Beta agonists in livestock feed: status, health concerns, and international trade.

Since the U.S. Food and Drug Administration approved ractopamine hydrochloride and zilpaterol hydrochloride in animal feeds, usage of those compounds has been a topic of worldwide debate. Ractopamine and zilpaterol are β-adrenergic agonists used as veterinary drugs to increase weight gain in certain animals raised for food. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) established maximum residue limits for ractopamine, which were adopted by the Codex Alimentarius Commission (Codex). No maximum residue limits for zilpaterol have been adopted by JECFA, and new reports of animal mobility issues confront the use of this feed additive. However, many countries disagree with the Codex standards and are restricting or banning meat products containing β agonists. The bans by major importers of U.S. meat products have prompted some to advocate that the United States use the World Trade Organization dispute settlement body. This paper looks at the developments to provide a fuller accounting of what the issues may mean to U.S. firms selling meat products containing residues of β agonists.