FDA offers new rules to reduce mad cow risk

WASHINGTON -- In response to the threat of mad cow disease, the Food and Drug Administration yesterday proposed banning the use of certain potentially infectious cattle parts in animal feed, but it brushed aside other safety measures it had appeared to endorse last year.

The new rules, to take effect early next year, are expected to reduce the risk of infection by 90 percent, Stephen F. Sundlof, director of the FDA's Center for Veterinary Medicine, said.

Mad cow disease, technically bovine spongiform encephalopathy, or BSE, is believed to be caused by abnormal proteins, known as prions, found in brain and nerve tissue. Cattle can become infected if they eat feed contaminated with the infectious agent.

The FDA's proposal bans the use of spinal cords and brains from cows 30 months of age or older and those that were not approved for human consumption in feeds marketed for poultry, pigs, and pets. It does not include a ban on other standard risk materials, or SRMs, such as cattle blood, poultry litter, or restaurant plate waste.

Critics said the government was not ''closing all the gaps" in the feed ban, as then-FDA Commissioner Lester Crawford had promised to do last month. Caroline Smith DeWaal, director of food safety at the Center for Science in the Public Interest, said that ''when you dig down, it appears that they have put in a new definition of SRMs to apply to this rule. We could call it 'SRM light.' "

Infection levels are believed to rise as cattle grow older, hence the 30-month age cutoff, but because there is no identification tracking system in the United States, it becomes difficult to assess the exact ages, said DeWaal.

The original feed rule, first imposed in 1997 as a result of the mad cow outbreak in Britain, banned the uses of cattle parts only in cattle feed.

Following the discovery of the first US case in December 2003, the FDA began work on revisions of the rule.