US poultry processor Pilgrim's Pride has said routine blood tests indicate an avian influenza infection has been found in a 52-week-old commercial chicken breeder flock (which lays eggs for hatching) at a contract grower's farm in Northeast Texas.

However, the company said there is very little evidence of clinical signs of disease in the birds, which indicates the infection may be a low-pathogenic strain of bird flu, according to the Texas Animal Health Commission.

The affected farm, located about six miles from the nearest commercial poultry farm, has been isolated and the flock has been destroyed on-site to prevent the potential spread of the disease, said O.B. Goolsby, president and chief operating officer of Pilgrim's Pride.

Goolsby said the virus was discovered as part of voluntary testing procedures in cooperation with Texas Poultry Federation and State of Texas authorities.

"Our poultry testing in Texas is believed to be the most aggressive in the nation, with every breeder flock tested every ten weeks," Goolsby said. "As a result of this diligence, we believe that the virus can be contained, particularly since this flock is so far from any other poultry farms. Accordingly, we believe this development will not have a material impact on net income."