Heritability of muscular cathepsin B activity in Italian large white pigs

Previous studies suggested that proteolysis lasting for many months after s laughtering could be responsible for excessive softness in dry-cured hams. Also, the long-term activity of muscle proteinases is mainly attributed to cathepsin B. Should an additive genetic component exist for the activity le vel of cathepsin B, such information could be used as a selection criterion for improving meat quality for dry-cured ham production. Data on the growt h race, carcass composition, and meat quality of 234 Large White pigs raise d in a test station under a 'quasi ad libitum' nutritive level and slaughte red at around 160 kg live weight were analysed using a BLUP-MT-animal model . The cathepsin B activity level showed a moderate heritability (0.23-0.28) in all analyses, and negative genetic correlations with daily gain (-0.34 to -0.52) and backfat thickness (-0.40 to -0.86), but, with large standard errors. These results suggest that a genetic component exists in explaining the variability of the cathepsin B activity level. Further studies are nec essary to confirm the outcome and to investigate genetic correlations with other traits currently under selection.