Cattle in such a state are not placed in the meat-manufacturing process, as a precaution against Bovine spongiform encephalopathy (BSE), known as mad-cow disease.

USDA officials said the meat, suspected to come from "downer" cattle, comes from animals slaughtered and processed since February 2006, when the Hallmark/Westland Meat Packing Company was first discovered to be breaking animal-inspection rules.

Firm suspended
Ed Schafer, the US secretary of agriculture, said that Hallmark/Westland has been suspended by the Food Safety Inspection Service (FSIS) after determining the cattle "did not receive complete and proper inspection".
The federal government has also suspended food and nutrition contracts with the company.

Schafer said: "I am dismayed by the inhumane handling of cattle that resulted in the violation of food safety regulations."

"[But] it is extremely unlikely that these animals were at risk for BSE because of the multiple safeguards - however, this action is necessary because plant procedures violated USDA regulations."