A study of the carcass traits of different rabbit genotypes.

The aim of this experiment was to study the carcass traits of rabbits when the same maternal stocks were mated with bucks of two well-known hybrids selected for growth traits or with Pannon White bucks selected for carcass traits by CT (computerised tomography). Three experiments were carried out at the same time. Experiment 1: Pannon White (P) or Hycole terminal (H) males were crossed with Pannon White (P) does (n=PP: 60, HP:59). Experiment 2: Pannon White (P), Hycole terminal (H) or Zika terminal (Z) bucks were crossed with Hycole (H) parent does (n=PH: 60, HH:52 and ZH:58). Experiment 3: Pannon White (P) or Zika terminal (Z) males were crossed with a Maternal line (M) stock (n=PM: 60, ZM:58). In all the experiments, hybrid males increased their body weight. Mating the same maternal stock with hybrid or Pannon White bucks, the body weight of the offspring of hybrid males was higher than that of the offspring of Pannon White bucks (Experiment 1: PP and HP:2644 and 2758 g, P<0.001; Experiment 2: PH, HH and ZH:2611, 2671 and 2890g, P<0.001; Experiment 3: PM and ZM:2534 and 2677 g, P<0.001). The most important carcass traits differences were found in rabbits originated from Pannon White males. Genetic origin influenced the dressing out percentage, which was 0.5% higher in PP rabbits compared to the HP group in Experiment 1 (60.6 and 60.1%, resp.; P=0.092); 1% higher in PH and ZH genotypes compared to HH animals in Experiment 2 (in PH, ZH and HH:59.6, 59.7 and 58.7%; P=0.008), and 1.5% higher in PM than in ZM rabbits in Experiment 3 (61.0 and 59.5%, resp.; P<0.001). The ratio of the m. Longissimus dorsi to reference carcass weight was also higher in rabbits derived from P males in Experiments 2 and 3 (Experiment 2: PH:11.2, HH:10.8, ZH:10.5%, P<0.001; Experiment 3: PM:11.5, ZM:10.6%, P<0.001), while it did not differ in Experiment 1. Significant difference in fat deposit was found only in Experiment 3, progeny of Pannon White males had higher weight (22.3 vs. 16.6g, P=0.002) and ratio of perirenal fat (1.65 vs. 1.25%, P=0.003) compared to offspring of Z males. Results of the dressing out percentage and the ratio of m. Longissimus dorsi proved that the selection based on CT (Pannon White genotype) was successful.