What now, mad cow?
by Tim Steury | © Washington State University
Weighing the effects of the BSE-infected Holstein in Mabton
It could have been worse
December 23, 2003, changed the way we think about beef. Fortunately, our complacency about its safety was the only major casualty.
Economically, the effects of the cow with bovine spongiform encephalopathy (BSE or "mad-cow disease") discovered in Mabton, Washington, could have been much worse, says Don Nelson, a Washington State University beef specialist.
The key, he says, "was that the cow came from Canada and that no subsequent cases were identified.
"Because of a mix of factors, it didn't do the damage we thought it would. It shows you the importance of timing."
The discovery of the BSE-infected cow knocked the market price down by about $3.00 per hundredweight. But prices had earlier reached better than $85.00 per hundred, the best price in years. Although nearly 60 countries closed their borders to U.S. beef, beef exports represent only about 10 percent of U.S. production.
Overall, says Nelson, the discovery of BSE within the U.S. provided a good wakeup call for industry and the USDA. "We had some rules that really needed to be tightened up," he says. "One of those was downer cattle. Any downer cattle cannot now go into the food supply."
All sick cattle condemned at slaughter will now be tested, says Terry McElwain, executive director of the Washington Animal Disease Diagnostic Laboratory (WADDL). McElwain oversees a new "high-throughput" lab at WSU, one of seven similar labs nationwide testing for BSE infection.
Meeting the June 1 opening of the lab required an extraordinary amount of work and negotiation.
"The whole issue of what we call a 'positive' in our labs has been debated for the past six weeks," he says. Secretary of Agriculture Ann Veneman was briefed on the progress of the testing daily. Tests in the seven regional labs will be labeled "negative" or "inconclusive." Samples deemed "inconclusive" will be sent to a central USDA lab in Ames, Iowa, for a more sensitive test.
Calling a test "positive" would have a tremendous effect on the cattle market, says McElwain. "The mere rumor of an animal being tested in Texas caused McDonald's stock to drop 30 percent in one day."
As a "surveillance laboratory," says McElwain, the facility is set up to be very sensitive, "so you pick up anything that's out there.
"These tests are probably the most robust tests we use in this lab."
In spite of the mysterious nature of the prions that cause BSE, testing for the disease is fairly straightforward. USDA inspectors remove samples of the brainstem from suspected cows and send them into the lab. Technicians at the lab take a slice of tissue from the region called the obex, which is where the prions first accumulate.
The basis of the test, says McElwain, is an antibody that recognizes normal prions, which accumulate throughout the body. The abnormal prion, which causes BSE, is very resistant to proteases, the enzymes that catalyze the breakdown of proteins. Prions are proteins.
The test, says McElwain, chews up all the normal cellular prions, leaving behind the disease-causing prions, which the antibodies will recognize.
Since field collection of brain samples had not yet started in early June, not many samples were yet reaching the WSU lab a week after its opening. But McElwain expects as many as 26,000 over the next year.
"We're doing what needs to be done at this point," says McElwain. But he also believes the response surpasses the actual risk. Even with the number of mad cow cases in Great Britain, the actual cases of Creuzfeld Jakov disease in humans, 141 worldwide, have been relatively few.
Still, the testing system is necessary to sustain consumer confidence, he says.
Also, says Jay Weidner, a veterinarian and the information systems manager for WADDL, the newly enacted BSE testing has greatly improved the national reporting system for the regional labs, building their capacity for responding to a more dire threat, such as the hoof and mouth epidemic that devastated the British cattle industry.
While U.S. beef producers avoided economic calamity, some niche producers actually benefited. Both Cheryl Cosner ('85 Agriculture) and Joel Huesby ('86 Agriculture), whose pasture-finished livestock never see a feedlot (Washington State Magazine, fall 2003), report their sales increased significantly following the mad cow incident.
Huesby, who started raising pasture-finished beef in 2000, says his business has doubled every year since then. "This year, our sales will triple or quadruple."
Regardless of the obvious impact of the scare on his sales, he says he never mentions the disease. Rather, he talks about the health benefits of pasture-fed beef.
"Customers buy from us for a rainbow of reasons."
Whatever the reasons, his sales are booming. He recently bought the Quick Freeze slaughter facility in Walla Walla and is finishing paperwork for an on-farm USDA-inspected kill room.
Because demand has grown so fast, Huesby has had to source livestock from other producers in the Walla Walla Valley. Huesby requires each grower to sign a "livestock production affidavit," which specifies how the animal was raised and treated and that the cattle have been fed no hormones, antibiotics, or animal protein supplements.
Another criterion is that the cow was born and raised on the supplier's farm. "No middlemen," says Huesby.
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