Effect of Age at Weaning on Growth Performance and Post-Weaning Survival Rate of Different Rabbit Genotypes in South-Eastern Agro-Ecological Zone of Nigeria

This study evaluated the influence of age at weaning on post-weaning growth performance and survival rates of different rabbit genotypes – New Zealand White (NZ), Chinchilla (CH), NZ×CH and CH×NZ in a completely randomized design. The weaning ages considered as treatments across the genotypes were 28 (T28), 42 (T42) and 56 (T56) days, respectively. Data from 67 kits NZ (19), CH (15), NZ×CH (17) and CH×NZ (16) were used for the study. Measurements taken from each genotype for 7 weeks after each weaning age include body weight (BW), body weight gain (BWG), feed efficiency (FE) and survival rate (%). The analysis of variance showed that there were significant differences (P < 0.05) among the different weaning ages on the growth parameters. Kits weaned at day 28 had significantly (P < 0.05) higher values for BW and BWG as well as better feed efficiency index followed by those weaned at 42 days and then 56 days. Estimates of BW both at the initial and final weeks were: NZ – 414, 809 (T28), 380, 766 (T42) and 234, 447 (T56), CH – 443, 935 (T28), 436, 751 (T42) and 302, 500 (T56), NZ×CH – 432, 834 (T28), 394, 678 (T42) and 241, 417 (T56) and CH×NZ – 436, 917 (T28), 425, 717 (T42) and 261, 462 (T56). Significant (P < 0.05) differences were only observed for survival rate at the final week of measurement for the crossbred genotypes. Generally, however, the survival rates of kits of the different genotypes across all weaning ages were quite high. It ranged from 72.00 – 100 % (NZ), 75.00 – 100 % (CH), 87.70 – 100 % (NZ×CH) and 85.70 – 100 % (CH×NZ). Results of this study highly encouraged weaning at 28 days for optimum production efficiency in the study region. Weaning traits such as weights and survival/mortality rates are not affected greatly by additive gene action and thus can be improved by good management decisions among which is age at which rabbits are weaned.