Relationships Between Performance Test Results of Gilts of Different Breeds

The relationships expressed as calculated correlation coefficients were determined between the results of 44 110 purebred gilts performance tested in the years 2004-2008. The animals came from the Bydgoszcz Breeding Region and represented 5 breeds (Polish Large White, Polish Landrace, Hampshire, Duroc and Pietrain) and synthetic Line 990. The traits taken into account were: age and body weight on test day, daily body weight gain standardized to 180 days of age, backfat thickness at P₂ and P₄ points, loin eye height at P₄ points, body meat content, and performance test selection index. Negative and highly significant correlations were found between growth rate and standardized backfat thickness at P₂ and P₄ points in all gilts of the tested breeds except Line 990. In the case of two breeds (Polish Large White and Pietrain) and Line 990, the correlation coefficients between daily body weight gain and standardized body meat content were negative and highly significant, which possibly suggests the unfavourable impact of high growth rate on the meat content. Higher correlation coefficient values were observed between the performance test selection index and the daily body weight gain than between the selection index and the body meat content of Polish Large White, Polish Landrace, Hampshire and Pietrain gilts.