Theses and Dissertations

Issuing Body

Mississippi State University


Rivera, J. Daniel

Committee Member

Vann, Rhonda C.

Committee Member

Ward, Stephanie H.

Date of Degree


Document Type

Graduate Thesis - Open Access


Animal Science

Degree Name

Master of Science (M.S.)


College of Agriculture and Life Sciences


Department of Animal and Dairy Sciences


One hundred crossbred beef steers were used in two experiments to evaluate effects of growth implants on performance. Steers were implanted either at 3.5 months and weaning (CALF); at weaning (WEAN); or not implanted (NONE). In Experiment 1 implanted steers weighed more at weaning (P = 0.01), and had a higher ADG for the entire trial compared to non-implanted steers (P = 0.03). In Experiment 2, at 80 d post wean, implanted steers outweighed NONE (P = 0.09). Overall ADG (P = 0.01) was greater for cattle that were implanted. In the feedlot the CALF group had the lowest ADG (P = 0.01), and final BW (P = 0.07). At harvest CALF had the highest dressing percentage (P = 0.04), smallest LMA (P = 0.1), and lowest IMF (P = 0.06). Implants can increase productivity in beef cattle however, marketing and management strategy will dictate use.