The study aimed to evaluate the effects of dietary crude protein levels on rabbit semen characteristics. Thirty crossbred male rabbits (New Zealand White x local), with an average weight of 2.59 ± 0.14 kg, were completely randomized design consisted of five treatments and six replications, with one buck rabbit as an experimental unit. The five experimental treatments were diets containing 14%, 16%, 18%, 20%, and 22% crude protein corresponding CP14, CP16, CP18, CP20 and CP22 treatment, respectively. Feedstuffs used in the experiment included fermented soya waste, soybean extraction meal, Operculina turpethum, and Pennisetum purpureum. The experiment was carried out for 12 weeks in which sperm of the experimental rabbits was collected and analyzed weekly. After 12 weeks of semen collection, 1 bucks per treatment with stable semen quality were used for mating with does to evaluate reproductive performance. Six does were used for each treatment (total 30 doe rabbits). The results of the study showed that there was a fluctuating tendency in sperm concentration over time (P < 0.05) among treatments. The sperm concentration of CP14, CP16 CP20, and CP22 tended to decrease during 12 sampling weeks, however, this result increased for the CP18. When the ratio of CP increasing in the diet gave higher results in terms of sperm concentration, live sperm rate, total motile sperm, and gross motility (P < 0.05) compared to 14% treatment. Those results gave higher values for the 18% treatment at 314.1 x 106/mL, 60.4%, 139.4 x 106, and 59.5%, respectively. There was no impact (P > 0.05) of dietary crude protein on the weight of male rabbits and reproductive performance in doe rabbits in terms of litter size at birth, mean weight at birth, and litter size at weaning. Results of this study showed that among the different diets, the 18% CP diet was suitable for the reproduction of male crossbred rabbits.
Keywords | Crossbred rabbits, Dietary crude protein, Membrane integrity, Motility, Testosterone, Sperm quality