Author
FOOTE, MONICA - IOWA STATE UNIV, AMES | |
Horst, Ronald | |
HUFF-LONERGAN, E - IOWA STATE UNIV, AMES | |
TRENKLE, A - IOWA STATE UNIV, AMES | |
PARRISH, JR., F - IOWA STATE UNIV, AMES | |
BEITZ, D - IOWA STATE UNIV, AMES |
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/21/2003 Publication Date: 1/20/2004 Citation: Foote, M.R., Horst, R.L., Huff-Lonergan, E.J., Trenkle, A.H., Parrish, Jr., F.C., Beitz, D.C. 2004. The use of vitamin D3 and its metabolites to improve beef tenderness. Journal of Animal Science. 82(1):242-249. Interpretive Summary: Vitamin D is required for the body to build strong, healthy bones and teeth. If mammals do not receive enough vitamin D, they are unable to get the proper amount of calcium into their body to allow normal bone and tooth formation. However, if they receive too much vitamin D, more calcium than is needed can enter the body and blood calcium concentrations can rise to 40-50% above normal. If blood calcium remains at these concentrations for several days, animals can become sick and eventually die. However, most mammals can tolerate an increase in blood calcium by 20-30% for 3-5 days without any detrimental effects on performance. In this report, we summarize results from experiments with beef cattle, suggesting that creating a 20-30% elevation in blood calcium by feeding excess vitamin D 2-3 days before slaughter results in a tenderizing effect on meat. We also created the same elevation in serum calcium with the active form of vitamin D, 1,25-dihydroxyvitamin D, but we did not observe an improvement in meat tenderness. Therefore, feeding excess vitamin D, but not 1,25-dihydroxyvitamin D, for short periods of time represents a very practical 'on the farm' method of improving meat tenderness, which would hopefully result in augmenting the acceptance of beef by the American and foreign consumers. Technical Abstract: Our previous work has shown that feeding 5 x 10**6 of vitamin D3 to beef steers can produce strip loin and top round steaks with greater tenderness. Our current experiment was designed to determine whether feeding 2 metabolites of vitamin D3, 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3, produces tender strip loin, top round, and top blade steaks more effectively than does supplemental vitamin D3 without leaving a substantial amount of residual vitamin D3 and its metabolites in muscle. Thirty-three continental crossbred steers were allotted randomly to one of four treatment groups. The first group was fed a placebo, the second group received 5 x 10**6 IU of vitamin D3/d for 9 consecutive d and were slaughtered 2 d later, the third group received one dose of 125 mg of 25-hydroxyvitamin D3 4 d before harvest, and the fourth group received one dose of 500 ug of 1,25-dihydroxyvitamin D3 3 d before harvest. Blood samples were collected before treatment and at time of slaughter for subsequent quantification of calcium, vitamin D3, 25-hydroxyvitamin D3, and 1,25-dihydroxyvitamin D3 concentrations in plasma. Steaks from the longissimus lumborum (strip loin) and semimembranous (top round) were collected from each animal and aged for 8, 14, and 21 d, and steaks from the infraspinatus (top blade) were collected and aged for 14 and 21 d. All steaks were analyzed for tenderness by Warner-Bratzler shear force determination and protein degradation was monitored by Western blot analysis. Concentrations of vitamin D3 in plasma were higher in vitamin D3-treated cattle (P less then 0.0001). Concentrations of plasma 25-hydroxyvitamin D3 were increased in 25-hydroxyvitamin D3-treated cattle but were not as high as those in vitamin D3-treated cattle (P less than 0.0001). 1,25-Dihydroxyvitamin D3 concentrations were higher in 1,25-dihydroxyvitamin D3-treated animals compared with all treatments (P less than 0.0001). Supplementing steers with vitamin D3 increased the concentration of vitamin D3 and 25-hydroxyvitamin D3 increased the concentration of 25-hydroxyvitamin D3 in meat but to an amount less than half that of cattle treated with vitamin D3. Warner-Bratzler shear force analysis showed that feeding 1,25-dihydroxyvitamin D3 did not significantly lower shear force values, but supplemental vitamin D3 and 25-hydroxyvitamin D3 produced longissimus lumborum and semimembranous steaks with lower shear force values postmortem age 14 d and 8 and 21 d, respectively (P less than 0.06). Analysis of Western blots showed that longissimus lumborum and semimembranous steaks from cattle fed supplemental vitamin D3 and 25-hydroxyvitamin D3 (but not steaks from cattle fed 1,25-dihydroxyvitamin D3) had greater proteolysis of troponin-T to a 30-kDa component. Antemortem feeding of supplemental 25-hydroxyvitamin D3 seems to be effective in producing tender strip loin and top round steaks without generating a large concentration of vitamin D3 residue in beef and generating a concentration of 25-hydroxyvitamin D3 in beef nearly half that of feeding vitamin D3. |