Genetic correlations between the performance of purebred and crossbred pigs

Abstract

Genetic correlations between purebred Duroc (DU), Large White (LW) and Landrace (LR) pigs and their crossbreds LWxLR, LRxLW, DUx(LWxLR) and DUx(LRxLW) were estimated for production and reproduction traits. Performance test and litter records from Government pig breeding stations in Thailand were used. REML bivariate animal models were used to estimate genetic correlations for each trait measured in purebreds and in crossbreds. Production traits tended to have very high genetic correlations (0.66 – 0.96) between purebreds and crossbreds, whereas reproduction traits tended to have low to moderate genetic correlations (0.21 – 0.52). The breeding procedure to improve production traits of crossbred pigs using genetic evaluation and selection based on purebred records is verified by the results of this study due to the high genetic correlations. However, for reproduction traits, purebred records seem to be less relevant for use to improve crossbred reproduction traits because of low genetic correlations between purebreds and crossbreds. Therefore, a joint genetic evaluation of purebred and crossbred records is recommended to improve reproduction traits in crossbred sows.