Investigators tentatively traced the first United States cow with mad cow disease to Canada, which could help determine the scope of the outbreak and might even limit the economic damage to the American beef industry.
In addition, some calves in a quarantined herd of 400 that included a male offspring of the sick cow likely will be killed, the Agriculture Department said on Saturday. The herd was at a farm in Sunnyside, Washington, which officials refused to name.
Dr Ron DeHaven, the US Department of Agriculture’s (USDA) chief veterinarian, said on Saturday that Canadian officials provided records indicating the sick Holstein was in a herd of 74 cattle shipped from Alberta, Canada, into the US in August 2001 at Eastport, Idaho.
”These animals were all dairy cattle and entered the US only about two or two-and-a-half years ago, so most of them are still likely alive,” DeHaven said.
The sick cow’s presence in that herd does not mean all 74 animals are infected, DeHaven said. Investigators will probably find where the other 73 animals are within a matter of days, he said. Finding them will help investigators determine if any other animals are sick and need to be tested.
In May, Canada found a lone cow with the disease in Alberta but has not been able to determine the source of infection.
If US and Canadian officials confirm that the sick cow in Washington state came from Canada, it might save the export market for the American beef industry because the US could keep its disease-free status and continue trade.
The National Cattlemen’s Beef Association in Denver said the indication that the infected cow was from Canada means US trading partners should reopen their borders to American beef. The farm organisation said a beef export monitoring program would allow importers to separate beef of Canadian origin if they feel additional precautions are needed.
Federal officials announced on Tuesday that tests indicated the cow, which ended up at a Washington farm in October 2001, had mad cow, a brain-wasting illness. An international laboratory in the United Kingdom confirmed it on Thursday.
Julie Quick, a department spokesperson, said on Saturday that officials are awaiting a recommendation from USDA scientists on whether to kill some calves in the Sunnyside herd, but that seemed likely because investigators cannot tell which among multiple young calves in the herd is from the sick cow.
”Since the calf was not tagged, all bull calves at the Sunnyside premises under 30 days of age will likely be depopulated,” the department said. It was not clear how many calves were in that category.
Mad cow disease, known as bovine spongiform encephalopathy, is a concern because humans who eat brain or spinal matter from an infected cow can develop variant Creutzfeldt-Jakob disease. In Britain, 143 people died of it after an outbreak of mad cow in the 1980s.
Federal officials insist US meat is safe because the brain, spinal cord and lower intestine — parts that carry infection — were removed from the cow before its meat was processed for human consumption.
Despite those assurances, more than two dozen countries banned US beef this week. The US lost 90% of its beef export market, industry officials say, and producers stand to lose up to $6-billion a year in exports and falling domestic prices.
USDA officials went on Saturday to Japan, a top buyer that has banned American beef, to discuss maintaining trade.
Connecting the infected cow to Canada could deal another blow to the Canadian beef industry, which has struggled since it found its case of mad cow disease last May. It lost $1-million in beef trade per day as countries cut off beef imports.
Dr Brian Evans, chief veterinary officer of the Canadian Food Inspection Agency, emphasised that the cow’s origins have yet to be confirmed. He noted that details on the cow’s records in the US do not match the ones kept in Canada.
Canadian papers show the cow had two calves before it was shipped to the US, which wasn’t documented by US officials.
Also, DeHaven said Canadian papers say the diseased cow was six-and-a-half years old — older than US officials had thought. US records say the cow was four or four-and-a-half years old.
Because of the discrepancies, Evans cautioned against ”a premature conclusion that the definitive animal or definitive birth place has been located”.
The age is significant because the animal may have been born before the US and Canada in 1997 banned certain feed, which is considered the most likely source of infection.
Cows get infected by eating feed that contains tissue from the spine or brain of an infected animal. Farmers used to feed their animals such meal to fatten them.
Although US officials have maintained the food supply is safe, the government recalled an estimated 4 500kg of meat cut from the infected cow and from 19 other cows all slaughtered on December 9 at Vern’s Moses Lake Meat Company in Moses Lake, Washington.
Ken Petersen, of the USDA’s Food Safety and Inspection Service, said, ”It’s too early to know how much of the product has been brought back, though we know that some of the product is beginning to be at least held at the retail facilities.”
Officials say the slaughtered cow was deboned at Midway Meats in Centralia, Washington, and the meat was sent to two other plants in the region, identified as Willamette Valley Meat and Interstate Meat, both near Portland, Oregon.
Meanwhile, the Food and Drug Administration is trying to find out if the cow ate contaminated feed — a difficult task because the animal may have gotten the disease years before it appeared sick.
The disease has an incubation period of four or five years.
Dr Stephen Sundlof, head of the Food and Drug Administration’s Centre for Veterinary Medicine, said the agency is accounting for all of the byproducts rendered from the cow, including items like soap and soil nutrients. — Sapa-AP