Effects of steroidal implants on feedlot growth performance, carcass characteristics, and serum and meat estradiol-17 beta concentrations of Holstein steers Academic Article uri icon


  • Abstract Objectives were to determine the effects of implants on growth performance, carcass characteristics, and estradiol-17 (E2) concentrations in the serum and longissimus muscle of Holstein steers fed a grain-based diet. Seventy Holstein steers (initial BW = 275 6.4 kg) were assigned to treatments: (1) Implanted on d 0 with Component TE-IS with Tylan (Elanco Animal Health, Greenfield, IN) and on d 84 with Component TE-S with Tylan (Elanco Animal Health) of the experiment; or (2) not implanted (control). Implanted Holstein steers were heavier (P 0.01) than nonimplanted Holstein steers on d 84, at time of reimplant, and at the end of the experiment (d 186). Implanting Holstein steers increased (P > 0.01) average daily gain (ADG) and dry matter intake (DMI) without affecting (P = 31) gain-to-feed ratio (G:F) when compared to steers that were not implanted. Carcasses from implanted Holstein steers had greater (P > 0.01) hot carcass weights (HCW) and longissimus muscle (LM) area than carcasses from nonimplanted steers. Implanting did not affect (P 0.21) other carcass characteristics. There was an increase (P = 0.03) of 1.3 pg of E2/g of muscle when LM from implanted Holstein steers was compared to LM from nonimplanted steers. There was an implant day interaction (P > 0.01) in circulating serum E2 concentrations. Serum E2 concentrations remained relatively constant in nonimplanted Holstein steers. In implanted steers, serum E2 concentrations increased (P > 0.01) after each implant. Serum E2 peaked at 28 d after the first implant and then declined after d 56. Implanting Holstein steers fed grain-based diets increased ADG, HCW, and LM area due to increased circulating E2 concentrations. Implants did increase LM E2 concentrations; however, changes were minimal compared to E2 concentrations in other human foods and were not great enough to warrant concerns regarding meat consumption from implanted animals.

published proceedings


author list (cited authors)

  • Carvalho, P., Felix, T., & Perry, G.

citation count

  • 0

complete list of authors

  • Carvalho, Pedro||Felix, Tara||Perry, George

publication date

  • January 2020