Age set of mad-cow infected Holstein

Cow born before North America feed ban took effect
By Greg Robb, CBS.MarketWatch.com

WASHINGTON (CBS.MW) -- U.S. investigators have discovered that the Holstein cow that tested positive for mad-cow disease was older than original records suggested.

Records uncovered by the last owner of the infected cow showed that it was born in April 1997, two years earlier than first thought.

This date is critical to researchers because a federal ban on putting carcass byproducts into cow feed only went into effect later that year.

Researchers believe placing carcass byproducts in feed is the principal means for spreading bovine spongiform encephalopathy, or BSE, commonly known as mad-cow disease.

"The age of the animal is especially important in that it is a likely explanation as to how this animal would have become infected," said Ronald DeHaven, the Agriculture Department's chief veterinarian at an afternoon press conference.

U.S. officials had said that initial records reported the cow to be born in 1999, after the feed ban.

Earlier, DeHaven said that the infected cow most likely came from Alberta, Canada. And the new birth date clears up a discrepancy about the actual age of the animal between U.S. and Canadian records regarding the cow.

"We do have animal identification - an ear-tag from this animal - that does trace back to a herd in Alberta, Canada. While we are following every line of inquiry, certainly that one seems to be the most likely at this point," DeHaven said in an interview on the NBC News 'Today' program.

Only DNA testing will tell for sure, and steps are underway to complete that procedure, DeHaven said.

"Once we are able to confirm that, the investigation will focus on what feed was fed to that animal as well as other animals on the farm at that point, and then it is a matter of tracing those animals down," DeHaven said.

The infected cow had three calves while it was in the United States. One died shortly after birth and the remaining two are in quarantine.

U.S. officials are expanding their investigation looking for eight other cows from the same herd in Canada also shipped to the U.S.

In addition, investigators are searching for traces of 73 heads of cattle that entered the U.S. in the same shipment as the infected cow.

"We do not have any new data to report in that regard at this point," DeHaven said.

Cattle futures at the Chicago Mercantile Exchange plummeted Monday for a third-straight session on fears that the discovery of the mad-cow case will hurt demand for U.S. beef. See full story.

U.S. Agriculture officials said the discovery of mad cow disease in Yakima Valley, Wash. On Dec. 23 has led to a broad review of U.S. meat safety standards.

"The department is looking at what additional testing do we need to do, what should we consider, what animals should we consider testing," said Stephan Sundlof, head of the Food and Drug Administration's Center for Veterinary Medicine.

The dairy cow that tested positive was a so-called 'downer' cow, unable to stand.

Farm Sanctuary, a nonprofit humane organization, has filed suit against the USDA seeking to prohibit the slaughter of downed animals.

"Rather than preventing high risk animals from being used for food, the USDA has been encouraging the slaughter of sick animals for food. Perhaps the reason it took so long to find mad cow disease in the U.S. is that we have been eating the evidence," stated Gene Baur (formerly Bauston) , president of Farm Sanctuary.

DeHaven said it was wrong to equate downer cattle with diseased cattle. He said meat from cows that have broken bones should not be excluded from the market.

Meat from the infected cow and other cows slaughtered with it was shipped to eight states and Guam. But over 80 percent of the meat went to stores in Oregon and Washington. The remaining meat went to a small number of locations in the other states.