Journal of Animal Science, Vol 74, Issue 8 1777-1783, Copyright © 1996 by American Society of Animal Science

JOURNAL ARTICLE

Influence of steroid implants and concentrate feeding on carcass and longissimus muscle sensory and collagen characteristics of cull beef cows

C. D. Cranwell, J. A. Unruh, J. R. Brethour and D. D. Simms
Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506-0201, USA.

Sixty nonpregnant, mature beef cows were used to determine the effects of steroid implants and concentrate feeding on carcass quality, longissimus muscle (LM) collagen characteristics, and LM sensory traits. Twelve nonfed cows were slaughtered at 0 d to establish basal carcass values. The remaining 48 cows were assigned randomly in a 2 x 4 factorial arrangement to an implant treatment and fed for either 28 or 56 d. The implant treatments were 1) nonimplanted (controls), 2) a 200-mg trenbolone acetate (TBA) implant, 3) a 200-mg testosterone propionate +20 mg estradiol benzoate (TEB) implant, or 4) both implants (TBA+TEB). Carcasses from cows fed for 28 and 56 d had improved (P < .05) LM marbling, lean maturity, and quality grade; a lighter (P < .05) LM color (higher Hunter L* values); a higher (P < .05) percentage of LM soluble (heat-labile) collagen; and a lower (P < .05) LM Warner-Bratzler shear force value (more tender) than carcasses from nonfed cows. Feeding for 28 and 56 d also improved (P < .05) LM sensory panel traits of flavor intensity, connective tissue amount, myofibrillar tenderness, and overall tenderness. Feeding cows for an additional 28 d (to 56 d) improved (P < .05) LM visual lean color, texture, and firmness and carcass fat color. All LM HunterLab color measurements were higher (P < .05) for cows fed for 56 d compared to 28 d, indicating a brighter, redder, more vivid color. Implant treatments did not influence (P > .05) carcass quality or LM color. Steaks from implanted cows compared to controls had (P < .05) more soluble (heat-labile) collagen, a higher percentage of soluble collagen, and improved sensory traits of tenderness (myofibrillar and overall) and connective tissue amount. Steaks from TBA-implanted cows compared to the other implant treatments had superior (P < .05) LM sensory evaluations for myofibrillar and overall tenderness. Feeding thin cows a high-concentrate diet for 28 d improved quality grade and LM sensory traits, and feeding for 56 d improved LM lean and carcass fat color. Implanting fed cows improved LM sensory panel tenderness.

This article has been cited by other articles:

				A. M. Stelzleni, L. E. Patten, D. D. Johnson, C. R. Calkins, and B. L. Gwartney Benchmarking carcass characteristics and muscles from commercially identified beef and dairy cull cow carcasses for Warner-Bratzler shear force and sensory attributes J Anim Sci, October 1, 2007; 85(10): 2631 - 2638. [Abstract] [Full Text] [PDF]

				J. M. Gonzalez, J. N. Carter, D. D. Johnson, S. E. Ouellette, and S. E. Johnson Effect of ractopamine-hydrochloride and trenbolone acetate on longissimus muscle fiber area, diameter, and satellite cell numbers in cull beef cows J Anim Sci, August 1, 2007; 85(8): 1893 - 1901. [Abstract] [Full Text] [PDF]

				C. A. Rogers, A. C. Fitzgerald, M. A. Carr, B. R. Covey, J. D. Thomas, and M. L. Looper On-Farm Management Decisions to Improve Beef Quality of Market Dairy Cows J Dairy Sci, May 1, 2004; 87(5): 1558 - 1564. [Abstract] [Full Text] [PDF]