Department of Animal Science


Date of this Version

January 2004


Published in 2004 Nebraska Beef Cattle Report. Copyright © 2003 The Board of Regents of the University of Nebraska.


One hundred steer calves were used to evaluate the effect of delaying initial implanting on feedlot and carcass characteristics. One-half the steers were implanted with Synovex S® after a 14 day acclimation period, the remainder were implanted 30 days after the 14 day acclimation period. All calves were re-implanted 112 days after the beginning of the study with Synovex Choice® and harvested 100 days later. Neither final weight (1269 lb) nor ADG (3.74 lb/day) were affected by implant regimen. Delayed implant steers had a higher percentage grading Choice (92 vs 68%). Delaying implanting resulted in a 24% increase in cattle grading Choice at harvest without compromising feedlot performance.