Work

Effects of growth hormone implants on animal growth performance, feed intake, carcass characteristics, feeding behavior, gas flux emissions, and relative profitability of finishing Angus steers

Year: 2026

Type: article

Abstract: The current study’s objective was to assess the relationship between animal growth performance, feed intake, carcass traits, feeding behavior, gas flux, and relative profitability of implanted and non-implanted finishing Angus steers. Sixty-two steers were blocked according to body weight into 2 pens and fed for 52 and 80 d, respectively. Steers within each pen were randomly assigned to a treatment: implanted with Component TE200 (IMP; Elanco Animal Health, Greenfield, IN) or not implanted (CON). Each pen was equipped with one GreenFeed automate head chamber system (AHCS) and 5 SmartFeed systems (C-Lock, Rapid City, SD) for gas flux and feed intake measurements, respectively. Data were analyzed as a randomized complete block design using JMP Pro (16.2.0), with significance declared at P < 0.05 and tendencies discussed between 0.05 ≤ P < 0.10. The IMP steers had a greater (P < 0.0001) final BW and ADG compared to CON steers. Dry matter intake (DMI) was greater (P = 0.01) for IMP steers compared to CON steers. Implanted steers had improved (P < 0.0001) feed conversion and feed efficiency when compared with CON steers and increased hot carcass weight (P < 0.0001). Ribeye area (REA) was larger (P = 0.01) in IMP steers compared to CON steers; however, marbling score and USDA yield grade were similar (P > 0.05). There was a difference (P = 0.04) in USDA quality grade, where CON steers had a greater proportion of more favorable quality grades (ie Choice + and greater) compared to IMP steers. The IMP steers tended to have larger (P = 0.08) session size (g of DM/visit) than CON steers. Enteric CH4 emissions of IMP steers were greater (P < 0.05) compared to CON steers. Implanted steers had greater (P < 0.05) oxygen consumption and hydrogen emission than CON steers. IMP had reduced (P < 0.05) CH4 emissions intensity (g CH4/kg ADG) compared to CON. Relative profitability was greater than $0.00 for each treatment, with a mean difference of $140.06/head. In summary, growth hormone implants improve productivity and efficiency of finishing steers, reducing emissions per unit of beef produced while improving profitability, especially with greater days on feed.

Source: Translational Animal Science

DOI: 10.1093/tas/txag072