ABSTRACT
This study was conducted to investigate the effect of diets containing raw or fermented cottonseed cake on reproductive characteristics of rabbit bucks. Eighteen (18) weaned crossbred (New Zealand White X Chinchilla) rabbit bucks, 6-7 weeks old, were randomly allotted to three treatments with six animals per treatment in a Completely Randomized Designed experiment. The treatment diets were T1, (Control) containing soyabean meal (SBM) as the main protein source; T2, Raw Cottonseed Cake (RCSC) - based diet and T3, Fermented Cottonseed Cake (FCSC) - based diet. The fermentation was done by inoculation with Aspergillus niger. Animals were acclimatized for one week. The feeding trial lasted for 9 weeks. At the end of this trial, 3 bucks per treatment were slaughtered and the reproductive organs dissected out for testicular and epididymal morphometrics as well as gonadal sperm assessment. Testicular morphometrics were not significantly (P>0.05) affected by the treatment. Treatment had significant (P<0.05) effect on the epididymal weight and length of rabbit buck. Testicular sperm count for the RCSC group (124.67x106) was significantly (P<0.05) lower than that of the control (182.22x106). Bucks on FCSC diet had comparable sperm count (181.50x106) with the control group. The proportion of motile sperm was significantly (P<0.05) increased from 48% in the control to 66.33% in the FCSC group. It was concluded that raw CSC had adverse effect on the sperm characteristics of rabbit bucks. However fermentation, using Aspergillus niger mitigated the adverse effect of CSC on the sperm characteristics. It is recommended that CSC to be included in diet of rabbit bucks meant for breeding purpose should be fermented by Aspergillus niger.