The Washington state cow infected with mad cow disease was born four months before the United States and Canada instituted bans on feed containing potentially infectious material, U.S. Department of Agriculture officials said Monday. The determination that the cow was more than 6 1/2 years old — not 4 1/2, as originally thought — is good news for the U.S. meat industry.
Feed that included cooked, ground-up cattle parts was legal in both the USA and Canada until August 1997. Ron DeHaven, USDA's chief veterinarian, said research has shown that eating this kind of feed is "the primary, if not the only way" the disease is spread from animal to animal.
The infection of a 4 1/2-year-old cow would indicate that the feed ban wasn't working, but an older cow could have eaten infected feed.
This means that while there might be stray cases of mad cow disease from the use of infected feed in the late 1990s, it is likely that very few of those animals are still alive because most U.S. beef cattle are slaughtered at 18-24 months old. The only cattle likely to have been alive prior to the feed ban would be the smaller number of dairy cattle and breeding bulls prized for milk output or excellent genes. Such animals are allowed to live as long as 10-15 years, said Deb Roeber, a beef specialist at the University of Minnesota.
The infected Holstein was one of thousands of dairy cows imported from Alberta, Canada, in 2001. The USDA hasn't confirmed the exact number. DeHaven said this weekend that the department will turn its attention to those cows after it has found the 81 cattle that came into the United States with the infected cow. U.S. officials originally thought they were looking for 73 cows.
Mad cow disease, or bovine spongiform encephalopathy, is a concern because humans who eat tainted tissue can get a brain-wasting illness, variant Creutzfeldt-Jakob disease. Officials have said, however, that potentially infectious tissue from the infected cow's brain, spinal cord and nervous system was removed at slaughter.
A recall of 10,415 pounds of meat produced at Vern's Moses Lake Meats in Moses Lake, Wash., on Dec. 9 — the day the infected cow was slaughtered there — is going well, said Ken Petersen of the USDA's Food Safety Inspection Service. More than 80 percent of the meat went to Washington and Oregon, and all major retailers that received it have been notified and have notified customers.
The recall has been extended to Alaska, California, Hawaii, Idaho, Montana, Nevada and Guam. But Petersen said that in each of those areas, there may be as few as one retail outlet affected.