Effects of a Terminal Sorting System with Zilpaterol Hydrochloride on Feedlot Steers

Crossbred yearling steers were utilized to evaluate the effects of Zilpaterol hydrochloride (Zilmax®) and terminal sorting 50 days prior to harvest on feedlot performance and carcass characteristics. Four treatments were used: an unsorted group not fed Zilmax (–CON), an unsorted group fed Zilmax, sorting by weight into two market groups and fed Zilmax, or sorting by weight into four market groups and fed Zilmax (4-Sort). Carcass weight was increased in cattle fed Zilmax by 33 lb and was further increased by 9 lb by 4-SORT. Yield grade and marbling score were lower for all cattle fed Zilmax compared to the –CON. Sorting four ways (4-Sort) increased HCW, reduced HCW variation, and decreased the percentage of overweight carcasses compared to not sorting