This study was carried out on 30 male dwarf goats to determine the effects of cypermethrin
(CY) on semen characteristics and at tissue level in testes. Animals were divided
randomly into five equal groups and each group was dipped with 0%, 0.1%, 0.4%, 0.8%
or 1.6% CY, on days 0 and 15. The semen was collected at day 0, then fortnightly till
75 days and evaluated for physical characteristics, sperm morphology and concentration.
None of the parameters studied showed any statistical difference on days 0 and 15
of sample collection. From day 30, effect of CY on semen characteristics started to
appear and was more pronounced from days 45 to 75. Significantly (P<0.01) decreased
ejaculatory volume, motility percentage, mass activity, and concentration of spermatozoa
were observed in treated groups as compared to control. With the treatment of CY,
pH of semen became more alkaline. Semen color changed from creamy (control) to milky
white to straw color in treated bucks. Percentage of abnormal spermatozoa (tailless,
bent tails, coiled tailed) was much higher in treated animals than in control. Dead
spermatozoa increased significantly (P<0.01) in the treatment groups from days 30
to 75 as compared to the control group. All these changes were dose dependent, being
less with low CY dose and more even extensive with high CY dose. Slight to moderate
improvement in the above parameters was observed at day 75 nearly in all treated groups.
Grossly decreased weight of testis and cyanotic epididymides were observed in bucks
treated with 1.6% CY. Histopathologically, degenerative changes and loss of spermatogonia,
spermatocyte, Sertoli cells, spermatids, and spermatozoa in seminiferous tubules were
also dose dependent. It was concluded that CY caused dose-dependent effects on all
parameters studied. High doses of CY (0.8% and 1.6% solution) affected the parameters
on semen characteristics, though this effect seems to be transient as improvement
in these parameters was observed at day 75; however, CY in goats should be used with
great care to avoid over-dosage.