seal  Purdue News

January 15, 2004

Purdue experts: test high-risk, older cattle for mad cow disease

WEST LAFAYETTE, Ind. - Purdue University experts say it's not necessary or economically feasible to test each cow that goes to slaughter for mad cow disease in the United States, even though there have been calls for complete testing in the weeks following the discovery of the illness here.

Leon Thacker, a Purdue veterinary pathologist and head of the Indiana Animal Disease Diagnostic Laboratory, instead proposes testing animals over 30 months of age as well as high-risk and disabled cattle for mad cow, or bovine spongiform encephalopathy (BSE). High-risk and disabled cattle already are tested in the United States.

High-risk animals are defined by the U.S. Department of Agriculture as cattle with neurological disorders, non-ambulatory cattle and those dying from unknown causes.

"We're looking at a disease that typically has an incubation period of five to six years - most of the cattle that go to market are 24 months old or less," Thacker said.

In the United Kingdom, all cows over 30 months of age are tested and removed from the food supply, as are high-risk and disabled cows. In the U.S. around 36 million cattle go to slaughter each year, compared to a combined 2-3 million in the United Kingdom and Japan.

Of the U.S. cattle processed annually, around 6.3 million were cows or bulls, according the 2002 National Agricultural Statistics Service slaughter report. These are likely to be over 30 months of age.

Chris Hurt, a Purdue Extension agricultural economist, said preliminary estimates place the cost of testing at about 1 percent of the value of beef animals, so economically speaking, testing cattle 30 months or older is feasible.

"At $50 per head for 6.3 million cattle, the cost is $315 million, which is less than 10 percent of the value of lost exports," Hurt said. Efficiencies in mass testing could make the cost much lower, he said.

The question is: Who pays for the testing?

Hurt said he sees two possible scenarios.

"If processors have to pay the added costs, they will shift some of the additional costs back to producers in the form of lower cattle bids," Hurt said. "Over time, producers will reduce production, and eventually the cost would be shifted primarily to beef consumers in the form of higher beef prices. However, this scenario may be financially difficult for processors and producers in the short run."

Taxpayers also might end up footing the bill if testing is subsidized, similar to federal meat inspection. In that case, the packing plant would receive compensation for every cow tested. While taxpayers would bear the costs, consumers would have somewhat lower beef prices, Hurt said.

"That alternative redistributes the cost of the program to the general taxpayers, and that pretty well distributes the cost to the people who eat beef and avoids the short-term disruption to packers and producers," he said.

Even if the price of beef goes up, experts agree that consumers would likely be willing to pay for the increased safety.

Hurt said another issue is how quickly testing capacity would become available as the number of cattle tested moves from about 20,000 per year to more than 6 million.

Will additional testing make consumers safer?

Tam Garland, a veterinarian and director of the cattle and ruminants division at the Indiana State Board of Animal Health, said even if an animal isn't showing mad cow disease symptoms at the time of slaughter, tests would still detect the disease.

"If the animal is affected, meaning the agent is there, but not showing clinical signs of the disease, the tests would show it," she said. "The cow that was positive in Washington had no clinical signs, but it still tested positive."

The U.S. Department of Agriculture has said that the Washington cow was what is called a "downer" not because of BSE, but because it was paralyzed while giving birth.

"The United States is getting a lot of flack saying we've tested a small percentage of our cattle," Thacker said. "But we've been looking at animals that have a higher risk."

Writer: Kay Hagen (765) 494-6682,

Sources: Leon Thacker, (765) 494-7460,

Chris Hurt, (765) 494-4273,

Tam Garland, (317) 227-0300,

Ag Communications: (765) 494-2722; Beth Forbes,
Agriculture News Page

Related Web site:
Purdue Mad Cow Backgrounder

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