Abstract:
The objective of this study was to evaluate the effect of commonly used diluents in storage of
caudal epididymal spermatozoa under different temperature treatments. Eighteen pairs of bull
epididymides were obtained from a local abattoir and caudal epididymal spermatozoa were
harvested and processed in the laboratory. Epididymal spermatozoa were pooled from groups
of three bulls to give six pooled samples for this study. The effect of three diluents namely, tris,
egg yolk citrate and Skim milk were tested under three temperature treatments of 4oC, 25oC and
39oC on their effect on viability of the caudal epididymal spermatozoa. The percentage motility
and the livability of the spermatozoa were considered as a measure of their viability. On
incubation for 96 hrs at 4oC tris maintained a high percentage of motile caudal epididymal
spermatozoa than any of the other diluents, with 24.2±2.2 percent motile spermatozoa, while
skim milk had 6.6±0.5 percent. The egg yolk diluent did not have any motile spermatozoa at 96
hrs of incubation (P<0.05). After the same period and temperature treatments, tris contained
25.9 ±0.4 percent live spermatozoa, skim milk 10.8 ± 1.2 percent and egg yolk citrate 6.8 ±0.2.
The difference was statistically significant (P< 0.05). The temperature of 4oC and tris were found
to maintain higher motile and live caudal epididymal spermatozoa than egg yolk citrate or skim
milk diluents. Caudal epididymal spermatozoa when stored in the commonly used diluents for
longer period of time can be used for artificial insemination (A.I) especially where a very good
bull cannot ejaculate due to one reason or another or in situations where the preservation of
genetic material is paramount.
