Medicated feed

food for various animals

Ractopamine () is an animal feed additive used to promote leanness and increase food conversion efficiency in farmed animals in few countries, banned in most. Pharmacologically, it is a phenol-based TAAR1 agonist and β adrenoreceptor agonist that stimulates β1 and β2 adrenergic receptors. It is most commonly administered to animals for meat production as ractopamine hydrochloride. It is the active ingredient in products marketed in the US as Paylean for swine, Optaflexx for cattle, and Topmax for turkeys. It was developed by Elanco Animal Health, a former division of Eli Lilly and Company.

Roxarsone is an organoarsenic compound that has been used in poultry production and to a lesser extent in pig production as a feed additive to increase weight gain, for greater feed efficiency, to improve pigmentation, and as a coccidiostat. Until June 2011, it was approved for use in the United States, Canada, Australia, and 12 other countries. It is no longer approved for use in most jurisdictions.

Nitarsone is an organoarsenic compound that is used in poultry production as a feed additive to increase weight gain, improve feed efficiency, and prevent histomoniasis (blackhead disease). It is marketed as Histostat by Zoetis.

Zilpaterol is a synthetic β2 adrenergic agonist. Under its brand name, Zilmax, it is used to increase the size of cattle and the efficiency of feeding them. Zilmax is produced by Intervet, a subsidiary of Merck & Co., and marketed as a "beef-improvement technology". Zilpaterol is typically fed in the last three to six weeks of cattle's lives, with a brief period (three days in the US) before death for withdrawal, which allows the drug to mostly leave the animal's tissues.