Heritability of muscular cathepsin B activity in Italian large white pigs

Previous studies suggested that proteolysis lasting for many months after slaughtering 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 level of cathepsin B, such information could be used as a selection criterion for improving meat quality for dry-cured ham production. Data on the growth race, carcass composition, and meat quality of 234 Large White pigs raised in a test station under a 'quasi ad libitum' nutritive level and slaughtered 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 necessary to confirm the outcome and to investigate genetic correlations with other traits currently under selection.