Genetic Parameters for Primal Cut Weights in Pigs

A study was conducted to estimate genetic parameters for phenotypes describing primal cuts recorded on 2,077 pigs with pedigrees comprising 5,011 animals over three generations. The four main primal cuts considered were: shoulder, leg, loin and belly. These were analysed as primal weights, or as a percentage of cold carcase weight. Heritabilities ranged from 0.10 (± 0.04) to 0.24 (± 0.06) for primal cut weights and from 0.12 (± 0.05) to 0.24 (± 0.06) for primal cut percentages. The loin primal was the least heritable. The genetic correlations between primal weights and primal percentages for the same primals ranged from 0.97 to 1.00. The genetic correlations among primal cut weights ranged from -0.45 to 0.07 which were similar to those found among the primal cut percentages (-0.63 to 0.06). The genetic correlations between the shoulder and leg primal with the belly primal were negative. The strongest negative genetic correlation was found between the leg and belly primals (-0.45 for weight trait and -0.63 for percentage trait). The leg weight was genetically uncorrelated with loin weight, suggesting that selection for high leg weights would not result in high loin weights. The phenotypic correlation between loin and belly was negative but the genetic correlation was not significant. Genetic correlations between the loin and other primal cut weights were weaker in comparison to the genetic correlations between the belly and other primal cuts. The genetic correlations amongst primal cut weight traits were similar to those found among the primal cut percentages. Incorporating these genetic parameters into a pig breeding program could help to increase the total economic return from pig carcases but would need to be done in association with other traits that impact pig production.