Quality of subcutaneous fat of raw hams for dry-curing: nongenetic effects and genetic parameters for iodine number and linoleic acid content

Subcutaneous fat from 930 raw hams was sampled with the aim of investigating sources of variation and genetic parameters of iodine number (IN) and linoleic acid content (LA%). Pigs, offspring of 25 Gorzagri Large White C21 line boars and 123 Large White-derived crossbred sows, were slaughtered in 14 monthly batches at 166±15 kg of liveweight. Herd, management and feeding regime were the same throughout the trial. IN and LA% were determined using Wijs and gas-chromatography procedures, respectively, and mean±SD was 68.8±3.3 for IN and 12.7±1.7% for LA%. Batch and sire were the most important sources of variation. R2 of models was > 60% for both traits and all effects included in the model were significant. IN and LA% decreased at increasing carcass weight, and were higher in barrows than in gilts. Variance components were estimated using an univariate bayesian via Gibbs sampling. Estimated h2 was 0.414 for IN and 0.378 for LA%, and the lowest values of h2 delimiting the 90% posterior probability density region were 0.321 and 0.251, respectively. Genetic correlation between IN and LA% was 0.837. Selection for reducing IN and LA% of subcutaneous fat of hams is feasible and can be achieved by focusing on IN only, which is cheaper to determine than LA%.