STUDIES ON DRY MATTER, ENERGY AND PROTEIN UTILIZATION OF THREE BREEDS OF DAIRY COUS • AT IBADAN BY ADEBISI ADEBOWALE B.Sc. (Hons.) in Agricultural Biochemistry and Nutrition (Ibadan) ■ r 4 A thesis in the Department of ANIMAL SCIENCE Submitted to the Faculty of Agriculture and Forestry in partial fulfilment of the requirements for the degree of DOCTOR OF PHILOSOPHY Df the UNIUERSITY OF IBADAN IBADAN JULY, 1076 UNIVERSITY OF IBADAN LIBRARY i i i ABSTRACTS ~ Comparative studies were conducted on exotic (German Broum and Friesian) and indigenous (White Fulani) lactating cotus to assess (a) the systems Df management best suited for the newly imported lactating, exotic cows for maximum production (b) the effects of seasons, stage of lactation, breeds and diets on feed dry matter (DM) intake, liveweight changes, milk yield and composition, respiration and body temperature of White Fulani (WF), German Brown (GB) and Friesian (F) lactating cows and (c) the effects of DM intake, dietary level, stags of lactation and breed on productivity, digestibility of feed, milk composition, energy and protein utilization, rumen and blood metabolites. Results on management studies indicated that the grazed cows produced more milk, solids-corrected milk (SCM), butter- fat, ash and less milk protein than the stall-fed (P^G.05). Although higher respiratory counts, water intake and body temperatures were recorded for the grazed cows than the stall- fed ones, the results were not statistically significant (P> D.05) Lactation studies showed that the exotic breeds consumed more forage DM than the indigenous, giving 5.92io.2l, 5.59io.l6 UNIVERSITY OF IBADAN LIBRARY i v and A.A9-0.16kg/day far the F, GB and WF cows respectively. The peak forage DM intake was attained between the 5th and 10th week of lactation. The mean milk yield and SCM were 27.55^6.15 and 29.B3i5.26kg/week respectively for the UF cows, £+0.16i6.15 and 36.91^3.26 respectively for the F and A1.16i8.19 and AO.16i5.6Akg/week respectively for the GB. Peak milk production was attained between the 5th and 9th week of lactation. Generally, results showed that the milk of the UJF cows possessed higher milk quality, producing higher percentage of butterfat and protein, than the exotic breeds. Although there were more forage DM intake during the dry season than the wet, higher milk yield was recorded during the latter season than the former. Liveweight losses occurred from the beginning of the experiment to about the 10th week of lactation. The results of the relationship between rumen metabolites and milk yield showed that when the ratio of acetate to propionate was lower, there was a higher yield of milk and protein but when the ratio was higher, there was an increased butterfat. The digestible crude protein'(DCP) values for maintenance were 0.39g/day/bjj^’7'^ (91.82g/day available protein (AP), O.A7g/day/iJ°*73a (113.28g/day AP) and 0.52g/dayA)°'73Zt (121.77g/day AP) for the LJF, GB and F cows respectively. The re­ balance studies indicated that 6.69gDCP/dayA!^*73it (30A.B0gAP/day) UNIVERSITY OF IBADAN LIBRARY I V were required by the UF cows to produce 3.35kg milk/day (0.519SN), 6.3tt^)CP/day/Uk°g*73if (353.93gAP/day) by the GB coujs to produce G.17kg milk/day (□.47y£f\l) and 6.5AgDCP/ day/ldFk1g*73^ (359.20g AP/day) by the F cows to produce 7.08kg milk/day (O.A9%M). The mean net efficiency of protein utilization were 27.95, A3.A3 and 53.73% for the LdF, GB and F cows respectively. The metabolizable energy values for maintenance were 0.53, 0.59 and 0.61 HJ/day/li)^*73^ for the UF, GB and F cows respectively. These are 72.29, 72.75 and 73.A3% of the Ministry of Agriculture, Fisheries and Food of the United Kingdom CMAFF)(1975) recommendation respectively. The gross energetic efficiencies for milk production were 10.23, 12.79 and 1A.33% for the LdF, GB and F cows respectively while the net energetic efficiencies were 25.A7, 31.31 and 37.50% respec­ tively. Finally, the conclusions from the trials have shown that 8.3% (LdF), 10.3% (F) and 11.2% (GB) of the energy intake were contributed by the protein fraction af the DM intake. UNIVERSITY OF IBADAN LIBRARY f vi. ACKNOWLEDGEMENTS Wards are inadequate to express my profound gratitude and appreciation to my Head of Department, Professor V.A. Oyenuga and Drs. A.U. Mba, F.O. Olubajo and E.A. Olaloku for their inspiring instructions and supervision during the course of this study. I wish to thank further Professor Oyenuga for his liberal encouragement of the pursuit of knowledge and Drs. Mba and Olubajo who were magnanimous enough to provide funds from their research grants for the construction of the metabolic cages used in this study. I would like to register my heart-felt gratitude to Professor J.K. Loosli who also contributed ideas, guidance and encouragement during the eatly part of this study. My thanks are extended to the staff of the Department of Animal Science, University Dairy Farm and Grassland Research Section particularly Messrs. S.B. Alade, Wale Adesuyi, S. Eweme and Idowu for the assistance and facilities extended to me. i ) Lastly, I am heavily indebted to my father and mother, Chief and Mrs. O.A. Adebowale, my father-in-law and his wife, Mr. and Mrs. F.A.O. Akomolede, my brother-in-law and his wife, Mr. and Mrs. Ifemidayo Adejuwon, Mrs. Oyinlola Lasebikan, and UNIVERSITY OF IBADAN LIBRARY vii my intimate colleague and his uife Mr. and Mrs. Francis Ogundola for their moral, financial and encouraging assistance in every phase of this work. To all those I find difficult to mention their names, not because of oversight but lack of space, I say a big thank you for your cooperation. UNIVERSITY OF IBADAN LIBRARY vlii CERTIFICATION BY SUPERVISORS We certify that this work was carried out by MR. ADEBISI ADEQOWALE in the Department of Animal Science, University of Ibadan. (Supervisor) (Supervisor) V.A. OYENUGA B.Sc. (Agric.) A.U. MBA B.Sc. (Agric.) Ph.D. (Dunelm), F.R.I.C. Ph.D. (Dunelm) Professor 8 Head of Department. Reader. Ia t C v--- (Supervisor) F.Q. OLUBAJO B.Sc. (Illinois), E.A. OLALOKU B.Sc. (Agric.) M.Sc. (Ohio), Ph.D. (Ibadan) M.Sc. (Nott.), Ph.D. (Ibadan) Senior Lecturer. Senior Lecturer. July, 1976 UNIVERSITY OF IBADAN LIBRARY ix DEDICATION Dedicated to ABOSEDE ------- my indispensable 'right hand'. UNIVERSITY OF IBADAN LIBRARY X TABLE OF CONTENTS Page T I T L E ............................................. ii ABSTRACTS ...................................... iii A CKNOULED GEMENT .. ....................... vi CERTIFICATION BY SUPERVISORS viii DEDICATION ...................................... ix TABLE OF C O N T E N T S .............................. x LIST OF TABLES xv LIST OF FIGURES xxiv LIST OF PLATES xxv CHAPTER 1 1.1 General Introduction .. .. .. 1 1.1.1 The Protein Gap .. .. .. .. 3 1.1.2 Factors affecting animal protein level .. k 1.1.3 Nutritional importance of milk and dairy products .. .. .. .. 11 1.1.A The production, supply and consumption of milk in Nigeria .. . . . .. 14 1.1.5 Some prospects of increasing milk production in Nigeria .. .. .. 17 1.2 Literature Review .* .. .. .. 18 1.2.1 Historical background and adaptation of the ruminant .. .. .. .. .. 18 UNIVERSITY OF IBADAN LIBRARY xi TABLE OF CONTENTS (CONTD.) Page 1.2.2. Ruminant feeds and feeding standards .. 22 1.2.3. Feed intake in Dairy cous .. .. .. 25 1.2. A. Importance of supplementary concentrate .. 27 1.2.5. Effect of feed on ruminal UFA'S. .. .. 31 1.2.6. Absorption and utilization of UFA .. .. 35 1.2.7. Ammonia absorption and utilization in the rumen .. .. .. .. .. 38 1.2.8. Chemistry of milk constituents .. .. A1 1.2.9. Effect of diet on milk yield and composition .. .. .. .. .. 55 1.3. General Objectives .. .. .. .. 63 CHAPTER 2 A COMPARATIUE STUDY ON THE EFFECT OF GRAZING AND STALL-FEEDING ON THE FEED INTAKE, MILK YIELD AND COMPOSITION OF GERMAN BROUN AND FRIESIAN COliJS .. 6A 2.1. Introduction .. .. .. .. .. 6A 2.2. Materials and Methods .. .. .. .. 65 2.2.1. Animals and their Management .. .. .. 65 2.2.2. Management and health of the animals .. 69 2.2.3. Diets and plan of the experiment .. .. 70 v 2.2.A. Uater intake of the animals .. .. .. 78 2.2.5. Milk sampling .. .. .. .. .. 80 2.2.6. Body temperature and respiration rate .. 80 2.3. Analytical procedure .. .. .. .. 81 UNIVERSITY OF IBADAN LIBRARY xii TABLE OF CONTENTS (CONTD.) Page 2. A. RESULTS ................................ BA 2.A.1. Dry Matter Intake .. .. .. .. BA 2.A.2. Milk yield and Solids-corrected milk.. .. B9 2.A.3. Milk composition .. .. .. .. .. 9A 2.A.A. Liveweight changes .. .. .. .. 10A 2.A.5. Water Intake, body temperature and respiration counts. .. .. .. .. .. .. 105 2.5. DISCUSSION................................ 110 CHAPTER 3 DRY MATTER INTAKE, MILK YIELD AND COMPOSITION OF WHITE FULANI, GERMAN BROWN AND FRIESIAN COWS MAINTAINED ON FORAGE AND LOW OR HIGH CONCENTRATES .. .. 120 3.1. Introduction .............. .. .. 120 3.2. MATERIALS AND M E T H O D S .................... 121 3.2.1. Animals and their management .. .. .. 121 3.2.2. Diets and plan of experiment .. .. 12A 3.3. Analytical procedure .. .. .. .. 12B 3.A. RESULTS ................................ 128 3.A.1. Bioclimatological data and chemical composition of the herbage, silage and concentrate supplement .. .. .. .. .. 130 3.A.2. Dry Matter Intake .. .. .. .. 130 3.A.3. Milk yield and Solids-corrected Milk .. 1A1 3.A.A. Milk Composition .. .. .. .. .. 151 UNIVERSITY OF IB DAN LIBRARY f . xiii TADLE OF CONTENTS (CONTD.) Page 3.A.5. Liveweight changes .. .. .. .. 166 3.5. DISCUSSION................................ 169 CHAPTER A ENERGY AND PROTEIN REQUIREMENTS FOR MAINTENANCE AND MILK PRODUCTION. 185 A.1. Introduction .. .. .. .. .. 185 A.2. MATERIALS AND M E T H O D S .................... 187 A.2.1. Animals and their Management .. .. .. 187 A.2.2. Diets and Plan of Experiment .. .. .. 188 A.2.3. Collection of faeces and urine .. .. 189 A.2.A. Milk Sampling .............. .. .. 193 A.2.5. Rumen and blood sampling .. .. .. 193 A.3. Analytical Procedure .. .. .. .. 19A A.A. RESULTS .............................. 199 A.A.1. Composition of the diets .. .. .. 199 A.A.2. Dry Matter Intake, Milk Composition, Rumen and Blood Metabolites of the Fistulated Coui .............................. 201 A.A.3. Milk Yield and Composition of intact Lactating Cows .. .. .. .. .. 207 A.A.A. Comparison of the digestibilities of the basal grass and supplements fed to the steers and lactating cdujs .. .. .. .. 212 UNIVERSITY OF IBADAN LIBRARY I xiv TABLE OF CONTENTS (CONTD.) Page A.A.5 Total digestible nutrient (kg/10Dkg feed) and metabolizable energy (MO/kg feed) 219 A.A. 6 Protein (Nitrogen) Utilization and Requirements for milk production .. 223 A.A.7 Energy Utilization 2AA A.A.a DPE : DE RATIO (Protein and Energy Interaction) 252 A.5 DISCUSSION 255 GENERAL SUMMARY OF CONCLUSIONS 27A R E F E R E N C E S .. 277 A P P E N D I X UNIVERSITY OF IBADAN LIBRARY I xv LIST OF TABLES TABLE HEADING PAGE 2.1 Components of dairy concentrate ration fed to German Broun and Friesian lactating cous .. .. 72 2 .2 Mean chemical composition of concentrate ration and forage fed to German Broun and Friesian lactating cous. .. .. .. 73 2.3 Mineral contents Qf the ration and forage per kg dry matter. .. 7L 2.A Feeding arrangements of cous uith their identification numbers on lou or high concentrates plus forage. ........... .. .. 76 2.5 Identification, bodyueight (kg), age and lactation records of the exotic cous used in the experiment. 2.6 Regression equations describing the relationship betueen total dry matter intake (kgDM/day) (Y), and metabolic size (X) of dairy cous. .. 85 2.7 Forage dry matter (kg/day) intake of stall-fed and grazed German Broun and Friesian lactating cous maintained on high or lou concentrate rations. 87 2.8 Total dry matter of forages and concentrates (g/dayAlP*7^ 1) consumed by exotic breeds of 9 cous under stall-feeding and grazing conditions. 88 2.9 Milk yield (kg/ueek) of the stall-fed or grazed German Broun and Friesian lacta­ ting cous maintained on high and lou concentrate ration. .. .. e# 91 UNIVERSITY OF IBADAN LIBRARY » xvi HEADING PAGE Salids-corrected milk (kg/uieek) of German Broun and Friesian milking cous grazed or stall-fed on high and lou concentrate ration. 92 Milk yield and composition of tuo breeds of cattle grazed or stall-fed on high and lou concentrate ration. .. .. .. 96 Milk fat (g/100g milk) content of stall- fed or grazed German Broun and Friesian lactating cous' milk maintained on high and lou concentrate rations. .. 97 Milk protein (g/100g milk) content of stall- fed or grazed German Broun and Friesian lactating cous* milk maintained on high and lou concentrate rations. .. 98 Total solids (g/1B0g milk) content of German Broun and Friesian cous’ milk grazed or stall-fed on high and lou concentrate rations. .. .. 99 Solids-not-fat (g/100g milk) content of German Broun and Friesian cous' milk grazed or stall-fed on high and lou concentrate rations. 102 Ash content (g/100g milk) of German Broun and Friesian cous* milk grazed or stall-fed on high and lou concentrate rations .. 103 Liveueight (kg) of the grazed or stall- fed German Broun and Friesian lactating cous on high and lou concentrate rations. .. 106 Volume of uater (litres) consumed by German Broun and Friesian cous grazed or stall-fed uith high and lou concentrate rations. 107 UNIVERSITY OF IBADAN LIBRARY I I xvii TABLE HEADING PAGE 2.19 Mean body temperature (DC) of German Broun and Friesian cous grazed or stall-fed uith high and lou concentrate rations .. 108 2.20 Body respiration (counts/min) of cous grazed or stall-fed uith high and lou concentrate rations .. .. .. 109 3.1 Components of dairy concentrate ration fed to the White Fulani, German Broun and Friesian lactating cous. .. .. 126 3.2 Identification, liveueight (kg), calving date and lactating records of the White Fulani, German Broun and Friesian cous used in the experiments. .. .. .. .. .. 127 3.3 Arrangements of the three breeds of cous for feeding grass _ad lib and lou or high concentrate rations. 129 3.A Bioclimatological data during the experimental period (June 197L - July 1975) uhen three breeds of cous uere maintained on grass ad lib uith lou or high concentrate supplement .. .. .. .. .. .. 131 3.5 Mean monthly chemical composition of the concentrate ration fed to three breeds of dairy cous uith high or lou levels from June 197** to July 1975 .............................. 132 3.S Mean monthly chemical composition of the grass and silage fed to three breeds of dairy cous uith high or lou level of concentrate from June 197A to July 1975.......................... 133 3.7a Dry matter intake (kg/day) of the three breeds of lactating cous fed on grass uith high or lou concentrate rations during the 2B-ueek experi­ mental period (ueeks 1-1L) 135 UNIVERSITY OF IBADAN LIBRARY xviii f TABLE HEADING PAGE 3.7b Dry matter intake (kg/day) of the three breeds of lactating cows fed on grass with high or low concentrate rations during the 28 week experimental period (weeks 15-28) ...................... 136 3.7c Percentage concentrate DM in total DM intake .. .. .. .. .. 137 3.8 Milk yield (kg/week) of the three breeds of lactating cows fed on grass with low or high concentrate rations during the 28-week experimental period .. .. .. 1L3 3.9 Salids-corrected milk (kg/week) of the three breeds of lactating cows fed on grass with low or high concentrate rations during 28-week - experimental period. 1^8 3.10 Milk fat (g/10Gg milk) content Df the three breeds of lactating cows’ milk fed on grass with Id w or high concentrate ration during 28-week experimental period. .. .. 152 3.11 Milk protein (g/100g milk) content of the three breeds of lactating cows' milk fed on grass with low or high concentrate ration during 28-week experimental period. .. 15A- 3.12 Lactose (g/100g milk) content of the three breeds of lactating cows’ milk fed on grass with low or high concentrate ration during 28-week experimEjntal period. 156 3.13 Total solids (g/100g milk) content of the three breeds of lactating cows' milk fed on grass with low or high concentrate ration during 28-week experimental oeriod. 158 UNIVERSITY OF IBADAN LIBRARY ! xix TABLE HEADING PAGE 3.1A Solids-not-fat (g/100g milk) content of the three breeds of lactating cows' milk fed on grass with low or high concentrate ration during 28-week experimental period........... 159 3.15 Ash (g/100g milk) content of the three breeds of lactating cows' milk fed on grass with low Dr high concentrate ration during 28-week experimental period........... 161 3.16 Calcium (mg/100g milk) content of the three breeds of lactating caws' milk fed on grass with low or high concentrate ration during 28-week experimental period........... 162 3.17 Phosphorus (mg/100g milk) content of the three breeds of lactating cows' milk fed on grass with low or high concentrate ration during 28-week experimental period. 163 3.18 Milk energy (K3/g freeze-dried milk) of the three breeds of lactating cows' milk fed on grass with low or high concentrate ration during 28-week experimental period. 165 3.19a Liveweight (kg) of the three breeds of lactating cows fed on grass with low or high concentrate ration during 28-week experimental period .. 167 3.19b Liveweight changes of the three breeds of lactating cows fed on grass with low or high concentrate ration during 28-week experi- mental period .. 168 it. 1 Mean chemical composition of ration and forage fed .. .. .. .. .. .. 2DD it. 2 Feed intake, milk yield and composition for the fistulated White Fulani cow fed on grass and high or low concentrate supplement 202 UNIVERSITY OF IBADAN LIBRARY xx TABLE HEADING PAGE A .3 Effect of feed intake and time of rumen sampling on the pH, total • and individual UFA, acetic/propionic acid ratio and ammonia nitrogen content of the fistulated lactating White Fulani cow's rumen liquor fed on grass and high or low concentrate supplement. .. .. •• • 205 A.A Effect of feed intake and time of blood sampling on total and indivi­ dual UFA, acetic/propionic acid ratio and urea nitrogen of a lactating White Fulani cou's blood fed on grass and high or low concentrate supplement. 206 A.5 Mean milk yield and composition of White Fulani cows maintained on grass and low or high concentrate supplement. 208 A . 6 Milk yield and composition of German Brown caws maintained on grass and low or high concentrate supplement. .. . 209 4.7 Milk yield and composition of Friesian cows maintained on grass and low or high concentrate supplement. . 210 A . 8 Mean coefficient of apparent digestibility of grass (%) (Cynodon, nlemfuensis var. nlemfuensis) fed to both the steers and the lactating cows. .. .. .. 213 4.9 Mean coefficient of apparent digestibility of grass and concentrate ration fed to both the steers and lactating cows. 217 4.10 Coefficient of apparent digestibility of concentrate supplement alone for steers and lactating cows. .. .. • 218 UNIVERSITY OF IBADAN LIBRARY I t xxi TABLE HEADING PAGE L.11a Total digestible nutrient (TDIM) and Metabolizable Energy (ME) intake from grass and concentrate rations fed to White Fulani steers and lactating cows. 22Q A.11b Total digestible nutrient (TDIM) and Metabolizable Energy (ME) intake from grass and concentrate rations fed to German Broun steers and lactating cows. 221 L.11c Total digestible nutrient (TON) and metabolizable energy (ME) intake from grass and concentrate rations fed to Friesian steers and lactating cows. 222 A . 12 Dry Matter intake (kg/day) and metabolic size (lilĵ -5̂ ) of three breeds of cows maintainid on basal forage and high or low concentrate supplement. .. .. 22J+ A .13 Summary of faecal N(g/kgDM consumed) and N-intake (g/day) for three breeds of lactating cows maintained on basal forage and high or low concentrate supplements. 225 b.V* Regression equations describing the relationship between faecal -rd( g/kgDM) Y, and l\]-intake (g/day) X for lactating cows in estimating metabolic faecal nitrogen (MFIM). .. .. .. 227 L . 15 Summary of urinary -N(g/day/lt].0.73A) ancj absorbed -N( g/day/uj^* '***) for® three breeds of lactating ^cous maintained on grass and high or low concentrate supplements. .. .. .. 229 k. 16 Regression equations describing the Q relationship between urinary -PJ(g/day/lir* ; Y, and absorbed -N(g/day/klj3*73i^ x for ̂ three breeds of lactating ^ cows in esti­ mating endogenous urinary nitrogen (EVN). 232 UNIVERSITY OF IBADAN LIBRARY I f xxii TABLE HEADING PAGE A .17 Summary of IM-balance (g/davAJ * ) and absorbed -N( g/day/ld9*7-5 )̂ 9 for three breeds of lactating cows maintained on grass and high or low concentrate supplement. .. 235 ft. 10 Regression equations describing the g relationship between IM-balance (g/day/ld. * ) Y, and absorbed -IM( g/day/ld9*7^ ) X in 9 estimating bilogical value. 9 .. 236 *».19 Summary of N-balance (g/day/ld?*7"^) and IM-intake (g/day/ld9,7^ ) for 9 three breeds of lactating cows maintained on grass and high or low concentrate supplements. .. .. .. 237 k. 20 Regression equations describing the Q 7,, relationship between l\l-balance (g/day/td * ) Y and IM-intake (g/day/ld9*7^ ) X, for 9 three breeds of lactating cows. 238 21 Estimation of digestible crude protein (DCP) requirement far three breeds of lactating cows for maintenance by factorial equation. .. .. .. .. 2L2 A . 22 Estimated DCP requirement for maintenance and maintenance with milk production from relationship between IM-balance (g/day/ld9*7^ ) and IM-intake (g/day/ldP*7-5̂ ) for the 9 three breeds of lactating cows. .. 2A3 A.23 Efficiency of protein utilisation for milk production for three breeds of cattle maintained on grass and low or high con­ centrate supplements. 2A5 UNIVERSITY OF IBADAN LIBRARY i xxiii TABLE HEADING PAGE k.Zk Summary of metabolizable energy, liveweight change, milk yield and energy of the three breeds of lactating cows maintained on grass and low or high concentrate supplements in the declining phase of lactation 247 A.25 Summary of regression equations describing the relationship between metabolizable energy (MJ/dayAlP*^^) and liveweight changes (kg/day) of ® lactating cows* «« .. •• • • •• 249 4.26 Efficiency of energy utilization for milk production. .. .. .. .. 251 A.27 Regression equations describing the Q relationship between N-balance (g/day/ld * ; Y, DPE : DE ratio X for three breeds or ̂ cows during lactation. 254 A.28 Comparison of the daily energy requirements for maintenance (KJ/day/ldP*^^) of the lactating cows in the present study with those in the literature. .. .. 266 4.29 Efficiency found in experiments with milking cows. .. .. •« .. .. 267 UNIVERSITY OF IBADAN LIBRARY i xxiv LIST GF FIGURES FIGURE HEAD I IMG PAGE 2.1 Water trough .. 79 3.1 Mean total dry matter intake (kg/day) .. .. 138 3.2 Mean total dry matter intake (kg/day/W^*73 )̂ .. 139 3.3 Graph showing milk yield of the White Fulani cows .. .. •» •• .. 1Mt 3.^ Graph showing milk yield of the German Brown cows .. .. •• .. .. 1A5 3.5 Graph showing milk yield of the Friesian cows • • 1A6 A .1 Diagram of the modified metabolism cage .. .. 19G i t . 2 Relationship between Faecal-!\) and N-intake for three breeds of lactating cows .. .. 228 i t . 3 Relationship between urinary -N and absorbed -IM for three breeds of lactating cows. .. .. .. .. .. 231 i t . i t . Relationship between [\l-balance and absorbed -N for three breeds of lactating cows .. .. .. .. .. .. 23A i t . 5 Relationship between N-balance and l\l-intake for three breeds of lactating cows .. 2A0 i t . 6 Relationshi between metabolizable energy (MG/day/W°- '*) and liveweight change (kg/day) of lactating cows .. .. .. .. .. 25G it .7 Relationship between IM-balance and DPE to DE ratio for three breeds of cows during lactation .. .. .. .. .. .. 253 UNIVERSITY OF IBADAN LIBRARY i f XXV LIST OF PLATES PLATE HEAD IMG PAGE 2.1 German Brown, White Fulani and Friesian cows 67 grazing on the paddock. *t.1 A lactating cow in the modified metabolism cage. 191 k.2 Rumen liquor sampling. 195 UNIVERSITY OF IBADAN LIBRARY CHAPTER 1 GENERAL INTRODUCTION 1.1 INTRODUCTION One qF the important features that characterise Nigerian agriculture is the imbalance in the activities expended on 'crop1 in relation to ’animal' production. It has been calculated from available data that 80% of the estimated agricultural output in Nigeria are derived from craps while 20% came from livestock (Oyenuga, 1973). This picture shows a sharp contrast to what exists in the agriculturally developed economies. Animal production accounts for 80% of the total value of agricultural out­ put in Denmark, 81% in Finland, 70% in France, 76% in Ireland, 78% in the Netherlands, 77% in Sweden, 73% in Switzerland and 68% in the United Kingdom. (F.A.O., 1955) Because of this imbalance between crop and animal produc­ tion, animal protein intake of an average Nigerian has been alarmingly low when compared with the F.A.O. (1966) recommended intake. According to the recent report of a committee on food crops set up by the Nigerian Federal UNIVERSITY OF IBADAN LIBRARY 2 Ministry of Agriculture and Natural Resources, it has been shown that proteins from animal sources contribute about 17% of the total protein consumption to the average Nigerian diet compared to a corresponding estimate of 60% in New Zealand, 71% in the United States of America, 67% in Denmark and 60% in the United Kingdom (Dyenuga, 1973; Loosli and Van Blake, 1973). A good reason why these agriculturally advanced countries attach more importance to animal production is the nutritive 'superiority' of animal protein to crop protein. Protein quality is assessed basically by its constituent amino acids and also its nutritive value. The nutritive value include factors like digestibility and absorbability of the food protein, the presence of toxic substances and inhibitors, damage by heat during cooking or processing and acidity. Vegetable proteins are less dige­ stible and the essential amino acids less complete and less balanced to meet human body requirements than those from animal products. For example, most cereals are deficient in lysine and tryptophan, while pulses are low in methionine, cystine, tryptophan and threonine (Oyenuga, 1971). Finally UNIVERSITY OF IBADAN LIBRARY 3 most vegetable proteins have lower biological value than animal proteins. Mitchell (1927) showed that the bio­ logical value of whole egg is 9h while that of whole maize is 60. 1.1.1 The Protein Gap. The F.fl.O. (1966) targets for world food production in 1975 visualized a total annual consumption in human diets of about 125 million tonnes of protein of which about 38 million tonnes would be animal protein given a plant protein to animal protein ratio of about 3:1. The huge increases over the 1960 figure are to be obtained by an increase of about 13 million tonnes of animal protein. The major problem here would be the production of enough animal protein to meet the needs of those in developing countries. For instance, while Oyenuga (1975) recommended a minimum daily crude protein intake of 65g by an average Nigerian for healthy living which should include 2Bg from animal sources in order to obtain the desired net protein r , utilization (NPU) value far the ingested crude protein, it has been revealed (Oyenuga, 1975) that during 197it-1975, an average Nigerian was obtaining only approximately 25% (7.5g) of the minimum animal protein level he should consume UNIVERSITY OF IBADAN LIBRARY k to meet his daily requirements. This intake apart from falling short of the recommendation, falls far below the F.fl.O. targets for 1975 already mentioned. It was earlier envisaged that the third National Development Plan 1975-80 will be able to tackle this problem but calcula­ tions have shown that the animal protein intake would rise to 9g/caput/day by 1980, attaining then approximately a third of minimum requirements. It is therefore necessary to re­ appraise the Development Plan so as to improve this situa­ tion. It has long been demonstrated that this low protein intake is partly if not wholly responsible for the high incidence of retarded growth in children (Collins, Dema and Omololu, 1961), high incidence of the deficiency diseases known as kwashiorkor and marasmus (in adults) coupled with a high rate of child mortality (Shaw and Colville, 1950; Wilson, 1954), low level of human productivity (Platt, 1954) and short life span existing among many African communities (Oyenuga, 1967). 1.1.2 Factors affecting animal protein level. Before there can be increase in animal protein level, there must be an increased livestock production. However, several factors have been found to militate against livestock UNIVERSITY OF IBADAN LIBRARY 5 production in the tropics. Among these are lack of properly managed pastures, disease pests, unfavourable climatic condition, poor feeding and management practices, poor economic condition of the people, land tenure system, lack of reliable livestock census, the astronomical increases in livestock feed prices, absence of the infras­ tructure necessary to supply the needed imputs for production, processing and distribution and low genetic potential of the indigenous animals. Highlights of these factors are discussed below. Low productivity of the IMigerian Livestock. Although the consumption of animal protein in the developed countries is about five times higher than in the developing countries, it has been shown (Dyenuga, 1967) that the proportion of livestock number to the human population is higher in the developing countries than in the developed countries. Furthermore, although more than half the world's cattle population are to be found in the tropics, Olaloku i (1973) pointed out that milk production from so vast a cattle population accounted for only 15% of an estimated world total production of W O , 932,000 metric tonnes of milk during 1970/71. UNIVERSITY OF IBADAN LIBRARY I - 6 - The remaining 85% came from cows in the technically developed countries most of which lie in the temperate latitudes. The problem, therefore, is not only that of increasing the number but aTso the productivity of the live­ stock in the tropical countries, like Nigeria. While there is room for considerable expansion in the numbers of livestock, the production of these animals is very much below expectation. The milk production of the dairy cattle is very low when compared with the dairy breeds kept in the temperate countries. The mature body weight of the indigenous cattle is small, having a carcass weight at maturity of about 150kg in the White Fulani (Zebu) cattle, 100kg in the IM'dama breed compared with 250kg in most of the European breeds of cattle (Flittendorf and Wilson, 1961; Loosli and van Blake, 1973). The slaughter rate is only about 9.2% in Nigerian cattle (Shaw and Colville, 1950) compared with 28% in the United States of America (Loosli and Oyenuga, 1963). Because the production seldom begins until between 3 and k years in the indigenous breeds (Oyenuga, 1958), the annual rate of increase of the cattle population is very low and very much below an estimated UNIVERSITY OF IBADAN LIBRARY 7 world average of 2.6% (Oyenuga, 1967). Impact of the involvement of the Government and Private Businessmen on animal production. Up till now, the only modern agriculture and livestock industry practised in the country has been provided mainly by the various State and Federal Governments. Many Govern­ ments are embarking on accelerated food production programmes which include the dairy industry in the Kano State, beef production in the various Northern States, vegetable oil production and urban dairy farm at Iwo road (Ibadan) in Oyo State and fibudu cattle ranch by the Cross River State. How­ ever, these various governments have got their shortcomings. There are growing interests in animal production but when compared with crop production, no great impacts are notice­ able. The Second and Third Development Plans of the governments revealed that smaller proportion of investments in the agricultural sector is being given to the livestock industry. While #616.70m was voted for crop production in the second year development plan, 1970-7^, only N2k.ZUm or k% was provided for the livestock industry. UNIVERSITY OF IBADAN LIBRARY » - 8 - Oyenuga (1971) has shown that while the capital voted for crop production represented 81% of the provision for agricultural sector, the proportion for livestock development was only 9%. The case Df the third develop­ ment plan, 1975-80, is only slightly better. For instance, while the Federal Government voted ?J1,645,845,ODD for agriculture, only £044,046,171 of this is to be devoted to livestock programmes. Apart from the fact that the total money devoted to agriculture is ridiculously low (only 5% of the whole budget), that of the livestock which is only 1% of the whole budget cannot arrest the present low animal protein intake trend. It is to be observed here that for the moment the enthusiasm shown by the private businessmen has been very appalling. It would appear that they are not reacting quickly to agricultural production, particularly livestock industry due perhaps to the land tenure system especially in the Southern States, lack of organised marketing including guaranteed market prices or to some other factors such as capitals which might militate against mechanisation of agriculture. Modern animal production requires heavy capital investments. The Agricultural Credit Bank was set UNIVERSITY OF IBADAN LIBRARY 9 up by the Federal Military Government for the sole purpose of improving the agricultural industry but the advantages taken by many businessmen have not been very encouraging. Maybe that the avenues and processes for giving out loans have been made very tight and rigorous. Availability of livestock feeds Feeds account for about 60-80% of the cost of raising animals depending on species, breeds and environment (Olayiuole, 1973; Oakonda, 1975). Cereal grains, such as maize, are the basic ingredients in the formulation of livestock feeds. The price of maize in 1975 has doubled that of 1969 due to very high demand on grains. It is even cheaper to purchase grains in the United States of America and United Kingdom than in Nigeria. Even at that, the grains purchased in Nigeria have no guraranteed standards uith regard to the moisture content, protein and foreign materials. Apart from the grains, other important components of livestock feeds like groundnut cake and fish meal are very difficult to obtain. The prices of fish meal rose from about ftlAO.OO per ton in 197D to ^700.00 in 1973/7A, an increase of about 500% though it is at present much less. It is now a general practice in developing countries to substitute fish - UNIVERSITY OF IBADAN LIBRARY 10 meal in poultry and pig diets with the cheaper soyabean meal. Soyabean meal is about the only plant protein uhich is high in lysine. It is deficient in methionine but this can be supplemented with sesame meal which is high in methionine or even with synthetic DL-methionine. With this fear of high feed prices, it is now becoming increasingly more difficult and less encouraging for a private businessman to plunge into livestock production. It seems to be a major obstacle militating against livestock production. Reliable figures of livestock population. Although agriculture has long been practised in Nigeria, yet no reliable livestock census is available. ’Guess esti­ mates' of the number of the Nigerian cattle have ranged from 5.6m (F.A.O./I.C.A.; I960) to a staggering figure of 15m by the Federal Ministry of Information (196A) including F.A.O.'s (1966) figures of 10.Bm head of cattle. One Df the difficulties adduced to this failure is the "jangali" (tax paid on cattle). Another is the transhuman system of live­ stock keeping in Nigeria. "Jangali" has been abolished. It is now hoped that this might lead to obtaining accurate live­ stock census. UNIVERSITY OF IBADAN LIBRARY i - 11 - 1.1.3 Nutritional Importance of Milk and Dairy Products Milk, with its products, serves as one of the most important sources of food for all nations. Milk has been known to man far centuries. Infact, the Holy Bible made a reference to the "land flowing with milk and honey" (Anonymous, 1611). Though little is known about the early history of dairy industry, archeaological excavations indicate that men of the old stone age were the first to domesticate the cow and that in prehistoric times, milk was common. Milk was evolved through the ages specifically for the nutrition of infant mammals, for bridging the gap between the dependent intrauterine and the independent adult life. Eckles (1951) painted out that the more highly developed and prosperous the people, the greater the amounts of milk and dairy products they consume. The importance of milk to the growth and health of the world population cannot be overemphasised. For instance, dairy industry is the backbone of American agriculture and consumption of dairy products the keystone of American nutrition (Brody, 196A). Although it is deficient in iron, copper and manganese, milk with its products is rich in body-building proteins, with a biological value of up to 78, phosphorus, UNIVERSITY OF IBADAN LIBRARY 12 calcium, vitamins, lactose and fats. The major proteins of milk is casein. Lactalbumins and lactoglobulins are present in small quantities. Cadein of different species are similar but lactoglobulins and lactalbumins vary with species and differ in their composition and properties. Because milk is poor in iron and vitamin C, supplementary sources of these must be supplied in diets based wholly or substantially on milk. Uitamin A varies with the nutrition of the cow while vitamin D is affected by the amount of sunlight as well as the nutrition nf the cow. Adequate calcium and phosphorus nutritim depends upon three facturs namely a sufficient supply of each element, a suitable ratio between them and the presence of vitamin D. These factors are inter-related and they occur in the most available form in milk. Milk with its easily digestible fat (90-97%), high amount of Uitamin A, excellent sources of riboflavin (Uit.B^), a fair source of thiamin (Uit. B^), ascorbic acid and lactose are of immense importance to the health of the growing population. The ascorbic acid content in cow's milk is about one-sixth and the iron content about one-third of that in woman's milk but the riboflavin content of icow's milk is about five-fold that of woman's milk (Brody, 196A). In fact, a former President of the United States of America, Mr. Richard Nixon, has lauded the sleep-inducing, bland, UNIVERSITY OF IBADAN LIBRARY I - 13 - soothing yet highly nourishing properties of milk (Davidson, 197*0. It had been used as a virtually exclusive diet in some digestive disturbances such as ulcer (Shay, 19A2). A quart of cow1 s milk a day furnishes an average man approximately all the needed fat, calcium, phosphorus, riboflavin, one-half of the needed protein, 25% of the needed energy, over 33.3% of the vitamin A, 20% of the thiamind and asc obic acid, considerable amounts of nicotinic acid, choline and other factors and with the exception of iron, copper, manganese, and magnesium which are low in milk, all the needed mineral (Brody, 196*0. Dairy products include skim milk, cheese, butter, evaporated and condensed milk chocolate and ice cream. Skim milk is milk whose butterfat has been removed. In the light Df modern research, investigators have recommended this type of milk for the elderly adults, because of the cholesterol which is present in milk fat (containing predominantly short- chain fatty acid) and associated with atherosclerosis - a disease commonest among the elderly. In fact it has also been suggested that elderly people above the age of 50 years should limit their fat intake to between 50-70g per day almost all being vegetable oil since vegetable oil contains higher proportion of unsaturated fatty acids with charac­ teristic phytosteroids (Kan and Cowie, 1966). UNIVERSITY OF IBADAN LIBRARY T - 1A - Milk powder is the milk containing no mater. In cheese, the curd contains virtually all the fat, 75% of total proteins and only traces of lactose and 66.7% of calcium of the whole milk. Butter is distinguished from other dairy products because of its high butterfat content (8A%) and high Vitamin E contents. Ice-cream which is particularly useful for quieting cqntakerous and noisy children at homes, on the streets and used in some homes for ' cooling down' particularly after an afternoon meal consists of 2A% cream, A6% whole milk, 1A% concentrated milk, 15.5% sugars, 0.5% stabilizers, eggs and flavours (Adeneye, 1972). 1.1.A The Production, Supply and Consumption of Milk in IMigeria Olaloku (1973) has shown that cows in the tropics including those in Nigeria are low producers compared with those in the temperate countries such as Denmark, United States of America and the Netherlands. He claimed that the low production was due to low genetic improvement, poor management and nutrition. There have been two systems of milk production in Nigeria - namely the traditional and Organised systems. The bulk of the milk is produced with traditional system of dairy UNIVERSITY OF IBADAN LIBRARY 15 husbandry by the normadic Fulani and Shuwa Arabs who are located at some considerable distance from the Urban centres and are generally scattered among the rural communities. Their animals are poorly managed, most of them are dual purpose animals. To them, milk is more or less a by-product of beef production. The little milk so obtained can barely meet the needs of the producer, hence very small amounts are sold. Feed inadequacy appears to be the most limiting factor influencing the productivity of the local cows. The only feed mostly available to them are coarse herbage of the savanna land during the rainy season. In the more northerly parts where the animals are reared the rainy season is limited to four or five months in a year. For the rest of the year the cow subsists on poor quality herbage and sometimes they have to trek long distances in search of food and water. Virtually no concentrate supplement is fed. Apart from the fact that the animals are always on the move, no form of shade is provided for them to rest. All these coupled with high incidence of disease infestations and the innate low genetic capacity of the local breed tend to limit the quantity of milk produced. There is also no well organised system of marketing even the small quantity of the milk produced. UNIVERSITY OF IBADAN LIBRARY 16 The organised 'system consists of large-scale operations involving considerable investments in capital and labour. This system is only practised by the various state ministries of agriculture, experimental stations, government corporations, special FAO/UI\IICEF projects and university research stations. Because of better management, nutrition, breed specialization and genetic improvement, these animals produce more milk than those in the hands of the nomadic herdsmen. The animals usually used by these stations include high-yielding exotic dairy breeds like the Friesians, the German Broun and the Jersey and some selected indigenous zebu cattle and their crosses uith the exotic dairy breeds. The above-mentioned stations are usually near urban centres uhere the milk could easily be sold. Houevar, these stations still produce far less than the amount required by the population. Therefore milk has to be imported. In 193A, 3B1.B metric tons of milk at a cost q- P&2,000 uas imported into the country (Federal Office cf Statistics (F.O.S.) 1951). In the first nine months pf 1970, a total of about filO.OOm (ten million naira) uorth of milk uas imported (F.O.S. 1970). There has bean a gradual increase UNIVERSITY OF IBADAN LIBRARY 17 of milk importation since then. In view of the need to conserve valuable foreign exchange and the nutritional importance of milk, it is no wonder that ten out of the former twelve states of Nigeria are planning to produce milk in the 3rd National Development Plan. 1.1.5 Some prospects of increasing milk production in Nigeria With increasing tendency for mass importation of exotic cows for milk production in Nigeria basic research is needed to establish the nutrient requirements of these animals in their new environments for optimal performance. Also a genetical improvement involving: (i) breeding and selection for high milk production especially among the indigenous breeds, (ii) crossbreeding programme between exotic male and indigenous female animals, and (iii) mass importation of exotic male and female far production with attendant cost of importation, maintenance of high nutri­ tional and health standards has to be embarked upon. Another prospect of increasing milk production is to improve the nutritional level of the livestock. Oyenuga (1958) was optimistic that given adequate nutrition, it was passible for the indigenous breed to produce more milk than its present performance. Holmes, Reid, Maclusky and UNIVERSITY OF IBADAN LIBRARY 18 LJatson (1956) and Burt (1957) have also shown that the milk yield of cows could be increased considerably by proper feeding and good management. 1.2 LITERATURE REUIEU 1.2.1 Historical Background and Adaptation of the Ruminant Palaeontologists the world over suggest that much of the evolution of ruminants as a separate branch of mammals occurred during prolonged dry periods of the earth's history (Houpt, 1969). It is likely that special modifica­ tions of digestive tract found in present-day ruminants were developed in response to such environmental pressures and that the ability to survive a long period of semi-starvation might be as a result of these adaptations. For instance, it is well recognised that ruminants are specially well adapted to survive and even thrive under environmental condi­ tion unfavourable to other large animals. Their ability to subsist under poor nutritional conditions is particularly noteworthy. The ruminant stomach is a physiological adaptation for biochemical and nutritional purposes. The ruminant animals depend to a large extent and by nature on vegetable feeds UNIVERSITY OF IBADAN LIBRARY f - 19 - far their energy supply. Because vegetable feeds gene­ rally have got low calorific values, the animals must consume a large volume of the feeds. This has given rise to a development of the gut into a four well-defined compartments viz: rumen, recticulum, omasum and abomasum which develop from embryonic stomach and not from the oesophagus. The rumen, reticulum and omasum are not glandular (Schmidt, 1971) and they represent the forestomach. While young, it is usual to compare the runinant stomach to that, of mononastric animals. McCarthy and Kc3ler (1956) in their investigations on the young ruminant found that at birth, and for a short time afterwards, the calf relies on glucose for its major energy needs. Later, the glucose level in the blood begins to fall while the concentration of UFfls in the blood increases. Within a year the four compartments of the ruminant stomach attain their relative permanent sizes (Jacobson, 1963). This period however varies and depends on the feed given to the animal. Wardrop (1961), Godfrey (1961), Sutton, McGilliard and Jacobson (1963) observed that the fdrestomach epithelia developed rapidly to adult form when roughage was given to the calves. The rumen accounts for 80% of the capacity of UNIVERSITY OF IBADAN LIBRARY 20 adult ruminant (Suttonjetjal, 1963). The rumen has two sacs, dorsal and ventral, each is divided into anterior and posterior portions and communicating with the reticulum over the rumen - reticular fold. The reticulum is lined with a structure like a honeycomb and both its inlet and outlet are on its dorsal surface (Houpt, 1969). Because of their connection the two together are often referred to as the reticulo-rumen. Next comes the omasum with its many laminated folds and finally there is the abomasum or the true stomach, which is more tubular than in non-ruminants. From the point where the oesophagus opens into the rumen, Phillipson (1965) has pointed out that there is at the cardia the oesophaeal groove which runs to the opening between the reticulum and the omasum. While feeding, the drier and the more fibrous materials tend to collect in the dorsal sac and the posterior region (Craplet, 1963), while the fluids and small particles collect in the ventral sac, the anterior region and in the reticulum, there is gas above the solid and liquid materials. Apart from this complex stomach, there is the phenome­ non of rumination which has been developed as a further rela­ tion to the biochemical reactions taking place in the UNIVERSITY OF IBADAN LIBRARY 21 stomach in the ingested vegetable material. Rumination which is the 'chewing of curd' consists of a number of reflex actions namely, (i) regurgitation which is a sort of controlled vomitting and is peculiar to ruminant digestion (ii) remastication - a process which increases the surface area of the vegetable feeds simply by decreasing the particle size of feed (iii) reinsaliva- tion and Civ) deglutition which is the reswallowing of the remasticated vegetable feeds (Tyler, 196<+). The most important nutrients needed in quantity by mammals are organic compounds which can supply carbon bond energy, water and nitrogen compounds. The greatest source of bond energy is the cellulose of plants and these are broken dawn in the rumen by the cellulases produced by the ruminal micro-organisms. Some ruminants which are subjected in their natural habitat to paucity of water have been shown to use special mechanisms to conserve body water. On the other hand, ruminants can also conserve body nitrogen or tap sources of nitrogen unavailable to other mammals. While the nitrogen content of mature vegetation falls drastically in dry season the cellulose content of the plant is still relatively high. In fact, there is some evidence that nitro­ gen or protein availability is the critical factor in the UNIVERSITY OF IBADAN LIBRARY 22 survival of some groups of ruminants subjected to natural starvation during dry season (Dasmann, 1956). In 1953, some observations put forward earlier were confirmed in camels in the Sahara on low-protein diets and evidence showed that this ruminant conserved body nitrogen and probably could utilize endogenous urea. The protein in the vegetable feeds can be extensively degraded in the reticulo-rumen and this depends upon the physical condition and solubility of the protein. The products are usually amino acids which in turn yield ammonia and various fatty acids. These degraded products can be used to build up microbial protein. Some of the ammonia which is produced is absorbed into the blood stream and converted to urea (Mba, 1972). Some of this urea is secreted in the saliva and thus finds its way back to the reticulo-rumen. In most cases, it is used to build microbial protein. The utilization of urea is increased by increasing level of starch and inorganic sulphur and by a low level of total nitrogen in the ration (Loasli, v r i Williams, Thomas, Ferris and Maynard, 19*+9; Lewis, 197*+). 1.2.2 Ruminant feeds and feeding standards After more than two centuries of concerted efforts, UNIVERSITY OF IBADAN LIBRARY 23 nutritional chemists are still striving to evolve more suitable methods to determine which among the numerous chemical substances present in the various natural foods are significant in animal physiological and biochemical processes in the body. It has long been shown that the animal body consists of water, fats and small amounts of carbohydrates largely in the form of glycogen. In addition small quantities of accessory growth substances, vitamins and hormones, are present in the body. The water, protein, carbohydrates, fats, minerals and vitamins are present in the feeds and are known as nutrients (Oyenuga, 1967). Feeding standards are tables or state­ ments showing the amounts of these feed nutrients which should be provided in the rations of different species for different purposes such as growth, fattening and lac­ tation. Feeding standards or nutrient requirements have been set at various levels at different times (Woodman, 1948; N.R.C., 1958, 1966; Evans, I960; A.R.C., 1965; MAFF, 1975). These tables of requirements are used solely for conditions prevalent in the temperate countries. Energy requirements are based on either Starch Equivalent (SE) system (Kellner's net energy system), Total Digestible UNIVERSITY OF IBADAN LIBRARY - Zb - Nutrient (TON), Metabolizable Energy (M E ) or the Scandinarian Feed Unit (FU). The first tuo systems are assigned to individual feeds of constant nutritive values which are independent of the other ingredients of the diet, the amount of the diet which is given or the type of production the diet is designed to support (A.R.C., 1965). The ME system involves the estimation of the efficiency with which the energy is likely to be retained by the animal. Although the ME value of food is relatively constant for a parti­ cular specie of animal (Maynard and Loosli, 1969), the efficiency with which ME is utilized varies according to the purpose for which it is utilized by each animal. The NE system in the scientific rationing of the animals has an advantage over the ME in that it allows both energy requirements and feed value to be expressed in the same unit (Mba, 1972). The NE system is mostly used in the Commonwealth countries while the ME is used in the Western world, East European countries and Union of Soviet Socialist Republic. All these systems have been criticized. For instance, Kessler and Spahr (196A) believed that high producing cows UNIVERSITY OF IBADAN LIBRARY 25 may require increased gross energy (GE) per unit of milk as a result of decreased digestibility of the diet when fed in sufficient amounts to support high milk production. Forbes, Fries, Braman and Kriss (1926) reported that ME provided in excess of main­ tenance is used for milk production and body weight increase at 98.5% and 76% respectively. 1.2.3 Feed Intake in Dairy Cows A general pattern of feeding the dairy cow derived primarily from the feeding standards is for the animal to graze _ad libitum and in addition to be given O.A5kg of concentrate for every litre of milk produced (Caro-Costas and V/incente-Chandler, 1969). The concentrate is assumed to be responsible for milk pro­ duction. A number of investigators (Hodgson and Sweetman, 19A7; Glover and Dougall, 1961) have called attention to the fact that feeding of forage alone can be used for both maintenance and production purposes especially when dairy cows are fed on good pasture. Hodgson and Sweetman (19A7) pointed out that milk production from good pasture in England and U.S.A. may be up to sixteen litres per day depending on amount of fat in the milk and apetite of the animal. Glover and Dougall UNIVERSITY OF IBADAN LIBRARY 26 (1961) working in East Africa have got similar results. Aryshire of average apetite could give thirteen and half litres of milk at k% fat; Jersey cow of 365kg liveweight and of average apetite could produce about nine litres of milk at 5% fat. Reid (1956) referred to studies which showed that when roughage alone was fed at increasing levels, there was no decline in the TDIM value. He compared this with maize silage containing maize grain in which there was a decline in TDM and also with mixed ration containing large proportion of concentrates in which the decline in TDIM with increased levels of feeding was quite pronounced. Morrison (1961) showed that Jersey cows fed only on roughage produced an average of 2636kg milk and about 155kg butterfat per year in the U.S.A.. Caro-Costas and Uincente-Chandler (1969) also pointed out that a Holstein cow produced over 2730kg of milk in an 8-month lactation period on an all-grass ration in Pueto Rico. Bo many factors have been shown to influence total roughage intake of cows. Some of these include feed, management, animal factor (breed of animal) and weather characteristic . Payne (1962) pointed out that UNIVERSITY OF IBADAN LIBRARY I - 27 - high water content of feeds prevents sufficient high dry matter intake. Mather (1959) found out that type and quality of roughage, frequency of feeding and amount of grain offered may affect feed intake. Animal factors include the capacity of the cow which is referred to as 'effective capacity' since the maxi­ mum may be reduced by several factors; the desire of the animal to fill that capacity could be defined as the apetite. Effective capacity may be affected by the encroachment of fat, previous feeding history and the rate of digestion and passage of feed. Temperature and humidity particularly when at the extremes will also affect forage intake (Payne, 1962). Glover and Dougall (1961), Rogerson, Ledger and Freeman (1968) observed that Bos taurus animals generally could consume more forage than Bos indicus cows. Also it has been shown that cows receiving no grain reached their peak consumption six weeks after calving whereas cows on medium and high grain did not reach their peak consump­ tion until about the 9th week or later (Mather, 1959). 1.2.A Importance of Supplementary Concentrate A forage may be said to be adequate when it is UNIVERSITY OF IBADAN LIBRARY 28 supplied in such a quantity of high palatability and its per unit concentration of usable nutrients is also high enough to permit the animal to meet its nutritional requirements concurrent with the satiety bulk. At present most of Nigeria's pastures are uncultivated and unselected and they are unable to meet this definition. Again from the point of view of efficient animal produc­ tion there is a limit to which the nutrient requirements can be supplied in the form of roughage. It is pertinent to infer here that temperate grass forages are low in energy (Blaxter, 196A) and that tropical grass forages are slightly higher (Mba, Oke and Oyenuga, 1973). This is in fact the basis for the stomach modification in ruminant animals to cope with large volume of forage with low energy content. It is often shown that a good quality grass would provide crude protein for the production of up to 22.70 litres of milk but the energy content could not meet the requirements for maintenance and production of up to 13 litres of milk. (Mba, 1972). A number of nutritionists have come out to support or oppose the use of supplementary concentrate. UNIVERSITY OF IBADAN LIBRARY I - 29 - Hancock (1953) supported the idea of supplementary concentrate with forage whereas MacLusky (1955), Seath, Douden, Broun, Jacobson and Rust (1959) were of the opinion that supplementary concentrate feeding was uneconomic. Castle, Drysdale and Watson (1960), Castle (196A) also showed that it was uneconomic to feed supplements at the prices that feeds were being sold particularly if the cows were on good leafy pastures. Kresler and Sparh (196*+) in a review of the effects of feeding various levels of concentrate on feed intake, milk production and composition concluded that although feeding high level of concentrate usually resulted in increased milk production especially with cows having high potentials of milk production, unlimited concentrate feeding did not always increase production. It is now known that increased milk production is due to high energy content of the diet. In support of this concept, Elliot and Loosli (1959) fed diets in which the level of estimated net energy (ENE) intake above maintenance was held constant and showed that production of FCM was not different on diets containing *+0, 60 or 80% of the ENE in the form of concentrates. Also a number of relatively UNIVERSITY OF IBADAN LIBRARY 30 recent studies have indicated that high concentrate feeding resulted in increased milk production whereas other workers have indicated no advantage in that respect. Broster, Ridler and Foot (1958), Ronning (1960), Rook and Line (1961), Boyd and Mathew (1962), Murdock and Hodgson (1962), Bernett and Olson (1963), Bishop, Loosli, Trimberger and Turk (1963) and Rumery and Plum (1963) have expressed various opinions on the use of supplementary concentrate. It would appear that all of them agreed that in cases where supplementary concentrate;; was not necessary, the cows were on good pasture. There­ fore in cases where there is no improved pasture as in this country, it is reasonable to suggest that feeding of supplementary concentrate is of paramount importance. Concluding from an experiment on the importance of supplemen­ tary concentrate, Hancock (1958) was of the opinion that pasture herbage was not a perfect diet for dairy cattle since concentrate are capable of giving a substantial lift in the milk yield when added to an _ad libitum diet of high quality, forage. It seems likely that this effect is due mainly to the UNIVERSITY OF IBADAN LIBRARY 31 fact that dairy cows are capable of consuming some concentrates even uhen they appear to have satisfied their apetite from pasture herbage because of high energy content of the concentrate. If this is true, it is obvious that one of the limiting factors to a maximum milk production grassland is the volume of grass with Iouj energy content which couis can consume even of good quality material. Finally, Murdock (1967) has given reasons for the use of supplementary concenti’ate as to encourage milk ejection, supplement the quantity and quality of the grass, improve milk production, increase total nutrient intake and energy, expedite 'tie-up' of cows and serve as a source of varying the nutritional level of free-grazing cattle. It is therefore advisable that milking cows should be given a certain amount of concentrate supplement to forage eaten ad libitum so as to increase total intake and digestibility of feed. 1.2.5. Effect of feed on ruminal volatile fatty acids Barcroft, McAnally and Phillipson (.19M+) found that the energy available for maintenance and production of milk and body weight increases are derived largely from the end UNIVERSITY OF IBADAN LIBRARY 32 products of microbial fermentation in the rumen. Quantitatively the most important end-products of ruminant digestion are the steam volatile fatty acids (V/FAs). Acetic, propionic and butyric acids form more than half of total energy supply of ruminants (Leng and Leonard, 1965; Darner, 196A; Rook and Storry, 196*0. The mixture of acids produced in the rumen varies with the chemical composition and physical nature of the diet (Rook and Storry, 196*+; Armstrong, 1960). Donefer, Lloyd and Crampton (1963), Raymond, Hinders and Dard (1961) and Stanley, Marita and Ueyema (196*+) showed that in supplemented feeds the acetic acid production was just over half of the total acid produced. The ratio of acetate to propionate was just over 2. In highly fibrous feeds more acetate was produced, level of propionate and perhaps that of butyrate fell. The ratio of acetate to propionate would be as high as 7 in a highly fibrous and unsaturated feed (Armstrong, 196*+). Dith increasing maturity of pasture, animals tend to increase their feed intake and this increase causes a reduction in digestibility and increased feacal loss (Armstrong, 196*+; Armstrong, Blaxter and Daite, 196*0. In general, Balch and Rowland (1957) put the mean molar percentage of these acids which varied with UNIVERSITY OF IBADAN LIBRARY - 33 - the different diets as follows: acetic acid .*+0.6-73.7%, propionic acid 16.5 - 39.1%, butyric acid 6.6 - 13.9% and higher acids at 2.5 - 12.7%. Owing to the fact that the crude fibre content of tropical forages are usually high while the crude protein contents are generally low (Oyenuga, 1958) it is usual to get high acetate level in the rumen of the ruminants in the tropics. High crude fibre in the feed favour high acetate production (Adebanjo, 1972). Leng (1969) pointed out that while the crude protein of the temperate pastures was high, that of tropical pastures at the same age was extremely low. Although it has been shown that there was a negative correlation between crude fibre and crude protein contents of the pasture grasses, Oyenuga (1966) and Olubajo (1969) showed that with proper management, the crude protein content could be very much increased to support a rapid liveweight increase and perhaps milk production in the livestock as the crude fibre fraction was very highly digested. Results from a considerable variety of feeds have been presented by Bath and Rook (1963, 1965) and Rook (196A). The general picture which emerged from these findings was that as the proportion of structural carbohydrate in the UNIVERSITY OF IBADAN LIBRARY 3A total feed decreased the proportion of acetic acid expressed as a molar percentage of total UFA mould also decline (Armstrong, 1968). Where the depression in structural carbohydrate content in the total feed mas due to the feeding of an increased proportion of cereal or cereal-based concentrate then the decline in the molar proportion of acetate might be associated mith an increased concentration of propionate or of butyrate or of both. When flaked maize mas fed, the decline in acetate mas associated mith a marked rise in propionate (Starry and Rook, 1966), mhereas mith barley, a compensatory increase in butyrate but little change in propionate mas found (Donefer, Lloyd and Crampton 1962; Sutton and Johnson 1969; lizuka and Yonemura, 196A). Increases in intake of roughages fed singly have little effect on the molar proportion of the acids present (Williams and Christian, 1957, Bath and Rook, 1963) but mith hay-concentrate mixtures mhere the propor­ tions mere kept constant as intake rase there mas evidence that the acetic to propionic acid ratio narroms mhen the plane of energy nutrition mas increased by feeding an increased proportion of concentrates (Bath and Rook, 1963). The UNIVERSITY OF IBADAN LIBRARY I - 35 - general effect was to narrow the ratio of acetic to propionic acid. The same effect was induced by grinding the roughage or by heat treatment of cereal before feeding (Balch, Broster, Rook and Tuck, 1965). Mba (1973) working with different breeds of tropical goats have also concluded that those rations which tended to depress the molar concentrations of acetic acid in the rumen resulted also in the corresponding increase in propio­ nic acid. He painted out that the consumption of grass- legume mixture always resulted in the high concentration of the acetic acid in the rumen of the goats. Butyric acid did not follow any general pattern. Armstrong and Blaxter (1957) working with sheep pointed out that the measurement of butyric acid in the rumen was complicated by the fact that it is actively metabolised by the rumen epithelia. It is well known that when a ruminant is abruptly changed from high forage to high carbohydrate concentrate, lactobacilli (lactate producing bacteria) rapidly increase in number and lactate accumulates in large amounts, pH is lowered, protozoa are inactivated and thd animal may go off feed (Armstrong and Prescott, 1970). UNIVERSITY OF IBADAN LIBRARY I - 36 - When the change is gradual, lactobacilli multiply rapidly but sc da lactate fermentors hence lactate does not accumulate and high levels of propionate are observed in the rumen fluid (Armstrong, I960). 1.2.6 Absorption and Utilization of UFA A considerable amount of effort has been devoted to the study of absorption of acetic, propionic and butyric acids from the rumen of the ruminants. The importance of this effort is .justified when it is known that \/FA is an energy source and the possible relationship between their absorption and the absorption or exchange of other substan­ ces across the rumen wall. The early studies of Barcroft (19AA) showed that most of the UFA produced in the sheep rumen was directly absorbed from its contents. It was also found that butyric, propionic and acetic acids were the principal acids present (Elsden, 19A5; El-Shazly, 1952; Warner, 196A; Leng and Leonard, 1965; Armstrong, 1960) and that these were absorbed from the rumen at a rate which increased with chain length. Danielli, Hitschcock, Marshall and Phillipson (19A5) showed that the increased absorption of UFA from rumen was associated with a decrease in the pH of rumen contents. They also demonstrated greater permea­ bility of the tissues to the undissociated form of the acids. UNIVERSITY OF IBADAN LIBRARY 37 At a slightly alkaline pH the absorption of a mixture of the three acids was accompanied by accumulation within the rumen of one equivalent of bicarbonate ion (HCO^) per two equivalents of UFA absorbed. It was shown by Stevens (1969) that lowering the pH of thd rumen bath from 7.A to 6.A increased the rate of absorption of all the three acids and resulted in a slight increase in acetate transports a two-fold increase in propionate and a four-fold increase in butyrate transport was due to increased absorption with no increase in the rate of metabolism to ketone bodies. In effect, it has been established that the fatty acids produced by fermentation are directly absorbed into the blood stream from the reticulo-rumen. Acetate and butyrate are lypogenic whereas propionate is glycogenic (Armstrong, 1957; Maynard and Loosli, 1969). Both acetate and butyrate are rapidly metabolised and serve the energy needs of the body. Both can enter the metabolic cycle of fat and thus form body fat. Acetate can be utilized by the mammary gland to form the short-chain fatty acids of milk (Armstrong, I960). It is also utilized in the tricar­ boxylic acid (TCA) cycle in the same mechahism by which the end-products of carbohydrate and protein are metabolised to UNIVERSITY OF IBADAN LIBRARY 36 furnish energy (Barcroft _et al; 19AA). '.2.7. Ammonia absorption and utilization in the rumen It has been established that ammonia is absorbed from the rumen carried from blood in the portal vein to the liver where it is converted to urea which is subse­ quently excreted in the urine. Level of ammonia in the rumen is highly correlated positively with level of ammonia in the portal vein. Estimates of ammonia absorp­ tion from sheep rumen ranges from A-13g per day (Mba, 1972). The rate of absorption depends on the pH of the rumen, being much more absorbed in the unionised form (Mba, 1972). Houpt (1969) pointed out that the lower­ ing of the rumen pH by a soluble carbohydrate fermented would decrease the rate of absorption because ammonia is rapidly absorbed in an unionised form at neutral or alkaline pH. Therefore this could explain the nitrogen retention observed when large amount of carbohydrate in addition to nitrogen source is fed to ruminants. The nitrogen is quickly converted to ruminal ammonium ion f which remains long enough in the rumen to be utilized for microbial protein synthesis. Ammonia is a weak base with a pKa in the vicinity of 8.BB - 9.15. An increase in pH UNIVERSITY OF IBADAN LIBRARY 39 near neutral or alkaline level causes the PJH* ion to be converted to NH-̂ which is rapidly absorbed (Hogan, 1961). The level of blood urea has been shown to be a good index of protein utilization (Preston, Schnakenberg and Pfander, 1965). Under some circumstances when the rate of absorption of ammonia from the rumen is high, toxic effects are associated with blood level of urea and ammonia (Lewis, 1975). The clinical symptoms observed are changes in electrolyte balance, ammonium carbamate formation in the rumen and disturbance of the acid-base status. Also, at high ammonia concentrations, some ammonia could pass into the systemic circulation. It has been suggested that a hepatic ammonia threshold exists in the sheep and that if this threshold is exceeded, the liver can no more cope with the high level of ammonia brought to it and therefore the ammonia concentration in the peripheral blood rises sharply (Houpt and Houpt, 1968). Carroll and Hungate (195A) have shown that when ammonium acetate was used to induce varying levels of ruminal ammonia, no signi­ ficant changes in arterial ammonia concentration took place until the partal blood contained about 0.8m - mole I\!Ĥ per UNIVERSITY OF IBADAN LIBRARY - AO - litre of blood. Above this level, it was fehown that the arterial blood ammonia concentration increases at almost the same rate as the portal blood. When the arterial ammonia concentration reached Q.A to 0.5m - mole IMĤ per litre, respiratory difficulties arose in the animals, and beyond this, death occurred probably due to a disturbance in acid-base equilibrium caused by excessive (\1Ĥ + ions. Acid administration usually prevents urea toxicity by preventing ammonia-carbamate formation. A high rate of absorption of ammonia from the rumen is certainly a great disadvantage as neither ammonia nor urea can be utilized for essential amino acid synthesis. It is estimated that the amount of ammonia carried to the liver per day is about 1Ag (Packett and Groves, 1965). Even if a portion of this is returned to the rumen via the saliva and through the rumen epithelia as urea, the nitrogen loss still represents an appreaciable proportion of the total nitrogen intake (Houpt and Houpt, I960). On a lorn dietary nitrogen intake, the addition through the rumen from the blood mould be very considera­ ble. This urea recycling is of considerable importance to the animal under conditions where nitrogen is in short supply as it could act greatly on the animal chances of UNIVERSITY OF IBADAN LIBRARY I - L1 - survival under such adverse conditions (Lewis, 1975). 1.2.8 Chemistry of milk constituents The nutritive value of milk depends on its composi­ tion which in turn is influenced by several factors. Milk is in three physical stages, viz., solution, emul­ sion and colloidal suspension (Markley, I960). These are so intimately associated that changes in any of the three are bound to have profound effects on one or both of the others. Numerous substances like phospholipids, steroids,. carotenoids and fat soluble vitamins are dissolved in the fat or held at the fat globule surface (Kon and Cowie, 1961). The aqueous solution holds in solution lactose, water soluble vitamins and some of the minerals. Proteins and the other minerals are held in colloidal suspension (Kon and Cowie, 1961). Milk Protein Kon and Cowie (1961) classified milk protein into two parts, casein and the milk serum protein. The milk i serum protein was subdivided into the heat-stable and heat-labile fraction. The former consisted of proteose _ peptone while the latter consisted of albumin and globu­ lin. Casein is the predominant protein of milk, making UNIVERSITY OF IBADAN LIBRARY I up to 80% of the total protein fraction of milk. Casein exists in milk as a colloidal suspension containing calcium both bound to the protein molecule and associated with it as tricalcium phosphate. Mellander (1939) classified casein into three compo- nents, viz;c^ , 6, and proportion of 75, 22 and 3% respectively and in decreasing order of mobility. However, Cherbuliez and Daudet (1950) claimed to have separated a fourth component,^ -casein which is a proteose (a substance found after casein is treated with rennet). The respective proportions of the four casein components was then given as(X(60%), & (25%), Q (10%) and The milk serum protein are denatured when milk is boiled but no precipitate takes place until the pH of 4.6 is reached when they are co-precipitated with casein. The proteose - peptone forms one of the largest part of milk serum protein. It makes up about 6- 1® of the total milk protein. It is heat-stable (Hon and Cowie, 1961); The classical proteose-peptone fraction of milk consists of soluble proteins not precipitated by heat (95 C, for thirty minutes) at pH of 4.6 but precipitated by 8-12% trichloroacetic acid and accounts for about 24% UNIVERSITY OF IBADAN LIBRARY A3 of the whey proteins (Kon and Cowie, 1961). Larson and Rolleri (1955) employing the Tiselius electrophoretic technique observed discernible gradient boundaries in the filtrate from acid-precipitated, heated skim-milk which they attributed to the proteose-peptone fraction. These electrophoretic boundaries were designated as serum components 3, 5 and 8 in ascending order of electro­ phoretic mobility. It has been demonstrated by Kolar and Brunner (1969) that components 5 and 8 appeared to be ubiquitously distributed within the protein system whereas component 3 was restricted to the serum fraction and was thought to be a blood serum. The albumin consists of - lactalbumin,^- lacto- globulin and serum albumin while the globulin (immune globulin) consists of euglobulin and pseudo-globulin. The^- lactoglobulin constitutes the major portion of the milk serum protein (Mba, 1972). It is of special interest as being the main source of sulphydryl groups which are liberated when milk is heated lactoglobulin may be crystallised from the conventional albumin fraction sub­ jected to prolonged dialyses at pH 5.2 (Markley, 1960). Aschaffenberg and Drewry (1955) discovered that there are UNIVERSITY OF IBADAN LIBRARY I - M* - two fractions o f ^ - lactoglobulin namely Q ̂ and ̂ but they later found out that the capacity to produce the different types of ^ - lactoglobulin was geneti­ cally controlled, both fractions became known as (̂ > - lactoglobulin A and B. Experiments showed that - lactoglobulin B was denatured at a more rapid rate than (̂> - lactoglobulin A (Aschaffenberg and Drewry, 1955). Although not identical with the albumin of blood serum , lactalbumin resembles it closely in amino acid composition. It contains approximately two and a half times as much sulphur as does casein. It contains no free sulphydryl groups though its cystein content is high. It contains 7% tryptophan. The serum albumin of milk is the same as blood serum albumin and has probably got into milk by direct infiltration from the blood (Kon and Cowie, 1961). The globulin fraction otherwise referred to as the immune globulins are present in ordinary milk in small concentration but occur in much larger amounts in colo­ strum (Schmidt, 197A). They are of extreme importance to the new-born. Crowther and Riastrick (1916) described two UNIVERSITY OF IBADAN LIBRARY - i n ­ fractions of immune globulins - the euglobulin which is insoluble in water and pseudoglobulin which is soluble in water. Both globulins do not however differ too much in their physical properties as well as in chemical composition. They bath contain 2.5 - 3% hexose and 1.3% hexosamine (Crowther and Riastrick, 1916). Carbohydrates Lactose, (a disaccharide, known as glucose -4- galactoside) is the most abundant carbohydrate of milk. Glucose, another milk carbohydrate, appears in trace amounts (Kirchgessner, Friesecke and Koch, 1967). Lactase is pecu­ liar to, or characteristic of, milk and exists in . The ̂ Y-form is more active than the fjS- form. Thec^and forms have specific rotation of +89.4 and +35.0 respectively. The osmotic pressure of milk is essentially the same as that of blood and this is maintained by concentrations of lactose and mine­ ral matter such as k, (Ma, cl. The lactase together with these salts are responsible,to the extent, of 75% of the osmotic pressure of the milk. The aqueous solution of lactose reduces Fehling's solution and ammonium nitrate solution and the reducing power increases when in aqueous solution. It is soluble in alcohol or ether and dissolves in hot acetic acid (Mba, 1972) UNIVERSITY OF IBADAN LIBRARY Milk oxidation results in the conversion of -CHO group into the corresponding -COOH group. When heated to between 110 - 130°C, the lactose hydrate looses its water of crystallisation, above 150°C it turns yellow and at 175°C it turns very brown called the lacto- caramel (Herrington, 1948). Milk lactose is readily attacked by various organisms in milk particularly the lactic acid bacteria (lactobacilli). The faintly sweet taste of raw milk changes gradually to a more stringent flavour with characteristic odour of souring milk. The favourable temperature condition is at 37°C when about 1% of the lactic acid is produced (Kon and Cowie, 1961). Suffice it to say that lactase is easily broken down by fermen­ tation to lactic acid 2c gh 12D6 ----------------- 7* ^ h 3chohcooh lactose lactic acid During the conversion of lactase to lactic acid, various byproducts are produced including carbon dioxide, acetyl methyl - carbinol, diacetyl and butyric acids (Markley, 1960). The last two acids produce powerful odours. The nature and quantity of the bi-products are determined by the type of bacteria. The production of lactic acid has UNIVERSITY OF IBADAN LIBRARY - 47 - been shown to affect casein and mineral matter (Jordan and Lohr, 1962). With increase in the quantity of lactic acid more and more calcium is removed from casein to form calcium lactate (Markley, I960), some of the colloidal calcium-phosphorus is converted to calcium-hydrogen-phosphate. Thus the physical equili­ brium between the soluble and colloidal condition is considerably altered with the resulting increase in osmotic pressure and corresponding decrease in the freez­ ing point of the sample (Markley, 1960). Commercially, lactic acid may be produced by contro­ lled fermentation of lactose in whey resulting in calcium- lactate (Kon and Cowie, 1961) from which pure lactic acid or lactic esters could be obtained. These substances may serve as raw materials for industries in the making of plastics, resin, textiles and pure chemicals. It could also be fermented to butyric acid, carbon dioxide and hydrogen. Lactase is also used for the preparation of infant and invalid food (Rook and Storry, 1964). It is an important source of galactose which itself is an important constituent of cerebroside of brain and nerve tissues. Lactose has been shown to be important in the UNIVERSITY OF IBADAN LIBRARY I - h a - manufacture of penicillin. Much studies are still required to elucidate the problem of lactose utiliza­ tion. It is now known that galactose need not be an essential constituent of the diet as lactose is very easily converted to glucose. In congenital galacto- saemia, infants are unable to metabolise galactose due to lack of galactose - 1 - phosphate uridyl transferase. The feeding of diets free Qf lactose and galactose is a good remedy in this instance. The feeding to rats and chicks of diets containg *+0% or more lactose results in the paralysis of hind limbs (rats) and nervous disorder (chicks) (Jordan and Lohr, 1962) All the other carbohydrates of milk occur in small quantities and may be present in the free or bound state with protein or lipids. Milk Fat The esters of glycerol and fatty acids are often referred to as fats and oils. The former are usually solids and the latter are liquids at room temperature. The group of compounds designated as fatty acids were so called because they were originally found to be consti­ tuents of animal and vegetable fats and fatty oils, (Markley, 1960). UNIVERSITY OF IBADAN LIBRARY I - A9 - The physical properties of cow's milk fat consists of its melting point at 2Q°C but not comple­ tely until the temperature has reached 33°C. The liquid sets over a similar but lower temperature rang­ ing from 2A°C to 19°C. As secreted, the fat globules are therefore liquid. Because of variation in the composition of milk fat, there are slight differences from sample to sample in specific gravity,ranging from 0. 936 to 0.9A6 at 15°C. Refractive index is between 1. A58 and 1.A6A at 15°C. Biochemically, the bulk of fat is constituted by the true fats - glycerides of numerous saturated and unsaturated fatty acids. As pointed out by Kon and Cowie (1961), and Folley (1956), the three hydroxyl groups of glycerol may be replaced by the same fatty acids or by two or three different fatty acids. It has been calculated that at least A,913 glycerides are passible in milk fat contained in a pint of milk (Kon and Cowie, 1961). The fatty acids of milk fat fall into well-defined groups. Saturated fatty acids contain even numbers of carbon atoms ranging from butyric acid to eisosanoic acid C^g. The major components is palmitic acid or n-heptadecanoic acid (C^giO) (Mba, 1972). In milk saturated fatty acids UNIVERSITY O IBADAN LIBRARY 50 the following are present: (a) Normal saturated acids with odd numbered carhons e.g. n-pentadecanoic and n-heptadecanoic acids predomi­ nate. This accounts for about 2% of the total fatty acids. (b) flethyl-branced-chain saturated fatty acids with odd and even numbers of carbon atoms. These also account for about 2%. Considering the proportion of saturated fatty acids, that of ruminants differ sharply from that of other species. The difference is also clear in its component fatty acids. For instance, human milk fat has only traces of acids below decanoic i.e. capric acid (C^rD). As pointed out by Kon and Cowie (1961) with ruminant fatty acids, there is an appreciable quantity of butyric acid (C^:0) whereas very small quantity is present in the cow's milk; that of cow is also substantial. The proportion of palmitic acid (0,^:0) in milk fat is fairly constant in both ruminants and non-ruminants except in the horse where it is low. As painted out by Smith and Jack (195A), Hon and Cowie (1961) and Riel (1963), the saturated fatty acids above CQ:0 (caprylic Dr octanoic acid), are solid at ordi­ nary temperature and the unsaturated ones are predominantly UNIVERSITY OF IBADAN LIBRARY I - 51 - liquid. This property determines some of the characte­ ristic physical properties of milk fat such as hardness and melting point. The unsaturated fatty acid consists of: (a) The monoethenoid acids, the most abundant being oleic acid (C1Q:1). (b) Diethenoid acids are mostly the series, e.g. the linoleic acid (0^:2) with double bonds. (c) Triethenoid acids - linolenic acid has been iden­ tified as the main component of the triethenoid acid fraction. It is an essential fatty acid (that which cannot be synthesised at sufficient rate to meet the needs of the body). The linolenic acid content of the mare is exceptionally high. (d) Polyethenoid acid - probably arachidonic acid is a member. It is also an essential fatty acid. Traces of and have been detected in cow's milk fat. Molecular structures of these groups of acids for the couj's milk fat have been fpund by the use of ultraviolet spectroscopy. Associated with the milk fat are the phospholipids. It is concentrated in the fat globule membrane.. It is about 1% in the cow's milk fat. The major components are lecithin, UNIVERSITY OF IBADAN LIBRARY 52 cephalin and a small amount of sphingomyelin and closely related cerebrosides. Hon and Cowie (1961) pointed out that the phospholipids are excellent emulsifying agents since they have both lipophylic and hydrophylic groups. The phospholipids of milk fat are prone to oxidation because of the notable proportions of highly unsaturated fatty acids and are believed to be responsible for ini­ tiating the changes leading to the development of oxida­ tive taints in milk. Also associated with milk fat are the sterols which consists of the cholesterols. Choles- terals are present in milk fat to the extent of 0.01it%. It is an invariable components of milk (Hon and Cowie, 1961). The percentage is however higher in women, goats, mares, ewes and sows. The other sterols are associated with ultraviolet irradiation (Markley, 1960). Minerals and Vitamins in milk By the mineral constituents In milk are meant those which contain only inorganic elements in their molecules or ions. The ash of milk is obtained qs whitish grey powder when the liquid is evaporated and the residue incinerated in a muffle furnace at £t00-500°C until it turns whitish grey. The ash content is basic. The minerals UNIVERSITY OF IBADAN LIBRARY 53 in milk can be broadly subdivided into trace and major elements depending on their concentrations. The members of the former group exist is relatively smaller concen­ trations in milk than the latter. The major elements in milk ash are calcium, phosphorus, magnesium, potassium, chloride, sulphur. The contents of each element is largely determined by genetic factors. This is to say that milk content of the major elements will remain constant even when the supply of individual elements and the animals requirements are very different. Where the supply is inadequate, a certain proportion of the skeletal reserves is mobilized and the concentration of the mineral in milk is thus maintained (Wright and Pappish, 1929). Even when there is extreme defficiency of one or more elements the mineral matter per volume of milk remains constant, though the milk yield will fall and with it the total secretion of mineral sub­ stances to strike a balance in the concentration. Colo­ strum (the first milk after parturition) contains all the major elements except potassium in higher concentrations than normal milk, and remain more or less unchanged for the greater part of the lactation period (Schmidt, 197*+). It is only towards the end of lactation that some alterations UNIVERSITY OF IBADAN LIBRARY t - 5A - occur in concentration of some of the major elements. The trace elements consist of iron, copper manganese, aluminium. It is noteworthy that minerals of milk originate from the feeds of the lactating animal or from bidy stores particularly the skeletal tissues. The vitamins can be classified into two groups - the fat and water soluble groups. Except Vit. K, the fat soluble vitamins (A,D,E) cannot be synthesised in the rumen by the microorganisms. Vit. A content of milk is positively correlated with the carotene content of feed. Fresh pasture yields milk highest in Vit. A content, followed by well preserved silage, then by hay, especially if dried by rapid-drying method (Hilton, Hange and Uiilbur, 1935). Loosli (197A) demonstrated that the concentration of tocopherol in the milk fat was directly related to the Vit. E content of the ration. Tocopherol is a pale, yellow, viscous oil. It is fat soluble, dissolves readily in presence of alkali but stable in acid, to heat and alkali in absehce of oxidi­ sing agents. Loosli (19A9) put the requirement of tocopherol for animals as 0.23 - 0.31mg. The two forms of Vit. D which are of importance in nutrition are UNIVERSITY OF IBADAN LIBRARY 55 ergocalciferol (Wit. D^) and 7-riehydrocholesterol (Wit. D^). Though Wit. D molecules are fairly stable, they may be destroyed through oxidation on exposure to oxygen and at high temperature. They are much more stable to oxidation than Wit. ft. Wit. melts at 11A-117QC while Wit. melts at 8A-05DC. Wit. D is fat-soluble and therefore it is present in the fat portion of milk. The vitamin D of milk varies with the Wit. D content of the feed. Witamin C (ascorbic acid) which is water-solubld is a white crystalline odourless substance with sour taste. It melts at 190-192DC. It is soluble in organic solvent. Ascorbic acid exists in two biological forms - the L-ascorbic acid (the more stable reduced form) and the oxidised form dehydro-ascorbic acid. Thiamine(Wit. B^) has been shown to be soluble in 70% alcohol as well as water and is readily destroyed by heat unless the pH is low. Thiamine is readily oxidised and has a melting point between 2ft8-250DC (West, Todd, Mason and Bruggen, 1970). r i .2.9 Effect of diet on milk yield and composition Rook and Starry (196A) observed that acetic, propionic and butyric acids produced from feeds within <4 UNIVERSITY OF IBADAN LIBRARY I - 56 - the rumen together accounted for 70% of the energy absorbed from the ruminant digestive tract and that the mixture of acids produced in the rumen varies uith the chemical composition and physical nature of the diet. In the milking corn, the continous infusion of individual volatile fatty acids into the rumen have elucidated the effect of different diets on milk yield and composition (Rook and Balch, 1961; Rook, Balch and Johnson, 1965; Btorry and Rook, 1966). Further studies have revealed that infusion of acetic acid into the rumen increased milk yield and also had a specific increase bn fat content while propionic acid had no effect on milk yield but decreased milk fat content and increased milk protein (Armstrong, 1968; Rook and Balch, 1961; Rook, _et jal 1965). Butyric acid is lipogenic and therefore increases milk content (Armstrong, 1968). This increase was associated with increased yields of C^-C^g acids and decreased yields of stearic and oleic acids. Suffice it to say that an alteration in the end-products of rumen digestion may not only change the overall efficiency of utilization of dietary energy but also may increase one productive process at the expense of another (Rook and Storry, 196A). UNIVERSITY OF IBADAN LIBRARY i - 57 - Milk fat content Fins grinding of the entire roughage in a ration or considerable reduction in roughage intake and an increase in the concentrate Feed reduced the percentage and yield of fat without affecting the yield of milk (Balch et _al, 1965). Furthermore, this phenomenon has been shown by Balch et al (1965) to occur also with cows on diets of kale, concentrates and small quantities of roughage and also with animals grazing on young herbage especially when supplemented with concentrate. Storry and Rook (1966) examined the effects of diets low in hay and high in flaked maize on the secretion and composition of milk fat. In the studies, the change from a normal hay-concentrate ration to the one low in hay and high in flaked maize resulted in a marked fall in milk fat content. The change from a diet high in hay to one low in hay was reflected in the rumen by a marked fall in the proportion of acetate, increase in that of propionate and little change in that of buyrate. Lactic acid increased appre­ ciably. Abrupt re-introduction of the normal hay-concen­ trate ration resulted in the return of the proportion of acids in the rumen liquour to their original levels within four days although milk fat recovery took some two to UNIVERSITY OF IBADAN LIBRARY I - 58 - three weeks (Storry and Rook, 1966). The fall in milk fat is usually associated with an increase in the iodine value and a decrease in the Reichert - Meissl value indicating that the proportion of the unsaturated acids are increased and those of the lower \lFA are decreased (Armstrong, 196Q). King and Hemken (1962) demonstrated a reduction in the yield of all fatty acids from lauric up to and including C^gD and C„lno 1. The most marked reductions did occur in C1. where: Y = volume of water taken by the animals in litres x = volume of water in the water-trough at the start of experiment. x^ = volume of water left in the water-trough after a 2£f-hour period. x^ = volume of water evaporated from the separate water-trough in the centre of the byre or grazing paddock. 2.2.5 Milk Sampling Cows were machine-milked twice daily at 5.30 a.m. and 2.30 p.m. respectively and bulked; daily records were kept for the period. Aliquots (about 30mls) of the daily milk yield of each animal were bulked weekly (after analysing for milk protein and butterfat)^ stored in clean dried bottles with stoppers before storage in a deep freeze at -5°C until required for analysis. 2.2.6 Body temperature and respiration rate Body temperature was taken at 7.OB a.m. and 3.00 p.m. daily by inserting a previously sterilised clinical UNIVERSITY OF IBADAN LIBRARY I - 81 - thermometer into the rectum of the cow for two minutes. Respiration rate was taken at 7.00 a.m., 2.00p.m. and 6.00 p.m. by counting the number of flank movements in one minute. 2.3 Analytical procedure The forage, concentrate and faeces were analysed for dry matter (DM), crude protein (CP), crude fibre (CF), ether extract (EE), nitrogen-free extractives (IMFE), gross energy (GE),and total ash as well as individual mineral content of forage and concentrate using A0AC (1970) methods. Determinations were made in duplicate. The results were expressed on dry-matter basis. 2.3.1 Moisture: 2g of each milled material was dried in an oven at 105°C overnight to a constant weight. 2.3.2 Total Ash: The dried material obtained from 2.3.1 was ignited at 600°C in a muffle furnace until grey or nearly white when ashing would have been completed. 2.3.3 Crude protein: This was determined by the macro-kjedahl digestion using sodium sulphate-copper sulphate selenium i catalyst mixture followed by micro-distillation using Markham distillation apparatus. Boric acid was used as the receiving medium. By multiplying the total nitrogen content by the factor 6.25, the crude protein was obtained. UNIVERSITY OF IBADAN LIBRARY 82 2.3.A Ether Extract; This was estimated by extracting moi­ sture-free milled sample with petroleum ether (Bp.AO- 60aC) for seven hours in a saxhlet extraction chamber. 2.3.5 Crude fibre: This was determined by the trichloroacetic acid method. The digestion reagent consisted of 500ml glacial acetic acid, A50ml water, 50ml cone, nitric acid and 20g trichloroacetic acid. 1g of the milled sample was boiled with 100ml of the digestion reagent for A0 minutes. It was filtered and washed with hot water and petroleum spirit. It was dried overnight cooled and weighed. The material was then ignited at 600°C for one hour, cooled and reweighed. The difference in the weighings divided by the weight of the milled sample taken multiplied by 100 is the crude fibre percentage. 2.3.6 Nitrogen-free extract : This was estimated by the difference between 100 and the sum of percentages of moisture, total ash, CP, EE and CF. 2.3.7 Gross energy was determined using adiabatic bomb calorimeter. Analysis nf Milk 2.3.0 Milk fat; Each sample of milk was analysed for concen­ tration of fat by the standard Gerber method described by Davis (1959). 2.3.9 Protein: This was described for feeds and faeces in section 2.3.3 except that the results were multiplied by the factor UNIVERSITY OF IBADAN LIBR RY I f - 83 - 6.38 to obtain the protein content of milk. 2.3.10 Lactose: This was determined colorimetrically using the phenol-sulphuric acid method developed by Barnett and Tawab (1957) and modified by Marier and Boulet (1959). 2.3.11 Total solids: This was estimated by evaporating off the moisture in a known weighed sample at between 100°C and 105DC to a constant weight. 2.3.12 Total ash: This was determined by igniting the dried milk sample from total solids determination in a muffle furnace at 550°C for A8 hours. 2.3.13 Mineral contents of feeds and milk were estimated using the modified Gomorris' (19A2) method. 2g samples were wet digested using Ami perchloric acid, 2ml cone.sulphuric acid and 25ml cone, nitric acid. The contents were transfered to 100ml flask and made up to mark with glass-distilled water, Ealcium, sodium, potassium, magnesium and manganese were determined using the Atomic Absorption Spectrophotometer while phosphorus was read on Acta III Beckman at 680nm. 2.3.1A Solids-not-fat: This was estimated by substracting the per- i centage value of fat from that of total solids. 2.3.15 Solids-corrected milk (5CM): This was obtained by using the equation of Tyrell and Reid (1965) UNIVERSITY OF IBADAN LIBRARY Llvewelqht changes of the anlmal9 Weights for three consecutive days were taken prior to the first day of each trial followed by fortnightly weightings throughout the period of the investigation. The weights were obtained in the morning before feeding and watering and just after milking in the case of milking cows. RESULTS Statistical analyses were carried on all the results using the methods outlined by Federer (1953) and Duncan (1955). Dry Matter (DM) Intake fldegbala's (197L) method was used to estimate the forage DM intake of the grazing animals by applying the regression equations of the DM intake of forages and metabolic size of the stall-fed cows. Table 2.5 shows the various regression equations relating DM intake (kg/day) (Y) to the metabolic size of the cows (X). Effects of System of Management; Grazing animals consumed more forage dry matter than the stall-fed cows as shown in Tables 2.7 and 2.11 (P< 0.D5). While grazing animals consumed an average of 7.9£»kg/day, the stall-fed had an average of 7.8Lkg/day. Expressing these data on metabolic size as shown in Table 2.8, UNIVERSITY OF IBADAN LIBRARY Table 2.6 REGRESSION EQUATIONS DESCRIBING THE RELATIONSHIP BETWEEN TOTAL DRY HATTER INTAKE (kgDM/day) ( Y ) . AND METABOLIC S IZE (X ) OF DAIRY GOV.'S STALL-FED BREED 'TREATMENT REGRESSION CORRELATION STANDARD(D IET) EQUATIONS COEFFICIENT ( r ) ERROR FRIESIAN H igh fo ra g e Y= 0.1056X-.1 .6665 0 .58* O.36 FR IESIAN H ig h c o n c e n t ra te Y=0.0839 X - 0 .6097 0 .55* 0.16 GERMAN BROWN H ig h fo ra g e Y= o.oo83X+5. 8i 27 0. 51* 0. 1*f GERMAN BROWN H igh c o n c e n t ra te Y= 0.0583X+ 0.990 if 0.^8* 0.18 Significant (P^0.05) UNIVERSITY OF IBADAN LIBRARY I - EE - the grazing cows also consumed more total dry matter than the stall-fed animals with an average of 99.39 and 98.99g/day/tiJ,ClJ * 7 31*Kg respectively although this was not significant (P>0.05) The intake of the forage DM alone differed from that observed for the total DM intake. The stall-fed cows and grazing animals consumed an average of 73.96 and 73.02§/ day/i'lĵ *7^ respectivdly. breed Fffects: The Friesian cows consumed more forage dry matter (8.11^0.19kg) than the German Brown cows (7.67^0.23kg). This was statistically significant (P<£0.05) (Table 2.7). Mean dry matter intake from concentrate showed that Friesian cows' consumption (2.05^0.1itkg/day) was slightly higher than the German Brown (2.CUtio.22kg/day). The results were however not statistically significant (P >11.05). Table 2.8 shows the dry matter intake of these cows when expressed on intake per metabolic size so as to eliminate differences in body weight . The general picture highlighted in this table differs slightly from that observed in Table 2.7. While on high concentrate feeding, forage DM intake of 95.28 and 101.82g/day/UJ^*7'% (stall-feeding and grazing respectively) were recorded for the Friesian cows, and 92.60 and 88.58g/day/li)'ukg* 73' for the German Brown, the UNIVERSITY OF IBADAN LIBRARY T A B L E 2 . 7 "̂ Forage Dry Matter (kg/day) i.ntake of ztall-fefl and grazed Sermon Brown and Friesian lactating cows maintained on high or l a x concentrate rations PERIOD WEEKS H I G H C O N C E N T R A T E H I G H F O R A G E GERMAN BROVIN FRIESIAN GERMAN BROVIN FRIESIAN .Stall-feeding Grazing Stall-feeding Grazing Stall-feeding Grazing Stall-feeding Grazing * ** * ** * ** * ** * *• ♦ ** * *♦ ♦ ** 1 7.i57 2.06 7.48 3.15 8.19 2.64 8.02 2.65 8.37 2.00 7.70 1.2 8 8.20 1.90 9.19 1.90 f 2 7.63 2 .1 2 7-A-1 3.43 8.17 2.62 7.97 2.55 8 .18 1.90 7.60 1.30 7.95 1.65 9.14 1.72 I 3 7 .16 1.91 7.50 3.40 7.89 2.6 1 8 .18 2.85 8.05 1.98 7.56 1 .1 8 8.22 1.68 9.17 1.65 i ■ 4 7.20 2 .06 7.42 3.10 7.45 2.73 7.89 2.55 8.76 1.90 7.75 1.35 7.91 1.65 8.83 1.6 1 Mean 7A2+0.014 2.Q4t_0.03 7.45+0. C2 3.28+0.02 7.93+0.17 2.65(0.07 8.02+0.06 2.65(0.05 8.34(0.15 1.95(0.0' 7(65(0.04 1.28(0.02 8.07+0.08 1.12(0.02 9.08+o.ce 1 .72+0.02 1 7.42 2.75 6.52 2 .10 7.14 2.36 8.22 2.03 7.92 1.43 8.85 1.92 7.89 1.85 7.69 1.96 2 7.62 2.33 6.37 2.25 7.19 2.28 8.36 2 .10 7.91 1.35 8.35 2.00 9.03 1 .65 8.06 1.77 II 3 7.75 2.41 6.17 2.05 7.15 2 .1 0 8.47 2 .1 1 7.83 1.30 8.70 1.80 8.16 1.6 0 7.93 1.82 4 7.53 2 .18 6.60 1.95 6.96 1.95 8.34 1.95 8 .11 1 .1 0 8.41 1.98 8.28 1 2+8 8.16 1.73 Mean 7.58+0.01 2Ji2 + 0 £ j2 6.42+0.09 2 .09+0.04 7.11+0.05 2.17+0.04 8.35(0.05 2.05(0.03 7.94+0.06 1.30+0.04 8.58+0.12 1^3+0.04 8.3^0.24 1.65+0.03 7.96+0.10 1.82+0.03 * Forage dry matter intake •• Concentrate dry matter intake + Forage DM intake of grazed animal3 were estimated from regression equations (Table 2 . 6 ) . UNIVERSITY OF IBADAN LIBRARY 88 Table 2.8 Total dry matter of forages and concentrates (g/day/W®^7̂ 1*) consumed by exotic breeds of cows under stall-feeding and grazing conditions DRY HATTER INTAKE HIGH CONCENTRATE HIGH FORAGE German Brown Friesian German Brown Friesian Stall- Grazing Stall- Stall-feeding feeding Grazing feeding Grazing Stall- feeding Grazing Dry Matter Intake from Forage 65-09 54.28 64.72 72.59 81.56 81.55 84.48 83.65 (e/day/W £*73S Dry Matter Intake from Concentrate ration 27.51 34.30 30.56 29.23 20 .26 20.04 21.77 21.92 (g/dayA°;754) % concentrate DM intake 29.71 38.72 32.07 28.71 19.90 19.73 20.49 20.76 Total Dry Matter mtake (£/day/w£-73S 9 2.6 0 88.58 95.28 1 0 1 .8 2 1 0 1 .8 2 101.59 106.25 105.57 UNIVERSITY OF IBADAN LIBRARY I - 09 - difference between the consumption of the two breeds was much lower under high forage feeding. The average DM intake nf concentrate ration was slightly higher for the Friesian (25.07g/day/LJ^*7'5S cows than the German Brown cows (25.53g/day/liJ^*^'5S . Diet: The DM intake from the cows under high forage (HF) feeding was higher than those cows on high concentrate (HC) feeding. This is shown in Table 2.7. The average intake of the HF cows from forage was 8.25^0.16kg/day while forage DM of the HC cows was 7.54io.21kg/day. Results were statistically significant (P<0.05). Concentrate DM intake of cows on HC (2.42^0.14kg/day) was statistically higher than those on HF (1.67^0.09) (P<_0.01). hJhen expressed on metabo­ lic size (Table 2.8), the results obtained follow the same pattern. For example, cows under the HF consumed 103.81, 82.81 and 21 .OOg/dayAJ^*^^ of total dry matter, dry matter intake of forage and concentrate ration respectively as against 94.57, 64.17 and 30.40g/day/lil^*^^ for those under HC. Table 2.8 also shows that while 32.30% of the total DM intake of cows on HC was contributed by concentrate supplement, the value for cows on HF was 20.22%. .^.2 Milk yield and Solids-corrected milk (SCM) Data used for statistical analysis were obtained by sub- stracting milk yield produced in succeeding weeks from the UNIVERSITY OF IBADAN LIBRARY - 90 - one obtained a week before the start of the experiment. That is,if milk yield a week before the start of the experiment was 30kg and the milk yield recorded during the first week of the experiment was 27kg, the figure to be used for statistical analysis would be -3kg. The same procedure was adapted for the solids-corrected milk. System of Management: Tables 2.9, 2.10 and 2.11 show the summary of the milk yield and SCM. Results in these tables show that the milk production of the grazed lactating cows was higher than that of the stall-fed ones. Statistical analysis (Appendix B2.1) also showed this was significant (P-Cn.01). Table 2.11 shows that while the grazed animals produced an average of 51.A0il.87kg milk/week, an average decline of 2.10kg/week, the zero-grazed ones produced an average of A6.66i2.50kg/week, a decline of 6.61kg/week at the end of the experiment. The results obtained for the SCn were similar except that the differences in yield and decline were more marked. The grazed cows produced *+8.28^1.5,1kg/week with a decline of 0.8Akg/week compared with A1.80^2.1Okg/week, giving a decline of 7.02kg/week for the stall-fed animals. Breed Effects; A close examination of the data obtained in Table 2.11 shows that the Friesian cows produced slightly UNIVERSITY OF IBADAN LIBRARY 4 - 91 = Table 2.19 Milk Jtield (kg/week) of. the, .stall-fed or graced German Brown and Friesian lactating cows maintained. .on -high. and low concentrate ration PERIOD (WEEKS) H I G H C O N C E N T R A T E B I G H F O R A G E Before GERMAN BROWN FRIESIAN GERMAN BROWN FRlESlAN start of ■ expt. Stall-feeding Grazing Stall-feeding Grazing Stall-feed ing Grazing Stall-feeding Grazing 40.69 61.82 52.16 51.14 6 1 .3 7 40.09 58.87 58.64 1 41.82 67.62 5 1 .8 2 50.91 5 9 .3 2 40.46 49.10 54.32 2 37.73 66.82 51.59 55.92 60.68 36.59 52.26 51.36 I 3 40.68 6 1.5 9 53.87 60.00 5 7.9 5 42.50 51.48 50.23 4 6 0 .23 57.96 62.73 55.00 42.28 46.36 40.00 Mean 4 1.3I2 .6 5 64.06-3 .3 8 53.31^3.28 57.39-4.11 58.2 4 13 .3 7 40.46l5.47 49.8ol2.88 48.98l2.92 1 46.02 43.0 7 44.89 40.91 39.78 71.59 48.92 55.68 2 47.50 39.09 40.23 41.59 40.57 56.60 48.86 57.27 II 3 42.96 39.4 3 37.96 38.41 36 .8 2 61.35 44.54 54.32 4 44.55 3 6 .14 38.64 44.86 36.14 57.50 41.82 58.19 Mean 45.26^3.30 39.43-4 .4 7 40.43-2.08 41,19^2,53 38,3312.25 61.76l7.75 46.04l3.60 56.36l4.25 UNIVERSITY OF IBADAN LIBRARY 8 ■i3r;\ tr - 92 - TABLE 2.10 Solids-Corrected MilJc (a'' (kg/week) of German Brown and Friesian milking cows grazed or 3tall-fed on high and low concentrate ration PERIOD (WEEKS) H I G H C O N C E N T R A T E H I G H F O R A G E Before GERMAN BROWN FRIESIAN GERMAN BROWN FRIESIAN start Stall-feeding Grazing Stall-feeding Grazing Stall-feeding Grazing Stall-feeding Grazing of expt. 38.54 58.69 46 .24 45.78 58.05 39.27 52.43 52.73 1 37.13 60 e56 45.55 44.78 54.86 40.27 42.89 49.73 2 34.74 59.47 42.19 50.20 55.74 36.57 46.47 47.89 I 3 36.26 55.77 43.90 51.78 52.27 42.62 46.35 46.85 V 39.67 52.58 45 .61 54.80 49.28 42.22 41.98 38.16 Mean 36.95+1.03 57.10+1.82 44.31+0.81 50.39+2 .10 53.04+1.45 40.42+1J 8 44.42+1.16 45.66+2.57 1 40.97 42.8 1 42.09 38.51 36.04 63.93 39.90 50.86 2 42.39 38.79 36.46 39.86 37.99 54.25 43.24 52.80 II 3 39.15 44.52 35.99 37.37 36.22 62.13 39.67 52.73 if 39.83 36.88 34.73 42.35 34.82 58.63 39.37 54.29 Mean 40.59+0.71 40.75+1.76 37.32+1.63 39.52+1.07 36.27+0i65 59.74+2.13 40.54+0.90 52.67+0.70 (») Calculated from Tyrrell and Raid’a (1965) Formula. SCM(kg) > 12.3(f) + 6.56(SN?) -0.0752M. SN? - a olid a-not-fat (kg) U m milk yield (kg) r Z . f . m SCH - aolida-oorraotad milk (kg) F • Butterfat (kg). UNIVERSITY OF IBADAN LIBRARY I - 93 - higher amount of milk than the German Brown cows. The Friesian cows produced an average of it9.25il.23kg/week with a decline from the start of experiment of 5.95kg per week and the German Brown cows produced it8.82i2.01kg- /week with a decline of 2.17kg/week. However statistical analysis showed no significant difference (P^>0.05). SCM production by the German Brown cows was slightly higher than that of the Friesian cows (Tables 2.10 and 2.11). While the Friesian cows produced itit.itSi 3.21kg/week with a decline of it.81kg/week, the German cows yielded it5.60iit. 15kg/week with a decline of 3.08kg/week. However there was also no statistical differences (P>0.05). Diet Effects: Results shown in Tables 2.9, 2.10, 2.11 and Appendices B2.1a had clearly indicated that although the two diets influenced the milk yield, the effects were statistically nan-significant. Lactating cows on HC feeds produced it7.87il.87kg/week with a decline of 3.58kg/week and those on HF feeds produced 50.20i2.18kg/week with a decline of A.54kg/week. The SCM production also differed r slightly but not significantly as that of the milk yield. The HC-fed cows produced it3.33io.95kg/week with a decline of 3.98kg/week and the HF-fed cows produced an average of it6.75il.02kg/week with a decline of 3.87kg/week. UNIVERSITY OF IBADAN LIBRARY 9 *+ Interaction: The interaction between the diet and breed, diet and system of management, breed and system of management and finally the breed, diet and system of management showed no significant differences (P^O.05). 2.*+.3 Milk Composition The results of mean quality of milk obtained from the chemical analysis of samples for fat, protein, total solids, Solids-not-fat (SNF) and ash are shown in Tables 2.12, 2.13, 2.1*+, 2.15 and 2.16 respectively. System of Management: Butterfat percentage of grazed animals was higher than the stall-fed ones. Results in Table 2.11 showed that the grazed animals yielded 3.93, 3.90, *+.25 and *+.0*+% butterfat with a mean of *+.03-0.08% butterfat and the stall-fed animals produced 3.80; 3.75; *+.08 and 3.83% with a mean of 3.81^0.08% showing that the butterfat per cent of the grazed cows was significantly higher than the stall-fed (P<0.05). However, the stall-fed cows produced a higher percen­ tage of milk protein than the grazed cows. The mean protein percentage of the grazed cows was 3.25io.06% while that of the stall-fed ones was 3.52^0.05%. The difference was highly significant (P<0.01) as shown in Appendix 02.1c. UNIVERSITY OF IBADAN LIBRARY I - 95 - The results in Table 2.1*+ also shamed the effect of management aver the total snlids of the milk. The total solids of the grazed corns mere 11.87^0.17; 11.68t 0.10; 12.69^0.03 and 11.56^0.05% during the first period, and 12.57^0.08; 11.69to.09; 12.1flto.fc2 and 11.9fcto.17% during the second period. The stall-fed cams produced 11.73to.39; 10.B9to.fc8, 11.79to.37 and 12.02to.16% during the first period and 11.fclto.20; 11.75to.02; 11.8fcto.23 and 11.22to.21% during the second period. A summary of these data calculated in Table 2.11 shomed that the grazed animals produced 12.02to.36g total solids/100g fresh milk and the stall-fed corns 11.5Qt0.25g/100g fresh milk. Results mere highly significant (P*C0.01). Table 2.11 shams that the grazed animals yielded a mean of fc.Ofcto.02g lactose/100g fresh milk and the stall-fed animals produced fc.00to.01g/100g fresh milk. There mas no significant difference (P^O.05). The results of the solids-not-fat (SfJF) in Table 2.15 shomed that the yield in the first period mas higher than the second period. The mean S!\IF content of the grazed corns' milk varied from 7.28to.06 to 8.56to.37 during the first period and 7.0fcto.06 to Q.19to.16 during the second period UNIVERSITY OF IBADAN LIBRARY - 96 - TABLE 2.11 *F6rage Dry Matter. Milk Yield and Composition of two breeds of cattle graced or stall-fed oh high and low concentrate ration NUTRIENTS H I G H C O N C E N T R A T E H I G H F O R A G E GERMAN BROWN FRIESIAN GERMAN BROWN FRIESIAN Stall-feeding Grazing Stall-feeding Grazing Stall-f eeuing Grazing Stall-feeding Grazing Forage Dry Matter(kg/day) 7.50 6.94 7.52 8.19 8.14 8 .1 2 8 .2 1 8 .5 2 Milk yield (kg/week) 43-34 51.74 47.12 49.29 48.28 5 1 .9 1 4 7.9 2 5 2 .6 7 Solids-Corrected Milk(kg/wk) 38.76 48.92 40.69 44.95 44.65 50.08 4 3 .1 1 4 9 .16 Butterfat % 3.80 3.93 3.75 3.90 4.08 4 .2 5 3 .8 3 4.04 Milk Protein % 3.53 3.27 3 .4 5 3.49 3 .5 7 ' 3 .1 3 3 .5 3 3 .1 0 Solids-not-fat % 8.04 8.96 7 .8 7 8 .19 8 .2 5 9 .30 8.09 8.6 5 Total Solids % 1 1 .5 7 12.23 1 1 . 3 2 11.68 1 1 .8 2 1 2 .4 3 1 1 .6 2 11.75 Lactose % 4.16 4.18 3.84 3.96 3.9 4 4.08 4 .0 1 4.04 Ash % 0.72 0.71 O .69 0.73 0.73 0 .7 2 0.68 0.72 Energy (KJ/g freeze dried 16.74 1 7 .6 1 17.49 17.57 16 .8 2 17 .7 0 16 .9 0 17.57 milk) * Mean of eight determinations UNIVERSITY OF IBADAN LIBRARY J ' t - 9 7 - TABLE 2.12 Milk fat (g/lOOg milk) content of stall-fed or grazed German Brown and Friesian lactatlng cows’ milk maintained on high and low concentrate rations PERIOD (WEEKS) H I G H C O N C E N T R A T E H I G H F O R A G E Before GERMAN BROWN FRIESIAN GERMAN BROWN FRIESIAN start Stall-feeding Grazing Stall-feeding Grazing Stall-fe eding Grazing Stall-feeding Grazing of expt. 3.71 3.20 3.17 3.28 3.35 4.10 3.21 3.76 1 3.67 3.13 3.18 3.20 3.45 4.08 3.48 4.05 2 3.80 3.16 3 .10 3.23 3.62 4.26 3.45 4.29 I 3 3.70 3.51 3.19 3.05 3.77 4.28 3.63 4.30 4 3.71 3.37 3.22 3 .10 3.93 4 .2 1 3.90 4.63 Mean 3.72+0.05 3.29+0.18 3.17+0.05 3 .14+0.08 3.69+0.20 4.20+0.09 3 .61+0 .21 4.31+0.24 1 3.88 4.28 4*16 4.50 3.96 3.65 3.15 3.40 2 3.76 4.40 4.20 4.63 4.15 4.15 3.88 3.70 II 3 3.83 4.52 4.38 4.78 4.70 4.60 4 .10 3.96 4 4.05 4.80 4.55 4.76 5.05 4.83 4.53 4.00 Mean 3.88+0.12 4.50+0.22 4 .32+0 .18 4.67+0.13 4.46+0.50 4.30+0.52 3.91+0.58 3.77+0.28 UNIVERSITY OF IBADAN LIBRARY ' (■ - 9 8 - TABLE 2.13 Milk protein (g/ 100s milk) content of stall-fed or grazed German Brown and Friesian lactating cows1 milk maintained on high and low concentrate rations PERIOD (WEEKS) H I G H C O N C E N T R A T E H I G H F O R A G E Before GERMAN BROWN FRIESIAN GERMAN BROWN FRIESIAN start Stall-feeding Grazing Stall-feeding Grazing Stall-feeding Grazing Stall-feeding Grazing of expt. 3.55 3.13 3.28 2.27 3.48 3.52 3.52 3.07 1 3.51 2.96 3.25 3.26 3.43 3.02 3.55 2.86 2 3.47 2.97 3.27 3.15 3.50 2.97 3.49 2.90 I 3 3.48 3.13 3.23 3.23 3.55 2.98 3.46 2.65 4 3.55 3.60 3.37 3.42 3.57 2.94 3.58 3.24 Mean 3.50+0.03 3 .16+0.30 3.29+0.05 3 .26+0 .11 3.51+0.06 2.97+0.03 3.52+0.05 2.96+0.24 1 3.58 3.06 3.06 3.42 3.61 3.48 3.45 3.32 2 3.55 3.31 3.60 3.71 3.65 3.35 3.54 3.23 n 3 3.55 3.55 3.61 3.81 3.63 3.24 3.58 3.17 4 3.54 3.58 3.62 3.37 3.68 3.12 3.60 3.20 Mean 3.55+0.02 3.37+0.24 3.60+0.03 3.70+0.20 3.64+0.03 3.30+0.15 3.54+0.06 3.23+0.06 UNIVERSITY OF IBADAN LIBRARY 99 TABLE 2.12*. Total Solids (g/l00g railk) content of German Brown and Friesian cows' milk grazed or stall-fed on high and low concentrate rations PERIOD (WEEKS) H I G H C O N C E N T R A T E H I G H F O R A G E Before GERMAN BROWN FRIESIAN GERMAN BROWN FRIESIAN start Stall-feeding Grazing Stall-feeding Grazing Stall-feeding Grazing Stall-feeding Grazing of expt. 12.34 12.83 11.91 11.95 12.64 12.88 11 .87 11.65 1 12 .22 12.04 11.53 11.79 12 .2 3 12.71 11.78 11.57 2 11.8 6 11.95 10.95 11.73 11.97 12.65 12 .10 11.48 I 3 11 .5 0 11.87 10.67 11.64 11.6 0 12.71 12 .10 11.59 4 11.34 1 1 .&+ 10.41 11 .5 6 11.38 12.69 12 .10 11.6 0 Mean 11.73+0.39 11.87+0.17 10.89+0.48 1 1 .68+0 .10 11.79+0.37 12.69+0.03 1 2 .02+0 .16 1 1 .56+0.05 1 11.32 12.54 11 .7 8 11.5 8 11.49 11 .6 1 11.04 11.70 2 11 X I 12.48 11.74 11.69 11.99 1 2 .1 1 11.13 11.9 8 II 3 11.6 6 12.65 11.76 1 1 .8 1 11.95 12.55 11.19 1 2 .1 2 4 11 .2 0 12 .6 2 11.73 11.70 11.95 12.44 11.53 11.95 Mean 11.41+0.20 1 2 .57+0.08 11.75+0.02 1 1 .69+0.09 11.84+0.23 12.18+0.42 1 1 .22+0 .21 11.94+0.17 i __\ UNIVERSITY OF IBADAN LIBRARY with a pooled mean value of 8.78^0.16g/10nn fresh milk. The mean SWF content of the stall-fed cows' milk varied from 7.76^11.51 to 8.A2i0.20 during the first period and 7.27^0.26 to 7.55i0.31g/100g fresh milk during tie second period with a pooled mean value of 8.06i0.25g/100g fresh milk. The SPJF content of the grazed cows' milk was higher than that of the stall-fed animals (P<0.B1). The ash content of the grazed animals was statisti­ cally significant to that of the zero-grazed. Though the energy value of the free-grazed cows was higher than the zero-grazed (Table 2.11), there was no statistical diffe­ rence (P>0.05). Breed: Though there was a gradual increase of butterfat as lactation progressed towards the late stage in the two breeds, results shown in Table 2.12 clearly indicate that both the German Brown (GB) and Friesian (F) cows' milk contained mean butterfat value of A.01^0.18 and 3.88^0.15% respectively with the value of the GR being slightly higher than for the F caws (P<0.B5). Apart from the fact that there was no well-defined trend in the milk protein percentage as the experiment progressed, there was only a little difference between protein percentage at start and end of the experiment. The mean GB protein percentage was UNIVERSITY OF IBADAN LIBRARY 101 3.38^0.02 while the F was 3.39^0.02 with nn breed diffe­ rences in the milk protein contents of these cows. Duncan's (1955) multiple range tests for means has revealed that both the SIMF, TS and ash contents of the GO cows' milk were significantly higher than those of the F cows' (p^0.05). However there was no statistical difference hetween the energy content of milk of the GB and that of F cows. Diet: Duncan's (1955) multiple range tests for means revealed that the butter fat percentage of cows on high forage rations were significantly higher than those on high concentrate diet, with the mean value of £*.05^0.21 and 3.85-0.1855 for the high forage and high concentrate diets respectively (P<0.05). There were no significant differences between the milk protein and SNF% for the caws maintained on the two dietary levels. However statistical analysis showed that the TS, fish and Energy contents of the milk (11.9055, 0.7255 and 17.35H0/g respectively) of the cows on HC were significantly higher (P<,0.01) than those on HF (11.70%, 0.70, 17.25K3/g respectively). Interaction: Significant interaction for the milk ash existed between diet and breed; and between breed and mana- UNIVERSITY OF IBADAN LIBRARY TABLE 2.15 Solid3-not-fat (g/lOOg milk) content of German Brown and Friesian cow1 Milk grazed, or stall-fed on high and low concentrate rations PERIOD (WEEKS) H I G H C O N C E N T R A T E H I G H F 0 R A G E Before GERMAN BROWN FRIESIAN GERMAN BROWN FRIESIAN start Stall-feeding Grazing Stall-feeding Grazing Stall-feeding Grazing Stall-feeding Grazing of expt. 8.64 9.63 8.7 6 8.70 9.29 8.78 8.82 7.90 1 8.57 8.94 8.43 8.59 8.78 8.66 8.33 7.57 2 8.06 8.80 7.85 8.53 8.37 8.40 8.66 7.28 I 3 7.80 8.37 7.57 8.59 7.85 8.^6 8.50 7.29 4 7.64 8.14 7.21 8.49 7.48 8.49 8.20 7.00 Mean 8.02+0.41 8.56+0.37 7.76+0.51 8.55+0.05 8.12+0.57 8.50+0 .11 8.42+0.20 7.28+0.23 1 7.47 8.29 7.63 7.08 7.54 7.96 7.59 8.30 2 7.72 8.08 7.54 7.09 7.84 7.96 7.38 8.28 n 3 7.86 8.15 7.56 7.03 7.35 7.95 7.09 8.22 — \- •i 4 7.15 7.87 7.43 6.95 7.15 7.64 7.03 7.95 Mean 7.55+0.31 8.10+0 .18 7.54+0.08 7.04+0.06 7.47+0.29 7 .88+0 .16 7.27+0.26 8.19+0.16 UNIVERSITY OF IBADAN LIBRARY - 103 - TABLE 2.16 Ash (k/100e milk) content of German Brown and Friesian cans' milk grazed or stall-fed on high and low concentrate rations PERIOD (weeks) H I G H C O N C E N f R A l ' E H I G H F O R A G E Before GERMAN BROWN FRIESIAN GERMAN BROWN FRIESIAN start Stall-feeding Grazing Stall-feeding Grazing Stall-feeding Grazing Stall-feeding Grazing of ejcpti o»7cd 0.714 0.676 o,7o1 0,736 0.695 Gi666 0,694 0.702 0.714 0,665 0.699 0,739 0,700 0,665 0,710 2 0.702 0.709 0,674 0.705 0*741. 0,696 0.693 0,732 i 3 0.706 0.704 0.662 0.704 0,751 0.6°6 0.654 0.723 4 0,704 0.711 0 *66t 0,711 0,751 0,696 0,659 0,738 Meatl 0.705+2.63 0.705+2.84 0.666+5.31 0.705+4.92 0.746+5.85 0697+2.00 0.667+0.02 0 ,726+0.01 1 0.747 0.700 0.691 0.744 0,721 0.721 0,656 0 ,712 2 0.746 0.699 0.696 0.745 0.724 0.737 0.654 0.712 It 3 0.746 0,702 0.731 0.742 0.733 0.761 9*663 0.711 4 0.733 0.702 0.728 0.747 0.737 0.757 0.663 0 .718 Mean 0.722±0.01 0.70111.50 0.711±0.02 0.744±2.08 0.73018.75 ).744.i0.02 0 . 6 6^0.01 0.713i 3.20 i UNIVERSITY OF IBADAN LIBRARY I - 1D*» - gement (P< 0.01). There was no significant interaction (P^>0.05) between the diet and breed for the milk protein, SI\IF, TS, fat and energy. Statistical analysis showed that there were significant differences in the interaction between breed and management (P< 0.05) but no significant interaction among the breed, diet and management for the protein, Sf\lF, TS, fat and energy contents of milk. Also there was no significant interaction between the breed and mananement for the butter-fat content of the cows' milk. .U.U. Liveweight changes The summary of mean body weight changes as influenced by management practices, breed and diet are shown in Table 2.17. System of Management: The cows under the grazing system showed the higher daily gain of 0.59kg as compared to the value of -1.30kg for the stall-fed cows. The differences were statistically significant (P<0.05). Breed: While the German Brown cows lost a mean of 0.26kg/ day, the Friesian cows lost 0.A5kg/day (P< 0.05) strongly indicating breed differences. UNIVERSITY OF IBADAN LIBRARY 105 Diet: Cous under the high forage diet tried better to maintain their weights than those on high concentrate. Those on high Forage lost 0.13kg liveweight per day and cows on high concentrate lost 0.5Bkg/day (P^Jd.05). Water Intake, Body Temperature and Respiration Rates Table 2.18 shows the water intake of the cows. The mean water intake of the stall-fed animals was 32.27^9.55 litres per day while that of the grazed animals was 33.80^10.^2 litres per day. Statistical analysis showed that any apparent differences in the mean daily water intake was not significant (P^O.05). The mean water intake of the Friesian cows was higher than that of the German Grown with the value of 38.02^4.02 litres per day for the former and 28.05^13.05 litres per day for the latter. The animals under high forage diets had intake higher than those on high concentrate. This was 33.58^10.17 litres per day for high forage and 32.49^7.56 litres per day for high concentrate. There was also no significant difference between the rpean body temperature of the grazing and stall-fed cows. The mean body temperature of the stall-fed cows was 38.92°C while that of the grazed ones was 30.9fi°0 Cable 2.19). Respiratory counts shown in Table 2.20 indicated that the UNIVERSITY OF IBADAN LIBRARY ' ■it ■ -106 - TABLE 2.17 Ilvewetfht (kg) of the gr-azed or stall-fed German Brown and Erie si an lactating cows on high and low concantrata rations PERIOD (WEEKS) H I G H C O N C E N T R A T E H I G H F O R A G E Before GERMAN BROWN FRIESIAN GERMAN BROWN FRIESIAN start Stall-feeding Grazing Stall-feeding Grazing Stall-feeding Grazing Stall-feeding Grazing of expt. 420.58 413.92 426.12 342.32 404.18 338.84 392.47 433.88 1 413.50 414.22 415.00 343.28 395.11 338.53 377.30 435.70 2 393.60 419.55 392.50 331.83 393-41 333.32 370 A3 437.05 I 3 385.43 431.42 385.55 332.08 391.25 328.87 366.05 441 *66 4 386.89 438.67 379.59 336.31 393.61 330.22 364.77 441.5 0 Mean 394.85+6.54 425.96+3.66 393.16+8.15 335.88+3.11 393.35+1-82 332.74+3.52 369 .a+1.94 43857+2.56 1 396.66 331.44 368.39 444.34 383.12 444.49 373.92 338.01 2 399.12 332.40 378.44 451.34 388.85 443.75 379.36 357.54 n 3 401.21 335.33 375.53 455.39 388.99 452.15 375.59 355.38 4 405-49 336.77 378.38 455.24 394.81 452.73 378.25 361.70 Mean 400.62+2 .18 333.98+1.62 375.18+3.15 451.58+4- .16 388.941,3.52 448.28+^.50 376.78+1.85 353.16+6.76 UNIVERSITY OF IBADAN LIBRARY /t - 107 - / Table 2.18 Volume of Water (litres) consumed by German Brown and Friesian cows grazed or stall-fed with high and low concentrate rations PERIOD DAYS H I G H C O N C E N T R A T E H I G H F O R A G E GERMAN BROWN FRIESIAN GERMAN BROWN FRIESIAN Stall feeding Grazing Stall- feeding Grazing Stall- Stall- feeding Grazing feeding Grazing 1 20.46 21.50 54.50 45.40 31.80 38.55 45.46 44.20 2 3 1 . 8 0 26.52 54.55 50.50 31.82 40.42 50 .0 0 52.15 3 23.41 30.40 59.10 52.17 31.85 40.55 50.00 53.18 4 30.84 32.55 47.73 49.55 2 2 .7 0 28.48 40.90 38.42 5 29.55 30.46 40.90 48.95 25.00 29.50 34.10 35.50 6 29.55 30.40 50.00 53.40 28.41 30.50 36.35 36.52 7 27.28. 29-55 39.78 46.55 2 7 .2 8 29.50 30.70 27.28 8 26.14 28.40 30.69 3 6 . 1 8 2 8 .7 0 31.50 27.20 27.20 9 23.87 25 .8 0 27.20 32.40 27.28 3 0.CO 22.75 2 6 .5 0 10 23.36 23.00 28.40 3 0 .60 2 7 .2 0 3 1 . 5 2 31.32 28.55 11 1 8 .1 8 20.00 26.14 23.15 . . 29.55 3 2 .6 0 37.50 36.55 12 23.85 25.44 1 8 .2 0 20 .80 27.28 27.28 36.35 38.90 13 24.00 26.00 27.40 2 8 .5 0 27.30 26.80 37.50 38.40 14 24.00 25.40 28.40 30.40 27.30 28.40 37.55 39.78 Mean 25.45+3.95 26.82+3.69 38.50+13.14 39.18+11.47 28.10+2.57 31.83+4.65 37.02+7.87 37.37+8.46 + Standard deviation UNIVERSITY OF IBADAN LIBRARY - 108 - • labia 2.19 *Hean body temperature (°C) of German Brovm and Friesian cows grazed or stall-fed with high and low concentrate rations Period (Weeks) 1st week 2nd week 3rd week *fth week 5 th week 7 th week 8th week Grand Mean 7 am 3 pm 7 am 3 pm 7 am 3 pm 7 am 3 pm 7 am 3 pm 7 am 3 pm 7 am 3 pm Mean of stall-fed 38.39 39.11 38.67 39.28 38.67 39.33 38.67 39.36 38.33 39-33 3 8. Mt 39-30 38.70 39.30 38.92 cows Grazed cows 38.38 39.28 38.70 39.39 38.67 39.16 38.56 39.30 38.56 39.33 38.56 39.22 38.78 39.22 3 8.9^ Week 6 not determined UNIVERSITY OF IBADAN LIBRARY ' t- I 109 - Table 2.20 *Body Respiration (counts tier minute) of cows grazed or stall-fed_____with high and low concentrate rations 3rd week 4th week 5th week 7th week 8th week 6 am 10 am 2 pm 6 pm 6 am 10 am 2 pm 6 pm 6 am 10 am 2 pm 6 pm 6 am 10 am 2 pm 6 pm 6 am 10 am 2 pm 6 pm Mean of stall- 22 48.5 59 48 22 48 59 46.5 22 48 5 7 . 5 48 22 44 62.5 48 22 56 63 48 fed cows Grazing cows 22 52 65 51 22 47 65 52 22 51 64 48 21 47 60 44 21 46 61 43 1st, 2nd and 6th weex - not determined UNIVERSITY OF IBADAN LIBRARY 110 highest counts were obtained at 2.00 p.m. fallowed by 10.00 a.m. and 6.0D p.m. and the least count was obtained at 6.00 a.m. The summary in Table 2.20 shows that the grazed cows had respiratory counts of h5.2 counts per minute and the stall-fed cows had *t3.7 counts per minute. 2.5 DISCUSSION Results tended to indicate that there was a decrease in the dry matter (DM) intake from the start of the experiment because the cows have reached their peak milk yield before the beginning of the experiment and were gradually declining in their milk yield before they were used. It has been shown by Mather (1959) that cows fed on grains reached their peak feed intake by about the 9th week after parturition and started to decrease thereafter and would appear to be in agreement with the observation in the present experiment. The regression equations obtained in Table 2.6 suggested that during lactation, intake seemed to be correlated with live-weight of the animals. This is in agreement with the results of Elliot, Fokkemma and French (1961) and Musangi (1969) that animal’s liveweight is a major factor affecting its organic matter intake. The finding that the heavier animals consumed the higher feed DM intake were in good agreement with those of many investigators that the UNIVERSITY OF IBADAN LIBRARY 111 metabolic weight is an important factor influencing intake (MacLusky, 1955; Holmes and Jones, 1965). Results obtained in the present experiment showed that those animals fed on high concentrate which contributed 32.30% on average to the total DM intake reduced their intake from grass. Indeed, similar observations were made by Mather (I960); Donefer Et al, (1963); Montgomery and Baumgardt (1965); Cowsert and Montgomery, (1969). The DM intake of cows used in the present experiment were relatively low compared to the DM intakes recorded in the temperate areas. However, it is to be noted that the forage DM calculated for the grazing animals was estimated from regression equations. There is every possibility that the animals consumed more since the regression analysis used was derived from the DM intake of the stall-fed animals. The low feed intake of the stall-fed animals was likely to be due to the fact that they were unable to select the more digestible and palatable com­ ponents nf mature herbage (Greenhalgh and Runcie, 1962). It is also probable that the relatively high crude fibre and dry matter content of the grass was associated with more chewing, low speed of eating and consequently reduced intake. The DM content of the grass (42.68%) used in this study was for most of the time higher than the critical figure of 24-28% UNIVERSITY OF IBADAN LIBRARY . i - 112 - suggested by Duckworth end Shirlaw (1950) when maximum DM intake could be obtained. Duckworth and Shirlaw (1950) have shown that the correlation coefficient of DM percentage and DM consumed was 0.B55 (P^O.DI). The milk yield was generally low throughout the experiment (6.% and 7.0^kg/day for the GB and F respectively). This might be due to two factors; firstly, the body temperature of 38.92°C and 38.9<*DC for stall-fed and grazed cows respectively, ambient temperature of 29°C, and respiratory counts of C*-3.7 and ^5.2 counts per minute for stall-fed and grazed animals respectively, were very high. Blaxter et _al (1959), Blaxter and IjJainman (1961) have suggested that with such high respiratory counts obtained in the tropics as in the present experiment, the exotic breeds of cattle in the tropical environment might undergo any thoracic, anatomical and perhaps abdominal changes resulting from their high respiratory rates forced on them by heat stress in the tropics, might reduce their feed intake and hence milk production. The animals were often noticed to open their mouths and change positions rapidly and frequently, their breathing lacked depth and was noisy. Standing seemed to facilitate rapid respiration. The exotic cows, as painted out earlier, are unadapted to the tropical environments, which when exposed to direct solar radiation UNIVERSITY OF IBADAN LIBRARY 113 may suffer severe stress. This has been manifested in these animals by increased respiratory rate, panting and excessive salivation. Bianca (1965); McDowell (1972); Loosli and van Blake (1973) pointed out that at such temperature and respiratory rates recorded in these studies, the milk yield of exotic cows would be lower than those cows maintained in the temperate countries. Bianca (1965), McDowell (1971), Johnson (1973) and Olaloku (1973) pointed out that temperatures above 20°C decreased milk yield, butterfat and SPJF. McDowell (1972) has also shown that high temperatures as recorded here increased water intake and decreased food intakes. Adeneye (1972) observed that cows maintained under the same environmental conditions as in this study often drank large quantities of water with increased volumes of urine showing that the water was used to cool their body and not to aid increased milk yield. Secondly, another reason for the low milk yield is the fact that the animals have just recovered from a widespread ’ foot and mouth’ disease when the experiment was started. The grazed animals produced more milk and higher butter fat than the stall-fed ones. This was in accordance with UNIVERSITY OF IBADAN LIBRARY the observations of Greenhalgh and Runcie (1962) that there is no evidence that the effects on milk production of a lower energy intake in stall-fed cows can be offset by a lower requirement of energy for muscular activity. Hardison, Reid, Martin and Woolfoik (1957) have pointed out that the digestibility of herbage grazed in the field was higher than corresponding forages eaten indoor. Topps (1962) has also concluded that materials harvested mechani­ cally is likely to be different in digdstibility from that grazed by animals because even grazed animals only graze the leaves. Baker, Richards, Haenlein and Weaver (I960) have demonstrated that there was indirect evidence that digested nutrients were metabolized less efficiently by stall-fed than by grazed animals which may eventually produce more milk yield in the latter than in the former. Results obtained from the present study indicated that the butterfat of the grazed animals which also consumed more grass was higher than 1hat of the stall-fed ones which consumed less grass. It is probable that the higher propor­ tions of forage DM intake in the animals grazed have resulted in ruminal fermentation favouring the production of a greater proportion of acetic acid in the rumen liquor and thereby UNIVERSITY OF IBADAN LIBRARY 115 increasing milk fat synthesis than in those onus on high concentrate feeding (Rook and Balch, 1961; Rook and Storry, 1964; Armstrong, 1960). Butterworth (1961) reported decreased butterfat percentage at the higher level of supplementary concentrate feeding. However, the stall-fed animals produced a higher percentage of protein than the grazed. Cobble and Herman (1951) have shown that total nitrogen of milk decreased at higher environmental temperatures. McDowell (1972) have also suggested that heat stress experienced by the grazing animals in tropical fields could result in the diversion of significant amounts of protein into non-productive sources. One of such sources was the functioning of the sweat gland which could result in additional losses of protein. The water intake of the animals reported in the present experiment was higher than those reported by Winchester and Morris (1950) in the temperate climate. The above-mentioned investigators demonstrated that animals’ demand for water was variable, no reliable estimates can be made of needs unless fairly accurate information was available on the type of animal's age, level of productivity, type of feeding and the climatic environment. These same investigators also concluded UNIVERSITY OF IBADAN LIBRARY 116 that with increase in temperature, there was a corresponding increase in water intake to a certain level. Johnson (1967) estimated this level to be at 35°C. The rise in water con­ sumption under high temperatures tends to support the well- known vital role water plays in thermal regulation. Winchester and Morris (1958) have concluded in their investi­ gation that adequate intake of free water was a means of maintaining efficient performance in hot climates. Higher respiratory counts than the ones recorded by McDowell (1967) were obtained in this study with those cows grazing in the field respiring faster than those fed in the pens. In domestic livestock, increased respiratory activity is an important means of increasing heat loss at high tempe­ ratures. McDowell (1967) asserted that it is the first visible sign of response to heat stress, but it has been placdd third in thp sequence of adaptates because the unnoticed processes of vasodilation and sweating usually occur earlier. The greater the volume of air that can be breathed in warmed and humidified climate like ours, the greater the resultant heat loss. McDowell (1967) concluded that the rate of respiration increased with increasing air temperature, the most pronounced rise securing above 29°C. McDowell (1972) painted out that between 18 and 20DC a cow would usually UNIVERSITY OF IBADAN LIBRARY 1'17 have a respiratory rate of about 20 breaths per minute and a volume of expired air of A0-60 litres, depending on body size and breed. At AD°C, the same bow might breathe 115 times per minute with an expired volume of 300 litres. Kibler and Brody (1950), McDowell and Ideldy (1967) had demonstrated that the Holstein couj had a higher respiratory rate under the same condition than the Zebu cow. Bianca (1965) asserted that a high respiratory rate could be an efficient means of increasing heat loss for short periods but continued high respiratory rates might interfere with feeding and rumination, add to body heat production from muscular activity, use energy that could be utilized for other purposes and lead to a reduction in the CO^ combining capacity of the blood plasma because of hyperventilation. Respiratory alkalosis may even occur above 35°C. Ragsdale et al (1951) had also demonstrated the interference with feeding of high respiratory rate. This means that with high respiratory rate, there is lower feeding resulting in lower milk yield. In conclusion, the present study has shown that though these unadapted animals were exposed to solar radiation and other field conditions while grazing, they still tended to UNIVERSITY OF IBADAN LIBRARY perform better than the zero-grazed ones. However, the practice was to 'let in' these grazed animals when the heat was becoming intolerable. The animals were observed to stop grazing during this period. Olaloku (1975) has expressed the opinion that the best practice for the newly imported lactating cows was to allow these animals to graze during the morning and evening hours but to stay indoors with free access to cool water at all times especially the hot afternoons as was practised in the present study. In summary, the results obtained on the system of management studies seemed to indicate that: (1) Grazing animals consumed more DM than stall-fed ones (7.9ftkn/day (99.39g/day/bjrx1g*7'̂ ) for the grazed and 7.8£+kg/day (98.99g/day/W^*77tt) for the stall-fed. (2) Milk production of the grazed lactating cows (51.it0il.B7 kg/week and average decline of 2.10kg/week) was higher than the stall-fed ones (tf6.66i2.50kg/week and an average decline of 6.61kg/week). (3) The grazed cows' milk contained higher content of butter fat, total solids, lactose, solids-not-fat and ash but less protein than the stall-fed. (<0 Hows grazing showed a daily liveweight gain of (1.59kg compared to a daily liveweight loss of 1.30kg recorded for the UNIVERSITY OF IBADAN LIBRARY 119 stall fed. (5) Mean uater intake of the grazed cows was 33.80^10.*+2 while that of the stall-fed was 32.27^9.55 litres/day. (6) Mean body temperature and respiratory rate of the stall- fed cows were 3Q.92°C and *+3.7 counts/min. respectively. Results obtained for the grazed cows showed mean body temperature of 38.9*+°C and respiratory rate of *+5.2 counts/min. UNIVERSITY OF IBADAN LIBRARY 120 CHAPTER 3 DRY HATTER INTAKE, MILK YIELD A PIP COMPOSITION OF WHITE F ULAN I, GERMAN BRDIJM AHD FRIESIAN CPUS MAIIMTAir-JED ON FORAGE AND LOW OR HIGH CONCENTRATES .1 irjTRODUCT ICIM Milk production presents particularly difficult problems in tropical, developing countries like Nigeria and this has meant almost total dependence on foreign supplies of milk particularly from the temperate countries. For instance, the contribution from the local sources in Nigeria has been minimal and inadequate to meet the needs of the people in the country. Indeed, Nigeria is yet to be at the threshold of developing what can be termed a dairy industry. In an attempt to increase milk production, basic research is needed to ascertain the nutritional require­ ments of dairy animals for optimal milk production and to find the effects of different dietary levels, seasons, breeds and liveuieight on milk production and composition. Certain investigators have embarked on some of these studies including the relationship between milk yield and liveuieight (Glesson, 197D; Olayiiuole, 1973), effect of feed UNIVERSITY OF IBADAN LIBRARY 121 on milk yield (Burt, 1957; Armstrong, 196B; Olaloku, 1972) and composition (Holmes, Arnold and Provan, I960; Rook and Balch, 1961; Castle, Drysdale and Waite, 1961; Rook and Line, 1961; Balch and Johnson, 1965; Starry and Rook, 1966; Huber and Roman, 1966; Armstrong, 1968; Armstrong and Prescott, 197D; Schmidt, 1971; Olaloku and nyenuga, 1971; end Olaloku, 1973) effect of seasons no milk production (Rowland, 19A6; Cobhle and Herman, 1951; Merilan and Bower, 1959; Bianca, 1965; McDowell, 1972 and Olaloku, 1973), relationship between UFA and milk production (McDonald, 1952; 1968; Blaxter, 1956; Armstrong and Blaxter, 1957; Mba and Olatunji, 1971 and Adebanjo, 1972). The main purpose of the present study was, firstly, to estimate the maximum voluntary intake of DM in fnrage to which has been added concentrate at two energy levels for milk production by the indigenous and exotic lactating cows; secondly, it was also necessary to examine the effects of these treatments on liveweight changes, milk yield and composition. MATERIALS AMD METHODS Animals and their Management Three breeds of cattle, four animals from each breed, UNIVERSITY OF IBADAN LIBRARY 122 were used in this investigation; viz., (a) White Fulani (Zebu) (indigenous breed) (b) German Broun (exotic breed) (c) Friesian (exotic breed). The characteristics of the last tuo have been discussed in Section 2.2.1. The White Fulani or Bunaji (Plate 2.1). This has been described as ’Sanga' Dr Zebu by various authors (Mason, 1951; Faulkner and Epstein, 1957) because its precise origin has been lost in antiquity. The breed has, in most cases, a uhite colour uith black spots. Williams and Payne (I960) have pointed out that there are some White Fulani cattle uith nrey colour interspersed uith black spots. Keay (1959) has also pointed out that they are available hetueen the Sudan and Guinea Savanna vegetational zones of Northern Nigeria. The White Fulani, humped,is a fairly large animal ueighing at maturity betueen 331.1kg (Faulkner and Epstein, 1957) and 3h8.1kg (Olaloku, 1972) for cous and 50Bkg ( Ogunsiji, 197*0 for bulls uith an average height of 130cm behind the humb. The body is compact and fleshy. The skin is thick and pigmented. The legs are usually long uhich afford them to trek long distances particularly during the dry season uhen they are in search of forage and uater (Olaloku, 1972). UNIVERSITY OF IBADAN LIBRARY 123 The males usually have big heads with curved long horns which resemble the musical instrument - lyre hence the name 'lyre-horned'. It was first described as lyre- horned by Rates (1952). The cows have dewlaps more pro­ minent in the bulls. The Females have averagely well- developed, strongly attached udder which according to Shaw and Colville (1950) make them rank as one of the best milkers among the indigenous breeds in Nigeria, though they compare fairly low among the good exotic milkers all over the world. They produce an average of 7.45kg milk per day in 21 lactations (Oyenuga, 1967). Hill (1970) has put the milk yield of the best individual as 2241kg per 365 days or 2951kg per 427 days (Hill, 1956). Their milk also contains high fat and protein when compared with the exotic breeds. Many experiments conducted at Ibadan and Shika pointed out that they could be good beef-type. They have a birth weight of about 25kg (Oyenuga, 1967). Faulkner and Epstein (1957) put the calving age at 43 months and calving interval as 376 days while they live for about 9-10 years. Finally, Hill (1956) pointed out that they are tolerant to trypano­ somiasis, to a certain degree. The White Fulani cattle at the University of Ibadan UNIVERSITY OF IBADAN LIBRARY - 12A - Teaching and Research Farm are offsprings of the first batch of cattle (ft bulls and 2b heifers and calves) purchased in June, 1950 from the Government stock Farm at Shika in the North Central State of Nigeria mainly for teaching and research purposes. After surmounting many problems, they have grown into a population of 89 cows and A1 bulls by 1975. Management of the animals was as described in Section 2.2.2 except that the White Fulani cows were hand-milked and all the animals were zero-grazed with about two hours exercise in bare paddocks adjacent to their byre each day excluding the trekking to the milking parlour twice daily, a distance of about five kilometers. The experimental site and housing of the animals were the same as in Section 2.2.2. The identification number, body weight, calving date and lactation records ofthe cows used are shown on Table 3.2. Diets and Plan of Experiment Cows were placed on the experiment five days after parturition. Since the animals calved at different times and periods of the year, they were introduced to the experiment at different periods and seasons ranging from the 21st of June 131b to the 18th of September 1975 as indicated UNIVERSITY OF IBADAN LIBRARY 125 in Table 3.2. All the animals were fed fresh Giant Star grass (Cynodon nlemfuensis uar nlemfuesis IBS) throughout the period of the experiment which was for 2Q weeks expept during January and February 1975 when due to shortage of fresh, green grass, they were fed silage. Two levels of energy were supplied to the lactating cows. These levels were supplied by varying the amount of supplement given to the animals. The higher level of energy (a) was supplied at the rate of 1kg DM of concen­ trate ration (Table 3.1) to every 2.5kg of milk produced as practised in the Teaching and Research Farm (Alade, 1973). This level was also recommended by Caros-Costas and Vicente- Chandler (1969) and was in agreement with 115% of the Ministry of Agriculture, Fisheries and Food (MAFF) (1975) recommendation. The lower level of energy (b) was supplied at the rate of 1kg DM of the concentrate ration to every Akg milk produced. This level also corresponded to the 75% of the MAFF (1975) recommendation. Two animals from each breed were placed on the same energy level. This gave room for two replicates. A changeover of cows on higher energy level to a 1ouet one and vice versa occurred at the end of the 1Ath week. UNIVERSITY OF IBADAN LIBRARY 126 Table 3.1 ♦Components of dairy cnncentratg ration fed ta the White Fulani, Herman Brown and Friesian Laotatinq Cows Components Maize (%) 55 Groundnut Cake (%) 15 Palmkernel Meal(") 20 Rice Bran ('*) 10 100 Calculated TOO (kg/100kg DM) 60.88 Calculated DCP " " » 15.35 Mineral & Uit. Mixture (microzone)* 5 (kg/tonne) *1kg of microzone contains Uit. A (I.U.) = 0.500 Cu (g) = ^.00 Uit. D ( " " ) = 0.25 Co (") = 3.00 Mn ( g ) = 16.00 I (") = 1.20 Zn (") = 12.00 Mg (") = 200.00 Fe (") = 6.00 TDN = Total digestible nutrients DCP = Digestible crude protein UNIVERSITY OF IBADAN LIBRARY J - 127 - Table 3.2 Identification, Liveueight (kg), Calving. Date and lactating records of the White Fnlani, German Broun and Friesian coujs used in the experiments Identification Calving Initial Weight Experimental Number of Breed Number Date at start of Period Lactation experiment White L62 30.6.7ft 319.09 5.7.7ft 16.1.75 2 Fulani ft 30 23.10.7ft 230.6ft 29.10.7ft - 12.5.75 2 386 1.11.7ft ft13.G0 6.11.7ft - 18.5.75 2 167 26.2. 75 36ft. 25 ft.3. 75 — 18.9.75 2 German 6L 3.9. 7ft ftlO.OO 12.9. 7ft 27.3.75 2 Broun 32 23.9. 7ft ft 30.00 29.9. 7ft - 12.ft.75 2 18 8.10.7ft ft67.00 1ft. 10.7ft — 28.ft.75 2 58 18.12.7ft ft 10. ft 2 23.12.7ft — 1ft.7.75 2 Friesia$ 98 1ft.6. 7ft ft20.00 21.6. 7ft ft.1.75 2 118 9.9. 7ft 385.00 16.9. 7ft — 29.3.75 2 100 1ft.9. 7ft ftftO.OO 21.9. 7ft — 3.ft.75 2 126 16.9. 7ft ft01.82 22.10.7ft 5.5.75 2 UNIVERSITY OF IBADAN LIBRARY - 128 - 3.3 Analytical Procedure The analytical procedures are the same as described in Sec. 2.3. 3. A Results The statistical analysis was carred out as indicated by Cochran, Autrey and Cannon (19A1). However, only three parameters were possible for consideration at a time in this instance. These were effects of the breed, lactation and diet and their interactions. The fourth parameter, the effect of seasons was considered alone and separately as indicated in Appendix B3.1. The Newman-Heuls (1955) comparison between ordered means was used for comparing the means. The dry season was taken to be the period between November and February, and the wet season, between March and October. After careful consideration and study of the lactation curves, the stages of lactation, for the purpose of statistical calculations and discussion, were taken as: early lactation : 1st - 9th week of lactation middle " : 10th -18th " " " late tl 19th -28th 1 it i UNIVERSITY OF IBADAN LIBRARY 129 Table 3.3. Arrangement of the three breeds of corns for feeding grass _ad lib and low or high concentrate rations White Fulani German Brown Friesian Number 1 2 3 U 1 2 3 k 1 2 3 A Period I a b a b a b a b a b a b Period II b a b a b a b a b a b a 1 . 2 , 3 , A number of animals from each breed a High energy level (High concentrate) b Low energy level (Low concentrate) Period I The first fourteen weeks Period II The second (last) fourteen weeks. UNIVERSITY OF IBADAN LIBRARY 130 3.A.1 Rioclimatoloqical data and chemical composition of the herbage, silage and concentrate supplement. The bioclimatological data during the experimental period (June 197*! - July 1975) is shown in Table 3.*!. The mean monthly chemical composition of the concentrate ration is shown in Table 3.5, while that of grass and silage during this period is shown in Table 3.6. The average annual precipitation aver the period of the experiment was 133.3Amm with peak periods between April and October. The highest precipitation occurred in April 1975 with A76.00mm. During the dry season, January 197A to February 1975, vegetative growth was seriously retarded and herbage fed during this period was replaced with silage (Table 3.6). The mean monthly minimum and maximum temperatures recorded were 63°F (17.2DC) and 93°F (33.9°C). The range between maximum and minimum temperature was greatest during the dry period especially in the months of November to February. During the months when relative humidity was highest, the lowest dry matter percentages were recorded particularly with the supplementary ration. 3.*!.2 Dry Matter (DM) intake Results of the DM intake of all the breeds while being fed on the high and low energy levels are shown in UNIVERSITY OF IBADAN LIBRARY 131 ■}/ Table 3.k. Bioclimatoloqical Data during the experimental period (June 197*» - July 1975) uihen three breeds of corns ujere maintained on grass ad lib mith lorn or high concentrate supplement Months June July Aug. Sept. Oct. roov. Dec. Jan. Feb. Mar. Apr. May June July Precipita­ tion (mm) 221.70 2W.91 26.70 130.00 128.15 15.80 - - 71.OD 132.90 V76.00 16<*.3£t 127.2 127.00 Mean Daily minimum 70 70 73 70 71 71 67 63 70 73 72 72 71 70 temperature °F Mean Daily maximum -86 83 Bh 83 85 90 91 93 93 93 90 88 87 83 temperature Relative Humidity % 10.00hrs 05 87 87 88 87 81 67 5k 75 80 81 85 86 89 16.00hrs 72 78 Ik 75 71 53 kO 27 kk 53 65 69 72 77 Nov - Feb. Dry season period March - Oct. Rainy " B UNIVERSITY OF IBADAN LIBRARY /V (r - 132 - TABLE 3.5 **Mean monthly chemical composition of the concentrate ration (determined on dry matter basis) fed to three breeds of dairy cows with high or low levels from June 1974 to July 1975 NUTRIENTS JUNE JULY AUG. SEPT. OCT. NOV. DEC. JAN. FEB MARCH APRIL HAY JUNE JULY Dry Matter (g/100g DM) 83.45 87.48 86.34 8 6 ,5 0 86.53 85.44 88.95 90.72 91.72 89.70 83.52 84.00 8 6 .2 0 88.52 Organic Matter 78.15 8 2 .2 6 82.45 82 .0 8 82.52 81.42 8 5 .0 0 8 6 .8 2 87.77 85.70 7 8 . 1 2 79.80 8 1 .0 0 83.52 Ash " " 5.30 5.22 3.89 4.42 4.01 4.02 3.95 3.90 3-95 4.00 5.4o 4.20 5 .2 0 5.00 Crude Protein " " 1 6 .0 0 16.52 1 6 .0 2 16.84 15.09 15.55 14.75 15.00 15 .0 8 1 6 . 8 5 1 7 . 2 8 17.54 1 8 .2 6 16.54 Crude Fibre " " 8.75 8 .8 3 7.03 7.00 8.73 6.00 7.14 6.15 6.32 6 . 6 5 9 .0 0 9.08 8 .4 5 7.74 Ether Extract n ** 1.95 2.01 1.54 2.00 1.44 1.35 1.33 1.35 1.30 1 . 3 6 1 . 3 2 1.62 1.41 1 . 8 2 +N F E " " 51.45 54.90 57.86 5 6 . 2 4 57.26 58.52 6 1 . 7 8 64.32 65.07 60.84 5 0 .5 2 51.56 5 2 .8 8 57.42 Calcium (mg/100g DM) 72.55 78.80 80 .20 80.00 79.30 80 .22 8 3 .1 2 79.00 8 2 .1 0 8 2 .0 0 8 1 .0 0 76.52 7 8 . 1 2 69.78 Phosphorus " " 63.8 0 64.00 62.0 0 6 3.0 0 63.50 62.70 56.40 55.00 58.42 6 3.OO 68.00 65.78 6 6 .5 0 60.00 Sodium " " 1 3 . 2 1 1 3 . 2 0 13.00 12.75 12.69 1 3 .0 0 12.75 1 2 .8 8 13.21 1 2 .8 0 13.45 13.55 12.95 13 .0 0 Potassium " ” 920.55 916.50 90 3.0 0 940.80 9 5 2 .0 8 906.00 882.10 838.00 900.00 902.40 9 8 8 .5 0 990.00 9 6 8 .5 0 970.00 Energy (KJ/g DM) 2 3 . 1 0 22.75 22.10 2 1 . 5 2 21.51 21.20 21.00 2 0 .90 20 .8 2 21.00 2 2 .8 5 2 2 .8 0 2 3 .0 0 2 2 .3 0 ••Mean of four determinations except the DM which was determined daily +Nitrogen - free extractives. UNIVERSITY OF IBADAN LIBRARY - 133 - TABLE 3.6 **Mean monthly chemical composition of the grass and silage (determined on dry matter basis.) fed to three breeds of dairy cows with high or low level of concentrate from June 1974 to July 19/5 NUTRIENTS JUNE JULY AUG. SEPT. OCT. NOV. DEC. JAN. FEB. MARCH APRIL HAY JUNE JULY •Dry Matter (g/100g DM) 30.45 3 2 .6 8 49.52 39.52 47.80 52.50 56.54 24.40 23.45 40.26 2 8 .9 0 32.83 3 5 .7 0 37.50 Organic Matter n ti 83.14 83.1*0 85.43 83.55 84.27 8 6.3d 86.99 8 6 .9 0 86.23 86.41* 85.03 83.71 8 3 .7 5 8 3 .6 0 Ash ♦ 1 11 8 .3 8 7.39 6 .3 6 8.45 7.56 5.52 4.87 8 .1 0 9.25 6 .0 0 6 .5 6 7.28 7 .0 0 7 .2 8 Crude Protein it 11 10.25 12.81* 5.84 5.56 9.88 9.00 5.28 9 .3 0 9.25 8 .2 5 11.71 10 .2 6 1 1 .2 5 13.55 Crude Fibre •t 11 2 2 .5 8 2 1.1*8 28.46 25.47 29.56 30.56 28.51 28.40 28.45 2 2 .6 2 25.45 29.52 3 0 .5 1 33.50 Ether Extract 11 it 1 .0 0 1 .11* 0.52 1.15 1.50 1.30 1 .0 0 2 .0 1 1.92 1.84 2 .8 0 2 .8 8 1 .9 5 1 . 1 0 +N F E it it 4 9 .3 1 1*7.9** 5 0 .6 1 51.37 43.33 45.44 5 2 .2 0 4 7 .1 9 46.61 53-75 45.07 41.05 40.04 35.45 Calcium (mg/l00g DM) 3 1 5 .4 0 295.00 320 .0 0 325.40 332.30 312.40 3 4 5 .2 0 3 10 .0 0 30 8 .50 2 9 8 .4 5 295.20 290 .0 0 3 0 1.0 0 308.40 Phosphorus " 11 12 5 .0 0 13 8 .0 0 13 0 .0 0 1 2 8 .1 5 12 5 .0 0 12 0 .0 0 1 2 0 .4 5 108.42 10 2 .0 0 104.25 14<*.50 1 3 2 .1 8 13 0 .0 0 13 2 .0 0 Sodium " n 8 2.1(1* 72.32 60.08 63.52 64.87 70.52 6 0 .4 5 60 .0 0 65 .0 0 64.88 68.77 70.52 81.44 63.45 Potassium ' " 11 2 8 5 2.1*0 2572.10 2352.45 2400.00 2447.20 2000.50 19 5 0 .0 0 210 0 .0 0 2000.00 2500.00 2547.50 2875.00 2538 .0 0 2450.70 Energy (KJ/g DM) 1 7 .6 2 1 7 .6 8 17.54 17.55 17.51 17.40 1 7 .3 2 17.40 1 7 .5 2 1 7 .6 2 17.33 1 7 .6 8 17.75 1 7 .6 0 ••Mean of four determinations except the DM which was determined daily. *Dry matter content of fresh grass. Chemical composition of the silages fed (30th Dec. 1974 - 3rd March 1975). +Nitrogen - free extractives. UNIVERSITY OF IBADAN LIBRARY Tables 3.7a, b The forage DM intake which increased with the stage of lactation reached the peak between the 5th and the 10th week of lactation. (Tables 3.7a,b and Fig. 3.1). The White Fulani cows reached their peak DM intake on the 9th week while the German Brown and Friesian cows reached their peak on the 7th week (Fig. 3.1). When the roughage intake alone (expressed on metabolic size) was platted against the lactation weeks (Fig. 3.2) peak feed intake was recorded for the White Fulani and German Brown cows on the 3th week and Friesian on the Sth week. After reaching the peak, there was a gradual decline in the roughage feed intake until between the 21st (White Fulani) and 23rd (exotic breeds) weeks when irregular fluctatians were observed in the feed intake till the end of the experiment. Appendix B3.1(l) indicates that there were significant differences (P4.0.01) between the three stages with the early and the middle stages of lactation being significant to the late. The values for the roughage DM intake of the White Fulani range from 3.26 to 5.98kg/day with a mean value of 4.49^0.16kg/day. The German Brown had feed intake values UNIVERSITY OF IBADAN LIBRARY Table 3.7a **Dry matter intake (kg/Day) of trie three breeds of lactatlng cows fed on grass with high or low concentrate rations during the 28-week experimental period (weeks 1-14) DM w e 0 k 3 Intake Breed EL 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 Mean + SE (kg/ day) White H V-?? 5*34 5.98 5.43 5.98 5.94 5.44 4.63 5.95 5.50 3-37 4.93 4.83 4.80 5.32*0.19Fulani L 3.90 3 . 6 0 3.26 4.43 3 . 7 0 3.?6 4 . 1 3 4.81 4 . 4 5 4-3? 3 . 7 0 3 . 6 6 3 . 6 8 4.24 4.0CU0.14 F Geraon H 4.5? 5 . 6 8 5.85 6 . 2 1 6.14 5-?4 6.32 6.17 6.07 5 . 9 1 5 . 6 0 5.58 5.43 5.24 5.76*0.15Brown L .90 4 . 6 6 5.06 3-74 6 . 0 6 6 . 4 3 6 . 9 3 6.23 6 . 6 9 6.42 6.45 5.71 5.56 5.53 5 .88±0 . 1 8 Frie- H 6.29 6 . 6 8 7.58 7.39 8 . 1 2 7.86 7.97 7.49 6.98 6 J*0 7 . 0 6 6 . 6 6 7 . 2 8 6.85 7.18+0.20 aien L 4.99 5.15 5.38 5.57 6 . 3 6 6 . 3 8 6.50 6 . 8 3 6 . 8 6 7.14 6 . 6 4 6 . 1 0 ?.73 5 . 1 6 6.06+0.19 Whito H 1.75 1 . 7 2 2.30 2.40 2.28 2 . 6 0 2.85 2 . 9 0 2.73 2 . 6 8 2.25 2 . 1 0 2 . 0 0 2 . 1 0 2.3310.10 Fulani L 1.58 1.29 1.30 1.34 1.41 1 . 3 0 1.3? 1.05 1.05 1 , 0 5 1 . 0 0 0.82 0 . 9 8 0.95 1.19+0.06 C Gorman H 2 .4 O 2.35 2.58 2.80 2.80 3 . 0 0 2.99 3-19 3 . 1 0 2.95 2.83 2.50 2.32 2 ^ 2.71+0.09Brown L 1 . 6 8 1.98 2.28 2.55 2.80 3 .O3 2.64 2.25 2.25 2 . 1 0 2.08 1.78 1.70 1 . 6 0 2.1910.12 Frie- H 1.75 2.08 2.75 3.41 3.50 3 . 6 8 3.38 3 . 6 3 3.50 3-43 3-1? 2 . 6 8 2.25 2.30 3.00+0.14 sian L 1 .6.5 1.55 2.25 2.39 2.58 2.48 3-59 2.50 2.35 2 . 2 0 1.95 1 . 6 8 1 . 6 0 itSZ- 2.1010.14 White H 6 . 1 4 7 . 0 6 8 . 2 8 7.83 8 . 2 6 8 . 3 4 8.29 7-33 8 . 6 8 8 . 1 8 7.62 7 . 0 3 6.83 6.90 7.6510.20 Fulan5 L 6 . 4 8 4.89 4.56 5.77 5.11 5,46 3.50 5.86 5.50 5 . 4 4 4.70 4.48 4.66 ..^12.. -3,1910.12__ T German H 6.95 8.03 8.43 9.01 8.94 8 . 9 4Brown 9-31 9 . 3 2 9-17 8 . 8 6 8 A3 8.08 7.75 7.-1I- 8 .4 7 1 0 . 2 0 h 6,58 6 . 6 4 7.34 8.29 8 . 8 6 9 . 4 6 9-37 8 . 4 8 8.94 8.52 8 . 5 3 ■ -7,49 7.26 . 7-ilL.. 8 .0 7+O . 2 7 Frie- H 8.04 8 . 7 6 10.33 10.80 11.62 11.54 1 1 , 8 5 1 1 . 1 2 10.48 9.85 1 0 . 2 1 9.54 9,59 9.15 1 0 .1 8 1 0 . 2 8 sian h 6.64 6 , 7 0 7,63 7,96 8.94 8 . 8 6 9,09 9,33 9.21 9.34 8,59 7,78 7,33 6,73 8,1610,27 y = Forage dm intake q = Concentrate dm intake T s Total BP Intake Eh = Energy Bevel r = htgh level gpncentrftte (high energy level) h = how level eeneentrate (lew energy level) ** = Twe enlmnle within a breed were maintained en eaeh level, Eaeh value is alee a Btean ef the week’ s BM intake, UNIVERSITY OF IBADAN LIBRARY - 1.56 Table 3.7b **Dry m atter Intake (kg/Day) o f the three breeds o f la c ta t ln g c ow3 fed on grass with high or low concentrate ra tion s duri ng the 28-week experim ental p e r iod (weeks 15-28) DM ❖ w e © k sIntake Breed EL 15 1 6 17 18 19 20 21 22(kg/ 23 24 I 25 26 27 28 Mean + SE day) '.Vhite L 4.84 4.49 5 . 0 0 JtsJL5_ 3.89 3 . 6 0 4.08 4 . 8 0 4 . 1 8 3 . 8 6 4.33 4.33Fulani H 4.27 -3.61 3..-81 ^ . 0 9 4.40 Z+.2? A A 3 4.15 5.0? 4.45 4.82 4.54 4.13 4.31^0.10 r Germai L 5 . 0 1 5.22 5.71 5.82 6 . 1 9Brown 5.39 4.8? 5.83 6 . 2 6 5.64 5.07 5.05 5.4610.13H 5 A3 5.25 5 . 1 2 5 . 0 0 5.03 4.80 4.81 5.20 5.69 5.55 3-29 5.27 5.70 5 . 6 8 5.2710.09 Frie- L 6.09 6 . ^ 9 5.98 5.15 5.50 si an ?.65 5.15 ^.57 5.55 5.21 W ° 4.80 4 . 6 1 4.42 5.27-40.20 H 5.16 4.89 4 . 8 4 5.50 5.8/+ 5.45 5.25 5 . 2 1 5.07 5.11 5.30 4.91 4.91 4 . 8 8 5.1710.08 White L 1 . 1 6 1.15 1.15 1 . 0 5 1 . 0 0 1 . 0 0 1 . 1 0 1.03 1 . 0 0 1 . 0 0 0 . 8 8 0.80 0.78 0.70 0.9810.04 Fulani H 1.58 1.46 1.44 1.35 1.42 1 . 3 0 1 . 2 3 1.15 1 .1 ? 1 . 1 0 0.98 1 . 1 0 1.05 0.99 1.2310.05 C German L 1.75 1.45 1.28 1.25 1.45 1.30 1 . 1 0 1 .1? 1.18 1 .2 ? 1 . 1 0 1.18 1 . 1 8 1 . 0 2 1.2610.05Brown H 2.55 2.23 2 . 0 8 1.95 1.95 2 . 0 1 1.98 2 . 1 8 2 . 1 2 1.?9 1.98 1.85 1 . 6 8 1.48 2.0010.07 Frie- L V?9 1.35 1.25 1 . 1 0 1.05 1.08 1 . 1 0 1 .08 1 .0 0 0.94 0.95 0.9/fc 0 . 8 8 0.83 1.0710.04 s i an H 2.08 2.38 2.34 2 . 1 3 _2 .2L 2 . 0 0 2 . 0 1 1.98 2 . 0 7 2 .?? 2 -0§. 1 . 9 8 1 . 6 0 1.50 2.0640.07 Whl te L 6 . 0 0 5.64 6.15 5 . 0 8 4.89 4.60 5.18 5.83 5.34 5.18 5.43 4 . 6 6 5.11 5.03 5-3010.13 Fulani H 5.85 5.07 5-25 5.44 5.82 5.5? 5.46 5 -?o 5.72 6.13 5.43 5.92 5.59 9.12 5.5410.09 T Gorman L 6 . 7 6 6.67 6.99 6.55 7.27 7.49 6 . 1 8 6 . 5 2 6 . 0 1 7 . 0 6 7.36 6 . 8 2 6 . 2 9 6.05 6.7210.13Brown H 7 . 9 8 7.48 7.20 6.95 6.98 6 . 8 1 6.79 7.?8 7.81 7-9° 7 . 2 7 7 . 1 2 7-?8 7.16 7.2710.10 Frie- L 7.44 7 -44 7.25 6 . 2 5 6.55 6 .7 ? 6 . 2 5 5.65 6.55 6.1? 3-7? 9-7^ 9.49 9.30 6.5410.23sian H 7.24 7.27 7 . 1 8 7.63 8 . 2 2 7.45 7.26 7.19 7.14 7.44 7.35 6.89 6.51 6.38 7.2310.12 F a Forage DM Intake C = Concentrate DM Intake T a Total DM Intake BL* = Energy level change of H = High level concentrate (high energy level) diet v L a Low level concentrate (low energy level) ** a Two animals within a breed were maintained on eaoh level. Each value is also a mean of the week's DM intake. UNIVERSITY OF IB VeJ1A ODAN LIBRARY C3\i J 139 Table 3.7c Percentage concentrate DM in total DM intake Breed High level concentrate Low level concentrate 1st period 2nd period 1st period 2nd period White Fulani 30.*+6 22.20 22.93 18. *+9 German Brown 32.00 27.51 27.1*+ 18.75 Friesian 29.*+7 28.*+9 25.7*+ 16.88 • 1st period = The first fourteen weeks (1-1*+ weeks) 2nd " = The second " 11 15-28 " ) UNIVERSITY OF IBADAN LIBRARY Fig. 3 1 Mean total drymatter intake (kg /day) . Drymat te r intake ( k g / d a y ) UNIVERSITY OF IBADAN LIBRARY VJ- /jH FIG. 3 2 Mean roughage drymatter intake( kg / day/W ) Roughage intake ( k g / d a y / W UNIVERSITY OF IBADAN LIBRARY 1.W3 ranging from ^-55 to 6.93kg/day with a mean value of 5.59^0.16kg/day. The^forage feed intake of the Friesian coujs range from A.A2 to Q.12kg/day with a mean value of 5.92io.21kg/day. There were thus signi­ ficant differences (P<0.H1) in the feed intake within the breeds with the Friesian and German Grown cows consu­ ming hinher forage DM than the White Fulani. The interaction between the breed and lactation was highly significant ( P < n.ni). The Friesian cnws at the early and middip lactation stages were significant to the others (P^B.m). The German Brown cows were significant at all lactation stages to the White Fulani (P<,[1.01). However the roughage DM intake consumed by the German Brown at the late lactation stage was significantly higher than the Friesian at the same stage of lactation (P0.05) between the consumption nf the Friesian and German Rrnwn cows at the low energy level intake, both of them consumed mnre forage DM than the White Fulani cow at the same level (P<0.G1). The'DM intake by the Friesian cows at the high energy level was higher than that of the German Grown and White Fulani cows at the same level (PB.D5) but both of them as in the early lactation stage mere significantly higher than the White Fulani (P0.C5). While the milk yield of the Herman Brown and Friesian cows under high energy level was significantly higher (Px^O.CI) than those fed low energy level, there was no significant difference (P>0.D5) between the two levels for the White Fulani. The interaction between stages of lactation and diets was significant (P<.n.05) both for the milk production and SCM. A break-down of the analysis showed that milk production at the high energy levels were significantly higher than at the low energy level (P<^0.05) during the early and middle stages of lactation. There was no difference (P>0.05) at the late stage of lactation. A 3-way interaction among the stages of lactation, diets and breeds were highly significant (P^FI.OI). A summary of this as given by the Plewman-Keuls (1955) comparison among ordered means showed that the milk yield and SCM of the exotic breeds at the early stage of lactation and under the high energy level were significantly higher than the other stages of lactation and at the lower energy level (P<’0.D1). This was not the situation with the indigenous breed. While milk production at the early lactation was significantly higher than the other stages UNIVERSITY OF IBADAN LIBRARY 151 □f lactation, the differences between the high and low levels of energy were not significant (P>0.05). The milk yield during the wet season was higher than that at the dry season (P<0.05). 3.b.U Milk’Composition Results of the milk quality of the breeds are shown in Tables 3.9 - 3.1Q. The statistical analysis are shown in Appendix 03.1. (a) Butterfat: The butterfat content of the milk decreased slightly for the first three or four weeks before increasing progressively till the end tf the experiment. This increase was more pronounced with the indigenous cows than the exotic breeds. Statistical analysis has shown a significant different (P< 0.01) between the three stages of lactation. The butterfat percentage at the late stage was statistically higher than that at the early and middle stages of lactation (P<0.01) while the middle was significantly higher than the early stage (P<0.05). The White Fulani butter- fat percent was significantly higher than that of the German Brown and Friesian cows (P<_0.01). The White Fulani, German Brown and Friesian cows produced milk containing an average of 5.33%, 3.9A% and 3.56% of butter­ fat respectively. The butterfat percent of the German UNIVERSITY OF IBADAN LIBRARY 152 Table 3.10 **Mllk fat (p/lOCy milk) content of the three breeds of lactating cows' milk fed on grass with low or high concentrate during 28-week experimental period WHITE FULANI GERMAN BROWN FRIESIAN ■WEEKS H L H L H L 1 4.88 4.91 3.95 3.73 3.48 3.44 £ 4.89 4.90 3.93 3.75 3.48 3.41 3 4.86 4.^4 3.82 3.65 3.27 3.42 4 4.84 4.70 3.83 3.53 3.31 3.35 5 4.85 4.76 3.56 3.54 3.25 3.38 6 4.83 4.89 3.61 3.57 3.28 3.37 7 4 .8 1 5.02 3.6 1 3 .6 1 3.25 3.43 8 4.96 5.30 3.65 3.69 3.32 3.43 ... 9 5.04 5.52 3.70 3.78 3.36 3.39 10 5.06 5+44 3.75 3.83 3.58 3.44 11 4-98 5.36 3.81 3.86 3.50 349 12 5.03 5.36 3.78 3.87 3.55 3.46 13 5.04 5.35 3.90 3.91 3.63 3.55 .14 5.11 5.38 3.95 3.94 3.66 3.54 Mean 4 .94+0.04 5.11+0.08 3.78+0.04 3.73*0.04 3.42+0.04 3.44+0.02 • L H L H L H 15 . 5.11 5.35 3.96 3.92 3.65 3.52 16 5.11 5.36 3.97 3.94 3.70 3.50 17 5.43 5.29 4.02 4.13 3.68 3.48 18 5.61 5.41 4.14 4.13 3.65 3.49 19 5.53 5.37 4.21 4.20 3.69 3.52 20 5.62 4.25 4.19 3.75 3.65 21 ___L & ___ 5.47 4.11 4.19 3.80 3.71 22 5.73 . 5.63 4.20 4.17 3.78 3.65 23 5.91 5.58 4.14 4 .1 6 3.81 3.52 24 6.07 5.66 4.11 4.17 3.82 3.56 ___ 6 .16 5.67 4.08 4 .1 8 3.83 3.61 26 5.97 5.68 4.06 4.19 3.84 3.64 27 5.99 5.86 4.18 4.20 3.93 3.69 28 6 .21 5.36 4.21 4.22 4.10 3.67 Mean 5.70+0.09 5.56+0.05 4.12+0.02 4.14+0.02 3.79+0.03 3.59+0.02 H = High level oonoentrate L = Low level oonoentrate * Change of diet '* = Two animals within a breed were maintained on each level. UNIVERSITY OF IBADAN LIBRARY 153 Brown was significantly higher than that of the Friesian (P<0.05). There was no interaction between the stages of lactation and diet, and among the stages of lactation, diet and breed but there was a significant interaction between the breed and stages of lactation (P O' 155 ( 3 tn 3.16%). This was statistically significant (P<0.05). Thera bias a significant interaction between breed and lactation (P< 0.05), breed and diet (p< 0.01) and among breed, diet and lactation (P<0.05). There were however on significant differences between lactation and diet (P>0.05). Considerable and highly significant differences (P<0.01) were found between the protein per­ centage during the wet season (3.38%) and dry season (3.06%). (c) Lactose: Apart from the fact that there was a high statistical significance between the lactose content of the milk of the three breeds (P<0.01), k.78% for White Fulani, h.55% for German Qrown and h.71% for the Friesian, there was no significant difference among the stages of lactation (P^ 0.05) and between the two diets (P >0.05). The lactose content of the White Fulani cows' milk was significantly higher than that of the Friesian (P<0.05), while that of the Friesian was significantly higher than that of the German Grown (P<0.01). There were no statis­ tical differences between the milk lactose percent during the two seasons, wet and dry (P 70.05). UNIVERSITY OF IBADAN LIBRARY - 156 - Table J . « »»Lactose (g/lOOg milk) content of the three breeds of lactating cons' milk fed on forage and low or high concentrate supplement during the 2 8-waek experimental period WHITE FULANI GERMAN BROWN FRIESIAN WEEKS H L H L H L 1 4.82 4.72 4.76 4.38 4*86 4.72 2 4.82 4.74 4.80 4.41 4.86 4.71 3 4.80 4.73 H-.81 4.80 4.83 4.73 4 4.31 4.69 4.75 4.55 4.82 4.69 5 4.80 4.73 4.76 4.39 4.77 4.73 6 4.80 4.70 4.74 4 .2 6 4.77 4.70 7 4.80 4.70 4.71 4.29 4.71 4.70 8 4.80 4.75 4.69 4.29 4.75 4.75 9 4.78 4.91 4.74 4 .28 4.72 4.75 10 4.79 4.72 4.79 4.32 4.69 4.74 11 4.80 4.76 4.76 4.34 4.^6 4.76 12 4.78 4.75 4.78 4.35 4.68 4.75 13 4.78 4.75 4.80 4.30 4.67 4.75 14 4.78 4.71 4.78 4.39 4.69 4.71 Mean 4.79+0.07 4.74+0.02 4 .76+0.02 4.35+0.02 4.79+0.02 4.73+0.01 ♦ L H L H L H 15 4.80 4.72 4.71 4.39 . 4.65 4.72 16 4.75 4.73 4.73 4,40 . 4.65 4.73 17 4.82 4.72 4.73 4.37 4.64 4.72 18 4.83 4.72 4.78 4.39 4 .6 8 4.72 19 4.82 4.80 4.72 4.41 4.62 4.80 20 4,83 ^.86 4.65 4.43 4 .6 2 4.86 21 4.84 4.81 U.6Q 4.45 4,56 4.81 22 4*86 4.80 4.69 4.45 4.55 4.80 4.83 4.80 4.69 4.36 4.58 4.80 24 4.88 4.79 4-67 4.35 4.49 4.79 25 4.89 4.64 4.60 4.53 4.74 26 4.89 4.70 4.65 4.39 4.51 4.70 27 4.88 4.74 4*88 4.44 4.51 4.74 28 4.88 4.73 4.83 4.47 4.46 4.73 Mean 4.34+0.07 4.75+0.02 4.72+0.03 4.39+0.02 4.58+0.02 4.76+0.03 H a High level concentrate L = Low level concentrate * Change of diet ®* = Two animals within a breed were maintained on each level. UNIVERSITY OF IBADAN LIBRARY K > CM 157 (d) Total Solids (T5): Table 3.13 shows the results of the total solids (TS) (g/100g fresh milk) of the three breeds. Apart from the fact that the pattern of values obtained were irregular as the lactation progressed, statistical analysis showed nn significant differences (P>0.n5) between the three stages Df lactation. However statistical significance existed between the values obtained from the three breeds of cattle (P^O.01). The TS percent of the White Fulani cattle (12.97^0.16g/100g fresh milk) was significantly higher than that of the German Grown (12.62in.D8g/100g fresh milk) (P-<_ 0.05) while that of German Broun was in turn significantly higher than that of the Friesian (12.03in.05g/100g fresh milk) (P<0.01). TS percent obtained from cows maintained on high energy ration was statistically higher than those on the low energy ration (P<0.05). There was a high statistical significance between the values obtained for the wet and dry seasons(P<0.01), with the wet season producing higher percentage of TS than that of the dry season. (e) Solids-not-fat (SIMF): Results obtained for the solids- not-fat (SHF) percent in Table 3.1?* showed a gradual decrease from the start to the end of the experiment. Significant differences therefore existed between the three stages of UNIVERSITY OF IBADAN LIBRARY - 158 - Tshla J»t® »*TotaI aoUde (r/lOOg milled content of the three breeds od* lactating eewa' rallk fed on grass and low or high goncentrate supplement during the 2 8-week experimental period WHITE FOUNT GERMAN BROWN FRIESIAN WEEKS H. X H. 1+ H L t 15.33 ; 12.70 : 12.85 12.48 11.95 11.85 2 15.56 12.70 12.85 12.41 12.00 11.89 5 15.15 12.72 12.80 12.27 12.11 12.02 4 i 15.03 ! 17.62 i 12.66 12.30 12.09 11.93 5 < 15.47 . 12.72 17.76 12.33 12.32 11 .9 6 6 15.fi? i 12.SK 17.81 12.50 12.38 11.95 7 15.53 ; 12.79 12.88 12.46' 12.35 11.97 a ! 15.41 12.37 12.85 12.50 12.21 11.94 9 i 15X6' ! 12.79 12.77 i 12XJ 12.22 11.88 to ! 15.39 i 12.31 1 12.72 12.54 12.21 11.89 t.t : 15.29 12.78 12.77 12.50 12.10 11.86 12 I 15.18 ! 12 .SO 1 2 .8 1 12.42 1’.29 11.83 15 i 15.02 12.81 : 12.88 12.41 12.31 11.76 14 . 15.08 12.75 ! 12.85 12.45 12.31 11.82 Hean 15.30+0.07 12.7640.16 12.00+0.03 12X5+0.05- 12.20+0.04 11.89+0.06 * i L- I h: 6 L H 15 1 15.07 12.78 12.80 12.40 12.29 11.80 16 : t5J5t 12.S1 : 12 .8 2 12.46 12.31 11.78 17 i 12.95 12.95 12.72 12.51 12 .2 6 11.80 IS ! 12.95 17.97 12.74 12.60 12.13 11.80 19 1543S 15.04 12.70 12.56 12.10 11.83 20 ! 12.94 15.05 12.51 12 .6 1 12 .18 11.81 21 12.96 15.10 12.55 12.72 12.31 11.78 22 ! 12.52 1 15.04 12.45 12.75 12.15 11.80 23 12.75 15.04 12X5 12.80 12.13 11.84 24 ! 12 .9 7 12.4a 12.38 12.81- 12.13 11.85 25 12 .9 1 12.75 12X9 12.82 12.23 11.86 26 i 1235 ! 12 .8 6 12.52 12.84 12.20 11.89 27 ! 12 .6 6 ! 12.06 ; 12 .2 9 12.85 12.24 11.91 28 i 12 jSt 12. aa 12 .5 2 12.8J 12.32 11.90 Khan, t2.88.0.08 12.94+0.17 ! 12.56+0.07 12.63+0.01+ 12.21+0.04 11.83+0.06 K sr High, level concentrate. t == tow laveX concentrate * Change of diet ** = Two animals- within, a. are ah were maintained- on. each, level. UNIVERSITY OF IBADAN LIBRARY - 159 - TWWU- 3,i4 +*Solida—net-fat (?/lOOv milk) content of the three b re ed 3 of lactating cobs milk fed or. gra3S with low or high concentrate during 28-week experimental period j -WHITE KJLANX GERMAN BROWN ERIE SIAN .WEEKS H 1 H L H L * 8,50 7.79 8.90 8.75 8.47 8.39 2 8,47 7.80 8.92 8.66 8.52 8.48 3 8.29 8,08 8.98 8.62 8.84 8.60 A ! 8,24 7.92 8.83 8.77 8.78 .5 ! 8 .62 7.96 9.20 8.79 9.07 8.58 <6 8,80 7.91 9.20 8.93 9.10 8.58 i 7 1 8,57 7.77 9.27 8.85 9.10 8 .a s : 6.45 7-57 9.20 8.31 8.89 8.51 <9 B A 2 7.27 9.07 8.65 8.86 8.49 ID 8,33 7.37 8.97 8.71 8.63 8.45 1 1 8.31 7.42 8.96 8 .a 8.60 8.37 12 8.15 7.44 9.03 8.55 8.74 8.37 13 7,98 7.46 8.98 8.50 8.68 8 .21 Ilf 7.97 7.35 8.90 8.51 8.65 8.28 ’.Mean 8,36+0.06 7.65+0.07 9.03+0.04 8.70+0.03 8.78+0.06 8 .46+0.06 m 1 H L H L H 15 7.95 7 A3 8.34 8.48 8.a 8.28 * 6 7.90 7.45 3.35 8.52 8.61 3.23 37 7.52 7.64 8.70 8.38 8.58 .8.32 IB 7.32 7.56 8.60 8.47 3.48 8.31 19 7.55 7.67 3.49 8.36 8.41 8.31 2D 7.50 7.41 3.26 8.42 8 .16 2 1 7.32 7.63 8.42 8.53 3.51 8.07 2 2 1 S.79 7+41 3.25 8.58 8.35 8.15 39 6.34 7.46 8.29 8.6k 8.32 8.32 24 6.90 6.32 8.27 8.64 8.31 3.29 225 6.75 7 .0 8 8.41 8.6k 8.40 8.25 . 128 1 6.98 7.18 8 8.65 8.36 3.25 ®7 ' 6.67 7 .0 0 8 .1 1 8.63 8.31 8.22 . ~ 28 6..k0 7-0 2 8.31 8 .6 1 8.22 8.23 'Mean j7.19+D.09 7-34+0.20 8.46+0.08 8.53+0.06 8.44+0.08 8.25+0.05 B = High level concentrate L = Low level concentrate * Change of diet = Two ,-azDLinalfl within a breed were maintained on each level. UNIVERSITY OF IBADAN LIBRARY OC 1 6 0 lactation (P<^0.01). Values obtained for the early lactation was higher (P<̂ 0.01) than those obtained for the middle which in turn was also statistically higher * than those of the late lactation (P<0.05). Significant differences existed between the three breeds of cows (P < n.01), with the exotic breeds producing higher values than the indigenous breed. 5r!F% obtained from the cows on high energy level was significantly higher(P^0.05) than those on low energy rations. Apart from the significant interaction (D< 0.05) which existed between breed and lactation, nn significant interaction existed between any of the parameters. Also values obtained during the wet season were not significantly different from those obtained during the dry season (P>0.05). (f) Mineral Pnntent of Milk: The mineral content (Tables 3.15-3.17) of the cows' milk at the late stage of lactation was significantly higher (P< 0.01) than those at the middle and early stages of lactation. The ash content of the German Frown daws' milk (0.719%) was significantly higher than those of the Friesian (0.708%) and the White Fulani (0.705%) (P0.05). The mean yield of calcium and phosphorus followed a similar pattern as that of the ash except that there were no significant differences among the three stages of lactatinn and the two dietary levels (P>0.05). (g) Energy content of Milk: Although the gross energy level of the milk of the Mhite Fulani (22.30^0.15K3/g) was slightly higher than that nf the Herman Brown (20.85in.09KJ/ g) and the Friesian (20.75io.09HJ/g), the differences between these means were not significant (P,>0.05). There were also non-significant differences between the means obtained at the three stages of lactation. Bn the other hand, there were significant differences (P<0.05) between the values obtained for the low (20.98^0.2IKO/g) and the high energy levels (21.60^0.1910/g). Though there were no significant differences between the values obtained for the two seasons, the interaction between the breed and lactation, breed and diet, there were highly significant differences (P^ 0.(11) between the lactation and diet and among the stages of lactation, breed and diet. UNIVERSITY OF IBADAN LIBRARY Table 3* 1S **Mll3c Energy (Kj/g freeze-dried ml 13c) content o? the breeds of lactgtlng cows' milk fed on grass with low or hlph concentrate during 28-week experimental period WHITE FULANI GERMAN BROWN FRIESIAN WEEKS H L H L H L 1 22.83 20.35 20.82 20.09 20.92 20.50 2 22.80 20.55 20.77 19.19 21.14 19.96 . 5 22.74-- .20.52 2C.67 19.77 22.64 20.04 4 22.92 20.46 20.63 19.35 21 .87 20.19 5 22.60 20.46 20.76 19.35 21.00 19.87 6 22.54 20.34 20.61 19.82 20.27 20.09 ‘ ? 22.56 20.80 21.03 19.77 . 20.37 20.05 8 22.83 20.85 21.09 20.02 21.17 20.25 9 = 22.94 20.80 21.42 20.25 20.90 20.36 \ 10 22.71 21,12 21.19 20.36 21.17 20.08 11 22.75 21.42 21.18 20.59 21.36 20.04 12 22.71 21.39 21.13 20.54 2 1.5 1 20.05 13 23.07 21.62 21.30 20.41 21 .72 20.51 14 23.21 21.62 21.59 20.26 21.94 20.36 Mean 22.80+0.09 20.88+0.13 21.01+0.08 20.04+0.11 21.28+0.17 20.17+0.06 * L II L H L H 13 23.06 21.91 21.56 20.42 20.97 20.46 16 22.98 21.86 21.13 20.55 21.45 20.44 17 22 .94 21.80 21.10 20.34 20.09 20.57 18 22.98 21.93 21.00 21 .24 19.73 20.71 19 23.10 21.89 20.54 21.40 19.68 20.82 20 23.09 22.10 20.36 21.21 19.94 20.88 21 23.29 21.70 20.63 21.02 20.44 20.92 22 23.21 22.16 20.63 21.31 20.20 21.01 23.44 22.31 20.46 21.52 20.59 20.88 24 23.54 22.35 2 1.2 6 21.67 20.73 21 .38 25 23.45 22.35 21.35 21.66 20.75 21.55 26 23.48 22 .92 21.04 21 .59 20.69 21.35 27 23.50 22.90 21.44 21.76 21.20 21.52 28 23.58 23.24 21.15 21.69 21 .22 21.6 2 Mean 2 3.26+0.06 22.24+0.13 2a 98+0 .10 21.28+0.11 20.55+0.15 21.01+0.11 H = High level concentrate L = Low level concentrate * Change of diet ** = Two animals within a breed were maintained on each level. UNIVERSITY OF IBADAN LIBRARY CSJ 166 3.^.5 Liveweiqht changes: All coujs showed liveweight. losses From the beginning of the experiment which was about a week after parturition. With a few exceptions, the losses in weight persisted until about the 8th to 10th week, of lactation. The summary of mean body weight changes as influenced by stages of lactation, breed, pasture and supple­ mentary concentrate treatments are shown in Tables 3.19a, b. Animals on the high concentrate feeding had faster weight gains than the cows fed on low concentrate. While the latter had an average increase of 35.51g/day, the former had 22.85g/day (P<0.05). It is interesting to note than on calculation the Friesian cows lost an average of 5.16g/day, the German Brown and White Fulani cows gained weight (5D.20g/day and 10.51g/day respectively). A significant difference I existed between them (P<0.05). Statistically significant differences were found between the mean daily gain per cow during the dry and wet seasons (P<0.G5), with 30.5li8.51g/day during the dry season and'27.85^10.52g/day during the wet season. UNIVERSITY OF IBADAN LIBRARY Table ;3;19a I*+XiYeweiEht (kp) of the three breeds of lactatlng ;cows fed on grass forage with low or high concentrate aiming the 28-week experimental period f — ! WHITE 7ULANI GERMAN BROWN FRIESIAN H x H L H L ; '2 7340.37 282.03 4 ’8.60 407.90 415.81 376.80 i -3 ; 4 '334 45 275.26 406.59 400.20 402.07 365.45 :5 66 : 329.54 282.14 408.99 400.59 396.13 357.82 • '7 ; ■8 '328.‘79 274.35 406..82 403.30 389.91 349.77 c9 ; '10 '326.30 ■282.97 413.34 409.73 378.86 349.23 . ! '11 i '12 '33045 294.30 424.77 419.35 376.82 357.05 ! '13 i ‘14 '337.30 292.88 433.27 420.01 382.19 363.29 1!Kean .'33246+1.91 28343+2..93 416..05+3.81 408.73+3.13 391.68+5.32 359.92+3.64 i >* . X H X H L H I M5 : -16 '348. 50 283.58 438.86 420.48 38341 365.68 : '17 ; 'is '340.20 289 .'30 437.63 423.48 390.68 372.92 ! <19 ! :2o '33841 '282.34 443.84 423.56 397.17 397.26 J '21 ! :22 '538.91 '291.92 438.60 426.80 395.15 380.77 ! :2 3 ' : :24 ‘344.90 '298.83 438.37 429.21 402.71 369.55 . '25 ■ 726 347.56 302.42 441.14 432.37 406.16 379.84 i '71 ?28 350.91 302.85 441 49 437.22 407.82 383.84 ; Mfeon- 344.20+1..91 293.03+3.23 439.99+0.84 427.59+2.20 397.59+3.31 377.12+2.99 >H= IHigh '.Level -concentrate * Change of diet X == 'Jjctw HoYel Lconcentrate ’** Two animals within a treed were ■maintained on each level. UNIVERSITY OF IBADAN LIBRARY - m - Table- 5-19b ' Bimonthly weight changes of the three breeds of lactatinn cows fed on +rass forage with low or hi+h concentrate during the 26-week "xnerimental period jWeeks White Fulani German Brown Friesian H L H L H L j T | | ! 2 ;-25-98 -15-37 -19-90 -12-31 -14 -19 -1 6 -6 1 3 | | 4 1-5-92 : -6-8 2 -12-01 -7-70 -1 3 .7 4 -11.35 ! 5 } 1 6 i-4-9l • +2.40 +0-39 -5-94 -7 -6 3 |i ! 7 } ! 8 • -0-75 -7.79 —2-17 +Z.7T -6-22 ,-8-05 , 9 : t o . -2.49 . +8 -62 +6-52 +6 .4 5 -11-0 5 -0-54 i T T 1 T2 |+4..15 ; +11-53 +11.45 +9 .6 2 1 -2.04 ;+7.82 1 75 j : +6.-85 -1-42 +8-50 : +Q.66 +5-57 +6-24 | T? £ j Mean i-5-34 -0-56 ■ -0 .6 5 -0..03 ■ -5-98 -3 .-7 7 1 i *» ! E H L H JTu. H ; i? | t 6 ;+H ..20 -9 -3 0 + 5.59 +0.47 ■ +1-22 +2.79 17 -rS -8 -5 0 -1 .2 5 +5-00 +7-27 +7.24 1? ■ 20 -1 -7 9 -6 .96 ' +6.21 +0-08 +6.49 +14.54 ; 2i 1 2 2 ! +0.50 '+9-58 -5 .2 4 +5,24 — 2-02 -6 .4 9 i 25 j 24 !+5-99 1 +6-91 -0 -2 3 +2-41 ■ +7-56 -11 -22 1i 25 ; 26 +2-66 '+3-59 +2-77 : +5-16 + 7 .4 5 +10-29 i 27 --- ^ j 28 i+ 5 -5 5 ■+o.4? +0-55 1 +4.25 +1.66 +4.00 1 | Hean |+1-70 } +T.-Z5 ; +1.05 : +2-15 +3.20 +2-57 | UNIVERSITY OF IBADAN LIBRARY DO b+- 169 3.5 DISCUSSION Keay (1959) classified Ibadan under the lowland rainforest vegetation zone with a two-peaked rainfall pattern and a dry season lasting between three to five months usually between November and March. Apart from the August 'break' , the data shown in Table 3.k were in good agreement with this observation. The differences in the chemical composition of the concentrate supplement were not as variable as the grass forage. The crude protein, phosphorus and ash were largely dependent on rainfall as could be deduced from Tables 3.5 and 3.6. This observation was also supported by Todd (1956). Calcium was relatively stable during the dry season but fell with the onset of the rains. A possible explanation is that the uptake of calcium during the rainy season is slow in comparison with the very rapid growth made by the grasses, so that, though the total amount of calcium may be increasing, the content of the foraoe dry matter may fall. As for the increase durino the dry season, the most likely explanation seems tn be preferential translocation. As is shown by the fact that deficiency symptoms first appear at the growing UNIVERSITY OF IBADAN LIBRARY 170 point. Calcium in plants is a relatively immobile element and if translocation of other fractions of the dry matter to the root system took place, the percentage of the calcium in the above ground portions would increase. Fiske and Subbarow (1925) expressed a similar view. Results obtained from this investigation have shown that consumption of DM after parturition was low but increased gradually until it reached a peak between the 4th and the 10th week. Hutton (1962), Mowat (1963) and Ogunsiji (1974) have observed that cows reached their maximum DM intake 6-16 weeks after parturition. The general picture emerging from the present investiga­ tion was that the DM intake by the exotic cattle was higher than that of the indigenous ones. Results of comparative studies undertaken by various investigators (Glover and Dougall, 1961; Rogerson_et al, 1968; Musangi 1969 and Rogerson, 1970) have shown that the DM intake, was generally lower in the Bos indicus cattle than in their Bos taurus counterparts of European origin. Many reasons could be adduced to the lower DM intake of the indigenous. During lactation, intake seemed to be related to metabolic weight, and the exotic cows in the present study with the UNIVERSITY OF IBADAN LIBRARY <3 - 171 - highest metabolic size consumed the highest amount of nutrients. This observation agreed uith the findings of many investigators that the animal size was an important factor influencing intake (MacLusky 1955; Elliot et al, 1961; Holmes and Jones, 1965; Musangi, 1969). Hill (1966) hypothetically described tropical breeds of cattle as 'respiratory' types, there being a relatively greater development of thoracic region com­ pared uith the more fully developed abdominal region in the temperate breeds, leading to larger capacity in the- rumen and greater appetite. However, these anatomical differences between the tropical and temperate breeds of cattle could only be regarded as one of the plurality of causes responsible for the variation in DM intake. Apart from the fact that DM intake, dictated by appetite or desire of animal to consume is partly controlled by inhe­ ritance which is described as "intensity factor" by Mather (1959); of more paramount importance however is the suggestion of Lander (19A9) and Gupta and Jackson (1968) that the generally low capacity for milk production may be related more to their relatively lower total DM intake. A general assessment of the DM intake has shown that while the intake of White Fulani animals ranged from 1.5A UNIVERSITY OF IBADAN LIBRARY 172 to 2.30kg of Of 1 per 100kg liveweight that of the German Brown woe 1.53 to 2. At and that of the Friesian 1.59 to 2.9nkp of DM per 100ko liveweight. Slightly higher DM irtake than the ones reported in the present experiment ranging from 2.1 to 2.3kg DM per 1D0kg liveweight had been recorded by Mather and Deeai (1953) for Zebu cattle in India. However a lower DM intake of FI.99 to 1.95% of liveweight among White Fulani cattle was reported by Miller (1961) in the Northern States of Nigeria. Olaloku (1972) reported a higher intake for lactating White Fulani cows. Higher DM intake than the ones recorded in the present experiment have been reported in the literature for the exotic breeds of cattle. Castle (1953) reported consumption of 2.9 and 2.5kg per 100kg liveweight for cattle grazing rye grass and cocksfoot herbage. Hashizume, Morimotn, Masubuchi, Abe and Hamada (1965) showed that the average DM intake was 2.6% of the body weight. The absolute daily feed consumption figure reported here are generally lower than the figure from the temperate countries. Several reasons may be advanced for this. All the animals were zero-grazed. Baker, Richards, Haenlein and Weaver (I960) have agreed that stall-fed animals were likely UNIVERSITY OF IBADAN LIBRARY 173 to feed on a quality of herbage inferior to that grazed by animals in the field since they have less opportunity for selecting their forages. Duckworth and Shirlaw (1958) have suggested that crude fibre content was very crucial in controlling appetite. There is no doubt that the amount of roughage consumed could have been limited partly by the relatively high crude fibre content (21.<+B to 33.50/0 of the grass fed in the present experiment. Though Duckworth and Shirlaw (1958) have suggested that optimum forage DM intake was guarranteed when the grass has a DM content not higher than 2i+.2($?o, results obtained from the present study reported an average DM intake of t+0.86% (ranges 23.1+5 - 76.51+%). Finally, one cannot underestimate the influence of the high ambient tropical temperature since such temperatures have been shown to have a depressing effect on appetite (Holme and Coey, 1987; McDowell, 1972; Loosli and van Blake, 1973). Results obtained in the present investigation have indicated that milk yield attains peak production between the 5th and the 9th week and that cows which were first placed on low energy intake attained peak production earlier than those first placed on high energy intake. Kartha (1931+) observed that maximum rate of secretion of milk which UNIVERSITY OF IBADAN LIBRARY preceded the decline uias attained at different .indivi­ duals but the large majority of animals of all breeds attained it between the third and sixth weeks after calving. The results of the investigations of Bailey (1952), Rook and Campling (1965), Olaloku and Oyenuga (1971) and Broster (197k) are in general agreement with the findings in the present investigations in which milk yields and SCM were declining as the lactation progressed. The hi nil energy ration fed to the animals at the receding stages of lactation (middle and late stages) did very little, if any, to improve the level of milk yield (Fin. 7.3 - 3.5). These observations were more pronounced in the high producing cows than in the low pro­ ducing ones. Results obtained in the present study have shown that cows which were first placed on low energy intake attained peak production earlier than those first placed no high energy intake. These results were also in support of the observations of Eckles and Shaw (1913) that the experienced husbandry man supplies his cows with practically the same amount of roughness throughout the lactation period, but a larger amount of grain is fed in the early part of the period than towards the end. UNIVERSITY OF IBADAN LIBRARY 175 Broster and Tuck (196A) have even observed that the pattern nf yield established by the level of feeding in early lactation persisted over the whole lactation. The present study appeared therefore to suggest that to increase milk production particularly in the exotic breeds of cattle and high milk yielding indigenous cows in PJigeria, attention should be given to the possibility nf not only raising their milk yield at the beginning of lactation by generous feeding but also extending the period at which lactation reaches its peak (persistency). In fact, several experiments under the temperate climates have shown that the response of the dairy animals to extra feeding is proportional to the initial yield of the cows. McCullough and PJevill Jr. (1960) and Broster (1963) have concluded that the high yielder benefited more from extra feeding particularly at the beginning of lactation than the low yielder. Admittedly, the cow's innate capacity can only be exploited by generous feeding at prepartum or early lactation only to get a good milk yield peak in early lactation and to keep the cow's rate of milk yield fall gradually throughout the lactation period thus ensuring persistency; but the productive potential of the animal cannot be extended for at any one UNIVERSITY OF IBADAN LIBRARY 176 time the milk yield of the cow is an amalgam of her genetic potential and her history including nutrition (Rlaxter 1956; 1967). The increase in milk yield that occurs with increase in plane of nutrition (high concentrate feeding) is probably associated with increases in the amounts of precausors for milk yield synthesis reaching the mammary gland. For instance, Rook and Line (1961) reported significant increases in volatile fatty acids (UFA's) in arterial blood and o( - amino nitrogen in venous blood with increase in energy intake. The bulk of experimental evidence from the literature (Bath and Rook, 1963; Button and Johnson, 1969; Mba and Olatunji, 1972) indicates that rations high in crude fibre tend to increase the molar proportions of acetic acid w)th corresponding lowering of the molar proportion of propionic acid while the reverse is true for the rations low in crude fibre. Mba and Olatunji (1971) postulated that such rations which severely depressed molar concen­ trations of acetic acid and correspondingly increased proportions of propionic acid could enhance production of meat and milk. UNIVERSITY OF IBADAN LIBRARY 177 The explanation to the higher milk yield obtained during the wet season than the dry season despite the higher DM intake in the latter than the former in the present studies may be due to the poor quality of the roughage intake during the dry season. Armstrong, Blaxter and McC.Graham (1957) showed that rumen liquor contained greater amounts of acetic acid relative to propionic and butyric acids after feeding poor quality roughages. The above authors have also observed that a change from lower to higher proportions of acetic acid of the total VFAs and a corresponding fall in the propionic and butyric acids proportion resulted in increased heat increment and a fall in the utilization of the metabolizable energy of the ration. The chemical composition of the milk showed that there was an increase in butterfat content as the lacta­ tion progressed. This is in agreement with the findings of Eckles and Shaw (1913), Azih (1963), Olaloku and Gyenuga (1971) and Adebcwale (1972). The result of the butterfat percentage obtained in the present study showed that while there was an increase in the milk yield with increase in energy intake, exotic breeds on low energy UNIVERSITY OF IBADAN LIBRARY 17Q produced higher butterfat percentage than when on high energy. Many experiments (Schultz, 197A; Armstrong and Prescott, 1970; Lofgreen and Warner, .1970) as well as field observations (Davis and Brown, 1970) have shown that fat content of milk tended to drop when concentrate levels in feeds were increased and roughage made up less than one-third of the ration DM. The butterfat percentage of the indigenous cows in the present studies was higher than those of the exotic cows. Apart from the fact that the indigenous cows have been genetically noted to produce milk of high butterfat, Ogunsiji (197*0 found that in cows giving a high milk yield, the butterfat and total protein content was lower than those producing low milk yield. The milk protein of the cows studied did not follow any well-defined trend but there were stage of lactation effects. This observation was also reported by Ogunsiji (197*0 who inferred that 5NF, protein and lactase of milk did not follow any definite pattern. Although statistical analysis in the present experiment showed that there were significant differences between the milk protein of those cows on high and low energy levels, IMewman-Heuls' (1955) comparison between ordered means revealed that this was only UNIVERSITY OF IBADAN LIBRARY 179 during the early stage of lactation when there was high milk yield and that there were no significant differences between the percentage protein during the middle and late lactation stages. Perhaps this shows that the protein requirement during the early lactation when there was a high milk yield was higher than the amount supplied with the low eneroy ration. The fact that this particular phenomenon did not occur during the last two stages in the present experiment is in agreement with the findings of Rnnk. end fine (196?) and Armstrong (1963) that dietary protein levels do not seriously affect percentage protein nf milk unless intakes were considerably below the recommended requirements.. The observation revealed in the present study that milk protein percentage was higher during wet season than the dry season was supported by the conclusion of Todd (1956) and Rook (1961) that protein contents of milk increased significantly with the commence­ ment nf grazing in May and dune and declined during the dry season when herbage was scarce and nf low nutritive value. There were no differences throughout in the lactose percentage. Rook (1961) has pointed out that lactose is a major determinant of osmotic pressure in milk and thus a regulator for the volume of water secreted by the mammary UNIVERSITY OF IBADAN LIBRARY 180 gland and therefore not easily altered. Armstrong and Prescott (1970) have asserted that an increase in the plane of nutrition does not increase lactose content but a small decline occurs when energy content is severely restricted. The conclusion generally is in support of the results obtained in the present study. The commonly observed increase in solids-not-fat (SNF) of milk with increase in the plane of energy nutrition (Lees, McMeekan and Wallace, 19L8; Campbell and Flux, 1948; Broster and Tuck, 1967) was found in the present experiment. Rook and Line (1961) and later on Rook and Storry (196A) postulated that an increase in the plane of energy nutrition increased the amount of propionate absorbed from the rumen and consequently the plasma propionate concentration in peripheral blood. This change in turn increased the rate of mammary synthesis of both lactose and protein. To maintain isotonicity of the mammary secretion with blood plasma, an increase in the synthesis of lactose will produce an increase in the output of water and therefore in the yield of milk. Results obtained for the ash content has shown that the phosphorus was relatively constant. Hanssan (19it8) showed that the content of phosphorus in cow's milk was governed chiefly by genetic factors and was therefore relatively constant for a particular breed. The increase observed in the UNIVERSITY OF IBADAN LIBRARY 181 ash content of milk however with increase in plane of nutri­ tion was likely due to the explanation of Holmes, Arnold and Provan (1960), Castle, Drysdale and Waite (1961), Rook and Line (1961) that an increase in the mineral fraction as energy intake increased may in part he due to increase in mineral content with rise in energy intake. The dietary energy effect was reflected in the milk energy nf the cows. Expressed on the values of the energy distributed in milk in relation to the gross energy consumed the values obtained in the present, study for White Fulani, 18.2/+% (High energy HL) and 22.81% (low energy LL); for German Grown, 1A.25% (HL) and 1A.9A% (LL); for Friesian 12.91% (ML) and 15.18% (LL) were generally within the range nf 12.9 to 10r' obtained hy Hashizume et _al (1965) for Japa­ nese Holstein rows but those of the White Fulani were outside this range, although they were very close. Flatt (1967) reported that the proportion nf milk energy in relation to gross energy consumed was high in early lactation, being 3A.9%, while it was 12.1% in late lactation. T+- is pertinent to note that there was an appreciable decrease in liveweight up to the twelveth week of lactation. The liveweight increased after this for some few weeks and remained almost constant till the end of the experiment. UNIVERSITY OF IBADAN LIBRARY Glessnn (1970) and Olayiwole (1973) have carried nut experiments in which liveweight fell just after calving and thereafter regained and remained almost constant on average. This loss in liveueight during early lactation observed in the present study was in general agreement with the findings of Mae and Flatt (1909) and Mae, Tyrell and Flatt (1971) that in early lactatinn dairy cows may rely nn body fat reserves as an energy source. They stated that milk may be produced from body tissue reserves with an efficiency of 82 - Bh%. Furthermore, Moe,et al 0971) stated that the amount of tissue energy used during early lactation for milk production would depend on the degree of fatness of the cow at the time of parturition, the genetic potential of the animal for milk production and feed intaked uring early lactation. Graves, Davison and Hpoland (1938)s howed that the total digestible nutrient (TDM) intake was only lk% of TDM requirements in the first month of lactation and that the intake did not equal the requirement until the Ath month. The lactating ruminants also have got the capacity to draw upon the body energy reserves to maintain milk secretion during early lactation (Armstrong, 1968). Ogunsiji (197A) explained that there was mobilization of blood tissue substances to support milk production during the early UNIVERSITY OF IBADAN LIBRARY 183 lactation. Flatt at al (1969) calculated the average daily loss of tissue substance in high yielding Friesian cows during early lactation to be equivalent to 20.9MJ or 0.72kg fat. Finally, Flatt, Cappock and Moore (1965) have pointe/d out that good-producing couis are often unable to consume enough feed in early lactation to prevent some loss of body reserves of energy, calcium, phosphorus and protein. These findings were generally in agreement with the low feed intake,increasing milk yield and loss of weight recorded in the present study during the early part of the lactation. In conclusion, the results obtained in these experiments seemed to indicate that: (1) Mean roughage DM intake were k . k 9 i o . 1 6 , 5 . 5 9 ^ 9 . 1 6 and 5.92in.21kg/day for the White Fulani (IjJF), German Broun (GB) Friesian (F) cows respectively. DM intake was higher during the dry season than the wet season. (2) Peak milk production for all the breeds was between the 5th and the qth weeks of lactation and declined thereafter. Average milk yield was 27.55ifl.15, ft1.16ifl.19 and kD.16i6.15 kg/riay fnr the White Fulani, German Grown and Friesian cows respective!'..'. Milk yield during the wet season was higher than the dry r'-nann. UNIVERSITY OF IBADAN LIBRARY 1 % ( i. i> A i 1 rm.in l net i.ipi qht immediately after calving until admit. the nth to 10th week of lantatinn. While the Fripsian nni'ia lost an average nf 5.16g/day, their Herman Brown and White Fulani counterparts gained 5n.2n and 1G.51g/day respectively. UNIVERSITY OF IBADAN LIBRARY HI IAPTER A EPERPYArip PROTEIN REQUIREMENTS FUR f1AIUTEUAPCE A IMP MILK PRODUCT I OR TruRnpiiGTinri Animals heing fed fnr growth, fattening, milk produc- tinn and other productive functions, need a substantial part of the food for supporting body processes, which must go on whether nr not any new tissues nr products are being formed. This demand for non-productive but essential function is the maintenance requirement. Maintenance need is usually determined by feeding trials. The method involves the determination of food required to keen animals at constant body weight. Enemy requirements for maintenance, growth, lactation and pregnancy are usually determined using enemy balance techniques or feeding trials (Brody, 19A5; Meyer and Lofgreen, 1959; Hashizume, Haishio, Ambo, Tanaka, Hamada and Takahashi, 1963; Elatt et al, 1967; Maynard and Laosli, 1969; Neville and McCullough, 1969; floe, Tyrrell and Flatt, 1970; Swanson, 1971; Neville, 197A; Patle and Mudgal, 1975) which facilitate the expression of requirement as Total digestible nutrient TDIM; digestible energy (DE) and metabolizable energy (ME) which are some of the feeding standards commonly used for energy UNIVERSITY OF IBADAN LIBRARY 186 values. In such trials, facilities far the measurement nf feed intake, urine, faecal loss and methane production are provided for the determination nf ME (Maynard and Lnosli, 1969). Since it is now known that before systematic compu­ tations of rations for livestock could be embarked upon, basic research is needed to ascertain the nutritional requirements for maintenance and production under tropical conditions, the objective nf this study is to compute in accordance with the conventional methods of estimating energy and protein require­ ments, the maintenance and milk production requirements for hath protein and energy of lactatinq exotic and indigenous cows under the humid tropical environments using local feeds and facilities. Experiments performed on the fistulated lactating cow will also elucidate the relationship between rumen metabolites, milk and blood constituents. Finally, it will also afford the effectiveness of the new modified' metabolism cages adapted for use of heavy lactatinq cows when results obtained from these animals without harnesses and in these canes are compared with those obtained from these animals without harnesses and in these cages are compared with those obtained from steers harnessed with collection bags. UNIVERSITY OF IBADAN LIBRARY 187 ? MATERIALS ADD METHODS 7.1 Animals and their management: Twelve intact lactating cows, six intact steers and one fistulated White Fulsni cow were used throughout the trials. The twelve lactnting cows ranging in liveweights Fran to £|OW i.p i cal nutated from the eguatinn: h ' h rr 1 . 7n j. p. i i ?d x L (f.i7 - n.nsn)-------d ) where L ‘s h'->e 1evel of feeding as a multiple nf maintenance level and n j.s the apparently digestible enemy at the maintenance level nf feedinn (Plaxter and Glappertnn, 1965). The methane was first expressed in Kcal/IOCKca! of the dietary gross energy and later converted to Kilojoules. The apparent digestibilities of the dry matter (DM), organic matter (nrl), Crude protein (CP), crude fihre (CF), Fther extract (FF) , nitrngen-free-extractives (FIFE) and Energy nf the nrass and ration were determined by using the equation UNIVERSITY OF IBADAN LIBRARY 197 nn(X) - inn X 21 in feed - X in faeces - - - - (2) X in the feed where, nn(X) = digestibility coefficient of X nutrient X = X nutrient in the feed or faeces. The digestibility coefficient of the different nutrients in the supplementary ration was then calculated using the formula of Cramption and Lloyd (1959) D = mn(d1 - ri2) + d2 --------------------------(3) 9 where 0 = percentage apparent digestibility rî = coefficient of digestibility of total ration (grass and concentrate) d2 = coefficient of digestibility of basal ration S = percentage of concentrate feed in the total ration. The data obtained frnm these analysis and calculation were used to compute the metabolizable energy (ME). Analysis of blood and rumen The blood plasma was estimated for urea, total and individual WFA's and the rumen liquor was estimated for pH, ammonia, total and individual l/FA's. UNIVERSITY OF IBADAN LIBRARY 19B About 50ml nf the rumen samples were squeezed through fine muslin cloth. To 5m1 of the squeezed sample were added 5ml 0.10 f-2U PHA saturated with MoSD,A . The solution was filtered and 2ml of the filtrate distilled in a Markham distillation apparatus. 35(lml distillate were collected and titrated against 0.010 flam to obtain the total steam \/FAs. For the estimation of the individual UFA a Pas Liquid Chromatograph Pye 10A using flame ionization detector was used. 25ml of each of the squee- ed liquor were poured into centrifuge tube and 5ml of 25% nrthophosphoric acid in 50 H,,50 ( were added to each liquor. It was left for at least 30 minutes and then centrifuged at 2,5nnr.o.m. for 10 minutes. The supernatant was poured into a small bottle and well stoppered. n . 3 m l of this was chromatographed in duplicate on the Pye 10A G.L.C. The column contained 2D per cent carbowax 2CM plus phosphoric acid on celite (10n-12rimm mesh). The working temperature was main- tained at 125'nC and attenuation was 1 x 500. The flow rate of compressed air was at 705.0ml/min, Argon at 61.Aml/min and Hydrogen at M.Aml/min. The separation was mainly into acetic, propionic and butyric acids and usually lasted between 75 and PC minutes. Calculations were done by calculation nf the area of the neak from the chromatograph using the formula (height x base at UNIVERSITY OF IBADAN LIBRARY 199 y, height), Standard mixture of VFA was also chromatographed and correction factor determined. The correction area so obtained was used to calculate the molar percentage of the individual acids as follows: Molar oercentage of individual acid: - corrected area for individual, acid x 199 hum of total corrected area The blood urea concentrations and rumen ammonia were (jn+orni nnrt "010° the methods of Fawcett and Scott (19(19) «nrt Pheney Mnrhech (19621. The colour developed was read at 6?Som unino Senkman Acta ITT and the concentration expressed in mn/199ml rumen liquor or 199ml blood calculated from standard curves prepared from ninmnnium sulphate solutions for ammonia and urea standard solutions for urea. RESULTS Composition of the diets: Components of the dairy concentrate supplement were the same as used In the previous study (see Sec. 3.9.2, Table 3.1). The mean chemical composition of the ration and grass (Cynndnn nlemfuensis var nlemfuensis) are shown on Table A.1. The mean crude fibre of.the grasses was high and the crude protein of the ration was also fairly high. UNIVERSITY OF IBADAN LIBRARY 200 Table 4.1 Mean Chemical Composition of Ration and Forage fed (on dry matter basis) Nutrient Concentrate Forage (C.nlemfuensis) Ration Dry Matter (g/1D0gDM) 88.12 31.49* Ash ( " ) 4.55 10.45 Crude ( " ) 17.65 9.25 protein Crude fibre( " ) 9.02 29.40 Ether Ext- ( " ) 2.05 0.51 ract Nitrogen- ( " ) 54.85 42.06 free extra­ ctives NFE Energy (KO/gDM) 22.30 20.50 Calcium (mg/1D0gDM) 79.30 332.30 Inorganic phosphorus 63.50 125.45 (mg/100gDM) Sodium (mg/IOCgDM) 12.69 64.87 Potassium (mg/100gPM) 952.08 2447.20 ♦Dry matter of fresh forage UNIVERSITY OF IBADAN LIBRARY 2D1 . - .2 PM intake, milk production, rumen and blood metabolites n ̂ the f i sti 11 at ed cow; Table h.2 shows the feed intake, milk yield and com­ position of the fistulated White Fulani cow. There was a oradual increase in the herbage DM intake from the start of the experiment tn the end. Because the experiment was started at the receding stage nf lactation, the concentrate ratinn intake when tie animal was on low energy was very low compared with ration intake on high energy level. The ratio of the forage DM intake to the concentrate ration was 2.10 for high energy level and 3.U9 for the low energy level indicating 32.3 and 22.3b, nf concentrate DM intake respectively. The fat percentage when on grass feed alone was higher than when concentrate rations were fed along with the grass despite advancing lactation. The protein level of the milk produced by the animal when concentrate supplement was fed was slightly higher than when grass alone was fed (3.19% on grass alone, 3.23% on low energy plus grass, 3.25% on high enemy level plus grass). The protein/fat ratio was highest when the animal was on high energy plus grass ration and least when it was fed grass alone. Table U.2 also indicates that liveweight of the animal increased when low energy was fed. UNIVERSITY OF IBADAN LIBRARY 202 T a b l e if.2 Feed Intake, milk yield and composition for the fistulated White Fulani ccm fed on grass and high or low concentrate supplement. F HC LC Concentrate Ration Intake (KgDM/day) - 2.30 1.if0 Forage Intake (KgDM/day) it.ifif A. 83 if.89 Forage to Ration Ratio (F/R) - 2.10 3. if 9 Milk yield (kg/day) if. 56 A. 69 if. 58 Butterfat (%) if.96 if .70 tf.7tf Protein (%) 3.19 3.25 3.23 Protein/fat ratio 0.6A 0.69 0.68 Initial weight 289.15 287.2if 288.15 Body weight (kg) Final weight 287.2A 288.15 292.lit ; HC : High concentrate (high energy level) + ad lib forage LC : Lou concentrate (high energy level) + ad lib forage F : Ad lib forage intake. UNIVERSITY OF IBADAN LIBRARY 203 The increase in liveweight may be due however to reduced milk yield as lactation advanced with increased feed intake. Table A. 3 shows the pH, total and individual UFA'S, acetic to propionic acid ratio and ammonia nitrogen of the fistulated lactating White Fulani cow's rumen liquor. Except for the low energy level, the pH of the rumen was higher when samples were taken one hour after feeding than two hours. The pH was least when high amount of concentrate was fed (pH 6.96) and highest when grass alone was fed (pH 7.50). The pH level also varied with the total volume of UFA available in the rumen; that is the rumen was most acidic when the highest volume nf total UFA was recorded. This was when the animal was fed the highest amount of concentrate ration (A.6Aip.75 Merf/i). When the now was fed only grass and rumen liquor was almost tending towards being slightly basic, the least amount, of total UFA was recorded O.ngin.AB meq?(). When grass alone was fed, highest molar percentage of acetic acid was recorded 77.5Bin.56 molar % to the low percentage of propionic acid 19.11-1.29 molar %. The lowest percentage of acetic acid and the highest percentage of propionic acid occurred when high amount of concentrate (high energy level) was fpd (67."7/1 io.53 molar % acetic acid and 27.2lil.21 molar % of propionic'acid). The molar % of acetic acid was UNIVERSITY OF IBADAN LIBRARY 72.U5in.75 and that of prnpionic acid 23.22^0.78 when animal was fed low energy level. The butyric acid content was low in the three dietary levels. The relationship betMeen the acetic and propionic acid a in the three feeds are also shown in Table U.3. The highest ratio of U.06 was recorded for the grass intake alone, 3.12 for the lower energy level plus grass and 2.U9 for the high energy level plus grass. A well-defined trend of ruminal ammonia nitrogen (mg/IOOml rumen liquor) was noticed. Results showed that ruminal ammonia nitrogen (mg/100ml rumen liquor) was noticed. Results showed that ruminal ammonia nitrogen was highest when the animal was on the high concentrate supplement (high energy level) 1U.7li2.nnmg/100ml liquor, 11.87io.99mg/100ml liquor for the low energy level and 10.88io.13mg/100ml liquor was recorded when only grass was fed. Table U.U shows the feed intake and time of blood sampling on total and individual UFA'S, acetic to propionic acid ratio and urea nitrogen level of the fistulated lactating White Fulani cow's blood. These results indicate that higher total UFA in blood plasma were obtained four hours after feeding. The highest total UFA production was obtained with animals given the high energy level (2.U5io.37 f1eq%). When the animal was fed low energy level 1.78^0.20 Mecf/ total UFA was UNIVERSITY OF IBADAN LIBRARY Table 4.3 - 205 - Effect of feed intake end time of rumen sampling on the pH, total and individual VFA, Acetic/Pronionic acid ratio and amnonla nitrogen content of the fistulated lactating White Fulani cow's rumen lienor fed on .crass and high or low concentrate supplement F HC LC Rumen sampling time after feeding. 1hr 2hrs Mean 1hr 2hrs Kean 1hr 2hrs Mean pH of rumen liquor 7.64 7.35 7.50+0.15 6.98 6.94 6.96,+0.02 7.02 7.06 7.04_+0.02 Total VFA of rumen liquor (Keq %) 3.53 3.57 3.05+0.48 5.39 5.88 4.64+0.75 4.03 4.01 4.02_+0.01 Individual VFA Acetic acid 77.02 78.14 77.58+0.56 69.20 66.25 67.73+0.53 71.70 73.20 72.45+0.75 rumen liquor . Propionic acid 17.82 20.40 (Molar 90 19.11+1.29 26.00 28.42 27.21+1.21 22.43 24.00 23.22+0.78 Butyric acid 5.16 1.46 3.31+1.85 4.80 3.33 4.07+1.74 5.87 2.80 4.34+1.54 Acetic acid to propionic acid ratio (A/P) 4.32 3-83 4.06 2.66 2.33 2.49 3.20 3.05 3.12 Ammonia nitrogen (mg/l00ml liquor) 10.75 11.00 10.88_+0.13 16.20 12.21 14.21+2.00 12.85 10.88 11.87^0.99 HC = High concentrate ration + ,&d lib forage LC = Low " " " " " F ad lib forage UNIVERSITY OF IBADAN LIBRARY Table 4.4 206 - Effect of feed intake and time of blood sampling on total and Individual VFA. Acetic/Prooionic acid ratio and urea nitrogen of a lactating White Fulanl cow's blood fed ua grass and high or low concentrate supplement F HC IC Blood sampling time after feeding 4hrs 5hrs Mean 4hrs 5hrs Mean 4hrs 5hrs Mean Total VFA in blood plasma (meq %) 0.83 0.62 0.73+0.11 2.82 2.08 2.45+0.37 1.58 1.98 1.78_+0.20 Individual VFA Acetic acid 89.26 90.11 89.69+0.^3 84.00 76.56 80.28+3.72 82.57 86.44 84.51+1.94 of blood plasma Molar Propionic acid 10.74 9.89 10.31+0.43 16.00 23. 44 19.72+3.72 17.43 13.56 15.50+1.94% Butyric acid e 0 e 0 a a Acetic acid to propionic acid ratio (A/P) 8.31 9.11 8.71 5-25 3-27 4.26 4.74 6.37 5.55 Urea nitrogen (mg/l00ml blood plasma) 13.20 11.10 12.15+1.05 19.10 19.50 19.30+0.20 16.14 16.25 16.20+0.06 HC = High concentrate ration + lib forage LC = Low " " " " " F = Ad, lib forage 0 = Negligible percentage. UNIVERSITY OF IBADAN LIBRARY 207 produced. The least total UFA produced was when the animal was Fed on grass alone and the value obtained was D.73-0.11 Meg:'. Only acetic and propionic acids were obtained when individual UFA of blond plasma was examined. The highest ratio nf acetic/propionic acid was obtained when only grass was fed (8.71), while the least ratio (A.26) was obtained when a high energy level was fed. The higher the inclusion nf concentrate ration (nr energy) the lower the molar % of acetic acid available in the blood and the hinher the propionic acid recorded. Urea nitrogen (mp/IOOml blood plasma) which is a good index of protein utilization varied according to the nature of the feed given to the animal. When the animal was fed grass and high energy level, 19.3nin.2Dmg urea nitroqen/100ml nf blood plasma was available in the blood plasma, when it was fed low energy level plus grass 16.2ntn.06mg/10nml was recorded and with grass alone 12.15tl.n5mg urea nitrogen/100ml of blood plasma was found in the blood plasma. A.A.3 Milk Yield and Oomposition of intact lactatlng cows Tables A.5, A.6 and A.7 show the milk yield and compo­ sition of the White Fulani, German Grown and Friesian cows used for the energy and protein requirement studies. UNIVERSITY OF IBADAN LIBRARY r ■ - 208 - Table 4.5 MEAN MILK YIELD ANT) COMPOSITION OF '.VHITB 'FOLAWI CO'.VS MAINTAINED OH GRASS AND 10ff OR HIGH CONCENTRATE SUPPLEMENT ANIMAL TREATMENT MILK YIELD TOTAL SOLIDS CRUDE PROTEIN LACTOSE PAT ASH GROSS ENERGY NO. (KG/DAY) % % % % % (KJ/G) 467 Ad lib 2.57 12.25 4.80 4.72 0.71 21.78 481 5.50 11.52 3.12 4.72 4.84 0.68 21 .82 242 3.96 12.00 3.07 4.75 4.63 0.67 21 .20 167 4.08 11.75 5.35 4.33 5.02 0.70 22.21 \ * ) Mean 3.53+0.34 11.88+0.16 3.15+0.07 4.73+0.02 4.80;+0.14 0.69+0.01 21.75+0.71 467 Ad lib 1.82 12.88 3.01+ 4.31 4.60 0.71 21.00 481 forage 5.02 11.61 3.10 4.73 4.46 0.68 21.52 242 and high 4.14 12.00 3.12 4.76 4.60 0.69 21 .10 167 level 4.01 11.86 ... 3.61 4.84 5.00 ____0.72 . . . 21.55... ... Mean ration (HC) 3.25+0.54 12.09+0.28 3.23+0.13 4.79+0.02 4.67+0.12 0.70+0.01 21.29+0.43 467 Ad lib 2.04 12.80 3.21 4.80 4.62 0.70 21.57 481 forage 3.36 11 .63 3.24 4.72 4.71 0.68 21.21 242 and Ion 4.60 12.00 3.12 4.76 4.64 0.69 21.25 167 level 3.15 11.90 3.58 4.86 5.20 0.72 22.15 Mean ration (LC) 3.29+0.52 12.08+0.25 3.29+0.10 4.79+0.03 4.79+0.09 0.70+0.01 21.55+0.56 UNIVERSITY OF IBA OD G\AN LIBRARY \ / • 209 - Table 4.6 MILK YIELD AND COMPOSITION OF GERMAN BRO'TN CC7TS MAINTAINED ON GRASS AND LO'.V OR HIGH CONCENTRATE SUPPLEMENT ANIMAL TREATMENT MILK YIELD TOTAL SOLIDS CRUDE PROTEIN LACTOSE PAT ASK GROSS ENERGYNO. (kg/day) * % /° % (kj/g) 69 Ad lib 6.20 12.00 3.00 4.70 3.95 ' 0.69 21.61 42 7.56 11 .80 2 . 9 5 4.78 3.85 0.70 20.74 66 7.26 11.92 2.85 4.65 3.60 0.70 21.20 57 v.*; 6.24 13.24 3.10 4.62 4.00 0.68 22.02Mean 6.82+0.35 12.24+0.34 2.98+0.05 4.69+0.03 3.90+0.03 0.69+0.00 21.39+0.48 69 Ad lib 6.35 12.20 3.10 4.70 4.00 0.70 21 .78 42 forage 6.36 12.00 3.00 4.76 3.70 0.71 20.20 66 and high 5.35 12.00 3.00 4.55 3.66 0.70 20.56 57 level 6.45 12.98 3.05 4.a 3.85 0.69 21.55 Mean ration (HC) 6.13+0.26 12.30+0.23 3.04+0.02 4.66^0.04 3.80+0.10 0.70+0.00 21 .02+0.18 69 Ad lib 5.22 12.25 3.15 4.71 3.90 0.70 21.70 42 forage 5.45 11.95 3.30 4.77 3.75 0.71 20.99 66 and low 6.00 11.92 3.00 4.52 3.80 0.70 21.00 level 5.65 12.95 3.02 4.63 4.08 0.72 21.911 57 Kean ration (LC) 5.58+0.17 12.28+0.15 3.08+0.04 4.66+0.05 3.88+0.14 0.71+0.00 21.40+0.33 UNIVERSITY OF IBADAN LIBRARY 210 Table 4.7 MILK YIELD AND COMPOSITION OF FRIESIAN COYS MAINTAINED ON GRASS .TOD LON OR HIGH CONCENTRATE SUPPLEMENT ANIMAL TREATMENT MILK YIELD TOTAL SOLIDS CRUDE 0.05). The mean digestibility values of 66.7Aio.52%; 65.98-0.63% and 65.19^1.10% were recorded for the German Brown, Friesian and White Fulani cattle respectively,there were no statistical differences between them (P^O.05). Table A.9 shows that the mean digestibility values of animal on high concentrate (67.Rpi1.52%) were higher than the low one (66.7A-1.BOO. Average digestibility coefficients of 66.6lip.A8; 67.6gii.22 and 67.7lil.26 were recorded for the White Fulani, German Brown and Friesian cattle respectively (P<^0.D5). Table A.10 shows a similar pattern to the above except that higher per­ centages of concentrate digestibility were recorded. UNIVERSITY OF IBADAN LIBRARY Table 4.8 213 Mean Coefficient of apparent digestibility of prase (90 (Cynodon nlemfuensis var, nlemfuensis) fed to both the steers and the lactating cows Nutrients White Fulani German Brown Friesian Steers* Cows** Steers* Cows** Steers* C ows * * Dry Matter 65.92+2.35 64.45+1.42 67.04+0.27 66.43_+0.72 65.99±0.71 65.96+0.43 Organic Matter 64.05+0.81 6 3.48_+i .6 5 6 3-97+.0.04 6 2.85^ 1 . 1 6 63-02.+0.23 62.77+0.47 Crude Protein 64.64_+o .55 64,45+0.60 67-97^0.56 6 8.1 9+1 .0 0 67.67+1.14 6 7.60^ 0 .4 1 Ether Extract 65.34+0.46 51.18+2.25 64.27+2.02 62.55i2.69 58.14+0.52 5 8.4o_+i .0 7 Crude Fibre 58.16+0.04 60.10+1.24 56.18^0.44 58.48_+2.o o 53.94_+0.71 53-35+4.14 NFE 64.10+0.39 6 2.90+1 . 7 7 64.37+0.56 6 5.66_fO.3 2 65.43^0.81 6 5 .02+2.0 6 Energy 60.43+0.25 5 8.09+1 .8 0 65.27+0.55 6 6.02+0 .6 9 66.32^1.09 6 0.1 6+2 .6 2 * Mean value of two animals * * Mean value of four animals UNIVERSITY OF IBADAN LIBRARY (b) Organic Matter digestibility As pointed out for the PM digestibility, mean organic matter digestibility values of the steers and lactating cows for the grass alone showed no statistical significance (P >0.05). However, results showed that the steers had higher digestibilities. Organic matter digestibility for grass and concentrate also followed a pattern similar to those of the DM, that is, animals on high concentrate ration had higher values than those on low concentrate ration. Coeffi­ cient of apparent digestibility of concentrate supplement alone as shown in Table 4.10 were slightly higher than the DM values. The highest mean values were obtained for the German Brown cattle (74.64-1.31$) and the lowest for the White Fulani (72.27-0.82^). The Friesian cattle had a 73.77-1.18$ * digestibility. There were no statistical differences between the steers and lactating cows (P>0.05). « (c) Crude protein (CP) digestibility The mean coefficient of apparent digestibility of the_ CP for the grass alone was fairly high. The highest values were obtained for the German Brown cattle. In the case of the grass and concentrate rations, higher values of apparent digestibility were recorded for the high-concentrate-fed cattle than the low fed ones. Coefficient of apparent digestibility UNIVERSITY OF IBADAN LIBRARY 215 of concentrate supplement alone for steers and lactating cows as shown in Table £+.10 indicated no significant differences (P^>0.05). However the steers had slightly higher values than the lactating cows ( lh.92-k.U2% for steers and 73.39^6.3!+% for lactating cows). (d) Ether extract (EE) digestibility The mean coefficient of apparent digestibility of content of grass alone for the White Fulani steers (65.3£+i 0.£+6%) was higher than that of the cows (51.18^2.25%) (P^'0.05). There was however, no statistical differences in the digesti­ bility values hetween the steers and the cows in the extbtic breeds (P^D.05). There were also no statistical differences (P^O.05) between the mean digestibilities nf EE content of the concentrate alone for the steers and the cows in all the breeds. Highest digestibility coefficient of 70.77^3.£+9% was obtained for the Herman Broun cattle, with the Friesian (69.78^2.33%) and White Fulani cattle (69.97^1.63%) having almost the same values. (e) Crude fibre (HF) digestibility The lowest values of digestibility coefficients were observed for the crude fibre. The reason for this may lie in the fairly high crude fibre percentage (29.£+0%) in the basal UNIVERSITY OF IBADAN LIBRARY - 216 - grass feci. Higher digestibility values for the grass were obtained for the indigenous breed (59.13^0.81%) than the exotic breeds, the Friesian cattle with 53.65^5.12% and Herman Brown with 57.33-1.82%. Contrary to the previous results obtained, Table ft.9 shows that addition of concentrate to the ration of the exotic breeds particularly the Herman drown tended to decrease the CF digestibility. The higher the inclusion of concentrate In the diet, the lower the CF riigestibi1ity coefficient. There were significant differences in the crude fibre digestibility of the concentrate alone among the breeds and between the steers and lactating cows (P< 0.05). (f) IMitroqen-free extractives (MFE) digestibility Mean apparent coefficient of digestibility of the grass alone, the grass and the concentrate and the concentrate alone were fairly high and followed similar patterns as those of the DM digestibility. Statistical analysis showed that there k were no differences between the values obtained for the steers and the lactating cows (P_>0.n5). (g) . Energy digestibility There were no statistical differences (P/^0.05) in the apparent digestibility coefficients of energy between the steers / UNIVERSITY OF IBADAN LIBRARY I - 217 - Table 4.9 *Maan Coefficient of apparent digestibility of grass (Cynodon nlemfuensis) and concentrate ration fed to both the 3teers and lactatlng cows Nutrients W h i t e P u l a n i G e r m a n B r o w n E r i e s i a n Steers Cows Steers Cows Steers Cows b 0 b 0 b c b 0 b 0 b c DM 67.93+3.02 66.89+2.38 66.08+1.27 65.55+1.31 68.74+0.02 67.96i0.44 67.27+0.92 66.51+0.73 68.a+0.07 66.70+1.46 68.63+0 5+2 66.86+0.59 OM 65.53+0.83 a . 97+1.02 67.42+0.63 66.23+1.23 65.87+0.34 65.39+0.35 67.48+1 5+1 66.76+1 .a 65.24+0.10 a . 67+0.45 67.35+3. a 65.67+1.01 CP 65.80+0.57 65.44+0.81 68.45+1.05 67.73+1.13 69.18+1.07 68.86+0.91 70.52+0.72 69.79+0.87 68.23i0.96 67.08+2.00 69.67+0.08 68.68+0.22 EE 68.27+0,68 67.01+0.51 66.19+2.13 a . 57+2.10 68.38+0.96 66.90+0.80 68.55+0.13 63.97+2 .a 61.98+2.a 63.47+0.37 a . 78+2 .07 62 .61 + 1 CP 59.53+0.24 58.66+0.03 60.15+1.42 60.02+1.49 56.45+0.58 55.28+0.02 57.69+1.51 56.15+0.47 a . a + 0.51 53.26+0.70 55.75+1.77 56.13+1.97 NFE 66.63;+0.58 65.80+0.10 65.36+1.74 a . 52+1.56 67.07+0.32 66.55+0.52 70.27+1.61 67.60+1.04 69.06+0.17 67.95+0.43 68.13+0.52 66.74+0.33 E 65.34+0.31 65.38+0.26 65.85+0.69 67.94+2.56 71.75+1.49 69.72+1.48 71.10+3.52 69.24+2.97 77.49+0.69 71.74+2.48 72.00+1.95 68.13+0.52 * Average of two values for steers and mean of four values for cows. b = High level concentrate ration + ad lib forage. DM = Dry matter EE = Ether Extract o = Low level concentrate ration + ad lib forage. Oil = Organic matter NFS = Nitrogen-free extractives CP a Crude protein E = Energy UNIVERSITY OF IBADAN LIBRARY i . i Tabla 4.10 - 218 - C o a f f ld a n t o f Apparent D l< e r t lb l l l t y * o f Concentrate Supplement alone f o r Staara and t a s t a t ln r cow» N utriant* Whi te Fulani German Brown F rie sia n D Staera Cowa Staera Cowa Staara Cowa b 0 b a b 0 b 0 b 0 b 0 OM 75.92+5.79 71.46+0.20 72.40+2.13 69.29+1.17 78.16+0.25 72.84+1.67 76.74+0.70 70.83+0.97 73.88+0.54 72.70+0.59 75.94*0.51 72.39;t0.91 DM 69.16+0.83 68.64+1.34 70.17+0.43 68.36+0.93 69.62+0.46 68.08+0.06 72.35+1.76 70.51+1.45 68.65+0.35 68.12+0.10 69.96+2.62 68.96^0.66 CP 73.04+1.67 73.46+2 .42 73.99+2.13 71.69+1.10 77.42+0.11 76.30+0.56 77.09+2.46 73.43+1.28 75.95+0.78 73.37+3.10 74.01+2.24 70.11+0.43 x s 70.67+1.25 69.11+0.89 70.71+0.67 69.38+0 A 3 73.28+0.70 70.60+1.02 72 .12 + 1.17 67.08+3.59 70.56+0.58 67.76+0.30 71.97+1.56 68.83+0.85 CP 65 J44+0.28 62.03+0.13 65.99+0.90 63.76+1.33 55.62+6.48 57.11+ 3.37 53.63+3.12 56.28+2.3 58.57+0.85 57 A 2 +0.82 60.15+4.03 58.59+2.69 NPK 70.28+0.60 68 .47+1.79 70.16+0.73 68.17+0.37 A . 53+0.50 69.48+0.51 79.05+2.98 72.72+1.70 75.49+3.39 73.57+ 1.17 76.54+2.05 72.76+1 A 2 X 77.94+2.33 76.23+1.98 77.25+0.31 A . 83+1.51 81.55+2.66 79.76+3.50 82.05+2 A 1 77.03+2.82 81.69+0.59 79.49+1 *91 82.70+1.64 78.87+0.56 •Average of two valuea for staara and Man of four Taluaa for oowa. +Xstiaated fron Cramp ton and Lloyd' a (1959) formula. DM a Diy Uattar OH » Organic Hat tar CP - Cruda Pro tain XI - Xthar Kztraot MIX - Nitrogen Proa Sitractlraa X ■ Energy, b a High loyal eoooantrata ration a ad lib forage. a > Loo loyal oonoantrata ration a ad lib forage. | UNIVERSITY OF IBADAN LIBRARY 219 and cows. Very high values were recorded for the digestibility coefficient of the concentrate supplements alone. Digestibility values for the breeds range from 76.66i3.58% (White Fulani) through 80.10^5.29% (German Brown) to 80.88^2.15% (Friesian). There were statistical differences between the values obtained for the indigenous and exotic breeds (P<0.05). Values obtained for the energy digestibility of those animals on high energy level were higher than those on the low energy ones but results were not significant (P> 0.05). it.it.5 Total digestible nutrient (TDIM) (kg/1Q0kq feed) and metabolizable Energy (ME) (MJ/kg feed) Tables it. 11a, b and c show the total digestible nutrient (TDIM) kg/100kg feed and metabolizable Energy (ME) MJ/kg feed intake from grass and the two levels of concentrate supplements for all the breeds. The TDIM values were converted to the NE by using Oagusch and Coop's (1971) value (IkgTDIM = 15.127M0 ME). In all the feeds used, highest values were observed when the animals were fed grass alone. The low energy ration values were slightly lower than the values for the high energy rations. The ME values obtained far the animals fed on the supplemented rations were statistically higher than when they were fed on grass alone UNIVERSITY OF IBADAN LIBRARY r ■ - 220 - Table 4.11a. Total Digestible Nutrient (TDN) an! Metabolizable Energy (ME) intake from grass and concentrate rations fed to White Fulani Steers and lactsting cows Nutrients Steers Cows a b c a b c Digestible Crude Protein (DCP) 5.98+0.06 12.89+0.33 12.97+0.48 5.96+ 0.07 13.06+0.41 12.6 5+ 0 .2 2 Digestible Crude Fibre (DCF) 17 .10 + 0 .0 2 5.90+0.03 5.60+0.02 17.67+0.44 5.95+0.08 5*75^.0.12 Digestible Ether Extract (DEE) o .75j+ o.oi 3.2^ 0.08 3.19 + 0 .0 4 O.59+O.05 3.26+0.03 3.20+0.02 Digestible Nitrogen free- extractives (DNFE) 26.96.+0.18 38.55+ 0.39 3 7 .5 6 + 1 .16 26.46+0.82 38.48+,0.50 3 7.39 + 0 .22 Total Digestible Nutrient (TDN) (kg)/l00 kg feed 50.79+ 0 .23 60.58+0.05 59.32+ 0.63 50.68+0.61 60.75+0 .64 58 .99+ 0.27 •Metabolizable Energy (ME) (MJ/Kg feed) 7.68+ 0.02 9.16^+0.01 8 .9 7+ 0 .10 7.6 7+ 0 .0 9 9 .19 + 0 .10 8.92_+o .o4 a = Grass alone b = High concentrate ration c = Low " " •TDN was converted to ME by using Jagusch and Coop's (1971) value. Ikg TDN = 15.127 MJ ME UNIVERSITY OF IBADAN LIBRARY Table 4.11b - 221 - Total Digestible Nutrient (TON) and Metabolizable Energy (ME) intake from grass and concentrate rations fed to German Brown steers and lactatintr cows Nutrients Steers Cows a b c a b c Digestible Crude Protein (DCP) 6.29*0.03 13.1*7+0.02 13.47+0.11 6.31+0.11 13.61+0.48 12.96+0.25 Digestible Crude Fibre (DCF) 16.52+0.16 5.02+0.14 5.16+0.31 17.19+0.71 4.84+0.28 5.08+0.21 Digestible Ether Extract (DEE) 0.74+0.05 3.76+0.41 3.26+0.05 0.72+0.02 3.33+0.05 3.10_+0.17 Digestible Nitrogen Free Extractives (DNFE) 27.07+0.95 40.88+0.32 38.11+0.33 27.62+0.15 43.36+1.93 39.89+;1.10 Total Digestible Nutrients (TDN) (kg/lOO kg feed) 50.62+0.80 63.32+0.88 60.00̂ 0.09 51.84+0.63 65.14+2.48 61.03+1.24 •Metabolizable Energy (ME) (MJ/kg feed) 7.66+0.12 9.58+0.14 9.08_+0.02 7.84+0.10 9.85+0.33 9.23.+0.19 a = Grass alone b = High concentrate ration c = Low " " • TDN was converted to ME by using Jagusch and Coop's (1971) value IKG TDN = 15.127 MJ ME UNIVERSITY OF IBADAN LIBRARY Table 4.11c 222 Total digestible Nutrient (TDN) and Metabolizable Energy (WE) intake from grass and concentrate rations fed to friesian steers and lac bating cows Nutrients Steers Cows a b c a b c Digestible Crude Protein (DCP) 6.26̂ 0.08 13.^1+0.16 12.83+0.61 6.25+0.04 13.06j+0.44 I2.37jf0.08 Digestible Crude Fibre (DCF) 15.86+0.26 5.29̂ 0.08 5.18+0.07 I5.68jfl.48 5.43jf0.36 5.30jf0.25 Digestible Ether Extract (DEE) 0.68̂ 0.01 3.26_+0.03 3.13+0.02 0.67jf0.02 3.32jf0.07 3.l8_f0.04 Digestible Nitrogen free- extractives (DNFE) 27.52+0.22 41.41+2.19 40.35+0.75 27.35+0.32 4l.98jfl.33 39.9ljfO.92 Total Digestible Nutrient (TDN) (kg/100 kg) feed) 50.32+.0.21 63.37+2.^5 6 i .49j+1.45 49.95jjl.44 63.79jfO.98 60.76jfO.68 ‘Metabolizable Energy (ME) (MJ/kg feed) 7.61^0.03 9.59+0.37 9.30+0.22 7.56+0.22 9.65+0.15 9.19+0.10 a = Grass alone b = High concentrate ration c = Low " " • TDN was converted to ME by using Jagusch and Coop's (1971) value Ikg TDN = 15.127 MJ ME UNIVERSITY OF IBADAN LIBRARY 223 ( P < n.P1). There were however, differences in the ME values between the high and lew energy level (p^n.05). Generally, values obtained for the steers were higher than those for the lactating cm.is but the differences were not, significant (Pj>(l.n5). The wean ME obtained for the Germon Brown cattle (B.87in.37) was only slightly higher than the value for the Friesian (8.82i[].A0). The lowest mean value was recorded for the White Fulani cattle (8.6pin.30MJ/kg feed). Values obtained for the German Brown and Friesian cattle were significantly higher than the White Fulani (P^0.G5). A. A. 6 Protein (Nitrogen) utilization and requirements for milk production Summary of nitrogen utilization data with estimates of biological value (PV), metabolic faecal nitrogen (fIFF-J) and endogenous urinary nitrogen (EIJTI) where necessary are shown in Tables A.13-A.22. Details of the statistical calculations are shown in Appendix BA.2. The dry matter (kgPM/day) consumed both from grass and the supplemented rations by the cows with their metabolic size are shown in Table A.12. Table A.13 shows the summary of faecal—W(g/kgDM consumed) and nitrogen intake (g/day) for the three breeds of lactating cows. The faecal-M was highly correlated with !\l-intake as shown in Table A.1A and illustrated in Fin. A.2. The coeffi­ cient of correlation (r) ranged from 0.73 for the German Brown UNIVERSITY OF IBADAN LIBRARY / • 221#. Table 4.12 Dry Matter (DM) Intake (kg/day) and metabolic size (Nkg0 of three breeds of cows maintained on basal forage and high or low concentrate supplement TREATMENT WHITE FULANI GERMAN BROWN FRIESIAN No. Diy Matter Metabolic Size No. Dry Matter Metabolic Size No. Dry Matter Metabolic Size F 3.60 74.99 4.60 83.88 5.77 93.50 ( HC 467 5.08(1.08) 76.21 69 5.23(2.18) 90.73 92 7.06(2.73) 93.a 1 LC 4.74(0.74) 77.98 4.99(1 .46) 92.08 5.12(1.71) 93.52 j MEAN 5.08+0.77 76.39 5.67+0.89 90.58 5.98+1.60 93.52 F 3.67 76.43 5.86 84.33 4.62 79.05 HC 481 3.98(1.20) 73.96 42 5.62(2.76) 85.27 117 5.02(1.85) 80.24 LC 4.67(0.84) 74.92 5.37(1.33) 87.10 5.65(0.85) 82.60 MEAN 4.79+0.57 75.10 6.98+0*74 85.57 6.00+0.70 80.63 F 4.00 72.35 5.01 79.25 5.62 81.58 i HC 242 4.82(1.a) 73.84 66 4.92(1.34) 78.57 90 6.02(2.51) 82.15 ! LC 4.85(1.15) 76.76 ; . . 5.65(1.00) 80.98 6.86(1.82) a . 55 | ‘ MEAN 5.49+0.76 74.32 5.97+0.49 79.60 7.61+1.00 82.76 F 4.83 79.45 4.84 91.83 4e68 a . 45 HC 167 5.28(1.50) 73.84 57 5.26(2.18) 90.20 127 5.21(1.72) 86.18 LC 6.27(0.72) 80.97 5.a(l.10) 90.99 7.24(0.80) 88.49 MEAN 6.20+0.69 78.09 6.34+0.78 91.00 6.55+0.99 86.37 t = Crass alone HC = High Concentrate level LC a Low Conoentrate level ( ) = figures in parenthesis are dry matter intake from ooncentrate supplements. UNIVERSITY OF IBADAN LIBRARY 225 Table 4.13 Summary of Faecal W(g/kgDM consumed) and N-Intake (g/day) for three breeds of lactating eow3 maintained on basal forage and high or low concentrate supplements TREATMENT WHITE FULANT GERMAN BROWN FRIESIAN | — No. FAECAL-N N-INTAKS No. FAECAL-N N-INTAKE No. FAECAL-N N-INTAKE j F 5.37 80.04 6.49 101.96 5.78 102.14 HC 467 5.94 125.44 69 7.73 184.45 92 8.00 208.56 I LC 5.60 118.28 6.62 135.20 6.32 142.78 j MEAN 5.64+0.29 107.92+24.41 6.95+0.68 140.54+41.50 6.70+1.16 151 .16+53.70 | F 5.69 71.20 5.34 80.04 ‘p «6fy. 80.39 ! HC 481 5.06 106.93 42 7.06 159A5 117 6.44 145.44 LC 5.11 107.64 6.49 141.15 5.54 125.00 MEAN 5.29+0.35 95.26+20.84 6.30+0.88 126.88+41.58 5.87+0.49 116.94+33.25 F 4.35 69 *6o 6.01 87.17 5.61 81.43 HC 242 6.40 135.37 66 6.24 127.69 90 6 Jt.6 144.65 LC 5.71 120.50 5.96 129.71 6.77 151.10 MEAN 5.49+1.04 108.49+34.49 6.07+0.15 114.86+24.00 6.28+0.60 125.73+38.50 F 5.01 84.04 5.47 101.62 5.63 97.79 HC 167 6.57 138.97 57 7.35 159.97 127 7.56 183.56 LC 6.25 131.71 6.02 132.63 7.40 176.51 MEAN 5.94+0.82 118.24+29.84 6.28+0.97 131.42+29.20 6.86̂ 1.07 152 .62+47.61 P = Grass alone HC * High level Concentrate LC = Low level Concentrate UNIVERSITY OF IBADAN LIBRARY 2 2 6 caws to 0.80 far the Friesian cows; the White Fulani cows had a correlation coefficient of 0.78. They were all statis­ tically significant (P<0.01). The intercepts on the ordinate axis gave the nitrogen excreted in faeces when the dietary nitrogen intake was hypothetically zero, that is, the metabolic faecal nitrogen (FIFO). These values (Table 4.14) ranged from 3.06g/kgDM consumed for the Friesian cows through 3.44g/kg DM consumed for the White Fulani cows to 3.82g/kgDM consumed for the Herman Brown cows. These values were taken directly from Fig. 4.2 and are therefore the mean for the respective breeds. Statistical analysis in Appendix 84.2 has shown highly significant differences (P<(0.ni) within the breeds and treatments for the faecal nitrogen (g/day/W^*7^S output. Duncan's multiple range tests showed that there were no signi­ ficant differences (PNkO.05) between the German Brown and White Fulani breeds but both were significantly higher than the values for the Friesian cows (P<0.05). Also animals on high energy ration produced significantly higher faecal -M than those on low energy ration (P^0.01). The summary of urinary-N (g/day/W^*7^S and absorbed -N(g/dayAl^'7'’ ) for the three breeds are shown in Table 4.15. The urinary -H was highly correlated with absorbed nitrogen. The correlation coefficients (r) ranged from 0.76 foi the Friesian cows to 0.79 for the German Brown cows; the White UNIVERSITY OF IBADAN LIBRARY 227 Table U . ' l k Regression Equations Describing the Relationship between Faecal-N (q/kqDM) Y , and [\i-intake (g/day) X for Lactatinq cous in estimating Metabolic Faecal Nitrogen (MFI\1) Breed Regression Equations Correlation Standard Interest MFN Coefficient Error on Y-axis g/kgPM (r) bJhite Y = 3.if385 + 0.D20X 0.78** 0.18 3 . W 3 .M» Fulani German Y = 3.8170 + 0.0201X 0.73** 0.3*t 3.82 3.82 Broun Friesian Y = 3.0619 + 0.0251X 0.80** 0.19 3.06 3.06 ** Highly significant (P-^ 0.01) / UNIVERSITY OF IBADAN LIBRARY 8 00 7-00 6-00 5-00 4-00 300 o------o White Fulani (WF) Y = 3- 4385 + 0 0 20 0 x 2 00 - x-----x German Brown (GB) Y = 3 • 8170 + 0 0 20 1 x A-----a F ries ian (F) Y= 3- 0619 + 0 0251 x 100 _____I--------------- 1 I .1.. I ,1 I ...... I n - l . . .........- I ..... - t 0 20 00 40-00 60 00 80 00 100 00 120 00 140 00 160 00 180 00 200 00 220 00 Nitrogen intake ( g / d a y ) FIG. 4 2 Relationship between Faccal-N and N-Intake for three breeds of tactating cows. Faecal nitrogen (g/kg DM consumed), UNIVERSITY OF IBADAN LIBRARY 229 Table 4.15 Summary of Urlnary-N ( r / d n and Absorbed-N (r/day/.'.'Sĝ ) for three breeds of lactatlng cows maintained on gra3s -,nd hlrh or low consentrate supplements TREATMENT WHITE FULANI GERMAN BROWN FRIESIAN No URINARY-N ABSOEBSD-N No. UPJNARY-N AB30RBED-N No. ORINARY-N ABS0R3ED-N F 0.35 0.80 0.30 0.80 0.34 0.78 HC 467 0.51 1.12 69 0.53 1.25 92 0.63 1 .39 LC 0.40 1.16 0.33 1 .05 0.30 1.12 MEAN 0.42+0.08 1.03+0.02 0.39+0.13 1.03+0.23 0.42+0.13 1.10+0.31 F 0.27 0.71 0.28 0.58 0.32 0.74 HC 481 0 AO 1.15 42 0.56 1.24 117 0.51 1.21LC 0.57 1 .12 0.43 1.18 0.30 1.12 MEAN 0.40+0.13 0.99+0.25 0.42+0.14 1.00+0.36 0.38+0.12 1.02+0.25 F 0.29 0.77 0.31 0.77 0.29 0.74 HC 242 0.50 1.22 66 0.45 1.18 90 0.52 1.17 LC 0.40 1.17 0.40 1.16 0.40 1.20 MEAN 0.40+0.11 1.05+0.25 0.39+0.07 1.04+0.23 0.40+0.12 1.04+0.26 F 0.27 0.80 0.35 0.82 0.28 0.84 HC 0.58 1.23 57 0.49 1.22 127 0.62 1.44 LC 0.39 1.15 0.30 1.07 0.50 1.32 MEAN 0.41+0.16 1.06+0.21 0.38+0.10 1.04+0.20 0.47+0.17 1.20+0.32 ; ? = Grass alone HC = High level Concentrate LC = Low level Concentrate UNIVERSITY OF IBADAN LIBRARY 230 Fulani cows had a correlation coefficient of 0.77 (Table <+.16), and the relationships are illustrated in Fig. A.3. They were all statistically dignificant (P^O.01). The intercepts on urinary -N axis gave the urinary -N at zero -N absorption which is the endogenous urinary nitrogen (EUN) in g/day/W^*7"5̂ . These values varied from 0.017 for the White Fulani, through 0.033 for the German Brcwn, to D.CUt2g/ day/wFK'y*7'5̂ for the Friesian lactating cows (Table ^.16). Statistical analysis has also shown that there were no signi­ ficant differences in the urinary-N of the three breeds of lactating cows (P>0.05) but differences occurred in the dietary levels. Animals on high-energy ration produced significantly higher urinary than those on the low-energy feed and on the grass intake alone (P0.05) among the breeds. However, there were significant differences among the levels of feed intake with the high energy ration being statistically higher than low energy ration and the grass forage alone (P^0.01). Substituting for the results already obtained for MFN (Table A.1A), ELIO (Table A. 16) both expressed in g/day/Wk?g’7^ , and GV (Table A.18), Table A.21 shows the factorial equation culminating in the digestible crude protein (DCP) (g/day/wkPg’7^ ) requirement for maintenance. Calculated DCP requirement (q/day1 /Wkpn*7 ̂) was 0.39 for the White Fulani; 0.A7 for the UNIVERSITY OF IBADAN LIBRARY FIG. U 5 Relationship between N-Balance and N- ̂Intake for three breeds of lactating cows. Nitrogen balance (g/day/W UNIVERSITY OF IBADAN LIBRARY Reman Ornwn and 0.52 fnr the Friesian lactation cows, '/slues ranging from 91.52 for the White Fulnni ,113.28 fnr the Cprmnn Rrni'jn tn 121.77g/day available protein far the Friesian cows were obtained when the above OOP requirements were converted tn available protein using the cnversinn factrr reenmmended by ARC (1985). Tn Tahle A.22, the OOP requirement fnr maintenance and milk production was given using the results ohtained from fin. A.5. OOP requirement for maintenance and production mas 6.69 fnr the White Fulani, 6.3A for the F1erman Proton and G.SAn/day/W^^'’̂ for the Friesian lactati.no cows. These values were obtained by multiplying with 8.25 the nitrogen intake at maximum IM-balance (g/day/W, * ) having previously corrected these values with their respective mean digestion coefficients. These values were summarised in Table A.22. Available protein for lactation White Fulani cows producing an average of 3.35kg/ day milk was 3nA.flGq/day. The ARC (1985) estimate was 272.1/'g/doy showing that enough protein was available for the White Fulani cows for milk production. 353.93g/day protein were available for the Herman Broun cows producing an average of 8.17kg milk yield per day. The ARC (1965) UNIVERSITY OF IBADAN LIBRARY Table 1*.21 ^ ” ESTIMATION OF DIGESTIBLE CRUDE PROTEIN (DCP) REQUIREMENT FOR THREE BREEDS OF LACTATING COWS FOR MAINTENANCE BY FACTORIAL EQUATION ENDOGENOUS METABOLIC CALCULATED URINARY FAECAL BIOLOGICAL DCP REQUIREMENT BREED NITROGEN NITROGEN VALUE G/day/W g 73** G/DAY/W°^73if G/DAY/u£*732f WHITS FULANI 0.017 0 .0 5 2 60 0 .3 9 GERMAN BROWN 0.033 0.01*8 66 0.1*7 FRIES­ IAN 0.0l*2 0.01*9 61* 0 .5 2 DCP (G/DAY/W^73*1) FOR MAINTENANCE = 6.25 /"(BUN X ) + MFN (Akinsoyinu, EUN = Endogenous Urinary Nitrogen (g/day/W0^.7 3^- ) "197*0 MFN = Metabolic Faecal Nitrogen (g/day/W^73**) BV Biological Value / UNIVERSITY OF IBADAN LIBRARY - 243 - Table V.22 Estimated DCP requirement for maintenance and maintenance with milk production from relationship between N-balance (g/&ay/fffc,̂ "'̂ ‘r) and N-Intake (g/day/.Y]e,gQ* ^ f) for the three breeds of lactating cows H-intake at Zero- Mean Digest­ DCP intake for N-intake at maxi­ balance g/day/tt£*734 DCP requirement •Available Recommended Breed ion Coeffic­ for maintenance mum N-balance for maintenance Protein available pro. ient % g/day/^l731*- g/day/.vgg734 and milk produc­ g/day tein ARC (1965) tion g/dayAkg734 g/day WHITS FULANI 0.22>3 66.83 0.93 1.60 6.69 304.801 272.141 German Brosm 0.0930 69.50 0.55 1 Jf6 6.34 353.932 337.292 FRIESIAN 0.2592 68.84 1.12 1.52 6.54 359.203 387.043 1 Milk yield = 3.35 kg/day BAP = gi- 6.25 (E + G) (Roy, 1970) 2 Milk yield = 6.1? " Where Hax* = Requirement of available protein 3 Milk yield = 7.08 " BV = 3iological value (as a coefficient) S = Endogenous urinary N(g/day) G =t N retention (g/day) l UNIVERSITY OF IBADAN LIBRARY - 2kh - recommended 337.29g/day. This also shows that enough protein was made available to the German Brown lactating cows. Available protein intake of the Friesian cows was 359.2Pn/day while producing an average of 7.nBkg milk yield per day. 3B7.nf+g/day available protein was recommended by the A7G (1965) for cows producing this amount of milk. Table A.23 shows the calculation of the efficiency of protein utilization for milk production for the three breeds of cattle. The Friesian lactating cows had the highest oercentage of net efficiency of protein'utilization (53.73?'-) while the German Brown cows had A8.A3%. The White Fulani cows had the least net efficiency of protein utilization (27.95%). Energy utilization A summary of the total dry matter intake of the animals and their metabolic weights are shown in Table A.12. A summary of the data on energy utilization by the three breeds of lactating cows are shown in Tahle b.2k while tiie detailed results are shown in Appendix CA.5. Both Tahle U.?J\ and Appendix GA.5 clearly show the gross energy (MJ/day), its partition on the body, utilization and the efficiency of utilization. Average gross energy intake of the White Fulani cows was 96.71^6.06 f 19/day while the ME UNIVERSITY OF IBADAN LIBRARY - 245 - Table 4.23 Efficiency of protein utilization for milk production for three breeds of cattle maintained on grass and loui or high concentrate supplementa Breeds Variable description Unit I'JF GO F Digestible Crude protein intake (DCP)(g/day) 529.1B 836.17 655.58 Digestible Crude protE.:n for " " 131.38 218.55 224.27 maintenance Total protein " " 111.20 203.24 231.75 secreted in milk ♦Net efficiency of % 27.95 48.43 53.73 utilization hJF = Uhite Fulani GB = German Broun F = Friesian * * = Protein yield in milk DCP intake - DCP for maintenance UNIVERSITY OF IBADAN LIBRARY intake was 43.79^5.22M3/day. This indicates that only 45.27% of the cross energy intake was metabolized. There was considerable loss of weight in all animals during the beginning of the experiment (early part of lactation) particularly when grass alone was fed and increasing high milk yield was produced. Towards the end of the experiment when low energy level was fed and there was increase in feed intake the animals gained weight. This recovery from weinht loss occurred in most of the animals when high energy was fed. fin the average, the White Fulani cows gained 0.25kn/riay liveweight. The Herman drown cows consumed 123.2kiit.9fl f 11/day and metabolized 52.35^3.48 MJ/riay indicating that ahoi.it 1+2.48;' nf the nross enery intake of the German Grown cows was metabolized. There was also body weight loss during early lactation and the animals lost an average of G.G5kg/day at the end of the experiment. The Friesian cows consumed an average of 123.19^9.18 MJ/day (gross energy). Their averane MF was 54.68^7.98 M3/day and only 44.37% of the gross enemy intake was in fact metabolized. Table 4.24 shows the summary of the ME intake (M3/day), liveweight changes (kn/day), milk yield (kg/day) and milk energy (M3/day) of the three breeds nf lactating cows. Comparative results of ME intake calculated from TON intake and the conventional method UNIVERSITY OF IBADAN LIBRARY 247 Table 4.24 Summary of Metabolizable Energy, Liveweight Change, Milk Yield and Energy of the three breeds of lacta.t-ing cows maintained on grass and low or high concentrate supplements in the declining phase of lactation Treat­ No. of Dry Matter Metabolizable ME Liveweight Milk Yield ; Milk Energy Breed ment Cows Intake (kg/Day) Energy (ME) (MJ/kgDM) Changes (kg/Day) (MJ/Day)(MJ/Day) (kg/Day) F 4 4.03 22.33 5.55 -0 . 6 1 3.53 4.76 White Fulani HC 4 6 .14 48.89 7.96 +0 . 0 2 3-25 4.39 LC 4 6 . 0 0 60.15 10.03 +0.53 3.29 4.30 Mean 4 5.39+0.68 43.79+6.69 7.85+1.30 -0 .0 2+0 . 2 6 3.36+0.09 if .if 8+0 . 1 if F 4 5 . 0 8 39.47 7.77 -0 . 8 1 6.82 7.50 German HC . 4 7.37 6 0 .09 8.15 +0.04 6.13 6 A 3 Brown LC 4 6 . 6 4 57.49 8 . 6 6 +0.54 5.58 6 . 1 6 Mean 4 6 .3 6+0 . 6 8 52.35+6.49 8 .1 9+0 . 2 6 -0.08+0.41 6.18+0.36 6.70+0.41 F 4 5.17 19.82 3.85 -0.98 7.50 8 . 1 2 Friesian HC 4 8.03 67.83 8.45 +0.30 6-95 . 7.22 LC 4 7.51 76.33 1 0 . 1 6 +0 . 6 2 6 . 8 0 6.95 Mean 4 6.90+0.88 54.66+17.61 7.48+1.89 -0 .0 2+0 . 5 6 7.08+0.22 7.43+0.35 F = Grass alone HC = High Concentrate + ad lib grass intake LC = Low Concentrate + ad lib grass intake. v UNIVERSITY OF IBADAN LIBRARY are shown in Appendix CA.6. ME intake From TON results are slightly higher than the conventional method in the case of the exotic breeds. The reverse is the case with the White Fulani breed. Table h.?.5 shows the summary of the regression equations describing the relationship between ME (fl.VdayAh*^J and liveweight changes (kg/day) for the three breeds of lactating cows. This relationship is depicted in Fig. if.6. There was a highly significant (P<,0.01) correlation between ME intake (MO/day/wjj0* 7 " j, and liveweight change - (kn/riay) for the three breeds. The correlation (r) ranged from D.81 for the German Prawn through 0.85 for the White Fulani to D. % for the Friesian lactating cows. The ME values at the point of zero liveweight change gave the ME (MJ/day/ Idk,'g“ ) reo■ uired daily5 for maintenance. The estimates so obtained ranned from 0.53 for the Mhite Fulam cows through O.nn frT the German Grown con’s to 0.61 Ml/da v1 /w. 0 k o* I'' M for the Friesian cows. The cross efficiency for rnilk production, which is the energy in milk divided by the energy intake without correction far maintenance expressed on percentage basis, was estimated by using the pooled means of the ME (Ml/day) intake for each breed and the energy of the milk produced (MG/day). The pff'r'pncy of cross energy utilization (Table *u26) for milk UNIVERSITY OF IBADAN LIBRARY I ,1- Table 4.25 - 249 - SUMMARY OF REGRESSION EQUATIONS DESCRIBING THE RELATIONSHIP BETWEEN METABOLIZABLE ENERGY (KJ/day/W°"75,!t) AND LIVEWEIGHT CHANGES (kg/day) OF LACTATING COWS REGRESSION CORRELATION STANDARD INTERCEPT ON ME REQUIREMENTS BREED EQUATIONS COEFFICIENT(r) ERROR (SE) Y-AXIS (a) FOR MAINTENANCE MU/day/W^73** WHITE FULANI Y = 0.5328 + 0.4216X 0.85’* 0.01345 0.5328 0.5328 GERMAN BROWN Y = 0.5894 + 0.1531X 0.81** 0.03546 0.5894 0.5894 FRIESIAN Y = 0.6103 + 0.3704X 0.9V* 0.01392 0.6103 0.6103 Significant (P{ 0.01) UNIVERSITY OF IBADAN LIBRARY 1 -2 - f ____I________I________I_______ I________I________________ I________I----- ---------- 1— 1-0 0 8 0 - 6 0 -4 0 -2 0 0-2 0-4 0 -6 0 -8 Liveweight changes (kg /d a y ) FIG. 4 6 Relationship between Metabolizable Energy (mj / day/W ^fgi 71A) and liveweight change ( k g / d a y ) of lactating cows.. Metabolizable energy ( m j / d a y / W ^ UNIVERSITY OF IBADAN LIBRARY < X c - 251 - Table 4*.26 ♦♦Efficiency of energy utilization for milk production Breeds Variable description Unit WF GB F ME intake MU/day 4*3.793 52.351 54*.658 ME for maintenance n 26.196 30.971 33.777 ME available for H 17.597 21.380 20.881 production ♦Energy secreted in w 4*.A82 6.694* 7.831 milk Gross Energetic % 10.234* 12.787 14*. 327 Efficiency (a) Net Energetic % 25.4*70 31.310 37.503 Efficiency (b) UF = White Fulani GB = German Broun F = Friesian ME = Metabolizable energy (a) = Milk energy (M3 ME/day) ME Intake (MU/day) (b) = __________ Milk energy_________ ME Intake - ME for maintenance ♦ME adjusted to mean milk production by multiplying by 1.1G2 Meal ME/kg h% FCM1 (Neville, 1974*). Fat corrected milk (FCM) was computed by using Gaine's (1928) formula *♦ Detailed results available in Appendix C4*.5. UNIVERSITY OF IBAD N LIBRARY - ?52 - nrnductinn canoed from 10.23/? (is°rt study her nine indicator) that the highest production of I'FA's was obtained when the animal was fed h’nher level of concentrate ration and least production when pT-nss alone mas fed. This observation would appear to be in agreement with the conclusion of Carroll and Hungate (195*0 that, the grain-fed animals shnwed the highest rate of produc- tinn of volatile acids, while the hay-fed ones were inter- modi ate opd the animals fed on pasture forage showed the lowest rate of production. Results obtained from the present study have shown that there was an increase in the acetic acid proportion of the total UFA'S with the corresponding increase in the butterfat content of the cows' milk and that there was also an increase in the proportion of the propionic acid in the rumen with the corresponding increase in milk protein. It has been shown by Maynard and Loosli (1969) that any ration which caused a marked lowering of the milk fat percentage would produce changes in the movements of the reticulo-rumen and in the physical and chemical composition of the digests. In such a case they pointed out that the production of acetic acid would thus be lowered and that of propionic acid would be UNIVERSITY OF IBADAN LIBRARY 257 increased and these chances were associated with the lowering of the fat content of milk. Investigations of Armstrong and Olaxter (1957) and Blaxter (1967) have revealed that while acetic and butyric acids were lypogenic, propionic acid was glucogenic and had protein-sparing effect. This therefore explains why the cows in the present study produced the highest milk protein percentage and the lowest butterfat content while on high concentrate rations. The pit value obtained one hour after feeding was higher than the value 2 hours after. Results also would appear to indicate that pH varied directly with the molar proportions of acetate and inversely with the proportions of the pro­ pionate. Mba and Olatunji (1971) observed that peak production of total 'IFA was observed one hour after feeding and the ruminal pH tended to vary directly with the molar proportions of acetic acid and also tended to be lower the higher the molar proportions of propionic and butyric acids. The results in the present study were in good agreement with this observation and that of Haleb (1958) who showed that feeding high concentrate rations to ruminants resulted in a marked reduction in salivary secretion with subsequent lowering of pH in the rumen. McDonald (1952), Mba, Awonivi and Pyenuga (1972) have demonstrated that high Bnergy substrate favoured the lowering of ruminal pH which delayed the UNIVERSITY OF IBADAN LIBRARY 25Q absorption of ammonia through the rumen wall. The ammonia eventually became available for the synthesis of microbial protein. There is abundant evidence in the literature to she.-.' that the end—products of readily availahle carbohydrates lower thp T'lninai pH (Helenco, 19SA; McDonald, 1 opp). Hhpn tiip low concentrate ration mas fed, milk production in the Fistidated com mas depressed and there was only a slight inorensp in the milk protein percentage above that obtained when grass alone mas fed. There was hnmever increased body meinht both in the fistulated com and intact ones fed the same diet, suggesting a change to a fattening metabolism mith hody fat synthesis increasing at the expense of milk fat synthesis. Schultz (197*0 explained that when an alteration like this occurs, there is a decrease in the proportion of acetic acid and an increase in the proportion of propionic acid. This may result in the enhanced circulation of the acetate in the blood and the subsequent uptake by the mammary gland being reduced. The high propionate tends to cause small increases in blnori glucose which may increase insulin secretion and stimulate hody fat synthesis (Schultz, 197ft). Results in the present study have shown conclusively that-the higher the energy intake, the higher the total ruminal UFA and therefore the higher the total UFA in blood UNIVERSITY OF IBADAN LIBRARY 259 plasma and urea-N in the venous blood. Explaining the reason why high energy intake was accompanied by increased milk yield, Rook and Line (1961) have demonstrated that an increase in the plane nf nutrition was associated with increase in the amount nf milk precausors getting into the mammary gland. Rook and Line (1961), and later on Sutton and Johnson (1969) reported significant increases in the UFA level in the arterial blood and nfO^aminn nitrogen in the venous blood as the dietary enprny intake was increased. Mba and Glatunji (-1971) have shown that rations high in crude fibre increases the acetic acid prnpnrtion of the UFA with a corresponding lowering of the molar proportion of propionic acid while the ruminal pH values were also increased. These observations were recorded in the present experiment when the animals were fed grass alone. Investigations nf Elliot and Loosli (1959) have indicated that when the molar proportion of acetic acid in the rumen liquor ranges from 5f!-6f]% the efficiency nf conversion of ME to milk was fairly cnnstant at 70% but the molar proportions of acetic acid outside this range would tend to lower the efficiency. Perhaps this might explain why the fistulated cow in the present study produced more milk when it was supplemented with concentrates than when fed on the forage alone. UNIVERSITY OF IBADAN LIBRARY 260 T'rp. mil!' composition nf the intact cows fed the same dietary levels also followed the same nattem as the fistulated cow. The level of - 0 concentration in the rumen depends on sn many factors. These include the nature and level of dietary protein,availability of readily fermentable car- bahydrate^, the acidity nf the rumen lipunr, and the rate nf fementat’on and absorption frnm the rumen. When ^r^ss was supplemented with different levels o^ concentrate ration in the present study, ruminal emmnnia conrentration increased. This is in agreement with the results nf Elliot and Topps (19610 who found that ruminal IMĤ -P concentration increased with increasing dietary nitrogen intake and percentage crude protein in the ratines. The increase in ruminal fJĤ -P concentration recorded when grass was supplemented with concentrate ration was also observed in the case nf blood urea nitrogen and this is in agreement with the results of Lewis (1957) who found that changes in ruminal ammonia concentration resulted in similar changes in the hlond urea level. Increase in the concentra­ tion of blond urea was observed to increase with increasing intake of dietary protein and also percentage crude protein in ration. Preston et aj_ (1965) suggested that blood urea-P levels could be used to assess protein utilization • From their results,they showed that blood urea-P in excess of 1Dmn/inriml blood plasma would indicate adequate protein UNIVERSITY OF IBADAN LIBRARY 261 intake in their ration. Results obtained from the ruminal and blood metabolites in the fistulated com tended to indicate that adequate protein intake was made available to the intact lactation cows in their rations. The milk yield of the intact >lactating cnuis used for the digestibility, energy ond protein utilization studies declined from the start of the experiment despite the intro­ duction of high concentrate rations. It could be due to the fact that the experiment was started at the receding stages nf lactation in which case the effect of lactation seemed to have had more overiding effects than the feed intake (Lucas, 1960). However this lowered milk yield was compensated fnr by the increase in liveweight. This alteration as explained inter alia in the case of the fistu­ lated White Fulani cow could be due to the decrease in the proportion of acetic acid, increased molar proportion of propionate, giving rise to reduced acetate uptake by the mammary gland, and the consequent high propionate tending to cause increases in blood glucose which with increasing insulin secretion could stimulate body fat synthesis. This could then explain the decreasing milk yield and increasing liveweight as lactation advanced as observed in the present study. The results of the milk composition obtained in the present experiment have also shown that the higher the butter- UNIVERSITY OF IBADAN LIBRARY 262 fat percentage the higher the milk energy and were in line with the conclusion of de Uleechauuer (1959) that the energy content of milk had a positive relationship with the butterfat. Except for the crude fibre values, the digestibility coefficients of the other nutrients in tbs basal forage and the ei inpi ompnted rati non fed to the cams and steers Showed no statistical differences. This would indicate that the modified capos used to separate the faeces and urine of the lantatinn animals were as good as those conventional ones incorporating the use of harnesses and collection bags with the steers (Hyenuga, 1961). The use of these modified cages would np a long way to facilitating balance studies of nutrients in female animals particularly the dairy cows as hitherto it has been a problem to harness female animals although such capes have successfully been used in balance studies with goats (Akinsoyinu, lq7t). niaxtor and Mtche.ll (19A0) defined metabolic faecal nitrogen OFF!) as that portion of faecal nitrogen which is not of dietary origin taut originating within the body from a variety of sources, such as epithelial cells, bacteria, mucus, residues from bile and digestive juices. The MFIM values obtained in the present study 3.kk for h!F, 3.B2 far GB and 3.n6o/kgPM consumed for F were lower than 5.5g/knDM UNIVERSITY OF IBADAN LIBRARY consumed recorded for ewes by Harris and Mitchell (19A1), A.Og/kg DM consumed for rams by Deif, El-Shazley and Abcu Akkada (1968), 5.0g/kgDM consumed often quoted for ruminants by ARM (1965) and Maynard and Lnosli (.1969), and A.3g/kg DM consumed for does by Akinsoyinu (197A); but these i/albes were higher than 2.Ag/kg DM consumed often quoted for lambs by Ellis, Garner, Muhrer and Pfander (1956). Maynard and Loosli (1969) defined endogenous urinary nitrogen (EMM) as the minimum urinary excretion on a nitrogen- free energy-adequate diet. Wide variations or differences in the values obtained for EUN of ruminants have been reported in literature. For .instance while in the present study values varying from F1.G17 (White Fulani) through 0.933 (German Rrown) to n.0A2g/day/W^ (Friesian) have been obtained, Robinson and Forhps (1966) also using a regression equation obtained a negative figure of -1.81-0.50gf,!/day for ewes, Sotola (1930) had a figure of 0 . 0 8 g / d,0 .!a 19 .8 6 6 . Hohenboken et al (19 7 2) Hereford 13 .0 0 7. Ogunsiji (1974) White Fulani 10.69 2 2.3 0(e/' 20.25 8. Neville Jr. (1974) Hereford 15*30(f) 33.60 '«■ White Fulani 10.23 25.47 27.95 Present German study (f) Brown 12.79 31.31 48.43 Friesian j 14.33 37.50 53.73 ---------------1 (a) Assuming maintenance requirement of 0.548 MJ HE///0.734kg (b) = Two types of rations used (c) = Ratio of the protein secreted in milk to the digestible protein intake (d) = Cows supplemented and non-supplemented at pasture (e) = Maintenance requirements based on A3?C (19 6 5) standard (f) = Maintenance requirements calculated using regression analyses with zero order correlation coefficient Not determined UNIVERSITY OF IBADAN LIBRARY 260 breed with a fairly low available protein when compared with the ARC (1965), adequate protein intake was made available to the lactating cows in the present study as shown from the above results and conclusions from the fistulated White Fulani lactating cow. The net efficiency of protein utilization for the cows ranged from 27.95% for the White Fulani breed through A3.A3% for the German Brown to 53.73% for the Friesian cows. The efficiency with which the indigenous White Fulani cows in the present study utilized feed protein for milk production was lower than the values reported for the high producing temperate breeds (Berman Brown and Friesian) of dairy catfe (Table A.29). However, the net efficiency obtained for the White Fulani breed in this investigation was much higher than 19.06% obtained by Olalnku (1972) and 20.25% hy Onunsiji (197*0. Reasons for the differences mew hp due to the composition nod amount of feed intake end the techniques of col lectins the faecal nn jn the different invegtinations. The net efficiency of protein utilization obtained for the exotic cows were within the range obtained hy other workers. For instance, Hashizume at. al (lR6g) working with Holstein cows had a value of 55% and Aumnh, Paul.ton and Apgar (1965) had a value of 66.k% for thn Friesian cows. UNIVERSITY OF IBADAN LIBRARY 269 The relationship between metabolizable energy (ME) intake anrl li.veweight change for the Instating cows was obtained in the present study. When the cows were neither gaining nor loosing weight, the White Fulani cows required 5 ?̂.nnii.T/day■/!',lkir'g*^^ when a diet with a concentratinn of 87P2.72!i,T/kg DM (E.flBlcal/kg) was being fed. ARC (1965) and I1AFF M.975) recommend 640.87K3/day/w!k g and 737.008,1/ dav' A 1̂k*g^ ~‘ly resn' ectivelyJ .7 when an animal is nn similar intake and production. This simply indicates that in a tropical environment when a White Fulani cow should maintain its body temperature by dissipating energy and not using some of its energy to produce heat, it would require B3.14% and 72.29% of the ARC (.1965) and MAFF (1975) recommendation respectively. The present investigation has revealed that the Rerman Brown cows required 589.A0KC/day/M^'^'^ while ARC (1965) and MAFF (1975) recommend 704.50 and 810.130/ day/ll^’/ respectively indicating that 83.66% (ARC, 1965) or 72.75% (MAFF, 1975) of the recommendations was needed hy the Berman Brown cnws. The Friesian cows required 610.30 I'vl/day/Ŵ * /jl> which is 84.45% of the 722.68K.Vday/ljjj^’̂ f+ recommended by ARC (1965) or 73.43% of the 831,0310/day/ ,,0.734 kg recommended by MAFF (1975). The values also obtained in the present study are lower than 92000/day/W,’’ obtained UNIVERSITY OF IBADAN LIBRARY - 270 - by NRC (I960), 766.63l1J/dayA)^'7j ̂by Neville and McCullough (1969) and 728.0n/1,]/dayAJ7*73ft by Neville Or. ( 1 9 1 k ) . Apart from the environmental climate which has a pronounced effect nn energy requirement, Neville and McCullough (1969) have also observed that actual energy requirements for main­ tenance and production were individualistic and subject to changes from time to time and place to place within cows. The gross energetic efficiency of milk production of 10.23?' calculated for the White Fulani cows (Table A.29) compared well with 10.69?$ obtained by Ogunsiji (1976) but lower than 12.06?5 obtained by Olaloku (1972) for the same breed of cattle. The low percentage of gross energetic efficiency of milk production obtained for the exotic breeds in.the present investigation were comparable to the values of 16.6?' obtained by Brody (1965) with Jersey cows; 13.D0?£ by Hnhenbnken, Hauser, Chapman and Cundiff (1972) with Hereford cows and 15.30?' by Mevill Jr. (197ft) also with ’Hereford cows. The net energetic efficiency for milk production obtained in the present study varied from 25.67?4 (HF)., through 31.315', (00) to 37.50?< (F). The 25.67?', obtained for the MF cows were higher but compared favourably with 20.31?', obtained by Olaloku (1972) and 22.30% by Ogunsiji (1976). The values also obtained for the exotic breeds UNIVERSITY OF IBADAN LIBRARY 271 compared well with the 33.6H% recorded by Deville Jr. 0.97*0. '’coven, Miller and Plowman (1968) found that variations m Feed efficiency depended more on milk yield than on feed consumed. Denuirements of dioestihle protein energy to digestible enemy (PPF : PE) ratio estimated from the repression ociatinn h"j o, lottinu-■ D-balanre (o/dayAlkPp’̂ 4) against DPE : DE ratio were P.D83 (|,,r), n. 112 (99) and 0.103 (c). This indicates that 8.3% of the energy intake of the White Fulani cows,. 11.2% of the Merman Drown and 10.3% of the Friesian cows were contributed by the protein fraction of the DM intake. The values obtained in the present study (with an overall mean value of 9.9% for al1 breeds) were slightly higher than 7.19% obtained for cows by Hegsted (196*+) but much lower than 25%) obtained by Akinsoyinu (197*0 for goats. The variations in the results obtained in literature could be due to the observation of Hegsted (196*+) that values often reported depended very much on a combined estimate of tine needs of the tissues which varied from one animal to the other and the capacity of the diets to provide these needs. In summary, the results obtained in these trials seemed to indicate that: UNIVERSITY OF IBADAN LIBRARY 272 (1) With increase in the level of concentrate supplements in the ration, there mas corresponding increase in milk yield, decrease in butterfat content of milk, increased percentage of milk protein, increase in the amount of total '.FA's in the rumen liquor, a decrease in the ratio of acetic to propionic acid, increased level of ruminal and also a decrease in the ruminal pH values. (2) The metabolic cages modified for use of the lactating cows without harnesses and collection bags are adequate for nitrogen and energy balance studies. (3) The digestible crude protein (DCP) requirement values for maintenance ranged from 0.39 for the White Fulani through 0.ft7 for the German Brown to 0.52g/day/W^*^+ far the Friesian breed. (ft) The digestible crude protein (DCP) requirement for milk production ranged from 6.69g/day/W^*^^ for a White Fulani cnw producing 3.35kg milk/day (3.25% protein) through 6.3hn/day/W^0.73ft for a German Brown cow producing 6.17kg milk/ day (3.03% protein) to Kg for a Friesian cow producing 7.08kg milk/day (3.10% protein). (5) Metabolizable Energy (ME) requirement for maintenance ranged from 532.80 for the White Fulani breed through 589.ft0 for the German Grown breed to 610.30K0/day/jJ^‘̂ for the rriesian breed. UNIVERSITY OF IBADAN LIBRARY 273 (6) H.y's nf the energy intake of the White Fulani, 11.2'' of the Herman Drown and 10.3% of the Friesian cows were contributed by the protein fraction of the DM intake. UNIVERSITY OF IBADAN LIBRARY ?nu GENERAL SUMMARY OF CUrJCLUSIGUS Tnvdstinntinns were carried out (a) tn study suitable system nf manssement for the newly imported exotic dairy nnt.is (German Brown (GG) and Friesian (F))# (b) tn estimate dry matter (HU) intake, liveweight changes, milk yield and composition of indirenous (Uhite Fulani (1 'JF)) and exotic lactoting onws ns affected by seasons and stages nf lactation, and (c) tn determine nutrient digestibilities, protein and energy util’ration by the three breeds of nows as well as liveweight changes, milk yield and composition ns affected by the rumen and blood metabolites particularly of the fistu­ la ted Mbits Fulani con. The results indicated that grazed exotic cows consumed more DM and produced more milk than the stall-fed ones. The milk composition nf the grazed cows including the butterfat, ash, solids-not-fat were higher, and protein lower, than those of the stall-fed ones (P<.0.05). Grazing cows gained weight while stall-fed ones lost weight. The water intake, body temperature and respiratory rate of the grazed corns were higher than the stall-fed ones. The mean roughage DM intakes of the cows, when placed on a 28-week lactation study 5 days after parturition were k.k9ifl.16, 5.59^0.16 and 5.9?io.21kg/day for the UIF, GB and F UNIVERSITY OF IBADAN LIBRARY 275 cows respectively. Peak milk production was attained between the 5th and 9th week of lactation and declined gradually thereafter far those first placed on high energy level and abruptly for the ones first placed on low energy level. Milk yield of the exotic cows were significantly higher than the indigenous ones (P<0.D1) although the latter produced milk of higher quality than the former. Though DM intake was higher during the dry season than the wet, yet milk yield was higher during the latter period than the former. All cows lost weight immediately after calving until about the Oth to the 10th week of lactation and recovered gradually thereafter. The trials on energy and protein utilization indicated that with increase in the level of concentrate supplements in the ration, there was corresponding increase in milk yield, dec­ rease in butterfat content of milk, increased percentage of milk protein, increase in the amount of total UFA'S in the rumen liquor, a decrease in the ratio of acetic to propionic acid, increased level of ruminal rjĤ -N and a decrease in the ruminal pH values and increased blood urea-f\l. The digestible crude protein (DCP) requirement values for maintenance ranged from D.39 for MF, through C1.A7 for HR to P.52g/dayAtJkpg’̂ ^ for the F breed. The DCP requirements for milk production UNIVERSITY OF IBADAN LIBRARY - 279 - ranoed from S.GOq/day/Uk?g*7^ for a UJF cow producing 3.35kg milk/day (3.25% protein) through 6.5^g/day/M^*7'+ for a GB now producing 9.17kg milk/day (3.03% protein) to 6.5^g/ dayA|7*7"7f for a F couj producing 7.G0kg milk/day (3.10% protein). The metabolizable energy (ME) requirements for maintenance ranged from 532.80 for the WF breed through 589. f+Q for the OR to S1O.30RO/day/k!^*7 '̂ for the Friesian breed. Finally, the trials also indicated that the protein fraction of the DM intake contributed 8.3% (IF), 11.2% (OR) and .10.3% (F) to the energy intake at the optima1 level for product-! on « UNIVERSITY OF IBADAN LIBRARY 277 R E F E R E N C E S AbQu Akkada, A.R. and Blackburn, T.H. (1963) Some observations on the nitrogen metabolism of rumen proteolytic bacteria. J. gen. Microbiol. 31 : *t61 Adebanjo, A.K. (1972) The relationship between the crude fibre content of pasture grass and volatile fatty acids of the rumen of White Fulani cow. Ph.D. thesis Ibadan University. Adebowale, E.A. (1972) The effect of breed and stages of lacta­ tion on the fat and fatty acids of cow's milk. Special Research Project Report, Department of Animal Science, Ibadan University. Adegbola, T. (1970) Special Research Project Report, Department of Animal Science, Ibadan University. ----------- (197*0 Digestion and Utilization of protein in the West African Dwarf sheep. Ph.D. thesis. Ibadan University. Ademosun, A.A. (1973) Utilization of poor quality roughages in the derived savanna zone In: Animal Production in the tropics pp. 152 (Ed. Loosli, J.K. Oyenuga, V.A. Babatunde, G.M.) Heinemann Educational Books (Nig.) Ltd., Ibadan. Adeneye, J.A. (1972) Energy and protein requirements of imparted Holstein cows for milk production at Ibadan. Ph.D. thesis Ibadan University. Agricultural Research Council (1965) The nutrient requirements of Farm Livestock No. 2 Ruminant. Technical Reviews and Summaries ARC London. Akinsoyinu, A.O. (197*0 Studies of protein and energy utilization by the West African dwarf goats. Ph.D. Thesis Ibadan University. Alade, S.B. (1973 Personal communications. UNIVERSITY OF IBADAN LIBRARY 278 Annison, D.G. (1965) In : Physiology of Digestion in the Ruminants, p. 272 (R.W. Dougherty, ed.) Washington : Butterworths. Anonymous (1611) In the Holy Bible, Deuteronomy Chap. 6 vs. 3 Am. Bible Society. King James Version, New York. A.O.A.C. (1970) Association of Official Agricultural chemists. Official methods of Analysis, 11th edition- Washington D.C. Armstrong, D.G. (196*+) Evaluation 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. 3. Agric. Sci. 62 : 399 --------------(1963) The amount and physical form of feed and milk sdcretion in the cow. Proc. Nutr. Soc. 27 : 57 — —— — — — — and Blaxter, K.L. (1957) The utilization of acetic, propionic and butyric acids by fattening sheep. Br. 3. Nutr. 11 : *+13 ------------------------- and McC.Graham, N (1957) The heat increments of mixtures of steam - volatile fatty acids in fastino sheep. Ibid. JM : 392 ----------------------- and Waite, R. (196*+) The evaluation of artificially dried grass as a source of energy for sheep iii. The prediction of nutritive value from chemical and biological measurements. 3. Agric. Sci. 62 : *+17 Armstrong, O.G. and Prescott, 3.H.D. (1970) Amount, physical form and composition of feed and milk secretion in the dairy cow page 3*+9 In ; Lactation (3.R. Falconer ed.) Butterworths, London. UNIVERSITY OF IBADAN LIBRARY 279 Arnon, T.p . (1G9AB5.9) Int. Grassld. Congr. VIII, Reading, U.K. Aschaffenburg, R. and Drewry, 3. (1955) Occurence of different beta-lactoglobulins in cow's milk. (Mature 176 : 216. Azih, '.'.A.A. (1963) Variations in the composition nf milk during lactation of 'White Fulani (Bunaji) Zebu cows at Ibadan University. Students Project Report for n.Sc. Ilona. Agric. Ibadan University. Hailey, G.L. (1952) Studies on variation in the solids-not- fat content of milk. II Variations due to stage of lactation. 3. Dairy Res. 19 : 102. Haker, T.A.; Richards, C.R.; Haenlein, G.F.W. and Weaver, H.G. (1960) Factors affecting the consumption of Sudan Grass by dairy cows. 0. Dairy Sci. A3 : 958. Raich, C.C. (1958) Observations on the act of eating in cattle. Hr. 3. JMutr. J_2 : 330. ---- - - --- ; Rroster, W.H.; Rook, J.A.F. and Tuck, V.J. (1965) The effect of growth rate and on milk yield and composition of grinding the hay and cooking (flaking) the maize in mixed diets for growing and for milking heifers. 3. Dairy Res; 32 : 1 — ----- nnd Rowland, S.3. (1957) Volatile fatty acids and lactic acid in the rumen of dairy cows receiving a variety of diets. Hr. 3. Uutr. _11 : 2B0. nnrcrgft, 3., McAnally, R.A. and Phillipson, A.T. (19AA) Absorotion of volatile fatty acids from the alimentary tract of the sheep and other animals. 3 . Exptl. Rial. 20 : 120. Bartlett, A.3.s. and Tawab, G.A. (1957) Rapid method for the determination nf lactose in milk and cheese. 3. Sci. Fdl. Agric. 8 : A37. UNIVERSITY OF IBADAN LIBRARY Rqth, T.1'. nnd nnnk, P.A.F. (1963) The evaluation nf cattle fends and diets in terms nf the ruminal concentration nf volatile fatty nnids. I. The effects nf level intake, frequency nf feeding,the ratio nf hay to concentrates in diet and nf supplementary foods, p, Anrlc. Pci . _61 : 3k 1. Rerrett, n .C. and nison, H.H. (1963) Ad 11hiturn vs. controlled feeding nf concentrates to Instating dairy cows. P. Dairy Pci. k-6 : 622 niancn, M. (1965) Cattle in a hot environment. P. Dairy Res. 32 : 291. Bishop, P.E.; Loosli, P.K.; Trimherger, G.lil. and Turk, H.L. (1963) Effect nf pelleting and varying grain intakes on milk yield and composition. P. Dairy Gci. k6 : 22 Clack, A and Uoris, L. (193k) A statistical study nf the relation­ ship between the constituents of milk. P. Agrip. Res. k8 : 1025. Clack, P.L.; Pearce, C.R. and Tribe, D.E. (1973) Protein require­ ments for erouiing lambs, cr. P. Cutr. 30 : k5. Olaxter, H.L. (1956) Starch equivalent, ration standards and milk production. Proc. Brit. Soc. Anim. Prod. 3 : 1 — - ---------- (196k) Utilization of the metabolizable energy of grass. Proc. Uutr. Soc. 23 : 62 — — - — — --- (1967) The feeding of dairy cows for optimal production. Beorqe Scott Robertson Memorial Lecture, queen's University Belfast Nov. 1966. ---- *— ----- (1967) The energy metabolism of ruminants (revised edition) Hutchinson, London. ----_ --- _____ 0ncl qianperton, P.L. (1965) Prediction of the amount of methane produced by ruminants. Fir. P. I\lutr. 19 : 511. UNIVERSITY OF IBADAN LIBRARY 281 Blaxter, K.L. and Mitchell, H.H. (1%8) The factorization of the protein requirements of ruminants and of the protein values of significance of the metabolic faecal nitrogen. J. flnim. 5ci. 7 : 351. Boyd, L.J. and Mathew, K.C. (1962) Effect of feeding various j hay to concentrate ratios for short periods on milk yield, SNF and protein. J. Dairy Sci. frO : 181 Boynes, B.M. (19<+7) Sudanese cattle as milk producers. Emp. J. Exp. Agric. XU : 27. Brody, S. C 19̂ 5, 196*0 Bioenergetics and growth Reinhold Publ. Co.; New York. Broster, liJ.H. (1963) Control of milk yield by nutrition. N.A.A.5. Quart. Rev. No. 62 : 76. ------------------ (197*0 Response of the dairy cow to level of feeding. Bien. Rev. Natn. Inst. Res. Dairy 197**. ------------------ ; Ridler, B. and Foot, A.S. (1958) Levels of feeding concentrates for dairy heifers before and after calving. Ji.' Dairy Res. 25 : 373. ------------------ and Tuck, U.J. (196*0 Influence of pre- and post calving level of feeding on milk production. Ann. Rep. N.I.R.D. pp. 51. Burt, A.kl.A. (1957) The effect of variations in nutrient intake upon the yield and composition of milk. J. Dairy Res. 2h : 283. Butterworth, M.H. (1961) Concentrate feeding of dairy caws on Pangola grass. Trop. Agric. Trin. 38 : 305. Campbell, I.L. and Flux, D.S. (19*t8) The relationship between level of nutrition during the dry period and subsequent performance of dairy cattle. Proc. Ann. Conf. N.Z. Sac. Anim. Prod, p. 61. Campling, R.C. and Murdoch, J.C. (1966) The effect of concen­ trates on the voluntary intake of roughages by caws. 2* Da^rV Res. 33 : 1. UNIVERSITY OF IBADAN LIBRARY - 23? - Pam-Costao, n end uinconte-Chandlerf 3 (1939) Milk production with all-grass rations from sheep intensively managed tropical pastures. 9. Anric. Univ. P. Rico. _53 : 251. Carrolt , E.3. onH Mnnpate, R.E. (195A) The magnitude of the micrnhial fermentation in the bovine rumen. Ajnpl. Microbiol. 2(A) : 2P5. Rastle, *'• .E. ( 195?) Grassland production and its measurement using the dairy com. 3. Rrit. Grassld. Roc. 8 : 195 — ----------(1.03A) The feeding of supplementary concentrates to dairy corns grazing good pasture. I hid. _19 : 381. ------ ---- — ; Prysdale, A.D. and Haite, R. (1961) The effect of root feeding on the intake and production of dairy cows. 3. Dairy Res. 28 : 67. ----- ------• Drysriale, A.D. and Matson, 3.P. (I960) The effect of feed supplements on the yield and composition of milk from cows grazing good pasture. Ibid. 27 : A19. Chaney, A.L. and Marbach, E.P. (1962) Modified reagents for analysis of urea and ammonia. Clin. Chem. 8 : 130. Cherhuliez, A and Oaudet, 3. (1950) In: Lings A testbook of Dairy Chemistry p. A2 (2nd ed.). Cobble, 3.M. and Herman, M.A. (1951) The influence of environmental temperatures on the composition of milk of the dairy cow. Hqnoqr. agr. exp, stat. Res. Hull : A85. Cochran, '3.0., Autrey, H.M. and Cannon, C.Y. (19A1) A double change-over design for dairy cattle feeding experiments. 3. Dairy 5ci. 2A : 937. UNIVERSITY OF IBADAN LIBRARY 283 Collins, U.R.F., Dema, I and Omalolu, A (1961) On ecology of child health and nutrition in Nigerian villages. I. Environment, population and resources. Trop. Geogr. Med; 14 : 140 Coppock, C.E.; Flatt, U.P. and Moore, L.A. (1964) Effect of hay to grain ratio on utilization of metabolizable energy for milk production by dairy cows. J. Dairy 5ci. 47 : 1330. Coujsert, R.L. and Montgomery, M.J. (1969) Effect of varying forage-to-concentrate ratio of isonitrogenous rations on feed intake by runinants. Ibid. 52 : 6A. Crampton, E.bJ. and Lloyd, L.E. (1959) Fundamentals of Nutrition. Freeman H.U. and Co. San Francisco and London. Crouther, C. and Raistrick, H. (1916) A comparative study of the proteins of the colostrum and milk of the cow and their relations to serum proteins. Biochem. 0. 10 : 434. Czerkauski, J.W. (1967) Effect of storage of the fatty acids of dried rye grass. Br. J. Nutr. 21 : 599. Danielli, J.R. Hitchcock, M.W., Marshall, R.A. and Phillipson, A.J. (19^5) Effect of ruminal pH on absorption of volatile fatty acids. 2* Exptl. Biol. 22 : 75. Dasmann, R.F. (1956) Protein availability in plants. Trans. N. Am. Ltiildl. Conf. 21 ; UB7. Davidson, R.P. (197 )̂ Milking the dairy cows In: American Time Magazine of July 29, 1974, page 31. Davis, J.G. (1959) Milk testing: The laboratory Control of milk, pp. 58 2nd Ed. Dairy Industries, London. Davis, C.L. and Broun, R.E. (1970) Lou fat milk syndrome In: Physiology of digestion and metabolism in the ruminant. A.T. Phillipson ed. Oriel Press Ltd. Neucastle-upon- Tyre, England. UNIVERSITY OF IBADAN LIBRARY - 28k Dcharity, B.A. (1968) Effect of microbial action on carbohy­ drates. flppl. Microbiol. 16 : 781. Deif, H.I.; El-Shazleyp K arid Abou-Akkada, A.R. (1968) The biological evaluation of urea, casein and gluten in the diets of sheep. Br. J. IMutr. 22 j k5'\, Oonefer, E; Lloyd, L.E. and Crompton, E.U. (1962) Effect of varying alfalfa : barley ratios on energy intake by sheep. J. Anim. Sci. 21 : 993. ----------------------------------------------------------- (1963) Effect of varying alfalfa, barley ratios on energy intake and volatile fatty acid production by sheep. Ibid. 22 : kZ5. Duckworth, J.E. and Shirlaui, D.!d. (1958) A study of factors affecting feed intake and the eating behaviour of cattle. Brit. J. Anim. Behav. 6 : 1A7 Duncan, D.B. (1955) Multiple range and multiple F tests. Biometrics 11 : 1 Eckles, C.H. (1951) Dairy cattle and milk production 2nd ed. page 1. ..... . ..... . - and Shaw, R.H. (1913) The influence of the stage of lactation on the composition and properties of milk. Gov. Printing Office, Idashington. —— —— — Elliot, 3.M. and Loosli, J.K. (1959) Relationship of milk production efficiency to the relative proportion of the rumen UFA. J. Dairy Sci. J+2 : 8L3. 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Stanley, R.U.; Morita, K. and Ueyema (156*0 The effect of feeding different roughage levels end sodium acetate in high grain rations on milk production, milk constituents and rumen volatile fatty acids. 3. Dairy Sci. *+7 : 25Q. Stevens, C.E. (1969) In: Physiology of digestion and metabolism in the ruminant p. 101 A.T. Phillipson (ed.) Oriel Press England. Stobo, I.3.F. and Roy, 3.H.B. (1973) The protein requirement of the ruminant calf. k . Nitrogen balance studies on rapidly growing calves given diets of different protein content. Br. 3. IMutr. 30 : 113. Stone, E .3. (1959) Effectiveness of various systems of forage utilization in the south. 3. Dairy Sci. k?. : 635. Stone, 3I.B., Trimberger, G.kl., Henderson, C.R. and Turk, K.L. (1959) Roughage capacity and efficiency of feed utilization in dairy cattle. 3. Dairy Sci. **2 : 915 (Abstr.) UNIVERSITY OF IBADAN LIBRARY 301 Storry, J.E. and Rock, J.A.F. (1962) Effects of large intra- ruminal additions of volatile fatty acids on the secretion of milk constituents. Proc. 16th Intern. Dairy Congr. Copenhagen, Uol. A, p. 64. ----------------------------- (1966) The relationship in the cow between milk fat secretion and the ruminal VFAs. Br. J. Nutr. 20 : 217. Sutton, J.D. (1970) Relation between rumen fermentation and milk fat secretion in cows given low-roughage rations. Proc. rJutr. Soc. 29 (2) : 63A. ------------ and Johnson, U.IlI. (1969) Fermentation in the rumen of cows given feed containing hay and flaked maize or rolled barley in widely different proportions. 0. Aqric. Sci. 73 : 459. -----------McGilliard, A.D. and Jacobson, r j.L . (1963) Functional development of rumen mucosa. I. Absorption ability. J. Dairy Sci. 46 : 426. Todd, J.R. (1956) Investigations into the chemical composition and nutritive value of certain forage plants at medium latitudes in the tropics. I. Seasonal variations in the chemical composition of the grasses. Bothriochloa insculpta; Chloris gavana and Br'achiaria dictyoneura, under rotational light grazing, with a note on the persistence of the grass. J. Agric. Sci. 47 : 29. Topps, J.H. (1962) Studies of natural herbage of the sub-tropics I. The digestibility of herbage grazed by cattle. Ibid. 53 : 387. Tyler, C. (1964) Animal Nutrition (2nd ed.) Chapman and Hall. Tyrell, H.F. and Reid, J.T. (1965) Prediction of the energy value of cow's milk. J. Dairy Sci. 48 : 1215. Uander Noot, G.U., Cordts, R.H. and Hunt, R. (1965) Comparative nutrient digestibility of silages .by cattle and sheep. J. Anim. Sci. 24 : 47. UNIVERSITY OF IBADAN LIBRARY Van Soest, P.3, and Wine, R.H. (1967) Use of detergents in the analysis of fibrous feed IV. Determination of plant cell-wall constituents. £. Ass. Official Agrlc. Chem. 50 : 50. Velu, 3.G., Baker, D.H. and Scott, H.M. (1971) Protein and energy utilization by chicks fed graded levels of a balanced mixture crystalline amino acids. 3. !Mutr. 101 : 12L9. Uaite, R., Oohnson, M.3. and Armstrong, D.G. (196L) The evaluation of artificially dried grass as a source of energy for sheep I. The effect of stage of maturity on the apparent digestibility of rye-grass, cocksfoot and timcthy. 3. Sci. 62 : 391. Wallace, R. (1961) Energy utilization by the New Zealand cows. Proc. N.Z. 5oc. Anim. Prod. 21 : 6L. Wardrcp, I.D. (1961) Preliminary observations on the histological development of the fore-stomach of the lamb, (ii) The effects of diet on the histological development of the lamb during post natal life. 3. Agric. Sci. 57 : 3f+3. Watson, S.3. and Runcie, K.V. (1960) Soiling or zero grazing Qut3ook Agric. 2 : 26L. Webster, C.C. and Wilson, P.N. (1966) Agriculture In the tropics. London, Longmanns Green and Co. Ltd. West, E.S., Todd, W.R., Mason, H.S. and Bruggen, 3.T. (1970) Testbook of Biochemistry p. 771 (Lth ed.) The Macmillan Co. London. Williams, V.3. and Christian, K.R. (1957) Rumen studies in sheep VI The effect of feeding increasing roughage on the ruminal VFA. N.Z..J. Sci. Technol. 36A : i»03. Wilson, D.C. (195L ) Nutrition of schoolgirls in Northern Nigeria. Br. 3. Nutr. 8 : 83. UNIVERSITY OF IBADAN LIBRARY 303 Winchester, C.F. and Morris, M.J. (1958) Water intake rates of cattle. 0. Anlm. Sci. 15 : 722. Woodman, H.E. (19A8) Rations for livestock. Mi'2. Aqric. Fish. Food Bull. A8. UNIVERSITY OF IBADAN LIBRARY . APPENDIX A2.1 Milk fat determination by Garber method, A number of butyrometer tubes were placed in the stand, open end upwards, lOmls of the sulphuric acid (for milk analysis) were run into each, care being taken not to wet the inside of the next neck of the tube. 11mls Df the mixed milk sample were allowed to run from the pipette down the sides of the butyrometer tubes and to float on the surface of the acid. The pipette was inserted in such a way that the milk did not wet the inside of the neck. Dne ml of amyl alcohol was then added. The stoppers were then firmly inser­ ted and the butyrometers were shaken until the curb dissolved. The tubes werethen placed in the water bath at 65DC for 5 minutes ar.d the fat columns adjusted by means of the stoppers to coincide with the scale. The tubes were then rapidly transferred to the centrifuge where they were whirled at 1,100 r.p.m. for 4 minutes and then replaced in the water- bath at 65°C for 5 minutes. The percentages of fat were quickly read off by holding the butyrometers up the light at eye-level where the fat coincide with one of the larger graduations of the scale; the reading was then taken from this point to the bottom of the upper meniscus of the fat column. UNIVERSITY OF IBADAN LIBRARY A2.2 Determination of lactose (Marier and Goulet) 1g of cow's milk was made up to 1 litre 10mls of this solution was pipetted into a 50ml. size volumetric flask followed by 0.5ml of 80% w/v phenol reagent (20ml water + 80g phenol; the reagent is stable for at least 3 months at room temperature). 60mls of cone. H^SO^ were added slowly letting the acid run down the side of the tube. Then it was swirled to obtain good mixing, and let stand for 10 minutes at room temperature, it was cooled and made up to the mark with distilled water and read at A90mm. A blank determination was run. It contained the same quantity of reagent except milk and was made up to the mark with distilled water in a 50ml size volumetric flask. Standard solution (Q.lg lactose in 2 litres of water) was prepared. 2,A,6,8,10mls Df this solution were pipetted separately into individual 50ml volumetric flask and reagents added as for the flask containing the sanple; made up to the mark and read at A90nm. A graph of the optical density was plotted against the lactose concentration (mg). Sample concentrations were estimated by means of this standard curve. UNIVERSITY OF IBADAN LIBRARY APPENDIX B2.1 STATISTI CAL ANALYSIS OF TEE DATA OBTAINED ON THE GRAZES AND STALL-FED LACTATING CQV/S (&) Milk yield (kg/week) P F Source of Variation d.f. S.S. M.S. calculated tabulated 0.05 0.0 1 Diet 1 45.03 45.08 1.56 3.92 6.85 NS Breed 1 44.70 44.70 1.55 3.92 6.85 NS 'Management (/*Jon.') 1 1015.09 1015.09 35.19 3.92 6.85 Die t/B reed 1 2.85 2.85 0 .10 3.92 6.85 MS Diet/Man. 1 81.47 81.47 2.02 3.92 6.85 NS Breed/Man. 1 52.33 52.33 1.81 3.92 6.85 NS 3-Way Interaction 1 16.00 16.00 0.55 3.92 6.85 NS Between Blocks 15 891.94 59.46 2.06 1.6 1 1.79 ❖ fc Residual 105 3028.71 28.84 Total 127 5173.16 * Manageaent: Systems of feeding (Grazing and Stall-feeding). NS = Not Significant = Significant at 1$ level (P^O.01) UNIVERSITY OF IBADAN LIBRARY 0 0 Ash (g/l00g milk) F F Source of Variation d.f. S.S. M.S, calculated tabulated 0.05 0.01 Diet 1 0.00011 0.00011 0.13 3.92 6.85 NS Breed 1 0.01481 0.01481 17.79 3.92 6.85 ' - -Jl1 'Management 1 0.01199 0.01199 14.41 3.92 6.85 * *v ..... Diet/Breed 1 0.00675 0.00675 8.11 3.92 6.85 **l Diet/Man. 1 0.00123 0.00123 1.48 3.92 6.85 NS! Breed/Man. 1 0.04137 0.04137 49.70 3.92 6.85 ti 3-Way Interaction 1 0.00176 0.00176 2.11 3.92 6.85 NS : Between Blocks 15 0.01215 0.00081 0.97 1 .6 1 1.79 N3! Residual 105 0.08740 0.00083 Total 127 0.17756 J NS = Not Significant ** = Significant at \% level (P<0.01) UNIVERSITY OF IBADAN LIBRARY (e) Protein (g/lOQg milk) • • -i P P Source of Variation d.f. S.S. M.S. caloulated tabulated 0.05 0.01 f i!i Diet 1 0.33 0.33 3.33 3.92 6.85 ..,is !i Breed 1 0.38 0.38 3.84 3.92 6.85 r|N3 | ''Management 1 0.77 0.77 7.76 3.92 6.85 ii i! Die t/B reed 1 0.08 0.08 0.78 3.92 6.85 NS | Diet/Man. 1 0.89 0.89 9.03 3.92 6.85 ** ! Breed/Man. 1 1.33 1.33 13.50 3.92 6.85 3-Way Interaction 1 0.15 0.15 1.50 3.92 6.85 NS Between Blocks 13 1.10 0.07 0.74 1 .6 1 1.79 NS j* Residual 105 10.38 0.10 Total 127 15.41 . NS = Not Significant ** = Significant at level (P<0.01) UNIVERSITY OF IBADAN LIBRARY (a) Solids-not-fat (g/lOOg milk) F F Source of Variation d.f. M.S. calculated tabulated 0.05 0.0 1 Diet 1 0.00006 0,00006 0.00 3.92 6.85 NS Breed 1 2,28178 2.28178 6.79 3.79 6.85 * ’Management 1 1.91346 1.91346 5.69 3.92 6.85 Met/Breed 1 0.13585 0.13585 0.40 3.92 6.85 NS Dtet/Man. 1 0.32906 0.32906 0.98 3.92 6.85 NS Breed/ttan, 1 1.65393 1.65393 4.92 3.92 6.85 * 3-Way Interaction 1 0.01926 0.01926 0.06 3.92 6.85 NS Between Blocks 15 7.72958 0.51531 1.53 1.6 1 1.79 NS Residual 105 35.28819 0.33608 Total 127 49.35117 NS = Not Significant ■'* * Significant at 5% level (P<0.05) UNIVERSITY OF IBADAN LIBRARY • CO • CO (9) Total Solids (g/lOQg milk) F F Source of Variation d.f . S.S. M.S. calculated tabulated 0.05 0 .0 1 Diet 1 1.39 1.39 7.99 3.92 6.85 Breed 1 4.87 4.87 28.05 3.92 6 .85 •Management 1 5.43 5.43 31.29 3.92 6.85 ** Diet/Breed 1 0.02 0.02 0.09 3.92 6.85 NS Diet/Man. 1 0.17 0.17 0.99 3.92 6.85 NS Breed/Man. 1 1.59 1.59 9.16 3.92 6.85 3-Way Interaction 1 0.09 0.09 0.51 3.92 6.85 NS Between Blocks 15 4.76 0.32 1.83 1.6 1 1.79 Residual 105 18.23 0.17 Total 127 36.55 NS = Not Significant ♦* = Significant at level (P<0.01) UNIVERSITY OF IBADAN LIBRARY ( f ) Fat (g/lOOg milk) F F Source of Variation d.f. S.S. M.S. calculated tabulated 0.05 0.01 Diet 1 1.52 1.52 6.10 3.92 6.85 * f Breed 1 0.69 0.69 2.76 3.92 6.35 NS j r ' " •Management 1 1.69 1.69 6.80 3.92 6.85 a *! Piet/Breed 1 0.18 0.18 0.74 3.92 6.85 NS | Diet/Man. 1 0.20 0.20 0.79 3.92 6.85 NS i i Breecl/M&n, 1 0.15 0.15 0.61 3.92 6.85 NS = 3-Way Interaction 1 0.0002 0.0C02 0.00 3.92 6.85 NS Between Blocks 15 11.30 0.79 3 .16 1 .6 1 1.79 Residual 105 26.14 0.25 Total 127 42.37 NS = Not Significant = Significant at level (P<0.01^ * = Significant at 5% level (kP<0.05) UNIVERSITY OF IBADAN LIBRARY (s) Dry Matter (DM) Intake (kg/day) P P Source of Variation d.f. S.S. M.S. calculated tabulated 0.05 0.01 Diet 1 22.31 22.31 83.80 3.92 6.85 ** Breed 1 1 .0 6 1 .0 6 3.93 3.92 6.85 a •Management 1 1.75 1.75 6.58 5.92 6.85 $ Die t/8 reed 1 0.03 0.03 0.11 3.92 6.85 NS Diet/Man. 1 3.84 3.84 14.41 3.92 6.85 Breed/Man, 1 4.17 4.17 15.66 3.92 6.85 ** 3-Way Interaction 1 0.89 0.89 3.35 3.92 6.85 NS Between Elock3 15 1.49 0.10 0.37 1 .6 1 1.79 NS Residual 105 27.96 0.27 Total 127 63.50 NS = Not Significant == SSiiggnniiffiiccaanntt aatt 5M7?°a level* level UNIVERSITY OF IBADAN LIBRARY APPENDIX 33.1 Statistical analysis of the data, obtained on the lactation studies with three breeds of cows fed on grass and low or high concentrate (a) Milk yield (kg/week) F F - Source of Variation d.f. S.S. M.S. calculated tabulated 0.05 0.01 Breed 2 13025.28 6512.64 91.47 3.00 4.61 ! Lactation (Lact.) 2 37321 .48 18660.74 262.10 3.00 4.61 t * Diet 1 86.27 86.27 1.21 3.84 6.63 NS I Breed/Lact. 4 2020.04 505.01 7.09 2.37 3.32 ; Breed/Diet 2 456.09 228.05 3.20 3.00 4 .6 1 * ! Lact./Diet 2 220.69 3.10 3.00 4 .6 1 * ]i 3 -Way Interaction 4 2 16 2.8 1 540.70 7.59 2.37 3.32 i Between Blocks 17 115 0 .22 67.66 0.95 1.52 1.79 NS Re sidual 289 20576.22 71.20 Total 323 77239.79 Seasons (wet and dry) effect on milk yield F F Source of Variation d.f. S.S. M.S. calculated tabulated 0.05 0 .0 1 Groups 1 1095.80 1095.80 4.63 3.84 6.63 * . _ . ..... Error 322 76144.20 236.47 Total 323 77240.00 NS = Not Significant (P>0.05) ** = Highly Significant (P^O .01) * = Significant (p^O.OS) UNIVERSITY OF IBADAN LIBRARY rco r* 3 (b) SoIlds-corrected-Mllk (kg/week) F F Source of Variation d.f. s . s . M.S. calculated tabulated 0 .0 5 0 .0 1 Breed 2 6246.36 3123.18 47.35 3.00 4 .6 1 #* Lactation (Lact.) 2 33125.46 16562.73 251.10 3.00 4 .6 1 ** Diet 1 70.20 70.20 1 .0 6 3.84 6 .6 3 NS Breed/Lact. 4 1107.89 276.97 4.20 2.37 3.32 ** Breed/Diet 2 320.23 1 6 0 .1 1 2.43 3.00 4 .61 NS Lact ./Diet 2 397.08 198.54 3.01 3 .0 0 4 .6 1 3-Way Interaction 4 2345.76 586.44 8.89 2.37 3.32 cs Between Blocks 17 1170.14 68.83 1.04 1.52 1.79 NS Residual 289 19062.63 65.96 Total 323 63845.75 Effect of Seasons F F Source of Variation d.f. S.S. M.S. calculated tabulated 0 .0 5 0 .0 1 Groups 1 734.94 734.94 3,77 3.84 6.63 NS Error 322 62758.96 194.90 Total 323 63493.90 NS = Not Significant (P>0.05) ** = Highly Significant (P-CO.Ol) * = Significant (P<.0,05) UNIVERSITY OF IBADAN LIBRARY (o) Fat (g/lOOg milk) ...... .. - .......-• F F Source of Variation d.f. S.S. M.S. calculated tabulated 0 .0 5 0 .0 1 , Breed 2 184.36 92.18 1418.40 3.00 4.61 ** Lactation (Lact.) 2 13.49 7.74 119.14 3.00 4.61 ** i ' il Diet 1 0.38 5.97 5.57 3.84 6.63 * Si Br-eed/Lact. 4 2.08 0.52 7.99 2.37 3.32 ** |ij Breed/Diet 2 0.91 0.25 3.90 3 .0 0 4 .6 1 ♦ | Lact./Diet 2 0.13 0.07 1.02 3.00 4.61 NS I 3-Way Interaction 4 0.13 0.03 0.51 2.37 3.32 NS Between Blocks 17 2 .61 0.15 2 .3 6 1.52 1.79 Residual 189 18.78 0.65 Total 323 224.48 Effect of Seasons F F Source of Variation d.f. S.S. M.S. calculated tabulated 0 .0 5 0 .0 1 Groups 1 3 .1 8 . 3.18 4.63 3.84 6.63 c Error 322 221.47 0.69 Total 323 224.65 -- NS = Not Significant (P>0.05) * * = Highly Significant (P<0.01) * = Significant (?<0.05) UNIVERSITY OF IBADAN LIBRARY (d) Protein (g/100s milk) F P Source of Variation d.f o S.S. M.S. calculated tabulated 0.05 0.01 Breed 2 4 .2 6 2.13 65.37 3.00 4.61 ** Lactation (Lact.) 2 0.83 0.42 12.74 3.00 4.6l ** Diet 1 0.40 0.40 12.40 3.84 6.63 Breed/Lact. 4 0.32 0.08 2.37 3.32 Breed/Diet 2 0.64 0.32 9.77 3.00 4 .6 1 ** Lact./Diet 2 0.19 0.09 2.88 3.00 4.61 NS 3-Way Interaction 4 0.38 0.10 2.93 2.37 3.32 * Between Blocks 17 2.15 0.13 3.87 1.52 1.79 ** Residual 289 9.42 0.03 Total 323 18.58 ___i Effect of Seasons F F Source of Variation d.f. S.S. M.S. calculated tabulated 0.05 0.01 Groups 1 0.79 0.79 14.31 3.84 6.63 Error 322 17.88 0 .0 6 Total 323 18.67 NS = Not Significant (P>«0.05) ** = Highly Significant (P < .0 .9 l) 0 = Significant (p<,0.05) UNIVERSITY OF IBADAN L rv> IB £C"O RARY (e) Lactose (g/l00g milk) F F Source of Variation d.f. S.S. M.S. calculated tabulated 0 .0 5 0 .0 1 I Breed 2 2.80 1.40 2 6 .1 6 3.00 4.61 ** Lactation (Lact.) 2 0.08 0.04 0.80 3.00 4.61 NS j Diet 1 0.08 0.08 1.51 3.84 6 .63 NS Breed/Lact. 4 0.39 0.10 1 .8 0 2.37 3.32 NS Breed/Diet 2 0.09 0.05 0.82 3 .0 0 4 .6 1 NS Lact./Diet 2 0.68 0.34 6 .3 6 3 .0 0 4 .6 1 3-Way Interaction 4 1.65 0.41 7.69 2.37 3.32 t-* Between Blocks 17 1.66 0.10 1.83 1.52 1.79 ** Residual 289 15.48 0.05 Total 323 22.91 Effect of Seasons F F Source of Variation d.f. S.S. M.S. calculated tabulated 0 .0 5 0 .0 1 Groups 1 0.00 0.00 0.00 3.84 6.63 NS Error 322 23.11 0.07 Total 323 23.11 NS = Not Significant (P>0.05) ** = Highly Significant (P-<,0.9l) * = Significant (p<.0.05) UNI ERSITY OF IBADAN LIBRARY (f) Total Solids (g/lOOg milk) F F Source of Variation d.f. S.S. M.S. calculated tabulated 0.05 0.01 Breed 2 48.26 24.13 143.27 3.00 4.61 ** Lactation (Lact.) 2 0.27 0.13 0.80 3.00 4.6l NS Diet 1 2.30 2.30 13.68 3.84 6.63 ** Breed/Lact. 4 0.31 0.08 0.47 2.37 3.32 NS Breed/Diet 2 1.50 0.75 4.45 3.00 4.61 * Lact ./Diet 2 2.76 1.38 8.19 3.00 4 .6 1 ** 3-Way Interaction 4 0.98 0.25 1.45 2.37 3.32 NS Between Blocks 17 12.90 0 .7 6 4.51 1.52 1.79 ** Residual 289 48,68 0.17 Total 323 117.97 Effect of Seasons P P Source of Variation d.f. S.S. M.S. calculated tabulated 0 .0 5 0 .0 1 Groups 1 5.77 5.77 1 6 .5 0 3.84 6.63 ** Error 322 112.50 0.35 Total 323 118.27 NS = Not Significant (P>0.05) ** = Highly Significant (p<0.9l) * = Significant (P^O.05) UNIVERSITY OF IBADAN LIBRARY (g) Solids-not-fat ( s / l0 0 g mi3k) F F Source of Variation d.f. S.S. M.S. calculated tabulated' 0.05 0.01 » Breed 2 62.85 31.42 96.50 3.00 4 .6 1 1! Lactation (Lact.) 2 19 *66 9.83 30.18 3.00 4 .6 1 ** | Diet 1 4.43 4.43 13.61 3.84 6 .6 3 ** Breed/Lact« 4 3.55 0.89 2.72 2.37 3.32 * Breed/Diet 2 1.72 0.86 2.64 3.00 4.61 NS Lact./Diet 2 1.81 0.91 2.78 3.00 4 .6 1 NS 3“Way Interaction 4 0.52 0.13 0.40 2.37 3.32 NS Between Blocks 17 7.22 0.42 1.30 1.52 1.79 NS Residual 289 94.11 0.33 Total 323 195.87 Effect of Seasons F F Source of Variation d.f. S.S. M.S. calculated tabulated 0 .0 5 0 .0 1 Groups 1 0.43 0.43 0.71 3.84 6.63 NS Error 322 195.56 0 .6 1 Total 323 195.99 NS = Not Significant (P>0.05) ** = Highly Significant (p^O.Ol) * = Significant (P<0.05) UNIVERSITY OF IBADAN LIBRARY 0 0 • Ash (g/ 100g milk) F F Source of Variation d.f. S.S. M.S. calculated tabulated 0 .0 5 0 .0 1 Breed 2 0.0118 0.00592 43.54 3.00 4 .6 1 Lactation (Lact.) 2 0.0039 0.00195 14.36 3.00 4 .6 1 ** Diet 1 0.0011 0 .0 0 1 0 7 7.90 3.84 6 .6 3 Breed/Lact. 4 0.0008 0 .0 0 0 1 9 1.43 2.37 3.32 NS Breed/Diet 2 0 .0 0 0 6 0.00029 2.10 3.00 4 .6 1 NS Lact./Diet 2 0.0020 0.00098 7.22 3.00 4 .6 1 & # 3-Way Interaction 4 0.0037 0.00217 15.99 2.37 3.32 ** Between Blocks 17 0.0025 0.00015 1.09 1.52 1.79 NS Re sidual 289 0.0393 0.00014 Total 323 0.0706 Effect of Seasons F F Source of Variation d.f. S.S. M.S. calculated tabulated 0 .0 5 0 .0 1 Groups 1 0.00056 0.00056 2.56 3.84 6.63 NS Error 322 0.07103 0.00022 Total 323 0.07159 NS = Not Significant (P>0.05) ** = Highly Significant (P<0.0-') 0 = Significant (P<0.05) UNIVERSITY OF IBADAN LIBRARY (i) Energy (KJ/ g freeze-dried milk) P P Source of Variation d.f. s.s. M.S. calculated tabulated 0 .0 5 0 .0 1 Breed 2 1 .5 8 0.78 0.45 3.00 4.61 NS Lactation (Lact.) 2 7.08 3.54 2.03 3.00 4.61 NS Diet 1 49.40 49.40 28.37 3.84 6 .6 3 Breed/Lact. 4 5.91 1.48 0.85 2.37 3.32 NS Breed/Diet 2 1.19 0 .6 0 0.34 3.00 4.61 NS Lact./Diet 2 134.88 67.43 38.72 3.00 4 .6 1 ** 3-Way Interaction 4 284.79 71.20 40.88“ 2.37 3.32 s}; Between Blocks 17 43.62 2.57 1.47 1.52 1.79 NS Residual 289 503.27 1.74 Total 323 1031.6 7 Effect of Seasons F F Source of Variation d.f. S.S. M.S. calculated tabulated 0 .0 5 0 .0 1 Groups 1 0.125 0.125 0.04 3.84 6.63 NS Error 322 1031.80 3.204 Total 323 1031.205 NS = Not Significant (P>0.05) ** = Highly Significant (P^J) .0') * - Significant (P<0.05) UNIVERSITY OF IBADAN LIBRARY (J) Calcium (mg/lOOg milk) F F Source of Variation d.f. S.S. M.S. calculated tabulated 0 .0 5 0 .0 1 Breed 2 15020.64 7510.32 145.30 3.00 4.61 ** Lactation (Lact.) 2 1 6 1 8 .0 2 809.02 15.65 3.00 4.61 ** Diet 1 12.13 12.13 0.23 3.84 6 .6 3 NS Breed/Lact. 4 1009.93 252.48 4.88 2.37 3.32 Breed/Diet 2 340.39 170.19 3.29 3.00 4 .6 1 # Lact ./Diet 2 2912.19 1456.10 28.17 3 .0 0 4 .6 1 3-Way Interaction 4 1455.13 363.78 7.04 2.37 3.32 ** Between Blocks 17 5197.06 305.71 5.91 1.52 1.79 Re sidual 289 14938.22 51.69 Total 323 42503.75 Effect of Seasons F F Source of Variation d.f. S.S. M.S. calculated tabulated 0 .0 5 0 .0 1 Groups 1 35.00 35.00 0.27 3.84 6.63 NS Error 322 42477.00 131.92 Total 323 42512.00 NS = Not Significant (P>0.05) * * - Highly Significant (P<0.0') 0 = Significant (P<0.05) UNIVERSITY OF IBADAN LIBRARY 0 0 Phosphorus (mg/lOOg milk) F F Source of Variation d.f. S.S. M.S. calculated tabulated 0.05 0.01 Breed 2 25394.86 12697.43 99.09 3.00 4.61 .Lactation (Lact.) 2 377.06 188.54 1 .47 3.00 4.61 NS Diet 1 7.02 7.02 0.05 3.84 6.63 NS Breed/Lact. 4 179.01 44.75 0.35 2.37 3.32 NS Breed/Diet 2 78.43 39.22 0.31 3.00 4.61 NS .Lact./Diet 2 343.02 171.51 1.34 3.00 4 .6 1 NS 3 -Way Interaction 4 383.34 95.83 0.75 2.37 3.32 NS Between Blocks 17 932.73 54*87 0.43 1.52 1.79 NS Residual 289 37033.65 128.14 Total 323 64729.15 Effect of Seasons F F .Source of Variation d.f. S.S. M.S. calculated tabulated 0 .0 5 0 .0 1 Groups 1 332.00 332.00 1.66 3.84 6 .6 3 NS Error 322 64423.00 200.07 Total 323 &755.00 NS = Not Significant (P>0.05) ** = Highly Significant (P0.05) * * = Highly Significant (F<0.0\) * ss Significant (p^.0.05) UNI ERSITY OF IBADAN LIBRARY (m) Body weight changes (kg) F F Source of Variation d.f. M.S. calculated tabulated 0.05 0.01 Breed 2 23.56 11.78 7.01 3.00 4.61 ** Lactation (Lact.) 2 15.65 7.82 4.66 3.00 4.61 ** Diet 1 8 .2 6 8 .2 6 4.91 3.84 6.63 * Breed/Lact. 4 43.59 10.90 6.49 2.37 3.32 ** 1 Breed/Diet 2 26.44 13.22 7.87 3.00 4,61 Lact./Diet 2 9.52 4.76 2.83 3.00 4.6i NS 3-Way Interaction 4 45.84 11.46 2.37 3.32 Between Blocks 17 40.62 2.33 1.41 1.52 1.79 NS Residual 289 485.65 1.68 Total 323 699.13 Effect of Seasons F F Source of Variation d.f. S.S. M.S. calculated tabulated 0.05 0.01 Groups 1 8.55 8.55 3.98 3.84 6.63 • Error 322 690.73 2.15 Total 323 699.28 NS = Not Significant (P>0.05) ** = Highly Significant (P<*0.0'.) * = Significant (p<0.05) UNIVERSITY OF IBADAN L •o\ I r0 B o3 RARY c•n to APPENDIX B4.1 ANOVA: Comparison of the data of coefficients of apparent digestibilities between steers and lactating cows DM : HC (WF) Source of variation a.f. s„s. M.S. F calculated F tabulated 0.05 0.01 H Total 5 42.15 Between means 1 4.53 4.53 0.48 7-71 21.2 ns : Within samples 4 37.62 9.41 i ----11 DM : LC (WF) Source of variation d.f, S.S. M.S. F calculated F tabulated 0.05 0.01 Total 5 34.35 Between means 1 2.40 2.40 0.30 7.71 21.2 NS Within samples 4 31.95 7.99 DM : HC (GB) Source of variation d.f. S.S. M.S. F calculated F tabulated 0,05 0.01 Total 5 12.93 Between means 1 2.88 2.88 1.15 7.71 21.2 NS Within samples 4 10.05 2.51 DM = Dry Matter WF = White Fulani NS = Not Significant HC = High Concentrate LC = Low Concentrate GB = German Brown F = Friesian UNIVERSITY OF IBADAN LIBRARY DM : LC (GB) Source of variation d.f. S.S. M.S. F calculated P tabulated0.05 0.01 Total 5 9.59 •Between means 1 2.80 2.80 1.65 7.71 21.2 NS Within samples 4 6.79 1.70 DM : EC (P) 1 i .'Source of variation d.f. s . s . M.S. F calculated F tabulated i 0.05 0.01 j1 '-Total 5 2.15 ! ^Between means 1 0.01 0.01 0.02 7.71 21.2 NS 1'Within samples 4 2.12 f 0.55 i _____ I DM : LC (P) | -'Source of variation d.f. S.S. M.S. F calculated F tabulated 0,05 0.01 j '.Total 5 8.59 | .Between means 1 0.04 0.04 0.02 7 .7 1 21.2 NS j Within samples 4 8.55 2.09 LDM-='Dry Matter WF = White Fulani NS = Not Significant HiC — High Concentrate LC = Low Concentrate GB = German Brown JF ~ Friesian UNIVERSITY OF IBADAN LIBRARY CP : HC )WF) Source of variation a.f. s . s . M.S. F calculated F tabulated 0 .0 5 0 .0 1 Total £ 23.29 - -- . . Between means 1 9.38 9.38 2.70 7.71 21.2 NS Within samples 4 13.91 3 .48 CP : LC (WF) Source of variation d.f. S.S. M.S. F calculated F tabulated 0 .0 5 0 .0 1 Total 5 23.68 ■ — Between means 1 6.99 6.99 1.68 7.71 21.2 NS Within samples 4 1 6 .6 9 4.17 CP : HC (GB) Source of variation d.f. S.S. M.S. F calculated F tabulated 0 .0 5 0 .0 1 Total 5 10.86 Between means 1 2.38 2.38 1.12 7.71 21 .2 Hi Within samples 4 8,43 2.12 DM = Dry Matter WF = White Fulani NS = Not Significant HC = High Concentrate LC = Low Concentrate GB = German Brown F = Friesian CP = Crude protein UNIVERSITY OF IBADAN LIBRARY CP : LC (GB) ' ' Source of variation d.f. s .s . F tabulated M .S. F calculated 0.05 0.01 Total 5 11.92 Between means 1 1 .17 1 .17 0 .43 7.71 21,2 NS Within samples 4 10.75 2.69 ---- SB : HC (f ) Source of variation d.f. S.S. M.S. F calculated F tabulated 0 .0 5 0 .0 1 Total 5 75.31 Between means 1 10.41 10.41 0.64 7.7.1 21.2 NS Within samples 4 65.40 16.35 --- ( ES : LC (P) Source of variation d.f. S.S. M.S. F calculated ? tabulated 0 .0 5 0 .0 1 Total 5 2 6 .7 3 Between means 1 0.99 0.99 0.15 7.71 21.2 ■[\TC Within samples 4 25.74 6.44 EM = Dry Matter W F = White Fulani NS = Not Significant HC = High Concentrate LC = Low Concentrate GB = Gennan Brown ¥ = Friesian SB = Sth' fir Extract CP = Crude Protein UNIVERSITY OF IBADAN LIBRARY CF : Forage (WF) Source of variation F tabulated a . f . s .s . M.S. F calculated 0.05 0.01 Total 5 23.37 Between means 1 5.01 5.01 1.09 7.71 21.2 NS Within samples 4 18.36 4.59 Energy : Forage (GB) Source of variation d.f. F tabulated s .s . M.S. F calculated 0.05 0.01 Total 5 51.58 Between means 1 0.08 0.08 0.006 7.71 21.2 TIm.t oo Within samples 4 51.50 12,87 Energy : HC (WF) Source of variation d.f. S.S. M.S. F calculated F J-~''viated r ~0-05 0.01 Total 5 6.25 Between means 1 0.34 0.34 0.23 7.71 21.2 NS Within samples 4 5.91 1.48 DM = Dry Matter WF = White Fulani NS = Not Significant HC = High Concentrate LC = Low Concentrate GB = German Brown F = Friesian UNIVERSITY OF IBADAN LIBRARY EE. HC (WF) Source of Variation Fa . f . S .S . M.S. F cal, . ?0.05 0.01 Total 5 99.52 Between means 1 15.47 (6.47 0.79 7.71 2 1 . 2 N3 Within samples 4 83.05 20.76 E3. In (WF) Source of Variation d.f. S.S. M.S. Pcal. F0.05 ?0.01 Total 5 23.93 Between means 1 6.30 6.30 1.11 7.71 21.2 NS Within sample 4 22.63 55 *66 Energy HC (GB) Source of Variation a.f. S.S. M.S. * cal. F0.05 Total 5 8.62 Between means 1 2.69 2 . 6 9 1.82 7 . 7 1 21.2 NS Within samples 4 5.93 1.48 Energy LC (GB) Source of Variation a . f . S.S. M.S. Fcal. F0.05 F0.01 Total 5 9.61 Between) gieans 1 2.11 2.11 1.12 7.71 2 1 .2 NS Within samples 4 7.50 1.88 DM = Dry Matter (/£) HC = High Concentrate. UNIVERSITY OF IBADAN LIBRARY *1 0 0 Energy : LC (WF) Source of variation d.f. s . s . F Calculated F tabulated 0.05 0.01 Total 5 87.47 Between means 1 8.71 8.71 0.44 7.71 21.2 NS Within samples 4 78.76 19 .69 UNIVERSITY OF IBADAN LIBRARY • CO • APPENDIX B4.2 TWO-WAY ANALYSIS OF VARIANCE FOR COMPARISON OF THE DATA BETWEEN THE BREEDS AND TREATMENTS MS Intake (MJ/day) Source of variation d.f. S.S. M.S. Foal F0.05 Treatment (T) 2 9758.93 4884.49 9.69 3.35 5.49 Breed (B) 2 4242.50 2121.25 4.21 3.34 5.49 * Interaction (T X B) 4 1683.69 420.92 0.84 2.73 4.11 NS Error 27 13604.09 503.86 Total 35 29299.26 ME Intake (Mj/da Source of variation d.f. S.S. M.S. F cali F0.05 r 0.~01 Treatment (T) 2 1.124 0.62 155.00 3.35 5.49 ** ! Breed (B) 2 0.025 0.0125 3.125 3.35 5.49 NS Interaction (T X B) 4 0.01 0.0025 0.625 2.73 4 .1 1 NS Error 27 0.11 0.0040 Total 35 1.385 ME = Metabolizable Energy WF = White Fulani df = Degree of freedom GB = German Brown SS - Sum of Squares Fr = Friesian p MS = Mean Square F = Forage ad lib cal = F calculated HC = ad lib forage + NS = Not Significant high concentrate ration ** = Significant at V/o level LC = ad lib forage + * = Significant at level. low concentrate ration. UNIVERSITY OF IBADAN LIBRARY •0O Nitrogen Intake (g/day/W^g^1-) Source of variation d.f. S.S. M.S. Fcal F .01 Treatment (T) 2 3.90 1.95 11 .6 1 3.35 5.49 ** Breed (B) 2 0 .18 0.09 0.535 3.35 5.49 NS Interaction (T X B) 4 0.06 0.015 0.089 2.73 4.11 NS Error 2 ? 4.54 0.168 Total 35 8.68 Nitrogen Intake (?Jday) 1 7 - - Source of variation d.f. S.S. M.S. Pcal F.05 .01 Treatment (T) 2 27416.10 13708.05 10 .22 3.35 5.49 ** Breed (B) 2 10783.00 5391.50 4.02 3.35 5.49 * Interaction (T X B) 4 10 18 .11 254 .53 0.19 2.73 4.11 173 Error 27 36 211.6 2 1341.17 Total 35 75428.83 ME = Metabolizable Energy WF = White Fulani df = Degree of freedom GB = German Brown SS = Sum of Squares Fr = Friesian p MS = Mean Square F = Forage ad lib cal = F calculated HC = ad lib forage + NS = Not Significant high concentrate ration ** = Significant at level LC = ad lib forage + * = Significant at level. low concentrate ration. UNIVERSITY OF IBADAN LIBRARY ion Ik.. i Faecal-Nitrogen (g/day/^g^^) Source of variation d.f. S.S. M.S. F cali F.05 F.01 Treatment (T) 2 8.67 4.335 12.90 3.35 5.49 ** Breed (B) 2 5.15 2.725 8.11 3.35 5.49 ** Interaction (T X B) 4 0.50 0.125 0.372 2.72 4.11 NS Error 27 9.07 0.336 Total 35 23.89 'Vi Urinary-Nitrogen (g/day/,V^g^^) Source of variation d.f. S.S. M.S. Fcal P.05 r;*.01 Treatment (T) 2 0.30 0.15 10.14 3.35 5.49 * $ Breed (B) 2 0.01 0.005 0.34 3.35 5.49 NS Interaction (T X B) 4 0.01 0.0025 0.17 2.73 4.11 NS Error 27 0.40 0.0148 Total 35 0.72 ME = Metabolizable Energy WF = White Fulani d f = Degree of freedom GB = German Brown SS = Sum of Squares Fr = Friesian p MS = Mean Square F = Forage ad lib cal = F calculated HC = ad lib forage + NS = Not Significant high concentrate ration *<■ = Signix'icant at Vfi level LC = ad lib forage + * = Significant at 55& level. low concentrate ration. UNIVERSITY OF IBADAN LIBRARY Absorbed Nitrogen (g / d a y / " v ) Source of variation d.f. M.S. Fcal F.05 F.01 Treatment (T) 2 1.53 0.765 173.86 3.35 5.49 $ .........., , j V 42 6.22(1.80) 90 8.36(2.50) 65 8.45(2.00) 88 8.00(1.68) 2 58 6.52(2.70) 127 3.35(1.70) 66 8.25(2.00) 120 8.11(1.86) 2 42 6.15(1.70) 90 3.44(2.40) 65 8.62(1.90) 88 7.69(1.78) ' 3 58 6.19(2.40) 127 3.50(1.82) 66 8.77(1.70) 120 8.17(1.86) 42 6.57(1.10) 90 3.36(2.30) 65 8.36(2.05) 83 7.96(1.60) V 58 6.63(2.80) 127 3.32(1.60) 66 8.45(1.90) 120 8.35(1.86) • Not determined ( ) Figures in parenthesis are the dry natter (DM) intake from concentrate ration. UNIVERSITY OF IBADAN LIBRARY (b) Total Dry Matter Intake (kg/dav) of the Stall-fed oows Period Weeks HIGH CONCENTRATE HIGH FORAGE No, G. Brown Ho. Friesian No, G. Brown No. 1Friesian Before Start of 37 “ 99 • 56 92 , ! Experiment 67 121 64 . 123 37 7.64(2.14) 99 7.86(2.28) 56 8 .26( 2 .00) 92 8.07(1*80) 1 6? 7.70(1.58) 121 3.52(3.00) 64 8.47(2.00) 123 8,32(2.00) 37 7.49(2.16) 99 7.51(2.04) 56 8.00(1.90) 92 7*62(1.30) ' 2 6? 7.76(2.07) 121 8.82(3.20) 64 8.36(1.90) 123 8.30(2.00) 4 37 6.89(1.89) 99 7.37(2.16) 56 7.96(2.00) 92 7.55(1 AO) 3 67 7.42(1.93) 121 3.41(3.06) 64 8.13(1.95) 123 8.89(1.95) 37 7 .00( 2 .06) 99 7.43(2.42) 56 9.31(1.80) $2 7.67(1.40) 4 67 7*40(2.06) 121 7.47(3.04) 64 8.20(2.00) 123 8.15(1.90) 56 7.43(2.50) 92 7.23(1.91) 37 8.02(1.43) 99 7.54(1.60) 1 a 7.35(3.00) 123 7.05(2.80) 6? 7.81(1.43) 121 8.24(2.10) 56 7.34(2.13) 92 7.03(2.12) 37 8.01(1.30) 99 3.76(1.50) 2 64 7.90(2.53) 123 7.35(2.35) 67 7*80(1.40) 121 9.30(1.80) 2 56 7.52(2.26) 92 7.01(2.00) 3? 9.00(1.30) 99 7.67(1.50) • 3 64 7.97(2.56) 123 7.29(2.20) 67 6.66(1.30) 121 3.65(1.70) 56 7.54(2.28) 92 7 . 16( 2 . 20) 37 7.65(1.00) 99 3.45(1.35) 4 64 7.51(2.07) 123 6.75(1.70) 67 3.57(1.20) 121 3.11(1.60) • Not data rained. ( ) Figures in parenthesis are the dry natter (DM) Intake from concentrate ration. UNIVERSITY OF IBADAN LIBRARY % APPENDIX C2«2 (a ) Milk yield (kg/week) of tho grasing coira 'V i Period Weeks HIGH CONCENTRATE HIGH FORAGE No. G. Brown No. Friesian No. G. Brown No, Friesian,, JdOi Oiw of 65 62.73 88 46.36 42 35.00 90 54.55 Experiment 66 60.51 120 55.91 58 43.13 127 62.73 * 65 67.73 88 48.18 42 36.82 90 48.64 1 66 67.50 120 53.64 53 44.09 127 60.00 n 65 65.00 88 56.38 42 35,91 90 50.00 2 66 68.64 120 55*45 55 37.25 127 52.72 , 4 65 62.73 88 62.73 42 34 «55 90 51.36 3 66 60.45 120 57.27 58 50.45 12? 49.09 65 60.45 88 62.27 42 37,72 90 51.30 4 66 60.00 120 63.13 53 46.82 ’ 127 28.64 . 42 34.32 90 49.10 65 62.73 83 52.73 1 58 51.82 127 32.72 66 80.45 120 58.63 v 42 32.27 90 47.25 65 59.55 88 55.91 2 58 45.90 127 35.90 66 53.64 120 38.63 2 42 23.40 90 45.00 65 64.55 83 50.00 3 53 55.45 127 31.82 66 58.15 120 58.60 i 42 18.18 90 43.86 65 56.36 83 51.82 4 58 54.09 127 43.86 66 58.64 120 64.56 UNIVERSITY OF IBADAN LIBRARY ■ (b) Milk yield (kft/wsek) of the stall-fed cows Period Weeks HIGH CONCENTRATE HIGH FORAGE 1 No. G. Brown No. Friesian No, G. Brown NOc Friesian Before Start of 42.28 Experiment 37 99 45.00 56 61.37 92 56.82 67 39.10 121 59.31 a 61.37 123 60.91 37 42.73 99 40.23 56 60.00 92 39.55 1 67 40.91 121 63.40 64 58.a 123 53.a 37 37.27 99 42.73 56 61.36 92 43.18 2 67 38.18 121 60J45 a 60.00 123 61.36 1 57 40.68 99 47.73 56 55.45 92 42.95 3 67 40.63 121 60.00 a 60.45 123 60.00 37 45.00 99 50.00 56 50.45 92 37.73 4 67 45.00 121 65.91 a 59.54 123 55.00 56 42.04 92 41.59 37 39.55 99 41.82 1 64 50.00 123 48.18 67 40.00 121 56.02 56 44.55 92 38 .a 37 40.23 99 45.45 2 &». 50.45 123 41.82 2 67 40.91 <21 52.27 56 45.00 92 42.73 37 34.55 99 40.00 3 a 40.91 123 33.18 67 39.09 121 49.09 56 42.73 92 42.05 37 36.37 99 35.91 4 a 46.36 123 35.23 67 35.91 121 47.72 UNIVERSITY OF IBADAN LIBRARY APPENDIX C2.3 (a) Solids-corrected milk (SCM) (kg/week) of tha grated cows Period Week3 HIGH CONCENTRATE HIGH FORAGE No. G. Brown No. Friesian No. G. Brown No. Friesian id© i or© oidi \j of 65 57.65 88 45.07 42 35.22 90 51.78 Experiment 66 59.72 120 48.48 58 43.31 127 53.67 65 61.13 88 43.96 42 36.94 90 46.59 1 66 59.99 120 45.60 58 43.59 127 52.36 65 53.16 68 55.00 42 36.10 90 47.65 2 66 60.73 120 47.39 53 57.03 127 48.12 65 56.60 88 55.72 42 35.25 90 49.05 3 66 54.94 120 47.84 53 49.99 127 44.67 65 54.34 88 57.74 42 37.97 90 49.71 4 66 50.82 120 51.86 53 46.46 127 26.60 , . - 42 54.23 90 47.07 65 57.52 83 50.33 1 58 51.58 127 29.95 66 70.33 120 50.83 42 52.79 90 46.15 65 58.36 83 53.66 2 58 44.79 127 33.56 66 50.14 120 51.93 2 42 54.50 90 44.36 65 66.07 83 49.80 3 58 54.55 127 50.37 66 58.19 120 55.66 42 19.11 90 43.11 65 57.17 88 51.17 4 58 54.64 127 41.58 66 60.09 120 57.41 UNIVERSITY OF IBADAN LIBRARY (b) Solids-corrected Kllk (SCiQ (kg/woek) of the stall~fed oowa Period Weeks HIGH CONCENTRATE HIGH FORAGE No. G. Brown No. Friesian 1No. G. Brown No. Friesian Before Start of Experiment 37 39.95 99 41.96 56 58.09 92 53.68 67 37.13 121 50.52 64 58.00 123 51.18 37 35.61 99 36.86 56 55.41 92 38.37 1 67 30.64 121 52.23 64 54*30 123 47.41 37 34.02 99 37.17 56 56.60 92 42 .42 2 6? 35.45 121 47.21 64 54.83 123 50.52 1 37 35.86 99 40.54 56 51.2? 92 42 A5 3 67 36.66 121 47.26 64 53.26 123 50.24 37 39.36 99 42.57 56 45.71 92 37.79 4 67 39.97 121 43.65 64 51.84 125 46.16 56 37.94 92 41.33 37 35.81 99 35.30 1 64 43.99 123 42.85 67 36.26 121 44.50 56 40.10 92 38.47 37 37.61 99 41 A3 2 64 44.67 123 34.45 67 38.37 121 45.04 0c 56 41.15 92 42 A3 37 34.86 99 37.13 3 64 37.15 123 29.54 67 37.58 121 42.21 56 37.03 92 41.83 37 38.47 99 34.47 4 64 42.62 123 27.62 67 31.16 121 54.2 6 v UNIVERSITY OF IBADAN LIBRARY T APPENDIX C2«> (a ) Idveweirfit (kg) of the grazed cows during the porlod of experiment Period Weeks HIGH CONCENTRATE HIGH FORAGE No. G. Brown No. Friesian No. G. Brown Friesian of 65 425.28 88 328.41 42 365.00 90 441.19 Experiment 66 402.56 120 356.22 58 302.67 12? 426.56 65 424.11 88 324.12 42 363.42 90 443.56 1 66 404.34 120 362.44 53 508.64 12? 427.84 65 426.56 88 305.26 42 366.24 90 442.84 2 66 412.55 120 353.40 58 300*41 12? 431.26 14 65 434.35 88 312.00 42 *.363.48 90 446.56 3 66 428,00 120 352,16 58 294.26 127 436,76 65 440.84 88 522.62 42 365.25 90 443.71 4 66 436.50 120 350.00 58 295.18 12? 434.23 42 364.45 90 452.68 65 456.57 88 324.40 1 53 298.42 127 436.00 66 432.41 320 351,62 42 368.56 90 468.28 65 450.64 88 356.28 2 53 296.25 127 434.40 66 436.85 120 358.80 2 42 370.42 90 469.52 65 465.75 88 348.55 3 58 300.24 127 441.26 66 438.55 120 362.20 42 373.55 90 471.22 65 463.84 88 362.18 4 58 300.00 127 439.25 66 441.62 120 361.22 UNIVERSITY OF IBADAN LIBRARY —0• — 55 (b) Live weight (kg) of the stall-fed oowa during the period of experiment Period Weeks HIGH CONCENTRATE HIGH FORAGE No. G, Brovm No. Friesian No. G. Brown No. Friesian Before O VsttJ» \j of 37 412.25 99 418.25 56 395.80 92 385*44 ] Experiment 67 428.90 121 434.00 64 412.55 123 399.50 37 400.00 99 410.00 56 382.10 92 373.20 1 67 427.00 121 420.00 64 408.12 123 581.40 37 375.20 99 333.51 56 386.60 92 ■ 365.40 2 67 412.00 121 401.50 64 400.21 123 375.45 4 37 370.41 99 372.45 56 334.25 92 363.60 3 67 400.45 121 398.64 64 598.25 123 368.50 37 375.50 99 368.65 56 386.42 92 364.10 4 67 398.23 121 390.52 64 400.80 123 365.45 56 390.50 92 368.25 37 380.00 99 361.00 1 64 402.82 123 368.52 67 386.25 121 386.83 56 392.40 92 375.45 37 390.13 99 369.21 2 64 405.84 123 331.42 67 387.52 121 389.50 2 56 394.21 92 372.27 37 385.46 99 364.65 3 64 408.20 123 378.80 67 392.51 121 386.52 56 398.56 92 374.75 37 391.12 99 364*10 4 64 412.41 123 382.00 67 398.49 121 392.40 UNIVERSITY OF IBADAN LIBRARY APPSNDIX C3. Animal No. .. * & ? ? !* ? . ?.°A ..... Mot: .%$» U w l ratten + ad U b f o n p . .... jrutrient 1 2 3 4 5 6 7 3 9 10 11 12 13 14 Bean Bilk yield (kg/wk) 38.64 50.45 66.36 64.55 67.73 68.64 65.00 60.91 59.36 57.27 45.90 30.45 32.73 32.27 52.88|+14.28 SCM (kg/nk) 35.82 46.64 61.73 59.00 61.95 63.71 60.70 57.16 55.77 54.74 43.31 28.93 31.33 30.89 49.41+12.96 Forage Intake (kgDM/iav) 5.87 6.57 7.44 7.44 7.77 7.02 7.44 6.70 6.36 5.84 5.24 5.57 5.72 5.64 6.48+0.23 Ration Intake (kgSM/davl 2.00 2.25 3.00 3.82 3.70 3.05 4.00 3.73 3.50 3.50 3.40 2.75 1.90 1.90 3.09*0.21 Total 7.87 8.82 10.54 11.26 11.47 10.87 11.44 10.45 9.86 9.34 8.64 8.32 7.62 7.54 9.57+0.39 Weight (kg) 421.50 398.64 390.15 381.82 371.52 365.00 370.28 385.56+7.48 Fat fo 3.5V 3.48 3.26 3.20 3.25 3.25 3.35 3.40 3.85 3.70 3.75 3.85 3.90 3.51+0.07 Protein fo 2.95 2.98 2.95 2.93 2.93 2.97 3.00 3.05 3.03 3.11 3.07 3.08 3.05 3.03 3.01+0.02 Lactose % 4-.80 4.81 4.82 4.80 4.82 4.85 4.80 4.80 4.80 4.80 4.75 4.78 4.77 4.85 4 .80+0.01 Total Solids % 12.05 12.15 12.41 12.30 12.25 12.14 12.50 12.48 12.45 12.30 12.25 12.30 12.32 12.28 12.32+0.01 SNF % 8.60 8.67 9.11 9.04 9.05 9.16 9.25 9.13 9.05 8.45 8.55 8.55 8.47 8.38 8.82+0.06 Ash $ 0.68 0.68 0.68 0.68 0.70 0.70 0.68 0.68 0.69 0.69 0.70 0.71 0.71 0.71 0.69+0.01 Calcium (mg/lOOg) 105.25 114.15 108.25 109.10 108.00 125.00 125.10 120.00 112.15 137.25 125.00 124.05 123.00 122.50 118.49*2.45 Phoaphorus(mg/lOOg) 45.62 44.25 45.50 47.00 52.07 53.05 54.05 54.00 55.00 54.00 52.00 52.00 52.00 53.00 50.97*0.98 Energy (Kj/g) 19.16 19.60 £6.59 18.41 17.57 18.83 19.71 19.62 19J46 19.66 19.96 20.21 20.54 20.88 19.54*0.24 UNIVERSITY OF IBADAN LIBRARY APPENDIX C3 Friasian No. 100 (oontd.) Diet- êT9^ ration ♦ ad lib forage Nutrient 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Mean Grand* GrardTotal Mean Milk yield 30.00 27.20 31.36 28.60 34.52 34.06 31.34 30.43 29.00 28.60 29.05 28.16 23.60 20.90 29.06+2.61 1147.16 40.97+15.86 SCM(kg/wk) 28.55 25.88 29.81 26.78 32.31 32.07 29.59 28.62 27.30 27.11 27.64 26.60 22.36 20.01 27.47+2.31 1076.32 38^4+14.52 Forage 4.26 4.79 4.23 4.91 4.96 4.67 4.76 4.95 5.42 5.44 4.71 4.95 4.34 4.34 4.77+0.10 1101.52 5.62+0.21 Ration 1.20 1.24 1.04 1.20 1.10 1.30 1.30 1.20 1.15 1.08 1.05 1.08 1.05 1.00 1.14+0.03 415.52 2.12+0.24 Total 5.4-6 6.03 5.27 6.11 6#C6 5.97 6.06 6.15 6.57 6.52 5.76 6.03 5.39 3.54 5.91+0.11 1517.04 7.74+0.98 Weight(kg) 375.00 336.25 395.25 400.20 417.23 418.82 420.00 401.82+4.84 - 393.69+5.31 Fat % 3.90 3.95 3.85 3.80 3.85 4.00 4.05 3.95 4.00 4.05 4.05 4.00 4.10 4.30 3.99+0.03 43.02 3.75+0.06 Protein % 3.00 3.05 3.03 3.00 2.98 3.01 3.02 3.04 3.05 3.10 3.15 3.13 3.20 3.18 3.07+0.07 34.87 3.04+0.02 Lactose % 4.80 4.80 4.81 4.75 4.76 4.80 4.80 4.79 4.77 4.65 4.75 4.73 4.74 4.68 4.76+0.01 54.83 4.73+0.01 TS fc, 12.20 12.15 12.22 12.05 12.00 11.95 11.95 11.93 11.95 12.00 12.05 12.00 11.95 11.98 12.03+0.02 139.61 12.17+0.03 SNF f i 8.30 8.20 8.37 8.25 8.15 7.95 7.90 8.03 7.95 7.95 8.00 8.00 7.85 8.00 8.06+0.04 96.82 8.44+0.04 Ash % 0.70 0.70 0.71 0.71 0.70 0.70 0.70 0.69 0.69 0.69 0.69 0.69 0.70 0.71 0.70+0.01 8.03 0.70+0.01 Calcium 110.00 109.00 1C8.0C 109.00 115.15 114.00 116.00 120.00 122.00 125.00 125.00 126.00 124.00 125.10 117.73+1.91 1.35 118.11+2.96 Phosphorus 45.00 46.00 43.00 50.45 55.45 56.00 60.00 62.00 60.50 59.50 58.50 59.50 60.00 62.00 55.93+2.02 0.61 53.44+1.51 Energy 19.25 19.+5 17.07 17.03 17.05 18.83 18.16 18.05 18.50 18.70 18.75 18.65 19.70 19.70 18.35+0.19 2.17*107 18.93+0.20 * Values given per 28 weeks UNIVERSITY OF IBADAN LIBRARY APPENDIX C3 n o . ?.0: . M 2;.... jjĵ . High lerel ratimi ^ ad_ lib̂ forage Nutrient 1 2 3 4 5 6 7 8 9 1P 11 12 13 14 Kean liilk yield (kg/wk) 23.61 35-42 40 A3 35 A4 38.84 47.20 46.18 47.30 45.21 35.30 34.20 34.00 33.86 33 A 1 37.87+6.76 SCM (kg/wk) 24.50 37.07 42.27 36 J41 41.92 51.34 48.36 50.38 48.20 37.58 36.25 35.93 35.48 35.25 40.07+7 A 6 Forage Intake (kgDH/day) if.62 6.21 6.75 6.79 7.00 7.02 6.55 5.67 6.85 6.41 6.16 5.30 5.11 5.18 6.12+0.21 Ration Intake (kri>M/day) 1.50 1.34 2.10 2.40 2.10 2.30 2.80 2.70 2.65 2.65 2.00 2.00 2.00 2.00 2.18+0.12 Total 6.12 7.55 8.85 9.19 9.10 9.32 9.35 8.37 9.50 9.06 8.16 7.30 7.11 7.18 8.30+0.27 Weight (kg) 302.10 298.64 294.52 289.09 281.20 279.09 282.10 289.53+3.45 Fat % 4.6l 4.72 4.73 4 «£S 4.71 4.70 4.63 4.92 4.88 4.76 4.80 4*36 4.92 4.77+0.03 Protein % 3.26 3.24 3.34 3.30 3.35 3.31 3.30 3.24 3.26 3.28 3.28 3.27 3.30 3.32 3.29+0.01 Lactose % 5.20 5.18 5.18 5.18 5.19 5.20 5.20 5.16 5.16 5.17 5.10 5.08 5.12 5.12 5.16+0.01 Total Solids fa 12.88 12.91 12.89 12.66 13A2 13.56 13.00 13.02 13.07 13.06 13.08 13.00 12.81 12.96 13.02+0.06 SHF % 8.27 8.19 8.16 7.98 8.71 8.86 8.37 8.10 8.19 8.20 8.32 8.20 7.95 8.04 8.25+0.07 Ash fa 0.72 0.73 0.73 0.74 0.72 0.73 0.70 0.70 0.70 0.70 0.70 0.70 0.70 0.70 0.71+0.01 Calcium (mg/l00g) 120.80 124.8s 124.26 125.25 126 AO 128.45 121.25 117A6 128.46 127.52 128.00 126.65 126.80 126.25 125.17+0.71 Phosphorus(mg/1OOg) 65.25 65.5C 65.50 65.50 65.26 67.20 68.25 66.21 64.22 65.25 64.00 65.20 63.2 6 63.00 65.20+0.83 Energy (KJ/g) 22.56 22.4* 22.30 22.52 22.60 22.52 2 2 M r 22 A 8 22.14 22A4 23.39 22.10 22 AO 22 A 8 22A2+0.05 UNIVERSITY OF IBADAN LIBRARY .1 f • APPENDIX C3 . , , „ Whits Tulani No. 462 (oontd.) . Low IstsI ration ♦ ad lib forage Animal No........................................ ; .......... . D ie t :................................... “ .TTV............ Grand* Grand Nutrient 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Mean Total Mean Milk y ield 30.70 28.72 28.31 29.21 27.95 17-42 17.26 16 .2 1 15.24 15 .3 ; 14.26 14.80 13.21 13.24 20.13+6.97 812.00 29.00+11.27 SCM(kg/Wk) 32.31 29.93 29.87 30.92 29.64 13 .14 13.20 17 .14 16.46 16.35 15 .12 15.82 13.88 14.23 21.29+7.29 859.04 30.68+11.99 Forage 5.25 5.00 5.0C 4.25 4.28 3.82 4 .13 4.35 3.85 4.00 4 .16 3.25 3.47 3.82 4.23+0.16 1013.32 5.17+0.22 Ration 1.2 0 1 .1 0 1 . 0C 1.05 1.00 1.0 0 1.00 0.95 0.90 o .so 0.85 0.80 0.75 0.70 0.94+0.14 305.76 1.56+0.13 Total 6 .k 5 6 .10 6.0C 5.30 5.23 4 .82 5.13 5.70 4 .75 4.90 5.01 4.05 4.22 4.52 5.16+ 0 .17 1319.08 6.73+0.38 Weight(kg) 290.21 289.00 290.00 233-41 283.41 285.00 283.60 292.56 288. 40+1.2 0 - 288.97+1.76 Fat % 4.86 4.85 5.21 5.21 5.20 4.50 5.28 5.50 5 . 8 1 5.57 5 .6 2 5.60 5.70 6.00 5.39i0.96 4 1.2 5 5.08+0.08 Protein % 3.28 3.28 3.2S 3.31 3.23 3.24 3.36 3.2 7 3.27 3.26 3.30 3.31 3.31 3.30 3.29+0.01 25.09 3 . 09+0.01 Lactose % 5.21 4.98 5.22 5.23 5.22 5.21 5.24 5.28 5 .1 6 5.2? 5.30 5.29 5.25 5.28 5.23+0.02 42.14 5.19+0.01 TS % 12.83 12.76 12.61 12.66 12.70 12.60 1 2 . 54 12.38 12.46 12.48 12.40 12.40 1 2 .1 1 12 .22 1 2 . 5 1+0.06 103.69 1 2 . 77+0.06 SNF % 8.02 7.91 7.40 7.45 7.50 7 .6 2 7.26 6.88 6.65 6.91 6.70 6.72 6-41 6.22 7.12+0 .15 62 4 4 7 . 69+0 .1 4 Aah $ 0.70 0.70 0.7C 0.70 0.69 0.70 0.71 0.71 0.71 0.71 0.71 0.72 0.71 0.71 0 . 7140.01 5.85 0.71i0 .Q 1 Calcium 122 J *5 122.45 128.62 130.20 136.44 138.26 139-42 130.65 134.00 132.47 137.26 138.00 138.00 141.20 133.53+3.00 1.05 129.35+2.37 Phosphorus 62.14 60.15 60.21, 60.00 63.25 58.65 59.23 58 .15 55.27 56.00 58.18 59.20 50.00 58.25 60.92+1.54 0.50 61.99+1.73 Bhergy 22.60 22.51 22.65 22.64 22.76 22.72 23.06 22.89 22.85 22.93 22.95 23.10 23.06 23.00 22.B4t9.09 1 .8 4 * 10 7 22.63*0.07 * Values g ite h pel" 28 Weeks. UNIVERSITY OF IBADAN LIBRARY r) APFKNDIZ C3 Animal No. G<3raan Erorrn No. 64 D ie t: le v e l ra tio n + ad U b forage Nutrient 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Kean bilk yield (kg/wk) 35 .45 43.63 45.68 49.32 48.18 47.27 49.09 53.a 55.00 55.05 51.82 50.00 49.09 45.00 48.44+5.13 SCM (kg/wk) 35.39 43.66 45.19 43.89 46.74 46.11 48.07 52.54 53.91 54.34 51.47 49.64 49.40 45.39 47.91+4.89 Forage Intake (kgPK/day) 5.41 6.77 6.42 6.80 7.28 6.77 6.45 6.09 5.29 5.99 5.49 6.08 5.21 5.11 6.03+0.14 Ration Intake ( kgDM/day) 2.00 1.85 2.25 2.30 2.55 2.50 2.25 2.55 2.70 2.90 2.90 2.40 2.35 2.00 2.39+0.09 Total 7+41 8.62 8.67 9.10 9.83 9.27 8.70 7.99 8.89 8.39 8.48 7.56 7.11 8 *48^0.15 Weight (kg) 385.20 372.73 385.50 390.CO 400.18 418.13 425.28 396.72+7.18 Fat % 4.02 4.00 3.92 3.90 3.42 3.50 3.52 3.58 3.55 3.68 3.72 5.70 3.92 3.99 3.74+0.05 Protein % 3.50 3.50 3.50 3.52 3.54 3.58 3.60 3.61 3.57 3.68 3.70 3.65 3.57 3.59 3.58+0.02 Lactose % 4.80 4.85 4.86 4.80 4.81 4.76 4.74 4.70 4.82 4.93 4.86 4.90 4.91 4.93 4.83+0.02 Total Solid3 12.80 12.85 12.75 12.80 12.90 12.91 12.95 12.80 12.94 12.93 12.99 13.00 13.01 12.98 12.90+0.02 SNP % 8.78 8.85 8.83 8.90 9.48 9.41 9.43 9.22 9.39 9.25 9.27 9.30 9.09 8.99 9.16+0.05 Ash % 0.72 0.72 0.72 0.72 0.73 0.73 0.73 0.73 0.73 0.73 0.73 0.73 0.75 0.73 O.73+O.OO Calcium (mg/l00g) 140.10 132.00 152.00 148.40 145.40 145.20 132.50 125.12 135.34 142.00 145.00 148.20 145.20 148.00 141.75+2.07 Phosphorus(mg/1OOg) 92.52 94.80 98.72 102.50 112.50 87.25 88.10 83.42 76.00 78.25 80.25 81.50 89.00 92.82 89.60+4.50 Energy (KJ/g) 20.71 20.59 20.50 20.54 20.67 20.71 21.46 21.67 21.92 21.42 21.35 21.10 21.50 21.72 21.13+0.13 UNIVERSITY OF IBADAN LIBRARY I APPENDIX C3. Animal No German Brown No. 64 (oontd.) Diet: Low leral ration + ad lib forage Nutrient 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Mean Grand* GrandTotal Mean Milk yield 42.73 37.27 35,00 30.00 30.00 30.00 26.36 25.00 25.90 24.45 26.36 28.64 22.73 20.45 28.71+6.15 1083.04 38.68+11.35 SCM(kg/wk) 43.12 37.65 35.39 30.23 30.30 30.33 26.72 25.39 26.07 24.5'?- 26.46 29.01 22.52 20.40 29.16+6.13 1078.84 33.53+10.99 Forage 4.32 4.62 5.77 5.25 5.79 6.03 4.51 5.70 5.50 6.22 6.71 5.18 4.43 4.81 5.35+0.24 1119.16 5.71+0.21 Ration 1.50 1.50 1.05 1.20 1.20 1.20 1,20 1.20 1.35 1.35 1.20 1.35 1.35 1.00 1.26+0.05 344.96 1.83+0.12 Total 5.82 6.12 6.82 6.45 6.79 7.23 5.71 6.90 6.85 7.57 7.91 6.53 5.78 5.81 6.59+0.OS 1475.88 7.53+0.19 Weight(kg) 420.91 415.00 419.50 420.00 434.93 430.28 432.98 424.80+2.94 - 410.76+5.39 Fat % 4.00 4.05 4.0S 4.07 4.06 4.10 4.12 4.15 4.07 4.04 4.08 4.12 4.15 4.20 4.09+0.01 42.46* 3.92+0.06 Protein % 3.60 3.58 3.55 3.53 3.54 3.56 3.50 3.49 3.50 3.48 3.51 3.48 3.51 3.50 3.52+0.01 38.45* 3.55+0.02 Lactose % 4.80 4.86 4.90 4-87 4.86 4.62 4.70 4.68 4.67 4.65 4.52 4.58 4.59 4.57 4.71+0.03 51.66* 4.77+0.02 T3 % 12.98 12.95 12.94 12.92 12.94 12.92 12.94 12.92 12.88 12.86 12.83 12.93 12.57 12.63 12.87+0.02 139.60* 12.89+0.01 SNF % 8.98 8.90 8.86 8.85 8.88 8.82 8.82 8.80 8.81 8.82 8.75 8.81 8,42 8.43 8.78+0.05 97,15* 8.97+0,08 Ash % 0.73 0.73 O.72 O.72 O.72 O .72 0.71 O .72 0.72 0.72 O .72 0.72 O .72 O .72 p.72+0.01 7,60* O.72+O.OI Calcium 148.82 145.70 148.OO 152.50 150.25 158.20 162.00 167.00 158.30 160.00 162.00 157.00 146.OQ 150.00 154,66+3.80 1*601 148,20+3,71 Ftiosphprus 95?2§ §§,29 85,11 §8.40 99.Q9 §2.42 §0.40 §0,25 §0,00 82,45 95.00 §§?19 99.20 99.50 §6*17±M1 10*95* §7,§3+2,p§ Snergy ?1,7§ ?1??§ ?1?55 21-69 ?9?§? ?9.72 ?9?25 29.10 15,11 29 M ?9?75 ?e?9§ ?9?1§ ?9??9 ?9?65±0?15 ?,?f*197 ?9?§5i9,11 fl Values given pen ?§ Neels? UNIVERSITY OF IBADAN LIBRARY ■> APPENDIX C4 Laetatlng Cows Total Digestible Nutrient (TPN) (kg/lOQir feed) of the grass an! concentrate B re ed N o . DCP DOF DES DNfE TDN (kg/100 kg feed) a b 0 a b 0 a b c a b 0 a b 0 467 5.86 13.89 13.13 18.38 6.19 6.09 0.53 3.35 3.25 24.46 37.67 37.58 49.23(7 A5) 61.10(9.24) 60.05(9.08) W h ite 481 6.06 12 AO 12.28 13.06 5.89 5.73 0.60 5.22 3.16 26.30 30.16 36.81 51.02(7.72) 59.67(9.03) 59.78(8.77) F u la n i 242 5.37 12.45 12.40 17.53 5.92 5.55 0.57 3.22 3.21 27.93 58.53 37.75 51.90(7.85) 60.12(9.09) 58.91(8.91) 167 6.06 13.50 12.80 16.71 5.81 5.64 0.65 3.25 3.18 27.14 5 ? .5 6 37.42 50.56(7.65) 62.12(9.40) 59.04(8.93) Mean 5.96 13.06 12.65 17.67 5.95 5.75 0.39 3.26 3.20 26.46 38 A8 37.39 50.68(7.67) 60.75(9.19) 58.99(8.92) 69 6.33 13.49 12.52 17.91 4.13 5.46 0.62 3A8 3.27 27.63 43.17 40.21 52.49(7.94) 64-27(9.72) 61 A6(9.30) 42 6.51 14.83 13.57 i7.a 5. JO _5..36 v.73 3.26German 2.60 27.35 47*94 42.08 52.23(7.90) 71.33(10.79) 63.61(9.62) Brow n 66 6.06 13.32 12.98 15.44 4.65 4.56 0.76 3.25 3.21 27.97 41.99 . 39.-72 50.23(7.60) 63.21(9.56) 60.47(9.15) 57 6.54 12.78 12.76 17.78 5.28 4.92 0.75 ?.?1 3.30 27.51 4°.?? 37-54 52.38(7.92) 61.70(9-33) 53.52(8.85) Mean 6.31 13.61 12.96 17-19 4 -8 4 5.08 0.72 3.33 3.10 27.62 4?.?6 39.89 51.83(7.84) 65.14(9.85) 61.03(9.23) 92 6.18 14.09 12.60 17.94 5 -37 5.43 0.69 .3.29 3.21 26.99 39.49 39.70 51.80(7.841 62.24(9 A2) 60.99(9.23) 117 6.22 12 A3 12.28 12.52 6.18 5.70 0.67 3.26 3.12 27.83 40.82 39.12 47.24(7.15) 62.69(9.48) 60.22(9.11) F r ie s ia n 90 6.36 12.45 12.29 15.07 5.69 5.45 0.64 3.53 3.27 27.87 4? .08 38.65 49-94(7.55) 64.75(9.79) 59.66(9.02) 127 6.26 13.28 12.32 17.21 Veif6 4.58 0.69 3.20 3.10 29.38 44-87 42.15 52.54(7.95) 65.81(9.96) 62.15(9.40) Mean 6.31 13.06 12.37 15.68 5 A3 5.30 0.67 3.32 3.18 27.77 42.09 39.91 42a?5.(L^l 63.-.Z219-&1 6o.76(9.19) ( ) V a lu e s I n p a r e n th e s is a re e x p re s s e d i n UJM E/kg fe e d UNIVERSITY OF IBADAN LIBRARY ■', 1f Appendix C4 STHSRS ^SiS^i^L*JfaiLgL9d>i.(kg/lOOkg feed) of the gras; and concentrate Bread No. Dig-3 s tibia rode Digestible Crude Digestib le Ktiier- Fr5tain (W:p)___ Fibre (DCF) Extract (ffiS) Digestible NiCrogenl Total Digestible Nutrient TDN Fro a ExtractiTes(DR!JS) (kir/100 ke feed) a b 0 a b 0 a b 0 a ' b 0 ft b 0 245 5.93 12.60 12.54 17.11 5.88 5.58 0.74 3.20 3.15 26.80 38.88 38.54 50.58(7.65) 60.56(9.16) 59.81(9.05) White 85 6.03 13.18Fulani 13.39 17.09 5.93 5.61 0.76 3.32 3.23 27.12 38.22 36.57 51.00(7.71) 60.65(9.17) 58.80(8.89) Mean 5.93 12.89 12.97 17.10 5.91 5.60 0.75 3.26 3.19 26.96 38.55 37.56 50.79(7.68) 60.61(9.17) 59.32(8.97) 6 k 6.23 13.68 13.56 16.39 5.60 4.85 0.76 3*41 3.21 27.31 41.15 38.39 50.69(7,67) 63.84(9.66)Oaraan 60,01(9.08) Brown 65 6.34 13.65 13.37 16.65 5.33 5.46 0.71 3.35 3.30 26.84 40.61 37.83 50.54(7.65) 62.94(9.52) 59-96(9.07) Bean 6.29 13.66 13.47 16.52 5.47 5.16 0.74 3.38 3.26 27.07 40.87 38.11 50.62(7.66) 63.39(9.59) 59.99(9.07) 132 6.36 13.54 13.50 15.65 5.36 5.25 0.69 3.28 3.14 27.86 43.26 40.99 50.56(7.65) 62.71(9.94) 62.88(9.50 Friesian 358 6.15 13.27 12.40 16.0S 5.21 5.11 0.66 3.23 3.11 27.13 39.55 38.71 50.05(7.57) 61.26(9.27) 60.33(9.13) Mean 6.26 13J41 12.95 15.86 5.29 5.18 0.68 3.26 3*13 27.52 41.41 40.35 50.32(7.61) 61.99(9.61) 61.61(9.32) a ■ Forage ( ) Metabolisable energy (UJ/kg/kg feed) confertad to MS by using Jagusoh and Coop's (1971) Formula, b m High Concentrate ' e m hem Concentrate. UNIVERSITY OF IBADAN LIBRARY 09 £ g g 1 1 w j s| ai d s. ! _________________________________________ 2_________________ ro r N s VP O' Ov f b> *■ s ON s ->J 8 -«J S s O' vo ? 5 -o g H 92 E so ot- EC E a E S to t- &B 35 3: 3:o o •* g E o E o c ■ o •* E O E E 3c :n ) E c ss1 *• E o *a t 9 «♦ tf N PO VO V* VM Ov 2 J s S ? 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J 2 0D Vo >-0 VO VP V £ 8 « VO a Cp o ODI O' 8 ro g s S' k Vk S k v« p m VP -o•o 0# A O o 1 o o A ♦o A A A o♦ 1 A ♦o A 1 O A A o o♦ • o A A o♦ o♦ A o♦ ♦O o e A A A A A ♦c A k k s i k is k V; CE o 8 if O' k fc VP b O'O' VP VP c vn VP k VP s VP k is Vro O'P VP VP 3 b if fe k ro £ k k 3 VOp' o♦-* v» g r r r f- * Vp vp Vp Vp VP .vO V pO Eip g § Co £ k £ R £ s g Co V0 3i s VP i --I P p £g g ? $ io -J o p 5 o i o g £ ~o § 3 O' a o b « ip o b o b b P-J ro b b b u Ov VP O' VP i £ 8 VPh O' O 8 k k O' s is is •ACp 3 bt ro b b VP ip ai P *o V- 8 S' P OD P fe ro U • (*oo/X*p/»*) »tox jo i [ rn • • i&L ) n»Jiu*oooo *ot ■ y\£anv\otjjs «toj$ M , (no^opa— oo«j ,D,I*Y Ĵ OOT) •q*naw«®3 q*TH ■ 3H(till) n ^ o j «.-*f •HT*m *OT«n *q »̂P/SII fl oq p t̂nfpr *, *w»X» oioaoi - i.NIVERSITY OF IBA AN LIBRARY APPENDIX C4.6 Comparison of MS Intake (MJ/day) obtained from actual dataruination on the cow ami that calculated from Total Digestible Nutrient (TDNl 2 Breed No. Treatment 1A ctual C alcu lated D ifferen ce Determination from TDN 467 F 23.12 26.82 -3.70 HC 47.86 47.82 ♦ 0.04 LC 53.80 43.04 +10.76 481 F 15.08 28.33 -13 .2 5 HC 34.71 4 1.5 7 - 6.86 White 58.98 Fulani LC 43.42 +15.56 242 F 22.47 31.40 - 8.93 HC 53.79 52.75 ♦ 1.04 LC 57.67 48.32 + 9.32 167 F 28.66 36.95 - 8.29 HC 59.22 54.49 ♦ 4 .7 3 LC 70.17 58.88 +11.29 Mean 43.79+3-22 42.82+4.16 + 0.97 63 F 43.33 39.52 ♦ 3.81 HC 65.08 62.72 + 2.36 LC 44.26 53.20 - 8.94 42 F 43.88 46.29 - 2.41 HC 53.91 74.18 -20+27 German LC 67.77 55.21 -13 .5 6 Brown 66 F 38.64 38.08 + 0.56 HC 69.29 50.20 +19.09 LC 59.61 59.30 ♦ 0.31 57 F 32.05 38.33 - 6.28 HC 52.09 62.00 - 9.91 LC 5».39 54.41 + 3.98 Mean 52.36+3.48 52.79+3.41 - 0 A 3 92 F 24.79 45.24 -20.45 HC 80.66 81.07 - 0 A 1 LC 62.74 40.14 +22.60 117 F 13.66 33.03 -19 .3 7 HC 60.82 54.72 ♦ 6.10 LC 64.28 48.14 +15.87 F r io - 90 F 18.27 42 A 3 -2 4 .16 sian HC 61.61 70.02 - 8 A 1 LC 90.84 71.6 5 +19.19 127 F 22.56 37.21 -14 .6 5 HC 68.20 58.55 ♦ 9.65 LC 87.45 75.58 +1 1 .87 Mean 54.66+7.98 54 . 82+5 .1 7 - 0 .61 1 a Figure* taken from Table 4 .26 2 a F igures ca lc u la te d from Table 4 .1 1 F a Forage and Appendix C.56 HC a High Concentrate ♦ forage LC a Low Conoentrate ♦ fo ra g e . 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