ABSTRACT
The experiment was carried out to investigate the effect of dietary vitamin C levels on growth performance, thermoregulatory response, and semen characteristics of rabbit bucks in the hot-dry and cool-wet season of Zaria Nigeria. A total of 55 10 month old rabbit bucks consisting of 40 (NZW) pure and 15 (NZW“CAL) crossbred Hyla rabbits were allotted in a 2“ 2“4 factorial arrangement in a Completely Randomized Design. The factors considered were vitamin C levels (100 control, 200, 300 and 400 mg/kg) season (hot dry: March-June and cool wet: July-August), breed (pure and crossbred). Results obtained showed that vitamin C levels had significant (p<0.01) effect on growth performance. Breed had significant (p<0.05) effects on growth performance. Season had significant (p<0.01) effect on growth performance. Month had significant (p<0.01) effect on growth performance. There was interactions between vitamin C levels and breed on growth performance (p<0.01). There was interaction between vitamin C levels and month on growth performance (p<0.05). There was interaction between breed and season on growth performance (p<0.01). There was interaction between breed and month on growth performance (p≤0.01). Vitamin C levels had significant (p<0.05) effect on thermoregulatory response. Season had significant (p<0.01) effect on thermoregulatory response. Month had significant (p<0.01) effect on thermoregulatory response. There was interaction between vitamin C levels and breed on thermoregulatory response (p<0.01). There was interaction between vitamin C levels and season on thermoregulatory response (p<0.05). There was interaction between vitamin C levels and month on thermoregulatory response (p<0.05). There was interaction between breed and season on thermoregulatory response (p<0.01). There was interaction between breed and month on thermoregulatory response (p<0.05). Vitamin C levels had significant (p<0.05) effect on semen characteristics. Breed had significant (p<0.05) xix effects on semen characteristics. Season had significant (p<0.05) effect on semen characteristics. Month had significant (p<0.05) effect on semen characteristic. There was interactions between vitamin C levels and season on semen characteristics (p<0.05). Vitamin C levels had significant (p<0.05) effect on sperm morphological abnormalities. Season had significant (p<0.05) effect on sperm morphological abnormalities. Month had significant (p<0.01) effect on sperm morphological abnormalities. There was interaction between vitamin C levels and breed on sperm morphological abnormalities (p<0.05). There was interaction between vitamin C levels and month on sperm morphological abnormalities (p<0.01). There was interaction between breed and season on sperm morphological abnormalities (p<0.05). There was interaction between breed and month on sperm morphological abnormalities (p<0.05). It is concluded from this study that crossbred bucks performed better on 200 mg vitamin C, while purebred bucks performed better on 400 mg vitamin C.
