Dec 30, 2003 (CIDRAP News) The US Department of Agriculture is banning the use of "downer" cattle for human food and taking several other new steps to keep beef products contaminated with the agent of bovine spongiform encephalopathy (BSE) out of the food supply, Agriculture Secretary Ann Veneman announced today.
Speaking a week after the first BSE case in the United State was revealed, Veneman said the USDA will also hold all cattle carcasses tested for BSE until tests show the animals are free of the diseasea step that would have kept meat from the BSE-infected cow discovered in Washington state out of the food supply. (Because the cow couldn't walk, its carcass was tested for BSE as part of routine surveillance. But inspectors, believing the cow had been injured during calving and was fit for food use, approved the carcass before the test results came back.)
Veneman also announced that USDA will ban from the food supply all high-risk tissues from cattle more than 30 months old. The "specified risk materials" (SRMs), which are most likely to carry the BSE agent in sick animals, include the skull, brain, trigeminal ganglia, vertebral column, spinal cord, and dorsal root ganglia. The agency also is banning the small intestine of cattle of all ages. The SRM ban matches a regulation set by Canada after a single case of BSE was found in a cow in Alberta last May.
About 20% of cattle are older than 30 months at the time of slaughter, said Dr. Daniel Englejohn of the USDA's Food Safety and Inspection Service. Because of the long incubation period for BSE, the infectious prion proteins associated with the disease are not found in cattle younger than 30 months, agency officials said.
Further, the USDA is broadening a rule intended to keep meat produced by "advanced meat recovery" (AMR) systems from containing spinal cord tissue, Veneman said. The new rule expands the ban to include dorsal root ganglia (clusters of nerve cells along the vertebral column).
The agency also is banning air-injection stunning, a method of humanely stunning cattle at the time of slaughter. The technique can drive brain tissue into other tissue, posing a risk of contaminating meat with the BSE agent if the disease is present, officials said in a news release. The agency is also prohibiting the use of any "mechanically separated" meat in human food.
Veneman further announced she would appoint an international panel of experts to review the government's response to the BSE case, just as Canada did earlier this year. She did not immediately name the members.
Finally, the USDA will intensify its efforts to establish a nationwide animal identification system to enhance the ability to respond to animal diseases, Veneman announced. She said the agency would speed the development of the information technology needed for the system.
At a news briefing and in a press release, officials insisted the new steps do not mean the existing system for preventing BSE has been inadequate. "These actions do not in any way suggest that the meat produced in the current system is in any way unsafe," said Dr. Ron DeHaven, the USDA's chief veterinary officer. "We are making these further enhancements to our system out of an abundance of caution."
"Effective immediately, USDA will ban all downer cattle from the human food chain," Veneman told reporters. The step means that cattle that can't walk when presented for slaughter will not be approved for use as food. Veneman estimated the annual number of downer cattle at about 150,000 out of a total of about 35 million slaughtered each year in the United States.
Because the number of downer cattle is relatively small, Veneman said she doesn't expect the ban to increase the retail price of beef. Also, she said the ban on downer cattle and on SRMs is not likely to cost either the beef industry or the USDA much money.
Veneman pledged that her agency will increase its BSE surveillance "considerably over what it's been the past couple of years." The surveillance program has focused on the postmortem testing of older and downer cattle presented for slaughter. Because the ban on downer cattle will reduce the number of such cattle being sent to slaughter facilities, USDA officials acknowledged that increasing BSE surveillance will be a challenge.
"Obviously we're going to be looking at other ways to test downer cattle than at the slaughter plant," Veneman said. "We'll look at a whole variety of actions. Whether that will include on-farm inspection hasn't been determined at this point. There will be follow-up measures that we'll be assessing as we go forward."
When cattle are tested, the hope is to get the results within 36 to 48 hours so that carcasses can be cleared for processing without long delays, DeHaven said. That will require the use of new, rapid tests for the infectious prion proteins. "For that kind of turnaround, we would contemplate going to one of the rapid tests," some of which are used in Europe and elsewhere, he said. The details of the revised testing program remain to be hammered out, he noted.
Also at the news briefing, the Food and Drug Administration said all of the rendered (nonmeat) materials that might have come from the infected cow have been found and contained. FDA Deputy Commissioner Lester Crawford said the materials are now under the FDA's control. Officials said earlier that brain, spinal cord, and distal ileum from the infected cow had been sent to a rendering plant.
DeHaven said USDA is continuing to trace cattle that were exported from Canada to the United States with the cow that later was found to have BSE. A total of 82 cattle, including the index animal, apparently came from a herd in Alberta, officials have said. "A number of those animals have been found in the index herd," where the infected was last kept, DeHaven said.
The fate of that herd, which is under a state quarantine, has not yet been decided, USDA officials said today.
The agency said the ban on downer cattle is effective immediately. The changes concerning SRMs and AMR systems will take effect when published in the Federal Register.
USDA's Dec 30 news release
USDA's Dec 29 update on the BSE situation