SALEM, Ohio – The USDA is narrowing its Washington state mad cow disease investigation to a farm in Alberta, Canada.
A U.S. dairy cow infected with bovine spongiform encephalopathy, known as BSE or mad cow disease, most likely contracted the disease from contaminated feed at her birth farm, believed to have been in Canada.
Officials have not indicated whether the investigation has uncovered potential sources of feed to blame for the diseased cow, or whether the U.S. cow is linked to the Canadian cow confirmed with mad cow disease last May.
DNA identification tests are expected back this week. Records indicate that the animal was approximately 6 1/2 years old at the time of slaughter.
Locating group. Investigators are tracking the location of 70 out of the group of 81 head that entered the United States with the infected cow in September, 2001. Nine remain in the quarantined index herd, the herd where the positive cow was housed.
One of the 81 has been located at a Mattawa, Wash., dairy farm, which is now quarantined. Another cow may still be in Canada.
From dispersal sale. The birth herd of the infected cow has not been identified, but officials say the suspected herd of origin was in Alberta, Canada. The imported group came from a dispersal sale.
Officials are trying to find the other herdmates because they may have shared a common feed source when young, not because the disease is spread from cow to cow.
The quarantine includes a third farm that purchased a group of calves that includes a bull calf born to the infected cow.
Calves depopulated. No cattle being held have been euthanized on the three quarantined farms, as of Jan. 5, but that will soon change.
The group of 450 calves in Sunnyside, Wash., that includes the bull calf born to the infected cow will most likely be euthanized this week, according to USDA’s Chief Veterinary Officer Ron DeHaven.
The calves will be taken to an unused slaughter facility and no products from the animals will enter the food chain, nor will products be rendered, he added.
The USDA and the owner must agree upon fair market value of the animals before the group is depopulated.
Risk level. “The science would suggest that only those animals that have a direct link back to the premises of origin and would be birth cohorts of the infected cow represent any kind of risk,” DeHaven said.
Progeny from the infected cow are also suspect, he said, adding that there is evidence that the cow had calves on both sides of the U.S.-Canada border.
The USDA is also tracing the dam of the positive cow. Officials suspect she could be part of the 81 animals that came into the United States in September 2001.
Downer ban. U.S. Agriculture Secretary Ann Veneman introduced additional measures Dec. 30 to bolster the food safety firewall.
New policies ban nonambulatory disabled cattle, including downer cows and risk material and tissues, from the human food chain.
In 2002, there were between 150,000 and 200,000 downer cows among the 35.7 million cattle slaughtered in the United States, according to the USDA.
Any meat from cattle that have been tested for bovine spongiform encephalopathy (BSE), or mad cow disease, must be held until the test has confirmed negative.
The new safeguards also prohibit air-injection stunning of cattle. (See related article for more complete details on the new measures.)
Animal ID. The USDA is also immediately implementing a national animal identification system.
No details are in place, DeHaven said, but the USDA is working with individual species groups to develop identification procedures.
Ideally, he explained, the ID would be put on animals at the time they leave the birth farm and would follow animals through slaughter.
The goal is to have a means of tracking animals electronically as they go through feedlots, livestock markets and slaughter.
Funding sources are still unknown, DeHaven admitted.
How now down cow? With the advent of the ban on nonambulatory cows in slaughter plants, just how many at-risk animals will be tested? What incentive will farmers have to have animals tested?
USDA’s DeHaven told reporters Jan. 2 that “all options are on the table” in terms of incentives for testing. But the USDA will have to refocus its emphasis from slaughter plant testing to rendering plants that process carcasses but not for human consumption, he added.
“We also need to work to get access to some of those animals on the farm,” DeHaven said.
He said they may work through the American Veterinary Medical Association and local vets to gain onfarm access.
Financial incentive. DeHaven said the USDA is still “developing plans on how we’re going to continue to have access to that population at other points.
“I would simply say that providing some financial incentive for bringing those animals to those other locations” is being considered, he added.
But DeHaven also said it was premature to speculate “what, if any, compensation might go to the owner.”
Opening borders. DeHaven also said the USDA will not make a final decision on the United States’ proposed resumption of live cattle imports from Canada without taking into account the “new situation” resulting from the BSE case in the United States.
A public comment period on the resumption closed Jan. 5.
The United States banned cattle imports from Canada following Canada’s discovery of its own BSE case in May 2003.
A connection of the two cases would have a “significant bearing on our overall evaluation of the prevalence of the disease in Canada,” DeHaven said.
High-level USDA representatives traveled to Japan last week and are headed to Mexico this week to discuss trade restrictions imposed by these governments after the finding of the positive case.
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Animal and Plant Health Inspection Service
Centers for Disease Control
The Humane Society of the United States
USDA’s October ruling to allow live animal imports from Canada