In 1997, the U.S. Food and Drug Administration issued a rule mandating the prohibition of ruminant feed containing animal protein derived from mammalian tissues. FDA regulations are intended to prevent the establishment and amplification of bovine spongiform encephalopathy (BSE) in the United States through feed and thereby minimize any risk to animals and humans. FDA regulations focus on animal feed ingredients because epidemiologic evidence gathered in the United Kingdom suggests an association between an outbreak of a ruminant transmissible spongiform encephalopathy (TSE), specifically BSE, and the feeding to cattle of protein derived from sheep infected with scrapie, another TSE. The BSE in cattle in the U.K. was amplified through the feeding of meat-and-bone meal derived from carcasses of cattle infected with BSE. BSE has not been diagnosed in the United States, and the FDA prohibition is intended to prevent the establishment and spread of BSE in the United States through feed and thereby minimize any risk to animals and humans.
