ABSTRACT
American cattle and swine producers are feeding animals feed mixes containing two beta agonists: ractopamine and zilpaterol. Beta agonists activate protein synthesis and decrease protein degradation on a cellular level to enhance animals’ muscle growth. The feed additives are fed to cattle and pigs for short periods of time prior to the slaughter and promote weight gain. Yet, residues of beta agonists are present in the meat products of these animals, and concerns exist whether they might adversely affect persons who eat the products. Foreign governments are not convinced that the meat products containing residues are wholesome, and some preclude the sale of products containing beta agonist residues.
