摘要: Some substances that produce anabolic effects have been approved for use in food-producing animals by a number of government regulatory authorities are responsible ensuring veterinary products safe and effective. At the same time, agencies other countries not permitted their and/or allowed foods from treated with such drugs to be imported. These metabolic modifiers include somatotropins, beta-adrenergic agonists, steroids. Although some these may used therapeutic reproductive purposes, most disagreements among regulators public centered on questions safety related uses intended enhance food production as increasing rate weight gain, improving feed efficiency, modifying muscle leanness, milk production.