SUPPLEMENTAL VITAMIN D3 CONCENTRATION AND BIOLOGICAL TYPE OF STEERS. II. TENDERNESS, QUALITY, AND RESIDUES OF BEEF

Authors: MONTGOMERY, J - TEXAS TECH UNIV.; KING, M - TEXAS TECH UNIV.; GENTRY, J - MIDDLE TN STATE UNIV; BARHAM, A - TEXAS TECH UNIV.; BARHAM, B - TEXAS TECH UNIV.; HILTON, G - ANGELO ST. UNIV, TX; BLANTON, JR, J - TEXAS TECH UNIV.; Horst, Ronald; GALYEAN, M - TEXAS TECH UNIV.; MORROW, JR, K - TEXAS TECH UNIV.

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/10/2004
Publication Date: 7/20/2004
Citation: Montgomery, J.L., King, M.B., Gentry, J.G., Barham, A.R., Barham, B.L., Hilton, G.G., Blanton, Jr, J.R., Horst, R.L., Galyean, M.L., Morrow, Jr, K.J. 2004. Supplemental vitamin D3 concentration and biological type of steers. II. Tenderness, quality, and residues of beef. Journal of Animal Science. 82(7):2092-2104.

Interpretive Summary: We have shown that creating 20-30% elevation in blood calcium by feeding excess vitamin D several days prior to slaughter results in a tenderizing effect on meat. In this series of experiments we supplement the diet of beef animals with 4 levels of vitamin D3 (0, 0.5, 1, and 5 million IU/(steer/d) for 8 days) before slaughter. We found that vitamin D3 supplementation increased muscle calcium concentration, which activated proteolytic enzymes resulting in improved tenderness of a variety of muscles within the carcass of beef steers. The improvement in tenderness of multiple muscles through the feeding of vitamin D3 8 days before slaughter provides the beef industry with a tool to improve the quality and consistency of beef at both the retain and food-service markets with little detrimental effect on feedlot performance traits, especially when a low dose (0.5 IU/steer daily) of vitamin D3 supplementation is employed. Supplementing steers at 1 million IU/steer or greater negatively affected feedlot performance and tissue residues. The improvement in shear force values noted in selected muscle tissues (longissimus, semimembranosus, and gluteus medius) by 3 days postmortem indicates that vitamin D3 improved beef tenderness without the necessity of a lengthy aging process. This research will benefit beef producers and beef nutritionists worldwide.

Technical Abstract: Because of the Ca dependency of the calpains, oral supplementation of vitamin D3 (VITD) can increase the Ca content of muscle to activate the calpains and improve tenderness. Feedlot steers (n=142) were arranged in a 4 x 3 factorial arrangement consisting of 4 levels of vitamin D3 (0, 0.5, 1, and 5 million IU/(steer/d) for 8 consecutive days antimortem using three biological types (Bos indicus, Bos taurus-Continental, and Bos taurus-English). Warner-Bratzler shear force (SBSF) was measured at 3, 7, 10, 14, and 21 d postmortem and trained sensory analysis at 7 d postmortem on longissimus lumborum, semimembranosus, gluteus medius, and supraspinatus steaks. The concentration of VITD and the metabolites 25-hydroxy-vitamin D3 and 1,25-dihydroxy-vitamin D3 were determined in longissimus, liver, kidney, and plasma. Biological type of cattle did not interact with VITD on sensory or tenderness traits, suggesting that feeding VITD for 8 d before slaughter will affect different biological types of cattle in a similar fashion. Supplementing steers with 0.5, 1, or 5 milliion IU decreased (P less than 0.05) longissimus lumborum WBSF at 7, 10, 14, and 22 d postmortem compared with controls. Vitamin D3 treatments of 0.5, 1, and 5 million IU decreased (P less than 0.05) semimembranosus WBSF at 3, 7, and 14 d postmortem. In general, VITD improvements in WBSF were most consistent and intense in longissimus lumborum steaks. Sensory panel tenderness was improved by all VITD treatments in longissimus samples. Sensory traits of juiciness, flavor, connective tissue, and off-flavor were not (P more than 0.05) affected by VITD treatments. All VITD treatments decreased micro-calpain activity and increased muscle Ca concentrations (P less than 0.05). Vitamin D3 concentrations were increased (P less than 0.05) by VITD supplementation in all tissues tested (liver, kidney, longissimus, and plasma). However, cooking longissimus samples to 71 C decreased (P less than 0.05) treatment residues. The vitamin D metabolite 1,25-dihydroxy-vitamin D3 was increased (P less than 0.05) only in plasma samples as a result of the VITD treatments. These results indicate that supplementation with VITD at 0.5 million IU/(steer/d) for 8 consecutive d before slaughter improved tenderness in beef steaks from different subprimal cuts by affecting muscle Ca concentrations, micro-calpain activities and muscle proteolysis, with having only a small effect on residues.