LITTLE ROCK, Ark. – Tyson Foods Inc. has begun killing and disposing of 15,000 hens from a flock in northwestern Arkansas that tested positive for a less virulent form of the bird flu.

 

Tyson told the Associated Press that preliminary tests on the flock showed the presence of antibodies for H7N3.

 

Routine blood tests conducted Friday found the possible exposure, Jon Fitch, director of the Arkansas Livestock and Poultry Commission, told the news service. Further tests done by the state and the U.S. Department of Agriculture found the birds did not have active infections.

 

"There is absolutely no human health threat," Fitch told the AP. "But we take this very seriously."

 

Tyson said in a statement that it is working with the USDA and the commission to manage the situation.

The company also said that it was stepping up surveillance of bird flu in the area. Tyson will test all breeder farms that serve the local poultry complex, as well as any farms within a ten mile radius of the affected farm.