PSVIII-32 Estimates of genetic parameters for sub-primal and meat quality traits in Canadian commercial crossbred swine populations

Abstract

Abstract The hypothesis that genetic relationships exist between loin muscle collagen characteristics and sub-primal and meat quality traits was tested. Data from 500 pigs from crosses between Duroc sires and hybrid Large White ✕ Landrace sows with pedigree back to about eight generations were used. Significant fixed effects (slaughter group and company) and a random additive effect were fitted in bivariate animal models to estimate phenotypic and genetic correlations using ASReml 4.1. Moderate heritabilities were obtained for sub-primal traits ranging from 0.21 for bone weight to 0.44 for loin muscle weight with a low estimate of 0.10 being obtained for loin weight. Meat quality traits were low to moderately heritable with the highest estimate being found for intramuscular fat (0.42). The heritability estimates for percentages of heat soluble and insoluble collagen were 0.12 and 0.15, respectively, while 0.33 was found for total collagen. Moderate to relatively high heritabilities imply the possibility of improving these traits through selective breeding. In general, moderate to high phenotypic and genetic correlations were obtained for sub-primal traits, whilst meat quality traits had moderate phenotypic and moderate to high genetic correlations. Strong negative genetic correlations between moisture traits and fat traits and a further negative correlation between fat and muscling traits were estimated confirming that selecting for improved muscling over time can negatively affect fat traits and indirectly decrease meat eating quality. The strong genetic correlation between pH and L* (-0.95) suggested possible pleiotropic gene effects on these traits. Warner-Braztler shear force (WBSF) had moderate genetic correlations with insoluble collagen (0.42) and soluble collagen (-0.38) suggesting a potential relationship between some of the genes impacting these traits. Genetic correlations between WBSF and collagen characteristics indicate that despite the relative youthfulness of pigs at slaughter, genetic selection for collagen solubility may decrease pork toughness.