Effects of implant regimens (trenbolone acetate-estradiol administered alone or in combination with zeranol) and vitamin D3 on fresh beef color and quality1

Abstract

In the first oftwo experiments, 123 calf-fed steers were used over a 2-yr period to evaluate the effects of trenbolone acetate (TBA)-based implants administered alone or in combination with zeranol implants on fresh beef muscle quality, color, and physiological maturity of the carcass. Implant treatments decreased (P < 0.05) a* values (d 0 and d 3 of retail display) and b* values (d 0, d 1, and d 3 of retail display) after 14 d of aging. Carcasses from cattle initially implanted with Revalor-S and reimplanted with Revalor-S on d 60 of the finishing period showed increased lean and bone maturity scores and ash content of the 9th to 11th thoracic buttons and Warner-Bratzler shear force values (WBS) compared to those initially implanted with Ralgro and subsequently reimplanted with Revalor-S or control cattle. In addition, implants decreased (P < 0.05) marbling, percentage of the carcasses grading Choice, and kidney, pelvic, and heart fat (KPH). Implant treatments increased (P < 0.05) ADG, hot carcass weights, and longissimus muscle (LM) area. In the second experiment over a 2-yr period, 166 steers fed as yearlings were allotted to one of two implant treatments and one of two vitamin D3 preharvest supplementation treatments. Implanted steers had heavier (P < 0.05) final body weights and higher (P < 0.05) ADG, less (P < 0.05) KPH fat, and larger (P < 0.05) LM. Also, implanted steers had more (P < 0.05) advanced bone maturity scores, higher (P < 0.05) ash content of the 9th to 11th thoracic buttons, and higher (P < 0.05) WBS values on 5-d postmortem loin steaks. Vitamin D3 feeding decreased (P < 0.05) final live weight, ADG (P < 0.05), and LM (P < 0.05), but did not significantly improve WBS values. In Experiment 2, neither implant treatment nor vitamin D3 supplementation had significant effects on L*, a*, or b* values of muscles in steaks before or during simulated retail display.

Carcass traits and M. longissimus lumborum palatability attributes of calf- and yearling-finished steers1

“…Foutz et al (1997) compared shear force and percentage of tough steaks coming from cattle receiving a 120 mg of TBA implant vs. those receiving 2 separate doses of a 120 mg of TBA implant and reported no implant effects. Reiling and Johnson (2003) found no difference in shear force when cattle were implanted with 120 mg of TBA vs. those implanted with 2 separate doses of an implant containing 120 mg of TBA each. Means within a row (WBS, sensory juiciness) or an item (sensory tenderness) without a common superscript letter differ (P < 0.05).…”

Meta-analysis of the published effects of HGP use on beef palatability in steers as measured by objective and sensory testing

“…et al (1991) 0.12 0.20 Huck et al (1991) 0.23 0.20 Hunt et al (1991) -0.15 0.39 Gerken et al (1995) 0.40 0.25 Samber et al (1996) 0.24 0.10 Foutz et al (1997) 0.32 0.17 Rumsey et al (1999) 0.95 0.33 Pritchard et al (2000) 0.00 0.20 Roeber et al (2000) 0.37 0.11 Barham et al (2003) 0.37 0.11 Platter et al (2003) 0.63 0.19 Reiling & Johnson (2003) WA-1 trial: Thompson et al (2008a) This trial, utilising three cooking methods, covered a wide range of muscles for heifers and steers. The details are covered in full in Thompson et al (2008a).…”

Steroid implants and markers of bone turnover in steers

“…This may be further evidence that E2 and other oestrogens act on the somatotropic axis to increase hepatic secretion of IGF-I, while TBA and other androgens act through a yet-unidentified mechanism. An increase in bone maturity scores when compared with nonimplanted controls has been associated with oestrogens (Turner et al, 1995), androgens (Moran et al, 1991) and the steroids in combination (Reiling & Johnson, 2003). Until now, however, there has not been a comparative study that evaluates serum IGF-I where treatments included E2 and TBA alone and where those amounts of E2 and TBA were represented exactly in a third combination treatment.…”

“…However, less is known about the impacts of these practices on bone growth and the metabolites that affect bone ageing. The same implantation system increased the percentage ash content of the cartilage of the 9th to 11th thoracic vertebrae and consequently advanced bone maturity scores (Reiling & Johnson, 2003). When implanted with E2 only, Kniffen et al (1999) found a dosage-dependent advancement in epiphyseal plate closure of metacarpal bones III and IV in beef heifers.…”