SALEM, Ohio – How the Holstein cow in Washington state became infected with bovine spongiform encephalopathy (BSE) or mad cow disease, remains the big question in the ongoing investigation that now spans two countries.
Contaminated feed is the focus on the investigation, which must also consider whether or not the cow ate feed prior to a ban on feeding animal protein to cattle.
Positive ID. DNA evidence helped to verify that the cow found infected with mad cow disease in Washington State originated from a dairy farm in Alberta, Canada.
The evidence is based on a comparison of DNA from the brain of the infected cow with the DNA from semen of her sire. It was confirmed by both U.S. and Canadian animal health laboratories.
There is still no word whether this incident is linked to the cow that was found infected with BSE in Canada last May.
“We do not have, at this point, sufficient evidence to make any definitive feed link between the two farms,” said Brian Evans, chief veterinary officer with the Canadian Food Inspection Agency.
“They did not buy from a common feed mill; they did not have similar type rations on their farm.”
He added that finding the feed records that go back seven years may be difficult.
Cattle slaughtered. DNA tests on a yearling heifer on the initial Washington farm where the infected cow was housed confirmed that the calf was out of the positive cow.
The USDA said it will slaughter approximately 130 animals from that 4,000-head dairy herd in Mabton, Wash., that housed the infected cow.
In addition to the heifer, some of the animals were herd mates of the BSE-infected animal in Canada and could have been exposed to the same feed source.
Calves killed. On Jan. 6, the USDA euthanized the entire bull calf herd from Sunnyside, Wash., that included the bull calf born to the cow infected with mad cow disease.
Farm operators couldn’t identify which calf came from the infected cow, which is why all 450 animals were slaughtered.
The carcasses were disposed of in a landfill Jan. 7. None entered the food chain or were rendered.
Tracking group. In the ongoing investigation of the group of cattle that entered the United States with the positive cow, USDA officials located two other animals from that group.
These cows are part of a dairy herd in Mattawa, Wash., that is already under a state hold order. Officials have said they may depopulate that herd, too.
As of Jan. 8, USDA has accounted for 13 of the 82 cattle listed on the Canadian health certificate for that imported group: the index, or positive cow; nine animals part of the index herd; and three animals on the Mattawa farm.
Officials also believe one of the animals listed on the certificate remained in Canada and did not enter the United States.
USDA and Canadian officials continue to track 17 animals from the BSE-infected animal’s birth herd that may have also arrived in the United States as part of a later shipment.
Investigators aren’t sure if any, or all, of these 17 animals entered the United States.
Quick tests. The ag department is also reviewing applications for quick turnaround BSE tests.
To date, the department has reviewed data from companies that have various rapid tests, but has not been considering the applications for license or permit until now.
Currently, the only BSE test approved in the United States is the immunohistochemistry, or IHC, test, with a two-week turnaround time from sample collection to final results.
Some of these new tests could be licensed in a matter of weeks, depending on the quality and depth of the application and data; others may take up to six months to get licensed. Still others , which may not have as much information available, may take a year or more to get USDA licensing.
Shift to rendering plants. With the ban on downer cows entering the food chain, the USDA’s surveillance will have to shift to rendering plants instead of slaughter plants.
USDA’s Chief Veterinary Officer Ron DeHaven said the program expects to target between 38,000 and 40,000 nonambulatory cows for testing this year.
Until the ban on downer cows is more fully understood, there is no restriction on nonambulatory animals found at slaughter from going to inedible rendering.
Export questions. High level USDA officials traveled to Mexico City last week to meet with Mexican agriculture officials to discuss the reopening of the Mexican market to U.S. beef exports.
Mexico, along with many other countries, suspended imports of live animals and beef products from the United States in the wake of the BSE announcement in Washington state. A team from Mexico is in the United States this week to get its own set of answers.
A Japanese fact-finding team also visited D.C. last week and then headed to the state of Washington to continue its investigation.
In 2002, Japan imported $854 million worth of U.S. beef.
Depend on exports. This disruption in exports will be significant, even if domestic beef prices recover, said Penn State ag economist Lou Moore.
“A full 10 percent of our country’s beef production is exported, so the industry will be able to recover quickly only if exports resume soon,” Moore said.
If the export market stays closed for any length of time, Moore said losses for the region’s cattle industry will increase sharply.
Of the 81 cows that came from Canada:
* One is the positive, or infected cow.
* Three are under a hold order at a Mattawa, Wash., farm.
* Seven may have gone to another dairy, now quarantined. USDA is trying to figure out if they’re still there.
* Nine are in the index herd.
* Some may remain in the index herd, but identification has not been confirmed.
In the index herd:
* 258 cattle could have been a part of this shipment of 81 animals.
* Records identified 129 of these cattle; they remain on the farm and will be depopulated.
* Computer records of 110 of these cattle show they have already been culled. The USDA is conducting trace-outs of these animals.
* The remaining 19 did not have records indicating culling and they were not found on the USDA inventory. Officials are still looking through the herd for any of these cattle.
STAY INFORMED. SIGN UP!
Up-to-date agriculture news in your inbox!