Growth performance of broiler rabbits under 3*3 diallel crossing

Abstract

A complete 3 x 3 diallel crossing was performed to study the growth performance of rabbits belonging to three different breeds viz. White Giant (WG), Soviet Chinchilla (SC) and Grey Giant (GG) at the University rabbit farm, Centre for Advanced Studies in Animal Genetics and Breeding, College of Veterinary and Animal Sciences, Mannuthy, Thrissur. Growth records of F1 progeny were taken at fortnightly interval up to fourteen weeks of age. Bunnies were weaned at four weeks. Effect of genetic and non-genetic factors on various growth and litter traits were analysed. Genetic groups were significant source of variation for body weights from birth to twelfth week. Among purebreds highest mean body weight from birth to fourteenth week were recorded by WG. While WG x GG averaged highest among crossbreds. Individual bunny weights declined gradually as litter size increased. This trend continued till ten weeks of age after which there were no significant difference between different litter groups. Weight of dam at kindling influenced body weights of second to eighth week. Higher bunny weights were recorded for does weighing two to two and a half kilograms. Body weights of bunnies at birth, fourth, sixth and eighth weeks of age were influenced significantly by age of dam at kindling. Season of birth had an influence on birth, fourth and sixth week body weights. Higher individual weaning weights were obtained in cold season. Genetic groups had no significant effect on litter traits and gestation period. Weight of dam had significant influence on litter size and weight at birth and weaning. Litter weight at weaning was influenced significantly by the age of dam. Season of birth had an influence on gestation period, litter size at birth and weaning and litter weight at birth. Among purebreds, SC recorded the highest mortality. Highest pre and post-weaning mortality was recorded for SC x WG and WG x GG, respectively among crossbreds. Pre-weaning mortality was high in cold season while, in hot season maximum of post-weaning mortality was recorded. Heritability estimates of weight at weaning, twelfth and fourteenth week were 0.380±0.239, 0.657±0.379 and 0.727±0.407, respectively. Highly positive General Combining Ability (GCA) effects of WG indicated predominant additive gene action for expression of pre and post-weaning body weights. Higher Specific Combining Ability (SCA) was recorded for WG x GG cross at slaughter age of three months. The maternal effects were highest for GG from sixth to fourteenth week and highest in SC during early periods. As per the findings of the study it would be beneficial to use WG male on GG female so that the higher GCA effect of WG breed, maternal ability of GG as well as higher estimates of SCA of particular WG x GG cross could be exploited.