Rumensin for Use on Grass and for Lighter Weight Calves

Abstract

Rumensin® is an excellent example of a new product that has gained extremely wide acceptance during its first year on the market. Estimates ranging from 65-80% have been proposed for the number of feedlot cattle being fed this new feed additive. The willingness of cattle feeders and feed manufacturers to incorporate Rumensin into their rations and supplements has stimulated other segments of the cattle industry to raise questions concerning the potential for using the new product in non-feedlot rations. The initial FDA clearance was specifically for feedlot cattle and any other use at this time would be a violation. Considerable research is being conducted in an effort to gain additional clearances for pasture cattle and beef cows. The purpose of this paper is to review some of the research concerning Rumensin for lightweight growing cattle and stocker cattle on grass.