Genetic parameters for quality traits of raw and dry-cured hams

Data on 1425 typical Italian dry-cured hams were analysed. Pigs were progeny of 74 Gorzagri C21 Large White boars and of 221 Large White-derived crossbred sows. Marbling (MB), fat thickness (FTS), ham firmness (HF) and fat quality (FQ, color, oiliness, firmness) were scored on both raw and cured hams. Total area, fat eye area (FEA) and fat thickness (FTM) of the cross section of dry cured hams were measured using computer image analysis (CIA). Records were analyzed with Bayesian methodology via Gibbs sampling using a univariate linear model for continuous traits, a univariate threshold model for scores and a bivariate threshold linear model to estimate genetic correlations between raw and cured ham traits. Besides animal effects, the effects of batch, gender, weight of carcass and interactions were included in the statistical models. For cured ham traits, heritabilities were 0.35 for MB, 0.07 for HF, 0.45 for FTS, 0.20 for FQ, 0.15 for FEA, 0.34 for FTM. Heritability of MB, FQ, and FTS of raw hams was similar to that of cured hams. Genetic correlations between quality traits of cured hams and corresponding traits of raw hams were greater than 0.80 with the exception of FQ. FQ of raw hams was positively related to FTS. Correlations between FEA and other raw ham traits were small.