Abstract: We proposed that aggressive treatment with anabolic steroids (Synovex? implants) would have no effect on meat tenderness when cattle of similar genetic background were fed as weanling calves and slaughtered at a constant fat thickness. A total of 416 Angus crossbred steer and heifer calves of similar genetic makeup were randomly assigned to five treatments. Treatments consisted of: (1) no implant, (2) no implant at branding (6 wk of age)+Synovex S? or H? at weaning (8 mo of age)+Synovex S? or H? 90 d later, (3) no implant at branding+ Synovex S? or H? at weaning+Synovex Plus? 90 d later, (4) Synovex C? at branding+Synovex S? or H? at weaning+Synovex S? or H? 90 d later, and (5) Synovex C? at branding+Synovex S? or H? at weaning+Synovex Plus? 90 d later. Calves were produced on two different ranches and were transported to a growing yard at weaning (206?29 kg). When calves reached 341 kg BW, they were transported to a feedlot where they were fed a finishing ration for approximately 90 d, prior to harvesting. USDA quality and yield grade factors were obtained and samples of m. longissimus thoracis were taken from each carcass. Meat samples were aged for 2 wk at 2?C before being frozen until they could be shear tested. The meat was prepared and sheared following established guidelines for the determination of Warner Bratzler shear force. There was no difference (P>0.05) in shear force among the five treatment groups. Differences (P<0.05) were detected in shear force due to ranch, sex, and slaughter group. Regardless of implant treatment, sex, or ranch of origin, more than 98% of the steaks required less than 4.55 kg of shear force. We conclude that treatment with the Synovex family of implants has no effect on meat tenderness in cattle of this breed type when calves are fed a growing/finishing diet immediately after weaning and harvested at a constant fat thickness.
E. W. Hawkins , C. W. Wiltbank , F. T. McCollum , D. K. Lunt , R. K. Miller , K. S. Barlin , R. L. Hale and S. B. Smith , 2004. Aggressive Implant Strategies do not Negatively Impact Beef Tenderness . Journal of Animal and Veterinary Advances, 3: 13-18.