March 27, 2006

 

US to use DNA test on suspected herds in Alabama BSE case

 

 

US government investigators will be making extensive use of DNA testing as they search for the birth herd of a cow that tested positive in Alabama last week for mad cow disease, or bovine spongiform encephalopathy (BSE).

 

"State and federal officials have discovered several herds of interest and they are planning to use DNA testing to determine DNA linkage between the (BSE-infected) cow and the herds," the Alabama Department of Agriculture and Industries said Friday (Mar 24). "Through the DNA testing of these herds, investigators will attempt to find a genetic path that could lead to the herd of origin."

 

US Department of Agriculture officials said they believe it is important to find where the infected cow was born because that may lead them to the source of infection and other cattle that may have contracted BSE.

 

But Alabama officials stressed Friday it may be too late to produce those kinds of results from the investigation.

 

"Even when an index animal is traced to its birth herd, often cohorts of that animal are no longer in that herd," the Alabama Department of Agriculture and Industries said. "In addition, even if an animal's cohort has been exposed to the same infective material in feed, the other animals will not necessarily contract BSE."

 

The US Food and Drug Administration banned bovine material from cattle feed in 1997 because it is believed that BSE can be spread in herds when cattle eat infected tissue from rendered cattle. The latest cow that contracted BSE--the third official case reported in the US--is believed to have been born before 1997, based on dental examinations of the animal.

 

USDA and Alabama officials said they are now concentrating on 13 suspect "locations," but they did not say where those locations are.

 

So far, government officials have announced finding two offspring from the BSE-infected cow found in Alabama. The latest offspring discovery--confirmed Thursday by USDA--is believed to have been a one-year-old calf that died and was buried in a landfill in July 2005. USDA Spokesman Ed Loyd said the remains of the calf were not found, but investigators are certain of the calf's fate and lineage based on records.

 

The infected "index" cow also gave birth to a calf that USDA is now observing at a facility in Ames, Iowa. That calf was six weeks old when USDA recently took possession of it.