Influence of breed and environmental factors on litter parameters of rabbits raised in a semi-humid environment
The influence of breed and environmental factors such as season, temperature, relative humidity, sunshine hours and wind speed on litter parameters of rabbits raised in a semi-humid environment was investigated using two hundred and twenty four (224) litter records collected between 1991 and 1997. New Zealand White does kindled significantly (P<0.05) larger and heavier litter at birth than the other breeds. Crossbred does produced kits with significantly higher preweaning daily gain and lower neonatal mortality compared with the purebred does. Chinchilla and Crossbred does raised kits with significantly (P<0.05) heavier weaning weights than New Zealand White and Californian does. There was a non-significant effect of season on litter site at birth, kits alive at birth and neonatal mortality. Does that kindled in the cool-wet season had significantly (P<0.05) higher litter birth weight and average kit birth weight compared with does that kindled in the cold-dry and hot-dry seasons. Kits kindled in the hot-dry season had significantly higher preweaning litter daily gain and lower preweaning mortality than those kindled in the other seasons. Does that kindled in the hot-dry and cool-wet seasons weaned more kits than those that kindled in the cold-dry season. There was a significant (P<0.05) negative correlation between maximum temperature and litter size alive at birth, litter birth weight, litter weaning weight, average weaning weight and litter size at weaning. Rainfall and relative humidity had significant positive correlation with average birth weight, while, wind speed was positively correlated with average weaning weight. This study indicates that the best season for rabbit breeding in the semi-humid environment is the hot-dry (February-May) season. Maximum temperature was also observed to be more critical to rabbit reproduction as it influenced negatively more litter parameters than other environmental factors studied.
Keywords: Environment, Season, Litter parameters, Rabbits.