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.


A commercial feedyard experiment evaluated initial implant strategies for feedlot heifers. Heifers were administered either Revalor-IH or Synovex-H at initial processing, with both treatment groups receiving Revalor-200 as a common terminal implant. Implanting heifers initially with Revalor-IH improved feed efficiency and ADG compared to heifers implanted initially with Synovex-H. In addition, Revalor- IH implanted heifers had higher marbling scores while 58% more carcasses achieved the upper two-thirds Choice category. There were no differences in USDA yield grades. Selling Revalor- IH implanted heifers on a carcass merit basis returned $14.22/head more than Synovex-H implanted heifers. New reduced-dose initial implants can improve both feed efficiency and marbling scores, suggesting carcass quality can be positively influenced with no negative impact on growth performance.