Toughness is a determinant of meat quality, a common cause of unacceptability in meat products and consumers are willing to pay higher prices for meat which is guaranteed to be tender. The calpain proteolytic enzymes are involved in the process of meat tenderisation through their degradation of muscle proteins postmortem (Sensky et al., 2001) and their activity is influenced by fluctuating levels of Ca2+, pH and temperature, all of which change rapidly in the immediate postmortem period. As vitamin D (vit D3) is responsible for Ca2+ homeostasis, we hypothesised that supplementing feed with vitamin D or vitamin D plus calcium propionate (CaPr) before slaughter would result in more tender meat through enhanced postmortem calpain system activity.