Genetic parameters for carcass composition and pork quality estimated in a commercial production chain

Breeding goals in pigs are subject to change and are directed much more toward retail carcass yield and meat quality because of the high economic value of these traits. The objective of this study was to estimate genetic parameters of growth, carcass, and meat quality traits. Carcass components included ham and loin weights as primal cuts, which were further dissected into boneless subprimal cuts. Meat quality traits included pH, drip loss, purge, firmness, and color and marbling of both ham and loin. Phenotypic measurements were collected on a commercial crossbred pig population (n = 1,855). Genetic parameters were estimated using REML procedures applied to a bivariate animal model. Heritability estimates for carcass traits varied from 0.29 to 0.51, with 0.39 and 0.51 for the boneless subprimals of ham and loin, respectively. Heritability estimates for meat quality traits ranged from 0.08 to 0.28, with low estimates for the water holding capacity traits and higher values for the color traits: Minolta [b.sup.*](0.14), [L.sup.*] (0.15), [a.sup.*] (0.24), and Japanese color scale (0.25). Heritability estimates diffeted for marbling of ham (0.14) and loin (0.31). Neither backfat nor ADG was correlated with loin depth ([r.sub.g] = 0.0), and their mutual genetic correlation was 0.27. Loin primal was moderately correlated with ham primal ([r.sub.g] = 0.31) and more strongly correlated with boneless ham ([r.sub.g] = 0.58). Backfat was negatively correlated with (sub)primal cut values. Average daily gain was unfavorably correlated with subprimals and with most meat quality characteristics measured. Genetic correlations among the color measurements and water-holding capacity traits were high (average [r.sub.g] = 0.70), except for Minolta [a.sup.*] (average [r.sub.g] = 0.17). The estimated genetic parameters indicate that meat quality and valuable cut yields can be improved by genetic selection. The estimated genetic parameters make it possible to predict the response to selection on performance, carcass, and meat quality traits and to design an effective breeding strategy fitting pricing systems based on retail carcass and quality characteristics. Key Words: Carcass Composition, Genetic Parameters, Heritability, Meat Quality, Pig