Here it is 0.6 percent and most of that material is free from scrapie. The reason is that scrapie is closely monitored by United States Agriculture Department veterinarians under a federal program. There are no knackers in this country and no greaves to infect cattle, Detweiler said. Few ranchers here feed meat and bone meal to young cows and American renderers usually treat the raw material at higher temperatures. But the key element in efforts to prevent the cow disease is a newly proposed Agriculture Department ban on feeding protein derived from ruminant animals to other ruminants.
Ruminants are animals that chew cuds, including cows, sheep, goats, deer and elk.
Mink are included in the ban because they can be affected by a disorder similar to mad cow disease. If the Agriculture Department rules are adopted, cow protein might still be fed to fish, chicken or pigs in hope that if mad cow disease were to appear, a species barrier would stop it from spreading. At the same time, the Agriculture Department continues to monitor American cows for signs of mad cow disease. But a major reason to worry is that the cow epidemic may have nothing to do with scrapie or the processing techniques used by renderers, said Dr. Richard F. Marsh, a veterinarian at the University of Wisconsin in Madison. There are reasons to believe that mad cow disease has already risen spontaneously in American cattle, he said.