The US Department of Agriculture has mandated one of the largest meat recalls in US history - a record 65 million kg of beef - after it determined a California slaughter house had pushed cows with poor health into the food chain.
US Secretary of Agriculture Ed Schafer on Sunday said the Hallmark/Westland Meat Packing Company had slaughtered cattle "unfit for human food". The meat was sold to schools, emergency food recipients and Indian reservations.
Schaefer said the packing plant had violated safeguards that protect against "food borne disease" by butchering non-ambulatory cattle. US law forbids using such animals because of the danger of bovine spongiform encephalopathy or BSE, more widely known as mad cow disease.
The disease causes a wasting disorder in the animals and humans who consume infected meat. The sickness in cattle has been traced to infected parts from other cattle that were added to the feed of the normally vegetarian cud chewers.
US officials have banned the use of parts of dead cows in cow feed and closely monitor herds for BSE since the first US case was discovered in 2003 at a farm in Washington state.
The investigation and recall followed release of a video over the past days by the Humane Society of the US showing workers kicking so-called "downer" cows and using electric prods and forklifts to make them move.