Genetic Correlations between Boar Taint Compound Concentrations in Fat of Purebred Boars and Production and Ham Quality Traits in Crossbred Heavy Pigs

SIMPLE SUMMARY: Boar taint (BT) is an off-odor and off-flavor affecting pork caused by the accumulation in the tissues of uncastrated male pigs of three main compounds: androstenone, skatole, and indole. The reduction in BT compound accumulation by genetic selection is a viable strategy to stop surgical castration of male piglets. Understanding the genetic relationships between BT compound concentration and carcass and meat quality is necessary to assess the potential effects of selecting against BT on other traits of interest. In pigs, selection is operated in purebred lines, but slaughter pigs are mostly crossbred. Therefore, before selecting against BT, it is crucial to evaluate the potential effects of such selection on commercial traits measured in crossbreds. The moderate heritability values estimated for BT compound concentrations confirmed that breeding strategies against BT can be successful. Results indicated that there is a correlation between BT compound concentrations measured in purebred pigs and carcass and ham quality traits of crossbreds. In particular, selection against BT might lead to a favorable increase in carcass backfat depth. However, such selection is also expected to negatively impact dry-cured ham quality through decreased ham fat thickness and increased proportion of unsaturated fatty acids in ham subcutaneous fat. ABSTRACT: Selecting pigs with reduced ability to accumulate boar taint (BT) compounds in their tissues is an alternative to male surgical castration. As the majority of slaughter pigs are crossbred, before selecting against BT in purebreds, it is essential to consider possible impacts on commercial traits in crossbreds. This study estimated the genetic correlations between BT compound levels measured in 1115 purebred pigs and carcass and ham quality traits collected in 26,577 crossbred Italian heavy pigs. Genetic correlations were estimated in bivariate Bayesian analyses including one BT trait and one production or ham quality trait at a time. Heritability of androstenone, skatole, and indole was 0.41, 0.49, and 0.37, respectively. A moderate negative correlation between skatole and carcass yield (−0.40), and between all BT compounds and backfat (from −0.26 to −0.55) was observed. Conversely, positive correlations (from 0.11 to 0.54) were found between skatole and ham fat thickness traits. Correlations between BT compounds and iodine number ranged from −0.07 (for androstenone) to −0.64 (for skatole), whereas those with PUFA ranged from −0.13 (for indole) to −0.33 (for skatole). Hence, reducing BT could decrease ham fat thickness and increase unsaturated fatty acids, with potential negative impacts on product quality.