Animal Science Department


Date of this Version

January 2004


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


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.