An experiment was designed to test the hypothesis that short-term oral administration of dietary vitamin D3 to beef cattle before slaughter would increase beef tenderness through greater calcium-activated protease (calpain) activity in postmortem aged skeletal muscle. Thirty Continental crossbreed steers were allotted randomly to three treatment groups housed in one pen. One group served as a control; two other groups were administered by bolusing with either 5 million or 7.5 million IU of vitamin D3 daily for nine days. Cattle were slaughtered two days later. Blood samples were collected at the same time daily and at the time of slaughter for the quantification of plasma calcium. The longissimus lumborum was excised from each carcass 72 hours postmortem and aged for 3, 7, 14, and 21 days and the semimembranous was excised and aged for 7, 14, and 21 days for subsequent Warner-Bratzler shear force determination and sensory evaluation. Concentrations of calcium in plasma and muscle from cattle treated with 5 million IU of vitamin D3 were higher (p < .05) than those from controls. Strip loin and top round steaks from cattle fed supplemental doses of vitamin D3 had lower (p < .05) Warner-Bratzler shear values at 14 days postmortem than did those from controls.
Available at: http://works.bepress.com/elisabeth_huff-lonergan/31/