Abstract: A novel zinc bacitracin--containing animal feed additive, in particulate form, has been discovered having an externally coating with a polymer such as an alkyl cellulose polymer. The novel composition shows significant improvement in stability with respect to long term storage over a wide range of temperatures and in admixture with a wide range of animal feeds, and a substantial reduction in odor. In a preferred embodiment, the zinc bacitracin--containing feed additive comprises zinc bacitracin, a fermentation residue and calcium carbonate. A novel process for producing the zinc bacitracin containing feed additive minimizes the formation of dust sized particles.