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 w ere fasted for various periods of time to generate differences in meat tend erness and to determine in tandem the expression of calpain 1, calpain 2, c alpain 3, and calpastatin. The assumption has been that increased calpain e xpression associated with an increase in tenderness indicates a role for ca lpain 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 express ion of the calpains and calpastatin were significant for calpains 1 and 3 b ut not for calpain 2 or calpastatin. Consequently, this study supports a ro le for calpains 1 and 3, but not for calpain 2, in the tenderization of the LD from fasted lambs during post-mortem aging.