Cow punchers.

"Cow Madness: Disease's U.S. emergence highlights role of feed ban" (SN: 1/10/04, p. 19) gives American beef eaters a false sense of security. Yes, only 1 cow out of the 20,000 tested has been discovered to have bovine spongiform encephalopathy (BSE). However, over 35 million cows were slaughtered in the United States last year, meaning that only 0.06 percent of all cows slaughtered were tested for BSE. Small wonder only one infected cow has been found to date. Japan, by contrast, tests all cows slaughtered, 1.2 million last year. If the government and the cattle industry want to convince me that a given cow is safe, test it before asking me to eat it. Until that time, I'm getting my protein from tofu. I've yet to hear of mad soybean disease.

JIM MONTGOMERY, REDONDO BEACH, CALIF.

The article contains an error, saying that the United States' 1997 cow-feed ban "prohibits feeding potentially infective animal parts to cattle" The ban applies only to feeding cow parts to cows. It doesn't cover feeding cows parts of other animals or feeding cow parts to other animals. Thus the "ban" was as ineffective a barrier as a volleyball net is against water, even if you ignore the mass willful violations that are on the record. Also, even though variant Creutzfeldt-Jacob disease (CJD) can be distinguished from sporadic CJD (all other), it's difficult to do so. Autopsies are rare, and it's easy to misdiagnose CJD as Alzheimer's disease.

TONY TWEEDALE, MISSOULA, MONT.

If mad cow disease is caused by aberrant proteins, why wouldn't cooking disrupt their structure and render them harmless?

VIRGIL H. SOULE, FREDERICK, MD.

The prions that cause bovine spongiform encephalopathy and Creutzfeldt-Jacob disease aren't broken down by normal cooking temperatures. --B. HARDER