| Calpain and calpastatin activity are thought to be the determining factors for meat tenderness, and calcium (Ca) plays a role in calpain activity. The present theory is to manipulate beef cattle diets to change muscle Ca levels and consequently calpain activity and shear force. To test whether dietary Ca manipulations affect tenderness, Angus-based steers (n = 20), from a single source, were assigned to pairs based on an allotment weight. One steer from each pair was assigned to the control treatment (CO) and the other to the dietary Ca depletion/repletion treatment (DR). All cattle were fed a typically high grain finishing (0.50% Ca) diet starting at 343 kg body weight (BW); dietary Ca depletions began 113 d later at 561 kg BW. The DR received a 0.28% Ca diet for 14, 21, or 28 d prior to harvest and was returned to the CO diet for one feeding 16 h prior to slaughter. Individual performance and carcass data were collected. (Abstract shortened by UMI.)... |
