Effect of preslaughter feed withdrawal period on longissimus tenderness and the expression of calpains in the ovine

The objective was to study the role of calpains in meat tenderness. Lambs were fasted for various periods of time to generate differences in meat tenderness and to determine in tandem the expression of calpain 1, calpain 2, calpain 3, and calpastatin. The assumption has been that increased calpain expression associated with an increase in tenderness indicates a role for calpain in the tenderization process and vice versa. Fasting lambs for 1 day caused a significant improvement in longissimus (LD) tenderness compared to the control. Correlations between the tenderness of the LD and the expression of the calpains and calpastatin were significant for calpains 1 and 3 but not for calpain 2 or calpastatin. Consequently, this study supports a role for calpains 1 and 3, but not for calpain 2, in the tenderization of the LD from fasted lambs during post-mortem aging.