Genetic parameters and breeding value stability estimated from a joint evaluation of purebred and crossbred sows for litter weight at weaning

Absztrakt

Authors analysed genetic parameters and breeding value stability in Hungarian Large White (HLW), Hungarian Landrace (HL) pigs and their reciprocal cross (F₁) for litter weight at weaning adjusted to 28 days of age. Data was collected by the legal predecessor of the National Food Chain Safety Office between 2001 and 2010. Data preparation was carried out using SAS 9.1.3 software. The litter weight records of the purebred and crossbred pigs were considered as separate traits. Genetic parameters were estimated by REML method using the VCE 6 software applying two-trait repeatability model. The total number of animal in the pedigree was 138 969. Heritability estimates were low for each breed and the cross. Corresponding values are 0.13 (0.004), 0.10 (0.004) and 0.13 (0.003) and 0.12 (0.002) for HLW, HL and F₁ from the two datasets, respectively. Magnitudes of permanent environmental effect were 0.008 for HLW and less than 0.001 for HL and F₁. Genetic correlations between purebred and crossbred performances were 0.23 (0.04) from the dataset HLW-F₁, and 0.03 (0.008) from the dataset HL-F₁. Breeding value stability was low regarding both methods. Number of common representatives from rankings of purebred and crossbred breeding value did not reach the 40 from 100 animals in either breed. The differences between average crossbred breeding values reached a maximum value of 3.47 kg in HLW and 3.16 kg in HL.