In a press conference held Saturday morning, Dr. Ron DeHaven, the chief veterinary officer with the U.S. Department of Agriculture, announced that investigators are now looking into leads that the Mabton Holstein infected with mad cow disease came from Canada.
With the new information, DeHaven said, the USDA now believes that the infected cow came to the United States as a part of a group of 74 dairy cattle entering the country at Eastport, Idaho. The dairy cows are believed to have come from a herd in Alberta, Canada in August 2001, said DeHaven.
"There is some discrepancy in the records that we have and the records that we obtained from the index herd owner and the Canadian records on the particular animal," said DeHaven. "U.S. records would indicate that the animal was 4 to 4-1/2 years old. The Canadian records indicate that she was born in April of '97, making her a 6-1/2-year-old animal."
The USDA is implementing DNA testing to determine if the animal is the same one that entered the country in 2001. DeHaven said that if it is the same cow, she had a calf in Canada and semen is still available from the animal believed to be the sire of the infected animal, which could help with the matching.
But, DeHaven said, there is a question as to how old the cow was when it was purchased for the 4,000-herd Mabton dairy.
"Initially, we had a verbal report from the herd owner of the indexed farm saying that based on his memory this particular cow came into the U.S. in October 2001, as a 2-year-old springer," said DeHaven. But in talking with the manager of the same farm, not the owner, he recalls this cow being a dry cow, which would suggest that she was an older animal and soon to give birth to her next calf, said DeHaven.
According to a report released this morning (Monday), the Mabton owner of the Holstein cow found to have BSE has located documents indicating the cow was an older animal, not a 2-year-old springer as initially thought, according to DeHaven.
The cow is now believed to be 6-1/2 years old, said DeHaven.
"Information now indicates that the animal was born before the feed bans were implemented in 1997," said DeHaven. "Only DNA tests will confirm that the cow is from a farm in Alberta, Canada.
The USDA was turned onto the possibility that the cow originated in Canada when a small metal tamper-proof tag was recovered from the slaughter house in Moses Lake.
DeHaven said the tag is similar to ones used in Canada.
He pointed out that just because the one animal has tested positive for mad cow disease, doesn't mean the other animals that entered the United States with the infected animal had the same disease.
After crossing the border, the animal was taken to a dairy cow finishing facility in Mattawa, which is where it was purchased for the Mabton dairy.
DeHaven said the quarantine on the Mabton dairy and a Sunnyside area bull calf feeding operation continues.
The bull calf operation was quarantined late last week after it was determined that the infected cow's most recent calf went into feed pens with about 400 other calves. Although, according to DeHaven, there is no research that indicates that BSE can be transmitted from cow to calf, the operation was quarantined as a precautionary step.
"The purpose of that quarantine or hold order is not to stop the spread of the disease," he said. "It's important to realize that BSE is not a contagious disease. It's not spread by direct contact, animal to animal."
He said the quarantine is to help prevent the movement of animals, making it easier in the investigation.
. Melissa Browning can be contacted at (509) 837-4500, or e-mail firstname.lastname@example.org