mn was cut vertically in 
the rubber tubing to release the gases produced during 
the anaerobic fermentation.
Artificial Saliva (buffer) solution
A large amount of buffer solution, 40ml was used.
This was to maintain the pH level of the samples within 
the limits usual for rumen digestion. This was to make 
sure the acid concentration did not exceed that found 
in the animal.
The buffer solution was made according to the formula 
proposed by McDougall. CaCl2 was added last. The solution 
was warmed to dissolve some of the insoluble chemicals.
C02was passed through the solution at 39°C until it was 
saturated. A clear solution was obtained.
315
UNIVERSITY OF IBADAN LIBRARY
Composition of the buffer solution
NaHC03 9.8 gm per litre
Na2HP04 12H20 9.3 gm IT II
NaCl 0.47 gm If II
KCL 0.57 gm II II
CaCl2 (anhydrous) 0.04 gm IT II
MgCl2 (anhydrous) or 0.06 gm II II
MgCl2 . 6H20 0.13 gm tl II
Casing
It has been found preferable by many workers to 
digest in glass tubes and to rely on the gas produced to 
maintain anaerobic conditions. But in this experiment 
the tubes were opened every 24 hours and CO2 passed 
over the sample to make sure that all.oxygen (O2 ) was 
removed*
Nitrogen supplementation
Alexander (1964) observed that unsupplemented rumen 
liquor gave variable digestibility coefficients. The 
digestibilty of the ration is affected by the level of 
crude protein in the ration. To reduce or remove this 
dietary effect, (NH4)2S04 was used by Alexander. This
316.
UNIVERSITY OF IBADAN LIBRARY
procedure is adopted in this experiment. 1 ml (NH^^oSC^
was added to 50 ml buffer liquor mixture-.
Pepsin solution
Aqueous pepsin solution was used (O.12 gm per 5 ml 
distilled water). Fresh samples were prepared for each 
experiment. The solution was kept in the refrigerator 
until needed. The pepsin powder was also stored in a 
cold room. The pepsin may be dissolved in normal HCl, 
but the former method is better and quicker. The pepsin 
used was of the order 1:2,500.
EL Meter
A Pye Ingold pH meter was used. A combined electrode 
was prefered to the separate electrodes. The combined 
electrode facilitated easy access to the solutions in the 
tubes while sitting in the water bath at 39°C. The meter 
was set with a buffer of PH4 and another buffer of PH7 .
The buffer solutions were cooled in the refrigerator for 
a few minutes before use, and the temperature noted 
before using them to set the meter. The meter was then 
set at 39°C.
317
UNIVERSITY OF IBADAN LIBRARY
Water bath
Incubation can be done using an incubator or a water 
bath. A water bath was used for this experiment because 
the pH of the solution in each test tube can be read and 
adjusted while the tube is in the water bath. The samples 
are to remain at 39°C throughout the experiment. To avoid 
cooling a water bath was used* If an incubator is used, 
it will be necessary to take out the tubes for pH reading, 
and also for the addition of reagents. The temperature 
of the water was kept constant at 39°C by the continuous 
stirring of a stirrer. The water bath used was the immer­
sion heater type and it was manufactured by Astell 
Laboratory Service Company of London.
Filter aid and Filter Paper
In order to avoid loss of the residue during Altera­
tion, a filter aid was used. The commonly used aid is the 
hyflo supercel. Instead of this very fine Celite was 
used. Celite is ashless and inert so that it has no 
effect on the result. It can be recovered and used over 
again. Filteration at the end of the pepsin digestion 
is difficult if no filter aid is used.
318
UNIVERSITY OF IBADAN LIBRARY
APPENDIX XI
Recovery of Chromic Oxide from faeces
The recovery of chromic oxide from faeces organic 
matter for the digestibility trials is given in table 
below.
Percent recovery of chromic oxide from faeces organic 
matter of Zebu cattle
Treatment 4 weeks treatment 12 weeks treatment
H 100.66 + 7.29 97.83 + 4.7
92.20 ±+ 77..229
99.01 +
96.25 9 97.16 + 4
4..77
101.18 ++ 7.29 103.22 +Mean 97.57 7.29 99.31 +
4.7
7.7
J 100.21 ± 4.02 96.92 2.88
9964..7626 ± 44..0022
±
100.27 + 2.88
i 100.21 ± 2.88
97.95 ± 4.02 98.02 + 2.88
Mean 97.63 ± 4.02 98.83 ± 2.88
K 100.49 + 4.34
99.22 T 99.66
+ 0.02
+ 4.34 99.58 +96.82 4.34 0.02
102.82 + 4.34
Mean 99.84 T 4.34 99.31 + 0.02
L 95.99 ++ 2.062.06 99.70
+
94.89 0.72■+ 95.68 T94.65 0.72
97.25 -b
2.06
2.06
Mean 95.69 + 2.06 94.09 4* 0.72
319
UNIVERSITY OF IBADAN LIBRARY
APPENDIX XI
Digestibility Coefficients of four treatments cut at 
4 weeks by White Fulani Yzebu'V cattle. ......
C%)
Zebu
AnimaH Treatment D.M. O.M. C.F. C.P. E.E. N.F.E. TotalNo Ash
49 H 71.1 70.7 75.9 80.8 33.3 66.7 63.4
198 73.8 73.3 78.3 83.4» 33.3 68.5 70.1
49 52.1 51.2 61.5 57.1 18.2 45.7 50.0
198 47.5 46.5 55.7 56.0 0.0 40.0 47.6
Mean 61.1 60.4 67.9 69.3 21.2 55.2 57.8
49 J 54.7 56.5 55.1 54.4 29.4 56.2 48.0
198 53.9 58.9 54.5 60.5 11.8 57.2 35.0
49 55.8 58.6 57.6 55.7 37.5 57.9 40.7
198 55.4 58.2 60.6 56.2 6.3 56.0 38.3
Mean 55.0 58.1 57.0 56.7 21.3 56.8 40.5
49 K 52.0 54.3 58.3 43.2 33.3 52.1 39.6
198 56.8 59.4 66.2 52.5 28.6 55.4 38.4
49 31.7 36.7 35.7 34.6 -20.0 32.7 17.6
198 33.7 39.5 48.0 38.8 0.0 28.6 1 1 . 1
Mean 43.6 47.5 52.1 42.3 10.5 42.2 26.7
49 L 52.5 59.9 60.3 54.2 -22.2 62.5 -4.7
198 53.1 56.3 61.8 55.8 -25.0 55.5 23.7
49 51.9 54.5 55.6 65.1 1 1 . 1 50.8 35.1
198 48.9 50.1 52.7 59.1 0.0 47.2 38.5
Mean 51.6 55.2 57.6 58.6 -9.0 54.0 23.2
320
UNIVERSITY OF IBADAN LIBRARY
APPENDIX XI
Dl2i gweesetkisb ilbiyt yW hiCtoee e"fFiucliaenni ts( Zeobfu )f oucra tttlree.atments cut at 
(%1
Zebu
Animal Tmernetat­ D.M. O.M. C.F.No C.P. E.E. N.F.E.
Total
Ash
114 H 53.3 54.1 62.7 62.7 0.0 46.0 31.0
194 56.7 56.4 63.9 68.1 64.7 52.7 45.5
114 55.0 54.2 60.5 62.2 9.1 53.1 38.4
194 56.1 56.1 64.2 58.7 60.0 52.6 35.0
Mean 55.3 55.2 62.8 62.9 33.5 51.1 37.5
194 \J 37.6 40.0 47.3 40.0 -14.3 35.1 23.9
114 60.2 64.3 68.1 51.2 26.7 63.3 65.8
194 47.8 52.4 57.3 46.3 0.0 46.3 32.0
114 58.2 57.3 66.2 54.2 41.2 58.0 39.4
Mean 51.0 53.5 59.7 47.9 13.4 50.7 40.3
194 K 45.8 50.1 53.6 36.8 27.3 45.8 33.1
194 46.4 49.7 54.0 41.7 41.7 42.0 42.8
Mean 46.1 49.9 53.8 39.3 34.5 43.9 38.0
194 L 57.0 57.1 58.1 61.2 27.3 57.6 50.5
194 58.8 59.2 59.3 61.2 27.3 60.0 54.5
Mean 57.9 58.2 58.7 61.2 27.3 58.8 52.5
321
UNIVERSITY OF IBADAN LIBRARY
APPENDIX XI
Faecal Chromic Oxide Determination 
Regagents:
1. Potassium Brornate , ( KBrO^):- 4.5 w/v solution.
2. Manganese sulphate, 10% solution.
3. Ortho Phosphoric acid,(H3PO4) 85% w/v solution
Mix 30ml 10% MnSO,̂ ,. 4H2O solution with 1 litre 
analar 85% H3PO4 solution.
4. Sulphoric acid, (H2SO4), 50% solution. (A.R*)i
Mix 5 ml of 10% MnSO^. 4H2O solution with 1 litr 
of 50% H2SO4.
5. Clearing solution:- Weigh 125 gm. (MH4 )2 1SO4 (A.R. )
pour into yOml HC1 (A.R.) and make to 1 litre.
6. Ferrous ethylene di ammonium sulphate N/20 solution
Weith 100 gm of ferrous ethylene di ammonium 
sulphate. Make it up to 5 litres with 5% H2SO4 .
7. H2S04 , 5% solution. A.R.
8. Ferroin, 0.025M (Vegel):- Dissolve 1.485 gm.
O-phenanthroline monohydrate in 100 ml 0.025M 
FeSO^. 7H2O solution.
322
UNIVERSITY OF IBADAN LIBRARY
9. Ferrous sulphate, (FeS04. 7H2O) solution-. 0.025M:-
Weigh 0.695 gm. FeS04. 7H20 and dissolve it in 100 ml 
distilled water.
10. Potassium dichromate, (^C^Oy) N/20 solution
Dry A.R. K2Cr20?, at 140°C to 150°C for 1 hour.
Cool, Weigh 2.452 gm. of it and make up to 1
litre with distilled water.
Standardization of Ferrous ethylene di ammonium 
sulphate solution
To 25 ml N/20 I^C^Oy solution add 100 ml distilled
water. Also add 6 ml A.R. O-H3PO4 , plus 5 ml A.R. H2SO4
plus  drops of ferrouse/t/h dyil2  enaemmonium sulphate FeC2H4(NH3 )2 
solution to the reddish brown end point. 1 ml N/20 Ferrous 
ethylene di ammonium sulphate = 1.266 mg 0 :303.
Method*
Weigh 2 gm dried milled faeces into silica dishes in 
duplicate, and ash at 600°C in a muffle furnace for 2 hours. 
Brush the ash into a 350 ml conical flask. Rinse the dish 
with 4 ml distilled water into the flask. Add 5 ml 
H3P0^/MnS04 mixture and 3 ml KBrO^ solution, and digest 
the mixture immediately on a hot plate until efferves­
cence and a purple colour appears. Remove from the hot
323
UNIVERSITY OF IBADAN LIBRARY
plate and cool for 15 30 seconds. Add 40 ml distilled
water, from wash bottle, followed by 10 ml HgSO^/MnSo^
solution and 4 ml KBr03 solution. Break any solid material
adhering to the flask with a glass rod. Add silica chips
to prevent bumping. Boil the solution for 5 minutes or
until it turns orange-red. Remove from the hot plate and
add 100 ml distilled water and 5ml clearing solution.
Boil the mixture until starch iodide paper shows it to be
free from bromine (10 minutes). Cool and titrate with
N/20 ferrous ethylene di ammonium sulphate solution,
using two drops of ferroin as an indicator.
Correlation and regression equations for *in vivo* Q.M. 
Digestibility trials of stall-fed arid grazing'Zebu 'animals 
using faecal Nitrogen as the index.
X = % Faecal Nitrogen
Y = % Digestibility of Dry Matter
Treatment H - 4 weeks Stall fed Animals
X X2 Y Y2 XY
1.30 1.2769 53.61 2874.03 60.5793
1.20 1»4400 57.64 3322.37 69.1680
1.05 1.1025 73.80 5446.44 77.4900
1 .10 1.2100 59.88 3585.61 65.8680
: 4.48 £X2=5.03 *Y=244.93 ^2=15228.45 2gXY=274.94
1 .1 2 Y=61.23
324
UNIVERSITY OF IBADAN LIBRARY
gx - xy (y - y) = exY- - (cx) pan
N
= 274.94  -  ( 4 . 4 8 ) 4 ( 244 . 9 3 ) = 274.94  -  274.32
= 0.6 2
Regression coefficient 
b = £(X - X) (Y - Y )
C x 2 - (£x)2
N
Y = y + b  (X - X) = 61.23 + 62 (X - 1.12)
= 61.23 + 62X - 69,44 
= 62X • 8.21 + 6.93
Correlation coefficient
£(X - X-)2 = 0.01
f(Y - T )2 = 15228.45 - (244.93)2
4
= 230.77
gXY = £XY - (£X) (£y ) = 0,62
N
0.62 = 0.62
10.01 X 230.77 /S73T T732
V
0,4
325
UNIVERSITY OF IBADAN LIBRARY
£xY 8 0.62 
= 0.03,
Reduction S.S. = (0.62)2 = 0.3844 - 38.44 (I.d.f.)
0.01 0 .0 1
Residual S.S. for Y = 230.77 - 38.44 = 192.33 (n-2.d.f.)
Analysis of Variance
Source D.P.______S.S.______M.S,____F. ^.0.05
X 3L 38.44 38.44 0.4 18.51
Residual 2 192.33 96.17
Sv2.X = M.S. = 96.17 - 48.063 
n - 2 2
SyX =
1 48.063 - 6.93
Treatment H 4 Weeks - Grazing Animals.
Using the regression equation Y = 62X - 8.21 + 6.93
X
1.63 92.85
1.44 81.07
1.43 80.45
1.51 85.41
S ’ 8 339.78
Y = 84.94%
326
UNIVERSITY OF IBADAN LIBRARY
treatment H 12 weeks mm Stall Fed Animals
X X2 Y Y2 XY
1.24 1.5376 37.55 1410.00 46.5620
1.36 1.8496 56.05 4262.60 76.2280
1.37 1.8769 53.34 2845.16 73.0758
1.25 1.5625 73.67 5427.27 92.0875
EX EX2 EY EY2 EXY
5*22 6.8266 220.61 13945.03 289.9533
X s 1.305 Y = 55.15
S x -  x ) (Y - Y) = 1.XY - m i
= 289.9533 - 11514.5842 =
IV 289.9533 - 287.8960
= 2.0573
Regression coefficient
b as 2.0573 „ = 2.0573 = 2.0573
6.8266 - (5.22)̂  6.836-6.81 0.02
4
-  102.86
Y = y + b (X - X) = 55.15 + 102.86 (X - 1.305)
= 55.15 + 102.86 X - 134.23 
= 102.86 X - 79.08 + 11.89
327
UNIVERSITY OF IBADAN LIBRARY
Correlation coefficient
^ X - X ) 2 = 6.8266  -  ( 5.22  ) 2 = 0.02
? (Y- Y ) 2 = 13945.03  -  ( 220 . 6 1 ) 2
4
= 13945.03 = 12167. 19 = 777.84
$x-x) (y-Y) = 2.06
r = 2.06 = 2.06 = 2.06
0.02 X 777.84 15.56 3.94
= 0.5228
-gXY =• 2.06 
tZ2 = 0.02
Reduction S.S. = {2.06)2 = 4. 2436 = 212.18 (1 d.f.)
0.02 0.02
Residual S.S. for Y = 777.84 - 212.18 = 565 .66 (n-2 d.f.)
Analysis of Variance
Source D.F. S.S. M.S. F. F
X 1 212.18 0.05212.18 0.75 18.51
Residual 2 565.66 282.83
Sy .x = M.S. = 282.83 = 141.41 
n-2 2
Sy.x =J 141.42 - 11.89
328
UNIVERSITY OF IBADAN LIBRARY
Treatment H 12 weeks — Grazing Animals 
Using the regression equation
Y =: 102.86X - 79.08 + 11.89
X Y
1.67 92.70
1.37 61.84
1.48 73.15
1.44 69.04
^Y " 296.73 Y - 74.18%
Treatment J 4 weeks - Stall Fed Animals
X X Y Y XY
1.47 1.1609 54.44 2963.7136 80.0268
1.31 1.7161 54.18 2935.4724 70.9758
1.38 1.9044 55,66 3098.0356 76.8108
1.35 1.82251.8225 55,53 3083.5809 74.9655
z x 2 s y 5SY2
5.51 7.6039 219.81 12080.8025 302.7789
X = 1.38 7 ~ 54.95
5(X-X) (Y-Y) = 302.78 (5.51) (219.81)= 302.78.^.31311,
4 4
= 302,78 - 302.79 = 0.01
329
UNIVERSITY OF IBADAN LIBRARY
Regression coefficient
b = -O.Q1______ = -0.01______ = -0.01 = -0.5
7.61-30.3601 7.61 - 7.59 0.02
4
Y = 54.95 - 0.01X + 0.01 = 54.94 - 0.01X + 0.65 
Correlation coefficient 
^ X - X )2 = 0.02
3;Y-Y)2 = 12080.80 - (219.81)2 = 12080.30 - 48316.44
4 4.
= 12080.80 - 12079.11 - 1.69
^(X-X) (Y-Y) =■ -0.01
r = -0.01 = -0.01 = -0.01 = -0.054
0.02 x 1.69 0.0338 0.185
>XY = &X) (<Y) = -0.01
N
£X2 = £X2 - (£X)2 - 0.02
Reduction S.S. = (-0.01)2 =-0,0001 = -0.005 (I d.f.)
0 .0 2  0 .0 2
Residual S.S. for Y = 1.69 - (-0.005) = 1.695 (n-2 d.f.)
330
UNIVERSITY OF IBADAN LIBRARY
Analysis of Variance
Source______D.F. ____  S.S. M.S. F. 0.05
X 1 -0.005 -0.005 0.005 18.51
Residual 2 1.695 0.848
Sy2.x = M.S. = 0.848 = 0.424 
n - 2 2
Sy.x >» \ 0.424 - 0.65
treatment J 4 weeks - Grazing Animals 
Using the regression equation 
Y = 54.94 - 0.01X + 0.65
X Y
1.50 54.90
1.57 54.92
1.37 54.93
1.52 54.92
1.72 54.92
1.58 54.92
1.66 54.92
1.39 54.93
1.35 54.93
1.58 54.92
1.29 54.93
1.62 54.92
-£Y = 659.08
Y = 54.92%
331
UNIVERSITY OF IBADAN LIBRARY
Treatment J 12 weeks — Stall Fed Animals
X X Y Y XY
1.56 2.4336 52.69 2776.42 82.1964
1.61 2.5921 45.17 2040.33 72.7237
1.42 2.0164 54.74 2996.47 77.7308
1.40 1.9600 51.26 2627.59 71.7640
& £x2 IX /z vX2 £ xy
5.99 9.0021 203.86 10440.63 304.4149
X = 1.50 Y = 50i.97
^X-X) (Y-Y) = ̂ XY - (^X) &Y)
N
= 304.41 - (5.99) (203.86) = 304.41 - 305.28
4
= -0.87
Regression coefficient
b = -0.87_______ = -0.87 = -0.87 = -29
9.00 -(54.99) 9.00 - 8.97 0.03
Y = y + b(X-X) = 50.97 + (-29) (X-1.50)
= 50.97 - 29X + 43.50 
= 94.47 - 29X +2.53
332
UNIVERSITY OF IBADAN LIBRARY
Correlation coefficient
^ C X - X)2 =  0.03
<H(Y-Y) = 10440.63 - (203.36)2 = 10440.63 - 10339.72
& X - X )  (Y-Y) = -0.87
r = -0.87 = -0.87 = -0.87 = -2.23
0.03x50.91 1.53 0.39
^ Y  = -0.87 
<4C2 = 0.03
Reduction S.S. = (-0 .87) = 0.7569 = 25 .23 (1 d. f .)
0.03 C)*03
Residual S.S. for Y = 50.91 - 25.23 25.68 (n-2d.f)
......  ' • ---  •Analysis of Variance
Source D.F S.S. M.S. F. F0.05
X 1 25.23 25.23 1.96 18.51
Residual 2 25.68 12.84
Sy2 .x = M.S. = 12.84 = 6,42
n-2 2
Sy.x = i 6.42 = 2.53
333
UNIVERSITY OF IBADAN LIBRARY
Treatment J 12 weeks - Grazing Animals 
Using the regression equation 
Y = 94.47 - 29X+
X Y
2.06 35.73
1.84 41.11
2.01 46.18
1.71 44.88
1.23 58.80
2.00 36.47
1.74 44.01
1.63 47.20
1 .,46 52.13
1.42 53.29
1*41 53.58
1.38 54.45
^Y = 567.83
Y = 47.32%
33 4
UNIVERSITY OF IBADAN LIBRARY
Treatment K 4 weeks - Stall Fed Animals
X X2 Y Y2 XY
1.50 2.2500 55.24 3051.4576 82,8600
1.37 1.8769 53.64 2877.2496 73,4868
1.35 1.8225 33.07 1093.6249 44.6445
1.33 1.7689 32.41 1050.4081 43.1053
^X £x2 £Y IEy2 ^XY
5.55 7.7183 174.36 8072.7402 244.0966
X' = 1.39 Y = 43.59
SX(X-X) (Y-Y) = SJ.XY -(«() (^Y) = 244.10
N - (5.55)(174.36)4
= 233.10 976.6980 =
4 244.1C - 241.92 = 2,18
Regression Coefficient
b = 2.18 = 2.18 = 2,13 -2.18 = 218 =: 109
< x 2 - (N^X)2 7.72-(5.55)2 74 .72-(30.8025) 7,72-7.704 0,02
Y = y + b (X - X) =45.59 + 109 (X - 1.39)
= 45.59 + 109X - 151.51
= 109X - 105.92 + 7.66
335
UNIVERSITY OF IBADAN LIBRARY
Correlation coefficient
^ X - X )2 = 0.02
^y-Y) = 8072.74 - (1744. 36‘>2 a 8072.74 - 304041.4096
= 8072.74 - 7600.35 = 472.39
^X-X) (Y-Y) a 2.18
r = 2.18_________ = 2.18 = 2.18 = 0.71
0.02 x 472,39 9.45 3.07
^XY = 2.18 SX2 = 0.02
Reduction S.S. = (2,18)2 = 4.7524 - 237.62 (l.d.f.)
0.02 0.02
Residual S.S. for Y a 472.39 - 247.62 = 234.77 (n-2d.f.)
Analysis of Variance
ipurce____D. F._______S.S.______ M.S, F,_____F0 .05
X 1 237.62 237.62 2.02 18.51
Residual 2 234.77 117.38
Sy2.x = M.S.
n - - 117.38 = 58.69 2 2
sy.x f 58.69 = 7.66
336
UNIVERSITY OF IBADAN LIBRARY
Treatment K 4 weeks Grazing Animals
Using the regression equation.
Y = 109X -■ 105.92 + 7.66
X ¥
1.40 46.68
1.45 52.13
1.40 46.68
1.46 53.22
1.31 36.87
1.52 59.76
1.35 41.23
1.55 63.02
1-.46 53.22
1-. 57 63.21
1.30 35.78
1-.44 51.04
= 604.85
Y = 50.40%
337
UNIVERSITY OF IBADAN LIBRARY
Treatment K 12 weeks Stall Fed Animals
X X2 Y Y2 XY
1.41 1.9881 45.84 2101.31 64.6344
1.51 2.2801 45.84 2101.31 69.2184
1.31 1.7161 45.84 2101.31 60.0504
1.37 1.8769 46.35 2148.32 63.4995
1.26 1.5876 46.35 2148.32 58.4010
1.35 1.8225 46.35 2148.32 62.5725
<*X2 <y2 <XY
8.21 11.2718 276.57 12748.89 378.3762
X = 1.37 Y = 46.10
gx-x) (Y-Y) = 378.38 - (276.57)(8.21) = 378.38-22'
6
= 378.38 - 378.44 - -0.06 
Regression Coefficient
b = -0.6______ = -0.06_________ = -0.06______=-0,Q6 =-1 . 3
11.27—(8.21)2 11.27-(67.4041) 11.24*11.23= 0.04
6 6
Y = y + b (X - X)
Y = 46.10 +- (-1.5X) - 2.06 = 46.10 - 1.5X + 2.06
= 46.10 - 1.5 (X-1.37) = 46.10 - 1.5X + 2.06 = 48.16-1.5X 
Y = 48.16 - 1.5X + 0.18
338
UNIVERSITY OF IBADAN LIBRARY
Correlation Coefficient
^gX-X)2 = 0,04
^ Y - Y )2 = 12748.89 - (276,57)2 = 12748.89 - 76490.9649
6 6
S= 12748.89 -  12748.49 = 0*40
X-X) (Y-Y) - 0.06
r = -0.06______ = 0.06 = On 06 = 0,47
0.04 x 0.40 0.0160 0.127
^XY = 0.06
<X2= 0.04
Seduction S.S-. = (-0.06)2 = .0036 = -0.09 il.d.f.)
0.04 0.04
Residual S.S. for Y = 0.40 - (-0.09) = 0,49 (n-2 d,f.)
Analysis of Variance
Source D.F. S.S. M.S.. 1 F0 .05 
X 1 -.0.09 -0.09 .75 18.51
Residual 4 0.49 0.12
Sy2.x = M.S. = 0.12 = 0.03
n-2 4
Sy.x =• 1 0.03 = 0.18
339
UNIVERSITY OF IBADAN LIBRARY
Treatment K 12 weeks - Grazing Animals 
Using the regression equation*
Y = 48.16 - 1.5X ± 0,18
X Y'
1,54 45.85
1.54 45.85
1.49 45.92
1.45 45.98
1.38 46.09
1.41 46.04
1.44 46.00
1.41 46.04
1.52 45.88
1.62 45.73
1.36 46*12
1.44 46.00
= 551.50
•
Y = 45.96%
340
UNIVERSITY OF IBADAN LIBRARY
Treatment L 4 weeks Stall Fed Animals
X X2 Y Y2 XY
1*40 1.9600 53.10 2819.61 74.3400
1.26 1.5876 53.52 2864.39 67.4352
1.62 2*6244 53.10 2819.61 86.0220
1*60 2.5600 53.52 2864.39 85.6320
1.49 2.2201 53.52 2864.39 79.7448
1.44 2.0736 48.88 2389.25 70.3872
1.55 2.4025 51.92 2695.69 80.4760
1.35 1.8225 48.88 2389.25 65.9880
1*52 2.3104 51.92 2695.69 78.9184
1.51 2.2801 48.88 2389.25 73.8088
1.60 2*5600 51.92 2695.69 83.0720
£X2 s*2 ^XY
16.34 24.4012 569.16 29487.21 845.8244
X = 1.49 ¥ = 51.74
£(x-x )Cv-y ) = *5xy - (ApNtfcx) = 845.82 - (569.16)(16.34) 11
- 845.82 - 9300.0744 = 845.82 - 845.46 = 0.36
1 1
Regression Coefficient
b. = 0.36 O=0.3624.40-(16.34 = 0.36 =0*36 = 24.40-(26r6.9956) 24 .40-24.27 0.13
11 11
Y: = y = b (X-X) = 51.74 + 2.77 (X - 1.49
-- 51.74 + 2.77X - 4*13 = 47.61 + 2.77X + 0.738
341
UNIVERSITY OF IBADAN LIBRARY
Correlation Coefficient
11X-X)2 = 0.13
•5{Y - Y)2 s 39487.21-(569.16)2 = 29487.21 - 323943>11
11 11
= 29487.21 - 29449.37 = 37.84
S X - X )  (Y-Y) = 0.36
r = 0.36 = 0.36 =  0.36
0.13 x - 37.84
= 0.105
1 1 .73 3.43
^XY = 0*36 £x y 2 = 0.13
Reduction S.l3. = (0.36) ZZ 0.1296 = 1 (1 d.f.)
0.13 0.13
Residual S.S . for Y = 37.84 - 1 =36,84 (n -2d,f ->
Anal vsis of Variance
Source D.F. S , S • M , S F, F0.05
X 1 1 1 0.204 18.51
Residual 9 36.84 4*9
UNIVERSITY OF IBADAN LIBRARY
Treatment L 4 weeks - Grazing Animals.
Using the regression equation.
Y = 47.61 + 2.77X+ 0.738
X Y
1.55 51.90
1.40 51.49
1.56 51.93
1.36 51.38
1.52 51.83
1.61 52.07
1.39 51.46
1.53 51.85
1.43 51.57
1.49 51.74
1.55 51.90
1.41 51.52
S* = 620.65
Y = 51.72%
reatment L 12 weeks Stall Fed Animals
X X2 .... ■' Y . Y2 ’ XY
1,36 1.8496 57.01 3250.14 77.5336
1.44 2.0736 57.01 3250.14 82.0944
1.51 2.2801 57.01 3250.14 86.0851
1.47 2.1609 58.80 3457.44 86.4360
1.49 2.2201 58.80 3457.44 87.6120
1.49 2.2201 88.80 3457.44 87.6120
4x2 & iY2 ^XY
8.76 12.8044 347.43 ;20122.74 507.3731
343
UNIVERSITY OF IBADAN LIBRARY
X - 1.46 Y ~ 57.91
tfx-X) (Y-Y) = <&Y - (^X) N (*&*! - 507,37 - (8,76) (347.43)6
= 507.37 - 304.4868 = 507.37 - 507.2478 = 0.12 
6
Regression Coefficient
b = 0.12 = 0.12________ _ = 0.12________=0.12 = 12
12.80-(8.76 )2 12.80-76.7376 12.80-12.7896 0.01
6"- ---6~
Y = y + b (X - X) = 57.91 + 12 (X - 1.46)
= 57.91 + 12X - 17.52 = 40.39 + 12X + 0.45 
Correlation coefficient
*Jx-x)2 = 0.01
^(Y-Y)2 = 20122.74 - (347.43)2 = 20122.74-120707.6049
6 6
- 20122.74 - 20117.93 = 4.81
^X-X) (Y-Y) = 0.12
r 0.12_________  = 0.12 = 0.12 0.545
| 0.01 x 4.81  ̂0.048 | 0.22
XY2 = 0.01
Reduction S.S. = (,12)2 = 0.0144 = 1.44 (l d.f.)
0.01 0.01
Residual S.S. for Y = 4.81 - 1.44 = 3.37 (n - 2 d.f.)
344
UNIVERSITY OF IBADAN LIBRARY
Analysis of Variance
Source D.F. S.S» M.5. F. F0.05 
X 1 1.44 1.44 18 *51
Residual 4 3.37 0.84
Sy^.x = M.S. = 0.84 = 0.21
n-2 4
Sy.x = 0.21 = 0.45
Treatment L 12 weeks - Grazing Animals.
Using the regression equation
Y = 40.39 + 12X + 0.45
X Y
1.31 56.11
1.46 57.91
1.52 58.63
1.41 57.31
1.56 59.11
1.48 58.15
1.40 57.19
1.37 56.83
1.42 57.43
1.41 57.31
1.46 57.91
1.49 58.27
= 692.16 
Y = 57.68%
345
UNIVERSITY OF IBADAN LIBRARY
LITERATURE CITED
Ackman, R.G., and Burgher, R.D. (1963). Quantitative gas
liquid chromatographic estimation of volatile 
fatty acids in aqueous media.
Anal. Chem. 35: 647. No. 6
Adegbola, A.A. (1964) forage crop research and development 
in Nigeria.
Niger. Agric. J. 1: 34
Adegbola, A.A. (1965) Gtylosanthes gracilis: A tropical 
forage legume for Nigeria.
Proc. Agric. Soc. Niger. 4: 57
Ademosun, A.A., and Baumgardt, B.R. (1967) Nutritive value
' of some Nigerian forages by analytical methods.
Niger. Agric. J. 4: 1
Ademosun, A.A. (1970) Nutritive evaluation of Nigerian 
'treatments: 11 The effect of stage of
maturity on the nutritive value of 
Gtylosanthes gracilis.
Niger. Agric. J. 7j 164
Adeneye, J.A., Oyenuga, V.A., and Olaloku, E.A. (1970).
mPirlekl imofi nWahriyt ef iFnudliangnsi  cona tttlhee. composition of 
Niger. J., Gci. 4: 181
346
UNIVERSITY OF IBADAN LIBRARY
Allen, R.S., Jacobson, N.L. , Ward, R.M. and Saletel, J.H.
(1956) The effect of various dietary lipids 
on the blood plasma polyunsaturated fatty 
acids of dairy calves.
J. DairV Sci. 39: 1161
Alexander, R.H. 7 and Mary McGowan (1961). A filtration
procedure for the 1 in vitro* determination of 
digestibility of herbage.
J. Brit. Grassl. Soc. 16: No 4, p275
Alexander, R.H., (1969) The establishment of a laboratory 
procedure for the ^ n  vitro1 determination 
of digestibility. The West of Scotland 
Agricultural College Research Bulletin No. 42
Anderson, R.L., and Hollenbach, E.J. (1965) Large scale 
separation of fatty acid methyl esters by 
column chromatography on acid washed florisil 
impregnated with silver nitrate. •
J. Lipid. Res. 6: 577
Annison, E.F., and Pennington, R.J. (1954) The metabolism 
of short chain fatty acids in the sheep*
Biochem. J. ,57: 685
Annison, E.F., and Lewis, D. (1959) Metabolism in the
ruminant. .Published by London: Methuen and 
Co. Ltd., New York: John Wiley and Sons Inc.
347
UNIVERSITY OF IBADAN LIBRARY
Anthony, VI.B., and Reid, J.T. (1958) Methoxyl as an indica­
tor of the nutritive value of the treatment.
J. Dairy 3ci. 41: 1715
Arnstrong, D.G., Thomas, B. and Cook, (1950) The lignin 
and cellulose contents of certain grassland 
species a.t different stages of growth.
J. Agric. Sci. 40: 93
Armstrong, D.G.’, and Blaxter, K.L. (1957) The heat increa- 
ment of steam V.F.A. in fasting sheep.
Brit. J. Nutr. 11: 247
Armstrong, D.G., Blaxter, K.L., and McCgraham, N. (1957) 
The heat increaments of mixtures of steam 
V.F.A. in fasting sheep.
3rit. J. Nutr. 11: 392
Armstrong, D.G., and Blaxter, K#L. (1957) The utilization 
foaf ttaecnetiincg,  sphereopp.ionic, and butyric acids by 
Brit. J. Nutr. 11: 413
Armstrong, D.G., Blaxter, K.L,, McCgraham, N*, and Wainma.n, 
F.W. (1958) The utilization of the energy 
osfhe etpw.o mixtures of steam V.F.A. by fattening 
Brit. J. Nutr. 12: 177
Armstro
348
UNIVERSITY OF IBADAN LIBRARY
Armstrong, D.G. (1964) Evalua.ti.on of artificially dried 
grass as a source of energy for sheep,
ii. The energy value of cooksfoot, timothy 
and two strains of rye grass at varying 
stages of maturity.
J. Agric. 3ci. 62: 399
Armstrong, D.G., Blaxter, X.L., and Waite, R. (1964) The 
evaluation of artifially dried grass as a 
source of energy for sheep.
iii. The prediction of nutritive value from 
chemical and biological measurements.
J. A9ric» Sci. 62: 417
Armstrong, D.G., Alexander, R.H., and Mary McGowan (1964).
The use of fin vitro* digestibilities of 
dried grasses for the prediction of their 
energy values for ruminants.
Proc. Nutr. Goc. 23: No. 2, XXVI
Arnold Kivimae (1966) Estimation of digestibility and 
feeding value of Thimothy.
Proc. 10th Intern. Grassl. Congr.
A.O.A.C. (1964) Official methods of analysis of the 
Association of Official Agricultural 
Chemists.
Published by A.O.A.C.,.P.0. Box 540, 
Washington 4, D.C.
349
UNIVERSITY OF IBADAN LIBRARY
/
Backer, R A. (1966) Volatile fatty acids in aqueous solu 
tion by gas-liquid chromatograph.
J, 9as Chromat. 4: 418 No. 11
Badawy, A M., Campbell, R.M., Cuthbertson, D.P., Fell, B.F., 
and Markie, S.W. (1958). Further studies on 
the changing composition of the digesta along 
the alimentary tract of the sheep. 1. Total 
and non-protein nitrogen.
Brit. J. Nutr. 12: 357
Badawy, A-,M. (1958) Further studies on the changing
composition of the digesta along the alimen­
tary tract of the sheep. 2. Volatile fatty 
acids and energy relative to lignin.
Brit. J. Nutr. 12: 384
Badawy, A M.,Campbell, R.M., Cuthbertson, D.P. and Mackie, 
W.3. (1958) Further studies on the changing 
composition of the digesta along the alimen­
tary tract of the sheep. 2. changes in the 
omasum..
Brit. J. Nutr. 12: 391.
Balch, C. Balch, DiA.., Bartlett y O y UOX y C.,P„, and
Rowland, S.J. (1952) Studies of the
of milk of low fat content by cows on sdeicertestion 
low in hay and high in concentrates. 1. The 
effect of variation in the amount of hay.,
J. Dairy Res. 19: 39
350
UNIVERSITY OF IBADAN LIBRARY
Balch, C.C., Balch, D.A., Bartlett, S., Cox, C.P. , Rowland, 
S.J, and Turner, J. (1954) Studies of the 
secretion of milk of low fat content by cows 
on diets low in hay and high in concentrates. 
11. The effect of the protein content of the 
concentrates.
J. Dairy Res. 21: 165
Balch, C.C., Balch, D.A,, Bartlett, 3., Hosking, Z.D.,
Johnson, V.W., Rowland, S.J., and Turner, J. 
(1954) Studies of the secretion of milk of 
low fat content by cow on diets low in hay 
and high in concentrates. 11. The effect 
of variations in the amount and physical 
state of the hay and a comparison of the 
short horn a.nd freision breeds.
J. Dairy Res. 21: 172
Balch, C.C., Balch, D.A., Bartlett, 3., Johnson, V.W,, 
Rowland, 3.J., and Turner, J. (1954)
Studies of the secretion of milk of low fat 
content by cows on diets low in hay and high 
in concentrates. IV. The effect of varia­
tions in the intake of digestible nutrients.
J; Dairy Res. 21: 305
Balch, C.C’.', Balch, D.A., Bartlett, S. , Hosking, Z.D.,
Johnson, V.W., Rowland, S.J., and Turner, J. 
(1955). Studies of the secretion of milk of 
low fat content by cows on diets low in hay 
and high in concentrates. V. The importance 
of the type of starch in the concentrate.
J. Dairy Res. 22: 10
351
UNIVERSITY OF IBADAN LIBRARY
Balck, C.C., Balch, D.A., Bartlett, S.,,. Bart rum, M.P.,
Johnson, V.W. , Rowland, S.J. , and Turner, J. 
(1955). Studies of the secretion of milk of 
low fat content by cows on diets low in hay 
and high in concentrates. VI. The effect 
on the physical and biochemical processes 
of the reticulorumen..
J. Dairy Res. 22: 270
Balch, C.C., Reid, J.T.., and Stroud, J.W. (1957).. Factors 
influencing the rate of excretion of admini­
stered chromium sequioxide by steers.
3rit. J .  Muter. 11: 184
Balch, D.A., (1958). An estimate of the weights of
volatile fatty acids produced in the rumen 
of lactating cows on diet of hay concentra­
tes .
Brit. J. Nutr. 12: 18
Balman, J.H., and Folley, S.J., (1951). Further observa­
tion on the ’in vitro’ stimulation by insu­
lin of fat synthesis by lactating mammary 
gland slices.
Biochem. J. 49: 663
Barcroft, J,, McAnally, R.A., and Phillipson, A.T. (1944).
Absorption of volatile fatty acids from the 
alimentary tract of the sheep and other 
animals.
J. Exptl. Biol. 20: 120
352
UNIVERSITY OF IBADAN LIBRARY
Barnett, A .J.G., and Duncan (1953). The determination of 
the volatile fatty acids (V.F.A,) formed 
during the fermentation of grass/water 
mixtures.
J. Agric. Sci. 43: 260
Barnett, A .J.G., and Tawab, A.G, (1957). A rapid method 
for the determination of lactose in milk and 
cheese.
J. Sci. Fd. Agric. 8: 437
Barnicoat, C.R., Logan, A.G. , and Grant, A.I, (1949), Milk 
secretion studies with New Zealand Romney 
ewes. Parts 1 and 11.
J. Agric. Sci. 39: 44
Barns, R.F (1965). The use of *in vitro1 rumen fermenta­
tion techniques for estimating forage diges­
tibility and intake,
Agron. J. 57; No. 2 p.213
Bensadoun, A., Paladines, O.L., and Reid, J.T. (1962), 
Effect of level of intake and physical form 
of the diet on plasma glucose concentration 
and volatile fatty.
J, Dairy Sci. 46: 835
Benzie, D. and Phillipson, A.T. (1957). The alimentary 
tract of the ruminant. Published by Oliver 
and Boyd.
353
UNIVERSITY OF IBADAN LIBRARY
Bills, D.D., Khatri, L.L., and Day, E*A* (1963). Method
for the determination of the free fatty acids 
of milk fat.
J. Dairy Sci. 46: 1342
Bishop, S.E., Loosli, J.K., Trimberger, G.W. and Turk, K.L.
(1963). Effect of pelleting and varying 
grain intakes on milk yield and composition.
J. Dairy Sci. 46: 22
Blaxter, K.L., (1962). The energy metabolism of ruminants.
Published by Hutchinson and Co. (Publishers) 
Ltd., Great Portland Street, London, W .1.
Boatman, C., Deootean, A.E., Hammond, E.G. (1961).
Trisaturated glycerides of milk fat.
J. Dairy Sci. 44: 644
Bowden, D.M., and Church, D.C. (1962). Artificial rumen 
investigation. 1. Variability of dry 
matter and cellulose digestibility and 
production of volatile fatty acid.
J. Dairy Sci. 45: 972
Boyne, A.W., Eadie, J.M., and Raitt, K. (1957)
J. Gen. Microbiol. 17: 414
Brich, W. R. (1964) The germination and purity of some
Kenya grasses. The results of ten years of 
seed testing in Kenya.
E. Africa. Agric. For. J. 30: 015
354
UNIVERSITY OF IBADAN LIBRARY
Brown, D. (1954) Methods of surveying and measuring vege­
tation. Commonwealth Bureau of Pastures and 
Field Crops. Bulletin 42 Farnham Royal. 
Bucks, England.
Brown, W.H., Gtull, J.V7. , and Stott, G.H. (1962) Fatty 
acid composition of milk. 1. Effect of 
roughage and dietary fat.
J. Dairy Sci. 45: 191
Brown, V7.H. , Still, J.V7. , and Stott, G.H. (1962) Fatty 
acid composition of milk. 1. Effect of 
pelleting and varying grain intakes on milk 
yield and composition.
J. Dairy Sci. 46: 22
Bryant, M.P., and Doetsch, R.N. (1954) 
J. Dairy Sci. 37: 1176
Bryant, M.P., Robinson, I.M., and Chur, H. (1959)
J. Dairy. Sci. 42: 1831
Burchfield, H.P., and Storrs, E.E. (1962) Biochemistry and 
Applied gas chromatography.
Burt, A.V7.A. (1957) The effect of variations in nutrient 
intake upon the yield and composition of 
milk.
J. Pairy. Res. 24: 283
355
UNIVERSITY OF IBADAN LIBRARY
Campling, R.C., Freer, M. (1963) Factors affecting the 
voluntary intake of food by Cows. 5. The 
relationship between the voluntary intake of 
food, the amount of digesta in the reticulo- 
rumen, and the rate of disappearance of 
digesta from the alimentary tract with diets 
of hay, dried grass, or concentrates.
Brit. J. Nutr. 17: 79
Campling, R.C., Free, M., and Balch, C.C. (1963) Factors 
affecting the voluntary intake of food by 
cows. 6. A preliminary experiment with 
ground, pelleted hay.
Brit. J. Nutr. 17: 263 No. 2
Cantarow, A., Schepartz, B. (1962) Biochemistry. 3rd
Edition. Published by W.B. Saunders Company. 
Philadelphia. London.
Chaney, A., and Marbach, E.P. (1962) Determination of 
blood urea and ruminal ammonia.
Clin. Chem. 8: 130
Christian, K.R., and Coup, M.R. (1954), Measurement of 
feed intake by grazing cattle and sheep. 
VI. The determination of Cr2°3
N.Z. J. Sci. Tech. 36: 328
Chou, K.C., and Walker, D.M. (1964) The effect on the 
rumen composition of feeding sheep diets 
supplying different starches.
I. The variation in rumen composition of 
sheep fed lucerne or wheat as the sole diet.
J, Agric. Sci. 62: 7
356
UNIVERSITY OF IBADAN LIBRARY
Clark, E.P . (1928) Studies on Gossypol. III. The 
oxidation of gossypol.
J. Biol. Chem. 77: 81
Clark, E.F. (1943) The determination of volatile fatty 
acids. Semi-micro quantitative organic 
analysis.
Clarke, R*T. (1964)
New Zealand J. Agric. Res« 7: 248
Clarke, R«T, (1964)
New Zealand J* Agric. Res* 7: 525
Clarke, J*R.P., and Fredricks, K.M, (1967) Gas chromato­
graphy of free fatty acids*
J. gas chromat. 5: 99 No* 2
Claypool, D*W., Jacobson, D.R., and Wiseman, R.F. (1961) 
J. Dairy Sci. 44: 174
Cole, H*H*, (1966) Introduction to livestock production.
Published by W«H. Freeman and Company. San 
Francisco and London,
Coombe, J.B., and Kay, R.N.B. (1965) Passage of digesta 
through the intestines of the sheep. 
Retention time in the small and large 
intestines.
Brit. J. Nutr. 19: 325
357
UNIVERSITY OF IBADAN LIBRARY
Conrad, H.R., Smith, H.R., Vandersall, J.H., Pouden, W.D. , 
and Hibbs, J.W. (1953) Estimating gastro- 
splenic blood flow and volatile fatty acid 
absorption from the forestomachs of calves.
J. Dairy Sci. 41: 1094
Conway, E.J. , and Cooke, R. (1939) Blood ammonia. 
Biochem. J. 33: 457
Corbett, J.L., Green-Halgh, J.F.D., Gwynn, P.E. and Walker, 
D* (1958). Excretion of Cr^O^;
Brit. J# Nutr. 12: 266
Coup, MUR*., and Lancaster, R.J., (1952) The measurement 
of feed intake by grazing cattle and sheep. 
II. The determination of Cr_0 .
£  O
N.Z. J. Sci. Tech. 34A: 347
Cowdry, W.A*R. , and Verhoeven, G. (1961) Stylo seed 
harvesting,
Qd. Agric. J, 87: 179
Cowie, A.T., Buncombe, W.G., Folley, 3.J., French, T.H., 
Glascock, R.F., Marsart, L., Feeters, G.J., 
and Popjock, G. (1951) Synthesis of milk 
fat from acetic acid (CPU ^COOH) by the 
perfused isolated bovine udder.
Biochem. J. 49: 610
358
UNIVERSITY OF IBADAN LIBRARY
Craplet, . (1963) The dairy cow. Published by Edward 
Arnold Ltd., London.
Crampton, E.W. (1956) Applied animal nutrition. The use
of feedstuffs in the formulation of livestock 
rations. Published by Freeman and Company, 
San Francisco.
Crampton, W.E. (1956) Applied Animal Nutrition.
Published by W.H. Freeman and Co. San 
Francisco.
Dada, M,0 (1971) Effect of different levels of phospho­
rus on Stylosanthes gracilis. Diploma 
project. Inst. Agric* Res. Training, 
University of Ife, Moor Plantation, Ibadan.
Davies, V7 and Skidmore, C.L. (1966) Tropical pastures. 
Published by Faber and Faber Ltd., London, 
W.C.l.
Davis, R. ., Woodhouse, N.3., Mark Keeny, and Beck, G.H. 
(1957) The effect of various levels of 
dietary protein upon the volatile fatty 
acids in the rumen of the dairy cow.
J. Dairy Sci. 40; 75
Davis, J. . (1959) Milk testing. The laboratory control 
of milk. Published by Dairy Industries Ltd. 
London.
359
UNIVERSITY OF IBADAN LIBRARY
Dehority, B.A. (1961) Effect of particle size on the 
digestion rate of purified cellulose by 
rumen cellulolytic bacteria *in vitro*,
J. Dairy Sci. 44: 687
Dehority, B.A. and Johnson, R.R. (1961) Effect of particle 
size upon the * in vitro1 cellulose digestibi­
lity of forages by rumen bacteria.
J. Dairy Sci. 44: 2242
Dehority, B.A. and Johnson, R.R., Conrad, H.R. and Davis, 
R.R. (1962) Relationship of Tin vitro* 
cellulose digestibility of undried and dried 
mixed forages to their * in vivo* matter 
digestibility.
J. Dairy Sci. 45: 250
Dehority, B.A., Johnson, R.R., Conrad, H.R. (1962)
Digestibility of fora.ge hemicellulose and. 
pectin by rumen bacteria 1 in vitro1 and the 
effect of lignification thereon.
J. Dairy Sci. 54: 508
Deinum, B. (1966) Influence of some climatological factors 
on the chemical composition and feeding 
value of herbage. Proceed Xth Intern.
Grassl. Congr.
Deinum, B. , and Van Soest, P.J. (1969) Prediction of 
forage digestibility from some laboratory 
procedures.
Neth. J. Agric. Sci. 17: 119
360
UNIVERSITY OF IBADAN LIBRARY
DeMan, J.M. (1964) Determination of the fatty acid 
composition of milk fat by dual column 
temperature programmed gas-liquid 
chromatography,
J. Dairy Sci. 47: 546
Donald Van Slyke (1927) Determination of urea by gasome- 
tric measurement of the carbon dioxide 
formed by the action of urease.
J. Biol, Chem, 73: 695
Donefer, E. , Lloyd, L.E., and Crampton, E-.W. (1963)
Effect of varying alfalfa: Barley ratios 
on energy intake and volatile fatty acid 
production by sheep.
J. Arumi. Sci. 22: 425
Dukes, H.H. (1947) The physiology of domestic animals
6th Edition, Published by Comstock Publishing 
Associates, New York,
Dukes, H.H. (1955) The physiology of domestic animals.
7th Edition. Published by Bailliere, Tindall 
and Cox. London
Dukes, H.H., (I960) The physiology of domestic animals.
Published by Comstock Publishing Company Inc.
Dunlop, G. (1933) Methods of experimentation in animal 
nutrition.
J. Agric. Sci. 23: 580
361
UNIVERSITY OF IBADAN LIBRARY
Eckles, C.H. and Macy, H. (1943) Milk and milk products.
Published by McGraw-Hill Book Company Inc. 
N.Y.
Edwards, D.C. and Bogdan, A.V. (1951) Important Grassland 
Plants of Kenya. Published by Isaac Pitman 
and Sons.
El-Shazly, K. (1952) Degradation of protein in the rumen of 
sheep. 1. Some volatile fatty acids, 
including branched chain isomers, found 
*in vivo1.
Biochem. J. 51: 640
El-Shazly, K. (1952) Degradation of protein in the rumen 
of the sheep. 2. The action of rumen 
micro organisms on amino acids.
Biochem. J. 51: 647
Ely, R.E.Kane, E.A., Jacobson, W.C., and Moore, L.A., 
(1953) Composition of lignin in orchard 
grass.
J. Diary Sci. 36: 346
Emery, R.S., and Brown, L.D. (1961) Effect of feeding
sodium and potassium bicarbonate on milk fat, 
rumen pH, and volatile fatty acid production.
J. Dairy Sci. 44: 1899
Enlow, C.R., and Dutton, W.L. (1954) Report of F.O.A. 
Grassland mission on Nigeria.
362
UNIVERSITY OF IBADAN LIBRARY
Evans, L. , and Stuart Patton (1962) Lipid exchange between 
bovine serum lipo-proteins 'in vitro'.
J. Dairy Sci. 45: 589
Faichney, G.J. (1967) Some notes on the separation of
volatile fatty acids in rumen fluid by gas 
liquid chromatography.
J. Chromat. 27: 482
F.A.C. (1955) Meeting report No. 1955/19,
Agric Div. F.A.O., Rome. F.A.C.
Faulkner, D.E., and Epstein, H. (1957) The indigenous
cattle of the British Dependent territories 
in Africa. London: Her Majesty’s Stationery 
Office.
Fawcett, J.K., and Scott, J.E. (1960) A rapid and precise 
method for the determination of urea.
J. Clin. Path. 13: 156
Fina, L.R., Teresa, G.W., and Bartley, E.E. (1958) An 
artificial rumen technique for studying 
rumen digestion 'in vivo1.
J. Anim. Sci. 17 No. 3: 667
Fisher, R.A., and Yates, F. (1953) Statistical tables 
for biological, agricultural and medical 
research. Published by Oliver and Boyd. 
London, W.C.
Fisher, L.J., and Elliot, J.M. (1966). Effect of intrave­
nous infusion of propionate or glucose on 
bovine milk production.
J. Dairy Sci. 49: 826 No. 7
363
UNIVERSITY OF IBADAN LIBRARY
Folley, S J., and French, T.H. (1949) The intermidiary 
metabolism of the mammary gland slices in 
precence of carbohydrates
Biochem. J, 45: 117
Folley, S J., and French, T.H, (1949). The intermediary 
metabolism of the production of mammary 
tissue during pregnancy, lactation and 
involution in the rat.
Biochem. J. 45: 270
Biochem. J. 45: 270
Folley, 5, J,, and French, T.H. (1950). The intermediary 
metabolism of lactating mammary gland slices 
with special reference to milk fat synthesis.
Biochem. J. 46: 465
Folley, S.J. (1956). The phisiology and biochemistry of 
lactation. Published by Oliver and Boyd. 
Edinburgh.
Forbes, R.M., and Gerrigus, W.P. (1948). Application of a 
lignin ratio technique to the determination 
of the nutrient intake of grazing animals.
J. Anim. 3ci. 7: 373
364
UNIVERSITY OF IBADAN LIBRARY
Forbes, R.M., and Garrigus, VJ.F. (1950) Some relationship 
between chemical composition, nutritive 
value, and intake of treatments grazed by 
steers and wethers.
J. Anim. Sci. 9: 354
Foster, W.H. (1961) Note on the establishment of a legume 
in rangeland in Northern Nigeria.
Exp. Agric. 29: 319
Frandson, R.D. (1965) Anatomy and physiology of farm 
animals. Published by Lea and Febiger.
French, M.H., (1940) The comparative digestive powers of
Zebu and high grade European cattle (Ayrshire). 
J. Agric. Sci. 30: 503
Gallup, W.D., and Briggs, H.M, (1948) The apparent
digestibility of prairie hay of various 
protein content with some observations of 
faecal nitrogen excretion by steers in 
relation to their dry matter intake.
J. Anim. Sci. 7: 110
365
UNIVERSITY OF IBADAN LIBRARY
Gander, G.W., Jensen, R.G. , and Sampugna, J, (1962)
Analysis of milk fatty acids by G.L.C.
J. Dairy 3 c i. 45: 323
Gilchrist, E.C. (1967) A place for stylo in N.Q. 
pastures.
Qd. Agric. J. 93: 344
Godfrey, N.W. (1961a) The functional development of the 
calf. i. Growth of the stomach of the 
calf.
J. Agric. Sci. 57: 173
Godfrey, N.W. (1961) The functional development of the
calf. ii. Development of rumen function in 
the calf.
J. Agric. 3ci. 57: 177
GreenHalgh, J.D.F., and Corbett, J.L. (1960) The indirect 
estimation of the digestibility of pasture 
herbage. 1. Nitrogen e.nd chromogen as fae­
cal index substances.
J. Agric. Sci. 55: 371
366
UNIVERSITY OF IBADAN LIBRARY
Gray, F.V. (1947). The absorption of volatile fatty acids 
from the rumen.
J. Exptl. Biol. 24: 1
Gray, F.V. (1947). The digestion of cellulose by sheep.
The extent of cellulose digestion at 
successive levels of the alimentary tract.
J. Bxptl. Biol. 24: 15
Gray, F.V. (1948). The absorption of volatile fatty acids 
from the rumen. 11. The influence of pH on 
absorption.
J. Exptl. Biol. 25: 135
Gray, F.V. Pilgrim, A.F.-,.-and Weller, R.A. (1951). .
Fermentation in rumen of the sheep. 1. The 
production of volatile fatty acids and 
methane during the fermentation of wheaten 
hay and lucerne hay 'in vitro' by micro 
organisms from the rumen.
J. Exptl. Biol. 28: 74
367
UNIVERSITY OF IBADAN LIBRARY
Gray, F.V. and Pilgrim, A.F., (1951) Fermentation in the
rumen of the sheep. 11. The production 
and absorption of volatile fatty acids 
during the fermentation of wheaten hay and 
lucerne hay in the rumen.
J. Exptl. Biol. 28: 83
Gray, F .V. and Pilgrim, A.F., (1952). Fermentation in the 
rumen of the sheep. Ill, Intermediate 
stages in the fermentation of wheaten hay 
'in vitro' by micro-organisms from the rumen. 
J. Exptl. Biol. 29: 57
Gray, F ,V., Pilgrim, A.F., Rodda, H.J., Weller, F,A. (1952) 
Fermentation in the rumen of the sheep. IV. 
The nature and origin of the volatile fatty 
acid in the rumen of the sheep.
J. Exptl. Biol. 29: 57
Gray, F V. and Weller, R.A. (1954). The passage of
starch through the stomach of the sheep.
J. Exptl. Biol. 31: 40
368
UNIVERSITY OF IBADAN LIBRARY
Gray, F.V., Pilgrim, A.F., and Weller, R.A. (1954).
Functions of the omasum in the stomach of 
the sheep.
J. Bxptl. Biol. 31: 49
Gray, F.V., Pilgrim,A.F., and Weller, R.A. (1958). The 
digestion of foodstuffs in the stomach of 
the sheep and the passage of digesta through 
its compartments.
1. Cellulose, pentosans and solids,
Brit. J. Nutr. 12: 404-
Gray, F.V., Pilgrim, A.F., and Weller, R.A. (1958). The 
digestion of foodstuffs in the stoma.ch of 
the sheep and the passage of digesta through 
its compartments.
2. Nitrogenous compounds.
Brit. J. Nutr. 12: 413
Gray, F.V., and Pilgrim, A.F. (1958). The conversion of 
plant nitrogen in the rumen of the sheep. 
Brit. J. Nutr. 12: 421
369
UNIVERSITY OF IBADAN LIBRARY
Gray, F.V., Weller, R.A., and Pilgrim, A.F. (1962).
Digestion of foodstuffs in the rumen of the 
sheep and the passage of digesta through its 
compartments. 3. The progress of nitrogen 
digestion.
Hammond, J. (1960). Farm animals. Their breeding, growth 
and inheritance. Published by Edwa.rd Arnold 
(Publishers) Ltd.
Hammond, H. (1962). Farm animals. Their growth, breeding 
and inheritance. Published by Edward Arnold 
(Publishers) Ltd., London.
Hansen, R.P., and Shorland, F.3. (1951). The branched 
chain fatty acids of butter fat. 1. The 
isolation from butter fat of branched chain 
fatty acids with special reference to the 
^17 acids.
Biochem. J. 50: 207
370
UNIVERSITY OF IBADAN LIBRARY
Hansen, R.P., and Shorland, F.B. (1952). Seasonal
variations in volatile fatty acids 
composition of New Zealand butter fat. 
Biochem. J. 52: 207
Hansen, R.P. and Shorland, F.B. (1952). The branched 
chain fatty acids of butter fat. 2. The 
isolation of a multi-branched saturated 
fatty acid freactions.
Biochem. J. 50: 358
Hcxwkins G.E., Gray, E. Paar, and Joe, A. Little (1963). 
Physiological responses of lactating dairy 
cattle to pelleted corn and oats.
J. Dairy Sci. 46: 1073
Hedrick (1961). Forage research in W. Nigeria.
I. C.A. project 61-13-050 report.
Hinders, R.G. and Owen, F.G. (1963). Relationships between 
efficiency of milk production and ruminal 
volatile fatty acid of cows fed isocaloric 
(estimated net energy) rations of varied
concentrate levels.
J. Dairy Sci. 46: 1246
371
UNIVERSITY OF IBADAN LIBRARY
Hobson, P.N., and Mann, S.C. (1955)
J. Gen, Microbiol. 13: 420
Hobson, P.N., and Mann, S.O. (1957)
J. Gen. Microbiol. 16: 463
Holmes, W,, Waite, R., Maclusky, D.S., and Watson, J.N.
(1956). The influence of level and source 
of protein and of the level of energy in 
the feed on milk yield and composition.
J. Dairy Res. 23: 1
Horrell C.R., and Newhouse, P.'W. (1966). Yield of sown
pastures in Uganda, as influenced by legumes 
and by fertilizers. Proc. 9th Int. Grassld. 
Cong. Sao Paulo.
Horrell (1964). Effect of two legumes on the yield of 
fertilized pastures at Serere.
E. Afric. Agric. For. J. 30: 94
Horrell, C.R., and Court, M.N. (1965). Effect of the
legume Stylosanthes gracilis on pasture
yields at Serere, Uganda.
J. Brit. Grassl. Soc. 20: 72
372
UNIVERSITY OF IBADAN LIBRARY
Horton, O.H. , Kendall, K.A. Nevens, W.3.,, and Hansen, R.G 
(1956). The value of animal fat in rations
for milk production..
J. Dairy Sci. 39: 1461
Howell, S.F. (1939). The determination of the urea in 
chicken blood.
J. Biol, Chem. 128: 573
Howell, S. F., (1939). The determination of blood urea.- 
J. Biol. Chem. 129: 641
Hungate, R •E. (1957
Can. J. Microbiol. 3: 289
Hungate, R .E. (1966). The Rumen and its Microbes.
Printed by the Academic Press, . New York and 
London.
Hungate, R,E. (1968). The Rumen and its Microbes. 2nd 
Edition. Printed by the Academic Press.
New York and London.
373
UNIVERSITY OF IBADAN LIBRARY
Jackson, R .3. (1966). Gas liquid chromatography of
volatile fatty acids from formic acid to 
valeric acid. 11. The instability of the 
Silicone oil-fatty acid stationery phases,
J. Chromat. 22: 251
James, A.T ., and Martin, A.J.P. (1952), Gas-liquid parti­
tion chromatography: the separation and 
micro-estimation of V.F.A, from formic to 
Dodecanoic acid.
Biochem. J, 50: 679
Jenness, R , and Patton, S. (1959). Principles of dairy 
chemistry. Published by Chapman and Hall 
Ltd. London.
Jennings, .G. (1957). Application of gas-liwuid chroma­
tography to the study of volatile flavour 
compounds.
J. Diary Sci. 40: 271
374
UNIVERSITY OF IBADAN LIBRARY
Jensen, E., Klein, J.W., Ranchenstein, E,, Woodward, T.E., 
and Smith R.H. (1942). Input-output 
relationships in milk production.
U.S.D.A. Tech. Sul. 815
Jensen, R.G., and Sampugna, J. (1962). Identification of 
milk fatty acids by G.L.C. and T.L.C.
J. Dairy Sci. 45: 435
John, A., Barnett, G., and Reid, R.L. (1957). Studies on 
the production of volatile fatty acids from 
grass by rumen liquor in an artificial 
rumen. 1. The volatile fatty acid produc­
tion from fresh grass,
J. Agric. Sci. 48: 315
Johnson, R.R., Dehority, B.A., Conrad, H.R, and Davis,
R.R. (1962). Relationship of 'in vitro1 
cellulose digestibility of undried and dried 
mixed treatments to their 'in vivo' dry 
matter digestibility.
J. Dairy Sci. 45: 250
375
UNIVERSITY OF IBADAN LIBRARY
Johnston, R.P., Kesler, E.M. and McCarthy, R.D. (1961).
Absorption of organic acids from the 
omasum.
J. Dairy Sci. 44: 331
Joseph Edwards (1950). Factors affecting the relationship 
between the secretion of milk and butter fat. 
J. Agric. Sci. 40:
Joshi, R.N ., and Phillips, R.W.' (1953). Zebu cattle of 
India and Pakistan. F.A.O. Agricultural 
Studies. Rome, Italy.
Joyner, A.E., Kesler, E.M^ and Holter, J.B. (1963).
Absorption from the omasum and subsequent 
metabolism of butyrate and acetate.
J. Dairy Sci. 46: 1108
Jumah, H.F., Poulton, B.R., and A*pgar, W.P. (1964).
Energy and protein utilization during 
lactation.
J‘. Dairy Sci'. 48: 1210
376
UNIVERSITY OF IBADAN LIBRARY
Kameoka, K. and Morimoto, H. (1959). Extent of digestion
in the rumen reticulum - omasum of goats.
Kammlade , W.G. (1947). Sheep science.
Published by J.3. Lippincott Company, U.S.A.
Kane, E.A. , Ely, R.E., Jacobson, W.C., and Moore,L.A. (1953) 
A comparison of various digestion trial 
techniques with cattle.
J. Dairy Sci. 36: 325
Kane, E.A. , and Jacobson, VAC. (1954). An improved method 
of using plant pigments as an indicator of 
digestibility.
J. Pairy. Sci. 37: 672
Keay, R.W. J. (1953). An outline of Nigerian Vegetation. 
Published by Government Printer, Lagos, 
Nigeria.
Kennedy, W •K., Carter, A,H,, and Lancaster, R.J. (1959). 
Composition of faecal pigments and faecal 
nitrogen as digestibility indicators in 
grazing cattle studies.
N.Z.J, Agric. Res. 2: 627
377
UNIVERSITY OF IBADAN LIBRARY
Kistner, i.L., Gouws, L., and Gilchrist, F.M. (1962 
J. Agric. Sci. 59: 85
Knox, K.L , and Wood, G.M, (1961). Rumen concentrations 
of volatile fatty acids as affected by 
feeding frequency.
J. Dairy Sci. 44: 1550
Kon, S.K. and Cowie, A.T. (1961). Milk: The mammary 
gland and its secretion. Volume II. 
Published by Academic Preiss. Netv York and 
London.
Kuramoto, S., Jezeski, J.J., and Holman, R.T.. (1957). 
Displacement separation of some of the 
component fatty acids of milk fat.
J, Dairy Sci. 40: 314
378
UNIVERSITY OF IBADAN LIBRARY
Lancanster, R.J. (1949). The measurement of feed intake 
by grazing cattle and sheep. 1. A method 
of calculating the digestibility of pasture
based on the nitrogen content of faeces 
derived from pasture.
N. Z. J. Sci. Tech. 25: 31
Lancaster, R.J., (1954). Measurement of feed intake of 
grazing cattle and sheep.
V. Estimation of feed-to-faeces ratio from 
the nitrogen content of the faeces of pasture 
fed cattle.
N. Z. J. Sci. Tech. 36: 15
Le Bars, H (1967). Urea as a protein supplement.
Published by Pergamon Press Ltd., Headington 
Hill Hall, Oxford, 4 and 5 Fitzroy Square, 
London, W.l.
Leiboff, S.L., and Kahn, B, (1929). A rapid and accurate 
method for the determination of urea in blood. 
J. Biol. Chem. 83: 347
379
UNIVERSITY OF IBADAN LIBRARY
Lewis, D. (1957). Blood urea concentration in relation to 
protein utilization in the ruminant.
J. Agric. Sci. 43; 438
Ling, E.R. (1964). A text book of Dairy Chemistry. Vol.
I. Published by Chapman and Hall Ltd., 
London.
Ling, E.R. (1956). A text book of Dairy Chemistry. Vol.
II. Published by Chapman and Hall Ltd. 
London.
Ling, E.R., Kon, S.K., and Porter, J.W.G. (1961).
The composition of milk and the nutritive 
value of its components. Milk: The mammary 
gland and its secretion. Volume II. 
Published by Academic Press. New York and 
London.
Ling, E.R. (1963). A text book of Dairy Chemistry. Vol.
I. Theoretical.Published by Chapman and 
Hall Ltd., 37 Essex Street, London, W.C.2.
380
UNIVERSITY OF IBADAN LIBRARY
Ling, E.R. (1963). A text book of dairy chemistry.
Vol.II. Practical. Published by Chapman and 
Hall Ltd. 37 Essex Street, VJ.C.2.
Lond, M.I.E. (1967) Investigations on the ’In vitro * 
digestibility techniques used under East 
African conditions.
East Afric. Aqric. Forestr. J . 33: 166 No.2
Luick, J.R., (1960) Milk fat synthesis,
J. Dairy Sc. 43: 1344
Mabbitt, L.A., and Mckinnon, G (1963) The detection of
volatile components of milk by G.L.C. and its 
possible application in assessing keeping 
quality and flavour.
J . Dairy. Res« 30: 359
Mahadevan, P. (1958). Dairy cattle breeding in the Tropics.
Published by Commonwealth Agricultural Bureaux, 
Bucks, England.
381
UNIVERSITY OF IBADAN LIBRARY
Mason, I.L. (1959) The classification of West African live­
stock. Commonwealth Agricultural Bureaux 
Technical Communication No.7; 23
Mason, I.L., and Maule, J.P. (1960). The indegenous live­
stock of Eastern and Southern Africa.
Published by Commonwealth Agricultural 
Bureaux, Bucks, England.
Maynard, L.A., Loosli, J.K., and McCay, L (1941) Further 
studies of the influence of difference levels 
of fat intake upon milk secretion.
Cornell. Agr. Exp. Sta, Bui. 753
Maynard, L.A,, and Loosli, J.K. (1962) Animal Nutrition.
5th Edition. Published by McGraw-Hill Book 
Company, Inc.
McCarthy, R.D. and Kesler, E.M., (1956) Relation between 
age of calf, blood glucose, blood and rumen 
levels of volatile fatty acids and 'in vitro1 
cellulose digestion.
J. Dairy Sc. 39: 1280
382
UNIVERSITY OF IBADAN LIBRARY
McDonald, I.W. (1954) The extent of convertion of food
protein to microbial protein in the rumen of the 
sheep.
Biochem. J. 56: 120
McDougall, E.I. (1948). Studies on ruminant saliva.
I. The composition and output of sheep's 
saliva.
Biochem. J , 43: 1948
Milford, R., and Minston, D.J, (1965a) The relationship 
between the crude protein content and the 
digestible crude protein content of tropical 
pasture plants,
J. Brit„ Grassld. Soc. 20: 177
Milford, R* and Minson, D.J, (1965) Intake of tropical 
pastures species. 9th Int, Grassld, Congr, 
Brazil.
Miller, T.B., and Blair Rains, A, (1963) The nutritive
value and agronomic aspects of some fodders in 
Northern Nigeria.
J. Brit. Grassl. Soc. 18; 150 No.2
383
UNIVERSITY OF IBADAN LIBRARY
Miller, T.B, Rains, A.B., and Thorpe, R.J. (1964) The
nutritive value and agronomic aspects of some 
fodders in Northern Nigeria. III. Hays and 
dried crop residues.
J. Brit. Grass1, Soc, 19: 77
Minson, D.J., Taylor, J.C., and Alder, F.E., Raymond, W.F.
and Rudman, J.E. (1960) A method for identifying 
the faeces produced by individual cattle or 
groups of cattle grazing together.
J. Brit. Grassl. Soc. 15; no.l, 86
Mitchell, H.H. (1962) Comparative nutrition of man and 
domestic animals. Vol.l
Published by Academic Press, New York and 
London.
Moir, R»J. (1951)
Austr. J. Agr. Res. 2: 322
Montgomery, M.J., Schultz, L.H., and Baumgardt, B.R.(1963)
Effect of introruminal infusion of volatile
fatty acids and lactic acid on voluntary hay 
intake.
J. Dairy Sci. 46: 1380
384
UNIVERSITY OF IBADAN
LIBRARY
Moore, A.W. (1962) The influence of a legume on soil
fertility under a grazed tropical pastures.
Emp, J, Exp. Agric, 30; 230
Moore, J.H. (1953) The effect of diurnal variations in
composition of the faeces of pigs on the deter­
mination of digestibility coefficients by 
chromic oxide method,
Brit. J_j_ Nutr. 12; 24
Moore, L.A. (1964) Feeding pellets and waters to dairy 
animals compaxed to chopped or long forage.
J. Anim. Sci, 23; 230
Moore, L.A. (1964) Symposium on forage utilization.
Nutritive value of forage as affected by 
physical form. Fart 1. General Principles 
involved with ruminants and effect of feeding 
pelleted or watered forage to dairy cattle.
Motta, M.S. (1953) Panicum Maximum
Emp. J . Exp.. Agric ., 21; 33
385
UNIVERSITY OF IBADAN LIBRARY
Naga, M.A., and El-Shazly, K. (1969). Activities of rumen
micro-organisms in water buffalo and in Zebu 
cattle.
J. Dairy. Res, 36: No.l; 1
National Research Council. (1958) Nutrient requirements 
for farm animals. No.4, Nutrient requirements 
for dairy cattle. Washington, D.C,
Nevens, W .B., Alleman, M.B., and Peck, T.L. (1926) The 
effect of fat in the ration upon the percentage 
fat content of the milk.
J , Dairy Sci. 9: 307
Newman, D .M.R. (1968) A comparison of the nutritional value 
of Stylosanthes humilis, Stylosanthes guya- 
nensis and introduced grasses in Northern 
Australia.
Aust. J, Exp. Agric. An. Husb. 8: 172
Nickerson , T.A. (1961) Inter-relationship of milk consti­
tuents .
J. Dairy Sci, 44: 1025
386
UNIVERSITY OF IBADAN LIBRARY
\
Nikelly, J,G. (1964) Gas chromatography of free fatty 
acids.
Anal. Chem. 36: 2244 No,12
Nwosu, N.A. (1960) Conservation and utilization of Stylo- 
santhes gracilis.
Trop. Agric, Trin, 37: 61
Nwosu, N fA, (1961) The propagation of Stylosanthes; esta­
blishment from stem cuttings,
Niger Scient, 1: 24
Ode, J,0, (1970) Effect of different soil depths on the
germination of Centrosema pubescens and Stylo­
santhes gracilis Diploma project, Inst, Agric, 
Res, Training University of Ife, Moor Planta­
tion, Ibadan,
Oke, 0,L. (1967) Nitrogen fixing capacity of some Nigerian 
legumes,
Exp, Agric, 3: 315,
Oke, S,0, (1961) Agege Dairy Farm Annual Report,
387
UNIVERSITY OF IBADAN LIBRARY
Okorie, I.I., Hill, D.H., and Mcllory, R.J, (1965) The 
productivity and nutritive value of tropical 
grass/legume pastures rotationally grazed by 
N'dama cattle at Ibadan, Nigeria.
J. Agric. Sci, 64, Part 2,: 235
01aloku,E.A. (1968) The effect of energy and protein
levels on milk yield and butterfat content of 
White Fulani cattle.
Niger. Agric. J . 5: 42
Olaloku, E.Af, Egbuiwe, A,Mi, and Oyenuga, V.A, (1971).
The influence of cassava in the production 
ration of the yield and composition of milk 
of White Fulani cattle,
Niger. Agric, J. 8: 36
Olubajo, F.O, (1969) Assessment of the productivity,
digestibility and the nutritive value of tropi­
cal pastures at Ibadan* Theses submitted to 
the Faculty of Agriculture, forestry and 
veterinary science, University of Ibadan.
388
UNIVERSITY OF IBADAN LIBRARY
Olubajo, F.O. (1970) Use of chromic oxide in Indoor dige­
stion experiments with tropical Grass-Legume 
mixture using White Fulani steers.
Niger. Agric. J. 7 i 105
Owen, E . . , Smith, J.A.B., and Wright, N.C. (1943) Urea 
as a partial protein substitute in the feeding 
of Dairy Cattle.
Biochem, J. 37; 44
Oyenuga, V.A. (1957) The composition and Agricultural 
value of some grass species in Nigeria.
Emp. J. Exp. Agric. 25: 237
Oyenuga, V.A. (1958) Problems of livestock nutrition in 
Nigeria: A review.
Nutr, Abs, Rev. 28: 985
Oyenuga, .A. (1959a) Effect of frequency of cutting on 
the yield and compsotion of some fodder grasses 
in Nigeria (Pennisetum purpureum, Schum)
J. Agric. Sci. 53: 25
389
UNIVERSITY OF IBADAN LIBRARY
Oyenuga, V.A. (1960b) Effect of stage of growth and
frequency of cutting on the yield and chemical 
composition of some Nigerian Fodder grasses. 
West African J . Biol. Chem. 3: 43-58
Oyenuga, V.A. (1960c.) Effect ofstacie of; growth and fre­
quency of cutting on the yield and chemical 
composition of Nigerian fodder grasses 
(Panicvm maximum Jacq)
J_ p̂ gricp_ Sci, 55: 339
Oyenuga, V.A, (1960b) Effect of requency of cutting on the 
yield and chemical composition of some Nigerian 
fodder grasses (Tripsacum laxum Nash)
W. Afr. J . biol, Chem, 4: 46
Oyenuga, .A, and Olubajo, F.O. (1966) Productivity and 
nutritive value of tropical pastures at Ibadan. 
Proc, X Inter. Grassl, Congr,
390
UNIVERSITY OF IBADAN LIBRARY
Packett, L.V. and McCune, R.W, (1965) Determination of 
steam volatile fatty acid in fermented media
by G.L.C.
Appl. Microbiol. 13 No.l: 22
Palmquist, D.L., Smith, L.M. and Ronning, M. (1964) Effect 
of time of feeding concentrates and ground 
pelleted alfalfa hay on milk fat per-centage 
and fatty acid composition.
J. Dairy Sci. 47; 516. No.5
Patterson, D.D. (1933) The influence of time of cutting on 
the growth, yield and composition of tropical 
fodder grasses. 1. Elephant grass. (P. purpu- 
reum).
J. Aqric. Sci. 23: 615
Patterson, W.J.A. and Hancock, J. (1957) The direct effect 
of tropical climate on the performance of 
European type cattle.
Emp. J. Exp. Agric. 25: 231
391
UNIVERSITY OF IBADAN LIBRARY
Patton, S., McCarthy, R.D., Laura Evans and Lynn, T.R.,
(1960) Structure and Synthesis of milk fat. 1. 
gas chromatographic analysis.
J. Dairy Sci. 43^ 1187
Patton, S,, McCarthy, R.D. , and Laura Evans (1960) Stru­
cture and a synthesis of milk fat. 11. Fatty 
acid distribution in the triglycerides of milk 
and other animal fats.
J. Dairy Sci, 43: 1196
Patton, S,, Laura Evans, Jeusen, R.G., and Gander, G.W., 
McCarthy, R.D. (1962) Structure and synthesis 
of milk fat. 111. Utilization of pentodecano- 
ate infused into the lactating goat mammary 
gland.
J. Dairy Sci. 45: 248
Patton, S., and McCarthy, R.D., (1963) Structure and
synthesis of milk fat. IV. Role of the mammary 
gland with specific reference to the choleste- 
roid esters.
J. Dairy Sci. 46: 396
392
UNIVERSITY OF IBADAN LIBRARY
Patton, S., and McCarthy, R.D. (1963) Structure and
synthesis of milk fat, V. A postulated seque­
nce of events from analyses of mammary tissue 
lipids.
J, Dairy Sci. 46: 916
Patton, S., Anita Durdan, and McCarthy, R.D, (1964) Stru­
cture and synthesis of milk fat. VI. Unity of 
phospholipids in milk.
J. Dairy Sci. 47: 489 No.5
Pastoi. ,J.K., Allison, J.R., and Washko, J.B. (1957) Ground 
cover and height of sward as a means of estima­
ting pasture production.
Agron. J, 49t 407
Payne, W.J.A., and Hancock, J. (1957) The direct effect of 
Tropical climate on the performance of European- 
type cattle. ii. Production.
Emp. J , Exp. Aqric. 25: 321
393
UNIVERSITY OF IBADAN LIBRARY
Pearson, R •M., and Smith, J.A.B,, (1943) The utilization 
of urea in the bovine rumen* 1» Methods of ana­
lysis of rumen ingesta and preliminary experi­
ments 'in vivo *
Biochem. J. 37: 142
Pennington , R.J., and Pfander, W.H., (1957) The metabolism 
of short chain fatty acids in the sheep;
5. Some inter relationships in the metabolism 
of fatty acids and glucose by sheep.
Biochem. J, 65: 109
Pereira, H .C., and Beckley, V.R.S* (1953) Grass establish­
ments on eroded soil in a semi arid African 
reserve.
Bmp, J. Exp. Agric. 21: 1
Pereira, H.,C; (1959) Lessons gained from grazing trials 
at Makavete, Kenya.
E, A.frica Agric. K  25: 59
394
UNIVERSITY OF IBADAN LIBRARY
Phillipson, A.T., and McAnally, R.A. (1942). Studies of the 
fate of carbohydrates in the rumen of the sheep, 
J. Exp, biol, 19: 199
Popjack, G. Glascock, R.F., and Folley, S,J. (1952)
Incorporation of (carboxy - C 14 ) acetate into 
lactose and glycerol by the lactating goat u^der, 
Biochem. J. 52: 472
Popjack, G. Glascock, R.F., and Folley, S.J. (1953) Bio­
synthesis of milk fat in the rabbit from acetate 
and glucose. The mode of convertion of carboh­
ydrate into fat.
Biochem. J , 54: 238
Poultney, R.G. (1959) Preliminary investigations on the
effect of fertilizers applied to natural grass­
land.
B. Afr. Agric. J. 25: 47
Pratt, D.J. and Knight, J. (1964) Reseeding denuded land
in Baringo district, Kenya.
iii. Techniques for capped red loam soils,
B. Afric. Agric. For. J, 30: 117
395
UNIVERSITY OF IBADAN LIBRARY
Putnan, '.A. Gutierrez, J*, and Davis, R.E. (1961) Effects 
of frequency of feeding upon rumen volatile 
fatty acids. Protozoal population, and weight 
gains in Angus calves.
J. Dairy Sci. 44; 1364
Raymond, W.F. (1948) Evaluation of herbage for grazing. 
Nature 161; 937
Raymond, W.F* (1954) Studies in the digestibility of her­
bage* 111» The use of faecal collection and 
chemical analysis in pasture studies (a) Ratio 
and tracer method.
J. Brit. Grassl. Soc, 9: 61
Raymond, W.F., Kemp, C.D., Kemp, A.W., and Harris,C.E*
(1954). Studies in the digestibility of herbage 
IV. The use of faecal collection and chemical 
analysis in pasture studies. 6. Faecal index 
methods.
J. Brit. Grassl. Soc* 9: 69
396
UNIVERSITY OF IBADAN LIBRARY
Raymond, W.F,, Minson, D.J,, and Harris, C.E. (1956) The
effect of management on herbage consumption 
and selective grazing.
Proc. 7th Int. Grassl. Congr. p,123
Raymond, G., Hinders, and Gerald Ward. (1961) Influence of 
various feeds on fin vivi' and 'in vitro' pro­
duction of volatile fatty acids. J.
J. Dairy Sci. 44: 1129
Raymond, W.F. and Terry, R,A, (1966). Studies of herbage 
digestibility by an 'in vitro' method,
Reid, J.T , Woolfolk, P.G., Hardison, W,A., Martin, C.M, 
Brundage, A.L., and Kaufmann, R.W, (1952) A 
procedure for measuring the digestibility of 
pasture forage under grazing conditions,
J. Nutr. 46: 255
Reid, J.T . (1953) Urea as a protein replacement - a 
review,
J, Dairy Sci. 36: 955
397
UNIVERSITY OF IBADAN LIBRARY
Research Techniques in use at The Grassland Research
Institute Hurley Bulletin 45..1965, Common­
wealth Agricultural Bureaux..
Richards, C.R. and Reid, J.T. (1952) The use of methoxyl 
groups in forage and faecal material as an 
index of the feeding value of forages.
J . Dairy Sci. 35: 595
Richards, C.R., and Reid, J.T. (1953) The digestibility 
and interrelationships of various carbohydrate 
fractions of pasture herbage and a resolution 
of the components of crude fibre and N.F.E.
J, Dairy Sci. 36: 1006
Rogerson, A. (1958) Diet and partial digestion in sections 
of the alimentary tract of the sheep.
Brit. J. Nutr. 12: 177
Rook, J.A, F. (1953) The effect of high plane of nutrition 
on the composition of milk,
Proc. Nutr. Soc, 12: viii
398
UNIVERSITY OF IBADAN LIBRARY
Salmon, S.C., and Hanson, A.A., (1964) The principles and 
practice of Agricultural Research. Published 
by Leonard Hill, London.
Salsbury, R;L;, Hoefer, J.A., and Luecke, R.W. (1961) 
Effect of feeding certain defined nutrients 
on cellulose digestion and volatile fatty acids 
concentration of the rumen.
J. Dairy Sci. 44; 122
Schaadt, H., and Johnson, R.R. (1966) Volatile fatty acid 
production in the rumen of sheep fed limestone
and urea treated corn silages.
J. Anim. Sci. 29: 839, No.5
Schneider, B.H., Lucas, H.L. Pavlech, H.M., and Cipolloni, 
M.A. (1951). Estimation of the digestibility 
of feeds from their proximate composition.
J. Anim. Sci. 10; 706
Shaw, T., and Colvile, G. (1950) Report of Nigerian live­
stock mission. Colonial Office. Published by 
his Majesty’s Stationery Office.
399
UNIVERSITY OF IBADAN LIBRARY
Scott, H.'W., and Dehority, B.A. (1965)
J. Bacteriol. 89: 1169
Shaw, J.C. Robinson, R.R. Senger, M.E., Lewis T.R., and
Lakshmannan, S., (1959) 1. Effect of quality and 
quantity of concentrate on the volatile fatty 
acid of the rumen and of the composition of the 
milk.
J. Nutr. 69: 235. No.3
Sijpesteijn, A.K. (1951)
J. Gen..Microbio 1. 5: 869
Sijpesteij, A.K., and Elsden, S.R. (1952) The metabolism 
of succinic acid in the rumen of the sheep. 
Biochem. J, 52: 41
Smith, L.M. and Jack, E.L. (1954) The unsaturated fatty
acids of milk fat. 1. Methyl ester fractiona­
tion and isolation of monoethanoid constituents. 
J . Dairy Sci. 37: 330
Smith, L.M, and Jack, E.L. (1954) The unsaturated fatty
acids of milk fat. 11. Conjugated and non- 
con jugated constituents.
J . Dairy Sci„ 37: 390
400
UNIVERSITY OF IBADAN LIBRARY
Smith, ,M. Freeman, M.K., and Jack, E.L. (1954) The
unsaturated fatty acids of milk fat. 111.Geo­
metrical isomerism.
J. Dairy Sci. 37: 399
Smith, .M., and Reid, J.T. (1959) Use of chromic oxide 
as indicator of faecal output for the purpose 
of determining the intake of pasture herbage 
by grazing cows.
J. Dairy Sci. 38: 515
Smith, L •M. (1961) Quantitative fatty acid analysis of 
milk fat by G.L.C.
J . Dairy Sci, 44: 607
Smith, C .A. (1961) Utilization of Hyparrhenia veld for the 
nutrition of cattle in the dry season, 
ii. Veld hay compared with in situ grazing of 
mature forage, and the effects of feeding 
supplementary nitrogen.
J. Aqric. Sci. 57: 311
401
V
UNIVERSITY OF IBADAN LIBRARY
Smith, C.A. (1961) The utilization of Hyparrhenia veld for 
the nutrition of cattle in the dry season, 
i. Effects of nitrogen fertilizers and mowing 
regimes on herbage yields.
J . Agric. Sci. 57: 305
Smith, L.M. and Lowry, R.R. (1962) Fatty acid composition 
of the phospholipids and other lipids in milk.
J. Dairy Sci. 45± 581
Smith, C.A. (1964) Studies on the Northern Rhodesia Hypa­
rrhenia Veld. iv. The effects of nitrogen fer­
tilizer and defoliation.
J. Agric, Sci. 62; 299
Snedecor, G.W. and Cochran, W.G. (1967) Statistical
Methods. 6th Edition. Published by Iowa State 
University Press. Ames - lowâ , U.S.A.
Somers, M. (1961)Factors influencing the secretion of nit­
rogen in sheep soliva. 3. Factors affecting the 
nitrogen factions in the parotid saliva of sheep
with special refence to the influence of ammonia 
production in the rumen and fluctuations in level 
of blood urea.
Aust. J. Expt, Biol. Med. Sci. 39; 133
/
402
UNIVERSITY OF IBADAN LIBRARY
Stanley, R.W., Morita, K., and Ueyama (1964) Effect of
feeding different rouphage levels and Na-acetate 
in high grain rations on milk production, milk 
constituents, and rumen V.F.A.
J. Dairy. Sci. 47: 258
Stewart, Stewart,D.G., and Schultz, L.K. (1958) Rates of 
volatile fatty acids production in the bovine 
rumen.
J, Anim. Sci. 1.7 No.3: 723
Stobbs, T.H. (1969) The effect of grazing management upon 
pasture productivity in Uganda. 1. Stocking 
rate.
Trop. Agric, 46; 187
Stobbs, T.H. (1969) The effect of grazing management upon 
pasture productivity in Uganda. 11. Grazing 
frequency.
Trop. Agric, 46; 195
403
UNIVERSITY OF IBADAN LIBRARY
Stobbs, T.H. (1969) The effect of grazing management upon 
pasture productivity in Uganda. 111. Rotational 
and continuous grazing.
Stobbs, T.H. (1969) The effect of grazing management upon 
pasture productivity in Uganda. IV. Selective 
grazing,
Trop. Agric. 46: 303
Storry, J.E., and Millard, D. (1965) The determination of 
steam volatile fatty acids in rumen liquor, 
blood plasma and milk fat.
J. Sci. Pd. Agric. 16: 417
Sullivan, J.T., (1959) A rapid method for the determina­
tion of acid-isoluble lignin in forages and its 
relation to digestibility.
J . Anim. Sci. 18 No.4: 1292
Sutton, J.D., (1968) The fermentation of soluble carbohy­
drates in rumen contents of cows fed diets 
containing a large proportion of hay.
Brit. J, Nutr. 22: 689
404
UNIVERSITY OF IBADAN LIBRARY
Sutton, J.D., McGilliard, A.D. , Jacobson, N.L. (1963)
Functional development of rumen mucosa. 1. Absorp­
tive ability.
J. Daily Sci. 46: 426
Synge, R.M. (1953)
J. Gen, Microbiol. 9: 407
Terner, C. (1951) Pathways of pyruvate metabolism in the 
mammary gland.
Biochem. .J. 50: 145
Terry, R.A., and Tilley, J.M.A. (1964) The digestibility
of leaves and stems of perenial rye grass, cock- 
stoot, timothy, tall fescue, lucerne and sain­
foin, as measured by an 'in vitro * procedure.
J. Brit. Grass 1. Soc. 19: 363
Todd, J.R. (1965) Investigations into the chemical compo­
sition and nutritive value of certain forage 
plants of medium altitudes in the tropics.
11. The digestibility and nutritive value of 
three grasses at different stages of growth.
J. Agric. Sci. 47: 35
405
UNIVERSITY OF IBADAN LIBRARY
Topps, J,H, (1962) Studies of natural herbage of the sub­
tropics. 1. The digestibility of herbage 
grazed by Cattle.
J . Agric. Sci. 58: 387
Tuley, P. (1968) Stylosanthes gracilis 
Herbage Abst. 38; 87
Van Keuren, R.W, and Ahlgren, H.L, (1957) A statistical
study of several methods used in determining the 
botanical composition of a sward. 11. A study 
of several forage mixtures.
Aqron, J. 49: 581
Van Soest, P.J., and Allen, N.N., (1959) Studies on the 
relationships between rumen acids and fat 
metabolism of ruminants fed on restricted 
rouphage diets.
J, D-airy Sci. 42: 1977
406
UNIVERSITY OF IBADAN LIBRARY
Van Soest, F.J. (1966) Non-nutritive Residues, A system
of analysis for the replacement of crude fibre, 
J. A. 0. A. C. 49: 546
Varley, H, (1967) Practical clinical biochemistry.
Published by William Heinemann Medical Books 
Ltd., and Interscience Books Inc, New York,
Vivian, L. . (1959) The leguminous fodder "Stylo" or 
"tropical lucerne" in Kelantan.
Malay. Agric. J. 42: 183
Waldern, D.E., Johnson, V.L., and Blosser, T.H, (1963)
Cardiac output in the bovine and its relation­
ship to rumen and portal volatile fatty acid 
concentration.
J., Dairy Sci, 46: 327
Wardrop, I.D. (1961) Some preliminary observation on the 
histological development of the fore-stomachs 
of the lamb i±. The effccts*of diet on the 
histological development of the fore-stomachs 
of the lamb during post natal life.
J. Agric. Sci, 57: 343
407
UNIVERSITY OF IBADAN LIBRARY
Warner, A.C. (1962)
J. Gen. Microbiol. 28: 119
Waite, R. , Margaret, J. Johnston, and Armstrong, D.G. (1964) 
The evaluation of artificially dried grass as 
a source of energy for sheep. 1. The effect of 
stage of maturity on the apparent digestibility 
of rye grass and timothy.
J. Agric, Sci„ 62: 391
Watkins, J.M., Mario Leny-Van Severen (1951) Effect of 
requency and height of cutting on yield, stand, 
and protein content of some treatments in El 
Salvador.
Agron. J. 43: 291
Weenink, R.O. (1958) The steam distillation of volatile 
fatty acids.
New Zealand J. Sci. 1: 18 No.l
Wegner, G.H. and Foster, E.M. (1960) Fatty acid require­
ments of certain rumqn bacteria.
J* Pairy. Sci. 43: 566
408
UNIVERSITY OF IBADAN LIBRARY
Wegner, G.H., and Foster, B.M. (1963)
Bacteriol . 85: 53
Wilier, R.A., and Gray, F.W. (1954). The passage of starch 
through the stomach of the sheep.
J. Bxpt. Biol. 31; 40
West, E.S. Todd, W.R., Mason, H.S., and Bruggen, J.T.U.
(1963) Text book of biochemistry. Fourth 
edition. Collier-Macmillan Ltd., London.
Whyte, R.O., Moir, T.R., and Cooper, J.P. (1959) Grasses 
in Agriculture. F.A.O.
Agric. Stud, No. 42. Rome. F.A.O.
William Davies and Skidmore, C.L. (1966). Tropical
Pastures. Published by Faber and Faber Ltd.
24 Russel Square, London,W.C.1.
Williamson, G., and Payne, W.J.A. (1959) An introduction 
to Animal husbandry in the tropics. Published 
by Longmans, Green & Co. Ltd. London.
Wilson, A.D. (1964) Parotid saliva and rumen digestion 
in the sheep.
Brit. J. Nutr. 18: 168
409
UNIVERSITY OF IBADAN LI RARY
Woodman, H.E., Evans, R.E. and Norman, D^B. (1934).
Nutritive value of lucerne. 11*. Investigation 
i; to the influence of systematic cutting at 
three different stages of growth on the yield, 
composition and nutritive value of lucerne.
J. Agric. Sci, 24: 284
410
UNIVERSITY OF IBADAN LIBRARY