While acknowledging that the risk is very small, experts on mad cow disease note that glandular material is more likely to be infected with prions, the disease's infectious agent, than most other tissue. Products must have labels listing ingredients like bovine pituitaries and adrenals, but manufacturers are not required to list the country of origin. Other beef byproducts that are still allowed in the country include milk, blood, fat, gelatin, tallow, bone mineral extracts, collagen, semen, amniotic fluid, serum albumin and other parts of European cattle that are widely used in American products, including vaccines and medicines. The federal Agriculture Department states that these tissues are not believed to contain dangerous levels of prions, but acknowledges that not all have been tested to prove that they pose no risk. United States health officials are just now closing some of these regulatory gaps documents posted on their Web sites say, One year ago, the Agriculture Department told supplement manufacturers to avoid neural and glandular material from domestic and foreign sheep flocks infected with scrapie.
Compliance is voluntary.
Although, cud-chewing animals, or ruminants, are the known carriers of mad cow disease, the Agriculture Department last month temporarily barred European feed supplements mad from nonruminant animals like chickens or pigs. This is because through November, many European farmers were still giving feed made from potentially infected cows to chickens and pigs and were then feeding chickens and pigs back to cows. This practice is now banned in Europe, and Agriculture Department officials are worried that European feed manufacturers will slash prices and try to dump their products on American farmers. In theory, prions could be spread in this feed. The agency maintains these vaccines are safe.