Genetic analysis for production and health traits in a commercial rabbit line
Résumé
Genetic parameters and trends were estimated for the selection criteria body weight at 70 days (BW70), carcass yield (CY) and resistance to infectious diseases (ID) in the paternal commercial rabbit line AGP59 of the Hypharm breeding company. The ID criteria is a binary trait based on presence (1) or absence (0) of clinical signs of diseases. This study included data recorded on 39,726 selection candidates and 5,372 slaughtered sibs between 2008 and 2016. All animals were weighed at 70 days. Clinical signs of disease were systematically recorded for all weighed animals and also for those which died between weaning and the end of the growing period. The sib-testing population is created at each weaning by collecting young rabbits in primiparous does litters. Their live body weight and carcass weight was recorded at 71 days of age and carcass yield was then estimated. Genetic parameters and genetic trends were estimated using REML and BLUP methodology. Heritability estimates were 0.28±0.02, 0.44±0.05 and 0.03±0.01 for BW70, CY and TI, respectively. Genetic correlations between the three traits were not significantly different from zero. Phenotypic correlations were also low, except for the negative value (i.e. favourable) between BW70 and ID (-0.42±0.05). The annual genetic gain, estimated in genetic standard deviation units (traits units) was 0.49 (92 g), 0.32 (0.38 points of carcass yield) and -0.12 (-0.004 points of diseased animal frequency) for BW70, CY and TI, respectively. The results demonstrate that selection for both production and health traits is possible.