Estimation of genetic parameters on test stations using purebred and crossbred progeny of sires of the Bavarian Piétrain

Genetic parameters were estimated for purebred and crossbred progeny of Bavarian Piétrain sires on two test stations. The data set used contained 4276 purebred pigs and 13,980 crossbred pigs recorded between 2000 and 2004. In total 332 sires having purebred and crossbred progeny were available to estimate the genetic correlations between purebred and crossbred performances. Though the genetic correlations between purebred and crossbred pigs are fairly high (0.7-0.9), their performances have to be considered as genetically different traits, because variance components and heritabilities differ substantially. Therefore, purebred and crossbred breeding values of candidates are not identical, and thus result in different rankings. However, due to the high correlations purebred pigs provide a lot of information for estimating the crossbred breeding values of the real selection criterion. The Halothan locus, whose effects have been analyzed in detail, affects both purebred and crossbred parameters. To avoid detrimental effects on the efficiency of the breeding programme, the n-allele could be either eliminated or the genotypes of all test animals should be known. Differences in the variance components between the two test stations have been found and are problematic with respect to the breeding value estimation utilizing the pooled data set. Hence, it should be attempted to further improve the standardization of the performance test on both stations.