Morphological Changes in Sperm Cells during Epididymal 
Transit in West African Dwarf Buck
OYEYEMI, M.O., OLA-DAVIES, OLUFUNKE E., OKE, O.A. and IDEHEN, C.O.
Faculty o f Veterinary Medicine, University o f Ibadan, Ibadan Nigeria.
Keywords: Sperm morphology, Epididymal transit, Spermatozoa, West African dwarf
'bucks. "
Abstract
The spermatozoa characteristics during epididymal transit were studied .in healthy West 
African dwarf (WAD) goat bucks. The caput epididymis had a value of 27.0% of abnormal 
sperm cell,-which is significantly different (P<0.05) from the 21.0% of corpus and 23.0% of the 
cauda epididymis. There was no significant difference (P>0.05) between the values of corpus 
and caudal epididymis. The caput epididymis also had 6.0% spermatozoa with proximal 
cytoplasmic droplets which differed significantly (P<0.05) from that of the corpus (1.20%) and 
the cauda (0.9%), The values for coiled tails and tire total abnormal sperm cells showed that 
caput epididymis had higher abnormal spermatozoa, which was closely followed by cauda while 
the corpus epididymis had the 1’east. There were more spermatozoa with looped tails in the 
cauda epididymis (1.68%) than in other segment (corpus: 0.95% and caput: 0.80%). The 
testicular and epididymal parameters were positively correlated (weight of testis and 
epididymis; weight of testis, scrotal circumference, testicular circumference, weight of 
epididymis and weight of testis (r = >0.05) except the correlation values between length of 
epididymis and length of tests (r = 0.30).
Introduction classification of speim defects into primary 
and secondary or major and minor defects 
'The morphological changes of (Bloom, 1973) although Moss et al. (1988) 
spermatozoa due to frequency of classified' these defects into primary', 
ejaculation and season have been studied by secondary and tertiary or miscellaneous.
Igboeli (1974), Okere et al., (1986) and Morris et al. (1979) and Coulter (1982) 
Oyeyemi .et al., (1996). The epididymis is discovered that within a species of animal 
an extremely large convoluted structure there is .a good fcorrelation between 
which is closely attached to the dorsal part spermatozoa production, testicular sizes and 
of the lateral" surface of the testicle the age of the animal. Skinner (1975) 
(Setchell,- 1977). Its functions include reported increase testicular weight 'as the 
storage, maturation and absorption of sperm age of Boer buck increases and this 
cell. Changes occurring in sperm determined the amount of spermatozoa 
morphology during epididymal migration present in the epididymis. It has been 
have been correlated with the functional reported that some sperm cells’ defects 
integrity of the testis and the epididymis such as the “knobbed acrosome” and the 
(Rao, 197.:). This has led to the “dag defects” are breed specific (in bull)
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Oyeyemi e t a l
was neatly and carefully trimmed off the 
and heritable (Bloom, 1977 and Akusu et body of the testis and semen samples were 
al, 1985). sucked into a Pasteur pipette from the three 
Comprehensive studies on the parts of the epididymis (caput, corpus and 
morphological changes of spermatozoa cauda) through an incision into the lumen 
during epididymis transit in WAD goat and using 2-4 drop of 2.9% sodium citrate 
bucks ha\se not been reported. Therefore as tire flushing fluid.
the study was carried out to investigate the 
differences in morphological characteristics Semen Preparation
of sperm cells in each segment of the 
epididymis of the buck in -order to The collected sperm sample from each 
accurately interpret morphological part was separated in sample tubes 
abnormalities of the sperm cells' in relation containing 0.5ml of 10% normal saline. The 
to their epididymal location. sodium citrate diluted samples were used 
for the estimation of spermatozoa motility 
and the preparation of smears stained with 
Materials and Methods Well and Awa .stain.for acrosomal integrity 
(Wells.and Awa, 1970). Formal saline was 
Animal Examination used to fix tire sperm cells during counting 
in tire haemocytometer. The semen sample 
Ante-mortem examination was carried was analyzed for odier characteristics by 
out on the bucks for obvious physical conventional methods (Moss et al., 1988).
abnormalities and infections such as mange 
and ectoparasites, The animals were then Data Analysis
weighed. The intrascrotal testes were 
palpated for proportional sizes, pendulum­ Mean percentage values were tested by 
like nature, cryptorchidism, flabbiness, and statistical methods as outlined in tire 
orchitis and testicular consistency. General Linear Models Procedure (Dunn 
and Clark, 1972), while “t ” test and 
Sample Collection correlation coefficients wrere calculated 
using procedure of Steel and Torrie (1986),
Forty testes (20 pairs) from sexually 
matured clinically healthy West African 
Dwarf (WAD) ĝoat bucks, aged between 2 Results d
and 4 years and weighing between 19-22kg 
from known farms were collected before The summary' of the percentage mean 
slaughter. The intrascrotal testes were values of spermatozoa pharacteristies at 
weighted immediately and placed in a well- different parts of the epididymis, regardless 
insulated box maintained at 37°C. of age of the anifhal, is presented in Table 
1. The caput epididymis has a significantly 
Semen Collection higher mean value of 2T8% (P<0.05) of 
abnormal sperm head compared to tire 
The weights of testes and epididymis, corpus 1.4% and cauda 1.4%. There were 
testes alone, epididymis alone and their more acrosomal damage in tire cauda 
lengths were determined using either a epididymis (0.63%) which differed 
weighing machine or flexible tape, as significantly from the value in the corpus
appropriate. Each epididymis (right, left)
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Morphological changes in sperm cells ...
and caput epididymis (0.40% and 0.38%, Discussion
respectively) (P<0.05).
The incidence of proximal cytoplasmic The observed morphological changes 
droplets is higher in the caput epididymis as which spermatozoa undergo in the caput 
shown in Table 1. Furthermore, the epididymis are at variance with the reports 
incidence of distal cytoplasmic droplets in of some other workers. For example, 
the caput, corpus and cauda epididymis Almquist and Amann (1962) observed a 
were 0.78, 3.08 and 6.18, respectively. decreased incidence of head abnormalities 
This shows that there is a significant from the caput epididymis to the cauda 
difference (P<0.05) in the incidence of epididymis, while in this study, frequency 
distal cytoplasmic droplets in tire cauda of abnormal sperm heads in caput (2.20%) 
compared to the corpus and the caput differed significantly (P<0.05) from that of 
epididymis. There was no significant corpus (1.40%) and cauda epididymis 
difference in the values of abnormal (1.40%).
midpiece in the caput, corpus and cauda The value of abnormal acrosome in the 
epididymis. The values in these three parts cauda epididymis (0.063%) is significant 
differed significantly (P<0.05) in detached higher (P<0.05) than values of corpus 
sperm heads and tail abnormalities. (0.40%) and caput epididymis (0.38%). 
Detached sperm abnormalities in caput was This may be due to cauda epididymis being 
3.40% corpus 4.3% and cauda 2.70% while more affected by constituent and defective 
simple bent tail abnormalities for caput, development. These findings agreed with 
corpus and cauda epididymis were 2.10%, the report of Setchell (1977).
3.40% and 4.4%, respectively. The level of immaturity of the sperm 
Total abnormal sperm cells in caput cells were indicated by cytoplasmic 
epididymis differed significantly (P<0.05) droplets which showed a significant 
to that of corpus and cauda epididymis. difference (P<0.05) between the values of 
There was no significant difference proximal cytoplasmic droplets in caput 
between corpus and cauda epididymis, epididymis compared with corpus and 
though the latter is relatively higher than cauda epididymis which did not differ 
the former. significantly (P>0.05). While the value of 
The correlation coefficient for the distal cytoplasmic droplets in the cauda 
testicular and epididymal parameters differed significantly (P<0.05j compared 
(weight of testes (WT), length of testes with the values of distal cytoplasmic 
(LT), testicular circumference (CT), weight droplets in the corpus and caput epididymis. 
of testis an epididymis (WTE), weight of The ability of the sperm to fertilize is 
epididymis (WE) and length of epididymis acquired in the distal half of the body 
(LE) are presented in Table 2. Except for (coipus) of the epididymis. This may be 
the length of testes and length of the reason for the lower value observed for 
epididymis that were not positively proximal cytoplamic droplets. This -agreed 
correlated (P>0.05) other testicular with the report of Cole and Cupps (1977).
parameters showed positive correlation The coipus epididymis had more of tire 
with each other. detached sperm heads than the caput 
epididymis and the cauda epididymis. The 
values of detached sperm heads in corpus 
epididymis differed significantly7 when 
compared with the other two segments of 
epididymis and this indicates that as the rate
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UNIVERSITY OF IBADAN LIBRARY
Oyeyemi et al
■ of maturation increases front caput to cauda parameters, weight of epididymis (WE) and 
epididymis the rate at which spermatozoa length of epididymis (LE) and scrotal 
lose their tails decreases. This is contrary- circumference (SC) except the length of 
to the report of Roberts (1977) that during epididymis (LE) and length of testes (LT). 
aging, the acrosome and implantation These results conform to the observation of 
region became loosened from the nucleus Willet and Ohm (1957) that lengths of 
starting at the apical ridge in the bull. The epididymis and testes did not differ 
, report of Rao (1971) in the bull supports significantly (P>0.05), testicular and 
this finding. epididymial growth parameters should be 
The tail abnormalities showed that there correlated. The analysis of Land and Carr 
were significant differences (P<0.05) in the (1957) support these findings that testicular 
incidence of tails coiled below and around and epididymal parameters, are positively 
the head in the caput epididymis than other correlated.
segments or parts of epididymis. Other 
abnormalities (looped tail, simple bent tails) References
in tins study may partly' reflect tertiary' 
abnormalities rather than the abnormalities Akusu, M.O. Ogwnegbu, S.O., B.O. Oke. 
that originated from spermatogenesis or Differences in morphology of bull 
epididymis. The results observed for spermatozoa from normal and patho­
detached sperm heads, in tins study was logical testis during epididymal transit. 
significantly higher (P<0.05) in caput Nig. Vet. J. 14: 30-33 (1985).
epididymis than the same values in corpus Almquist, J.O. Amann, R.P. Reproductible 
and cauda epididymis. The findings agreed capacity of dairy' bull, VII: Morphology7 
with the report of Akusu et al. (1985) who of Epidiymal sperm. J. Dairy Sci: 44: 
stated that detached normal head, broken 337-248 "(1949).
neck and'tail coiled around the head are Bishop, M.W.H., Campbell, R.C., Hancock, 
common and higher in the caput epididymis J.L., Walton, A. Semen Characteristic 
than other segments of the epididymis. and Fertility in the Bull. J. Agric. Sci. 
The increase in the incidence of tail 44: 227-248 (1949)
abnormalities in the caput epididymis may Bloom E. The ultrastructure of some 
be due to scrotal temperature of the animal characteristic sperm defects and a 
prior to slaughter. This is in agreement proposal for a new' classification of a 
with the report of Bishop et al. (1949) and bull spermiogram. Attidel VIII Symposio 
Moss et al. (1988) that as the temperature Internationale de. Zootechia. Milano, 
increases or decreases from 37°C there is 125-139 (1973).
tendency for more tail abnormalities in this Bloom, E. Spenn morphology with 
species despite its pendulous descended reference to bull . fertility. Paper 
testes and or may be due to heat or cold presented at thp Is1 All India Symposium 
shock during the experiment in die on Animal Reproduction. Ludhiana, 
laboratory. India, pp. 61-81 (1977).
There was high correlation (P<0.05) Cole, H.H., Cupps, P.T. Reproduction in 
between testicular weight and scrotal domestic animals. 3rd Ed. Academic 
circumference. All the testicular Press, New'York, pp. 665 (1977).
parameters, weight of testes and epididymis Coulter, G.H. This business of testicular 
(WTE), weight of testes (WT), length of size. Proc. of 16th Conference of 
testes (LT), testicular circumference (CT) artificial insemination and embryo
showed high correlation with epididymal
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Morphological changes in sperm cells
; transfer in Beef cattle. Natl. Ass. Anim. ejaculation on the semen characteristics 
Breeding. Columbia Missouri (1982). of West African dwarf goats. Prop. Vet. 
Dunn, O.J., Clark, V.A. Applied Statistics: 14: 71-75 (1996).
Analysis of Variance and Regression Rao, A.R. Changes in the Morphology of 
Wiley, New York (1972). sperm during their passage through the 
Igboeli, G.L A Comparative study of semen genital tract in bulls with normal and 
and seminal characteristics of two impaired spermatognesis. Ph.D. Thesis, 
breeds of goats. J. East. Afr. Agric. Stockholm pp. 88 (1971).
40(2): 132-137 (1974). Roberts, S.J. Veterinary Obstetrics and 
Land, R.B., Carr, W.R. Testes growth and Genital Diseases (Theriogenology), 2nd 
plasma LH concentration following Ed., Edwards Brothers Inc. Ann. Arbor, 
hamicastation and its elationship with Michigan, pp. 776 (1971)
female prolificacy in sheep. J. Reprod. Setchell, B.P. Male reproductive organs and 
Fert. 45: 475 (1975). semen. In: Reproduction in domestic 
Morris, O.L., Smith, M.F., Parish, W.R., Animal. 3rd Ed., Academic Press, New 
William, J.D., Wilbank, J.N., The effect York 229-256 (1977).
of scrotal circumference, libido and Steel, R.G.D., Torrie, J.H. Principles and 
semen quality on fertility of American Procedure of Statistics. A Biometrics 
Brahaman and Santa Gertudis Bull. Approach 2nd Ed. McGraw Phil, New 
Proc. Anim. Mgt. of the Society for York (1986).
Theorigenology. Oklahoma City (1979). Skinner, J.D. Reproductive physiology of 
Moss, J.A., Melrose, D.R. Vanderplassche, indigenous and exotic male animal in 
H.C.B. Spermatozoa, semen and South Africa. Agric. Res. A.B.A. 43: 
artificial insemination. In: fertility an 4628 (1975).
infertility in Veterinary practice. 4th Ed. Wells, M.E. and Awa, O.A. New* 
Eds: J.A. Laing, W.J. Brinley Morgan, Technique for assessing acrosomal 
W.C. Wagner (1988). characteristics of spermatozoa. J. Dairy 
Okere, C., Chiboka, 0., Montsma, G. Effect Sci. 53(2): 227 (1970).
of frequent ejaculation of West African Willet, E.L., Ohm, J.I., Measurement of 
Dward Goats on semen characteristics. testicular size and its relation to the 
Anim. Reprod. Sci. 11: 249-258 (1986). production of spermatozoa by buck. J. 
Oyeyemi, M.O., Akusu, M.O., Olaoye, Dairy Sci. 40: 1559-1569 (1957).
Omobowale, O.T. Effect of frequent
Acceptedfor publication August 30, 1999.
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Table!: Mean percentage values of morphlogical characteritics of spermatozoa in the epididymis
P a rts  o f  T o ta l n u m b e r  A b n o rm a l A b n o rm a l P ro x im a l D is ta l A b n o rm a l D e ta c h e d S im p le  T a il T a il L o o p e d T o ta l 
e p id id y m is o f  e p id id y m is s p e rm a c ro s o n ie c y to ­ c y to ­ m id -p ie c e s p e rm b e n t ta il c o i le d c o i le d ta il a b n o rm a l 
h e a d p la sm ic p la s m ic h e a d a ro u n d b e lo w s p e rm  ce ll
d ro p le t d ro p le t h e a d h e a d
C a p u t 4 0 2 .1 7 5 " 0 .3 7 5 b 6 .0 2 5 0 .7 7 5 "  • .1 .5 5 0 6 .3 5 0 " 2 . 100b 0 .9 2 5 8 .9 2 5 " 0 .8 0 0 ' 27 .00*
C o rp u s 4 0 1 .4 0 0 “ 0 .4 0 0 “ 1.200 3 .0 7 5 “ 1.475 4 .2 5 0 b 3 .4 0 0 “ 9 .3 2 5 4 .6 5 0 “ 0 .9 5 0 ' 2 1 .1 2 5 “
C a u d a 4 0 1 .4 0 0 “ 0 .6 2 5 " 0 .9 0 0 6 .1 7 5 " 1 .600 2 .6 7 5 ' 4 .4 2 5 " 0 .3 2 5 2 .9 0 0 “ 1.675" 2 2 .7 0 0 ’
Means with different letters on vertical column differ significantly (P<0.05).
Table 2: Correlation Table for Testicular and Epididymal Parameters
WTE w r WE LE LT CT SC
WTE 1
WT 0.99 1
WE 0.91 0.891 1
LE 0.63 0.6044 0.709
LT 0.78 0.8039 0.604 -0.29 1
ST 0.96 0.9584 0.869 0.643 0.8 1
SC 0.92 0.9091 0.821 0.615 0.7 0.934 1
WTE - Weight of Testis and Epididymis
WT Weight of Testes
WE Weight of Epididymis
LE Length of Epididymis
LT Length of Testes
CT Testicular Circumference
SC Scrotal Circumference
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