Estimating dominance effects and inbreeding depression of carcass traits in Pannon White rabbits

Absztrakt

Authors analyzed the slaughter records of 527 Pannon White rabbits. These records were collected in the course of three experimental slaughters conducted in 2013, 2014 and 2015, respectively. The examined traits were: weight of thigh fillet (THIGHW), dressing out percentage (DoP) (calculated as the ratio of the chilled carcass weight and live body weight at slaughter), hind part percentage (HIND%) (compared to the reference carcass) and weight of perirenal fat (FATW). Genetic parameters were estimated using basic and extended (with dominance effects) single trait animal models using the REML procedure. Inbreeding depressions for the examined traits were determined by the BLUP procedure. Applying the basic model, heritability estimates were moderate for THIGHW (0.18±0.07), DoP (0.19±0.06) and for HIND% (0.23±0.07). On the contrary, high heritability was estimated for FATW (0.68±0.08). Extending the models with dominance effects the heritabilities did not change except for FATW (0.59±0.16). According to these results the estimated dominance effects were practically zero for THIGHW, DoP and HIND% and moderate for FATW (0.16±0.06). Concerning inbreeding depression 10% increase of the inbreeding coefficient resulted in severe decrease (-24.4 g) for THIGHW. DoP and HIND% were less sensitive for inbreeding depression (-0.06% and -0.02%). On the contrary, similarly to THIGHW, FATW showed substantial inbreeding depression (-2.88 g). Presenting inbreeding depressions as the percentages of the mean values of THIGHW, DoP, HIND% and FATW, the received values were 6.2%, 9.8%, 5.2% and 17.1%, so the largest depression was observed for FATW.