April 24 (Bloomberg) -- The first U.S. case of mad cow disease in six years has been found in a dairy cow in central California, before it entered the human food chain and posed any threat to consumers, officials said.
The cow was identified as part of routine testing for the brain-wasting disease, known as bovine spongiform encephalopathy, John Clifford, the U.S. Department of Agriculture’s chief veterinarian, told reporters today at a briefing in Washington.
The animal arrived April 18 at a Baker Commodities Inc. facility in Hanford, California, where dead livestock are held before going to a rendering plant, Dennis Luckey, executive vice president of operations at Los Angeles-based Baker, said in a phone interview.
The carcass “was never presented for slaughter for human consumption, so at no time presented a risk to the food supply or human health,” Clifford said in a statement. Mad cow disease cannot be transmitted through milk from dairy animals, he said. “USDA remains confident in the health of the national herd and the safety of beef and dairy products.”
Cattle futures tumbled the most in 11 months in Chicago, and feeder-cattle prices fell by the exchange limit. The world’s largest beef producer, Brazil’s JBS SA, fell by as much as 5.2 percent before closing 0.3 percent lower in Sao Paulo. Tyson Foods Inc., the second-biggest U.S. beef processor, pared earlier gains to close 1.5 percent higher in New York.
This is the fourth BSE case found in the U.S. herd, and the first since March 2006. Clifford said the age and the source of the animal in the latest case were being investigated. Luckey said the animal was at least 30 months old and the disease was discovered as part of random testing conducted to meet USDA quotas. He said it’s possible that a diseased animal could be processed without being tested.
Scientists say the disease is spread through feed that contains brain or spinal cord tissue from infected animals. People can get it from eating products containing such tissues, such as head cheese. Since 1997, feed made from mammals has been banned from cattle rations, and high-risk materials such as brains have been kept from the human food supply.
Comes from Protein
Much is unknown about how the disease, which comes from a protein that changes form rather than a virus or bacteria, said Michele Jay-Russell, a veterinarian and researcher at the University of California in Davis, in an interview.
State veterinary diagnostic labs do surveillance to identify any cattle in the U.S. showing neurological symptoms that may indicate mad cow, she said. California officials are holding the carcass at the rendering facility, the USDA said without identifying the plant or its location.
The latest BSE case was “atypical,” Clifford said, meaning that its disease form is very rare and not generally associated with an animal consuming infected feed. Such cases can occur spontaneously in older animals, said Guy Loneragan, an epidemiologist and professor of food safety and public health at Texas Tech University in Lubbock.
Cattle futures for June delivery fell by the exchange limit of 3 cents, or 2.6 percent, to settle at $1.11575 a pound at 1 p.m. on the Chicago Mercantile Exchange. That’s the lowest level since July 1 and the biggest percentage drop on a most-active contract since May 23.
Feeder cattle futures for August settlement declined by the 3-cent limit, or 1.9 percent, 1 $1.51225 a pound on the CME. That’s the biggest loss since Sept. 22.
Mad cow disease has been most prevalent in the U.K., which has had 184,000 cases since 1987. Last year only 29 cases were reported worldwide, Clifford said. Canada, the biggest U.S. agricultural trading partner, has had 19 occurrences as of February 2011, according to the Centers for Disease Control and Prevention.
“It’s been rare” Jay-Russell said. “We have a fairly robust surveillance system.”
Still, the new case shows a need to boost surveillance, said Michael Hansen, a staff scientist at Consumers Union, a Yonkers, New York advocacy group.
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