2012 Annual Report 1a.Objectives (from AD-416): The effects of feeding traditional versus elevated dietary crude protein with or without ractopamine hydrochloride to finishing cattle on feedlot performance, carcass characteristics, and E. coli O157:H7. 1b.Approach (from AD-416): This will be a joint effort between ARS, who will conduct a finishing beef cattle study and Elanco Animal Health, who will be responsible for providing the ractopamine hydrochloride and assisting in the data analysis. Both partners will collaborate in designing the experiments and interpreting the results. This approach to determine the protein requirement of beef cattle fed ractopamine hydrochloride is novel. 3.Progress Report: ARS scientists at Clay Center, Nebraska teamed with Elanco Animal Health to determine whether there was a benefit to feeding additional protein in conjunction with ractopamine hydrochloride. Elanco Animal Health provided the ractopamine hydrochloride for this project. The year 1 finishing study feeding traditional vs. elevated protein diets to feedlot steers with or without ractopamine hydrochloride was completed by USDA-ARS at the U.S. Meat Animal Research Center and the data is currently being analyzed.