Effects of a Growth-promoting Implant Containing Tylosin Tartrate on Performance, Buller Incidence and Carcass Characteristics of Feedlot Steers

Abstract

A total of 13,732 animals were allotted to 64 pens (average 215 head per pen) in two commercial feedyards to compare the effects of growth-promoting implants with and without tylosin tartrate on performance, carcass merit and buller incidence in yearling steers. Implant formulations used in the study included 120 mg trenbolone acetate and 24 mg estradiol with 29 mg of tylosin tartrate (120/24 T) and 120 mg trenbolone acetate and 24 mg estradiol (120/24). Steers implanted without tylosin tartrate tended to have a lower incidence of bullers (1.17 vs 1.49%; P =0.08), and had a greater percentage of USDA quality grade Prime and Choice carcasses (42.51 vs. 40.26%; P =0.02) than steers given an implant with tylosin tartrate. No other differences in performance or carcass characteristics were noted ( P >0.10). Under the conditions of this study, there was no benefit to using tylosin tartrate in generically comparable growth-promoting implants.