(CNN) -- A slaughterhouse that has been accused of mistreating cows agreed Sunday to recall 143 million pounds of beef in what federal officials called the largest beef recall in U.S. history.


Officials said this is the largest recall in the United States, surpassing a 1999 recall of 35 million pounds.

1 of 3 Keith Williams, a U.S. Department of Agriculture spokesman, said investigators have found no cases of illness related to the recalled meat.

But Dick Raymond, the undersecretary of agriculture for food safety, said there was a "remote probability" that the meat from the Hallmark/Westland Meat Packing Company in Chino, California, could cause illness in humans.

The amount of beef -- 143 million pounds -- is roughly enough for two hamburgers for each man, woman and child in the United States.

The largest U.S. meat recall before Sunday came in 1999, when about 35 million pounds of product possibly contaminated with listeria were ordered off shelves. USDA officials said that was Class I recall, involving a known risk to human health.

Sunday's action was a Class II recall, under which authorities say there is little risk of illness.

Raymond said cattle that had lost the ability to walk since passing pre-processing inspections were slaughtered without an inspector having examined them for chronic illness -- a practice he said violated federal regulations and had been going on for at least two years.

Federal regulations are aimed at preventing the spread of bovine spongiform encephalopathy, or BSE -- the scientific name for "mad cow" disease.

It's important to keep downed cattle out of the food supply because they also may pose a higher risk of contamination from E. coli or salmonella because the animals tend to wallow in feces and have weaker immune systems, according to AP.

Raymond said the average age of the cattle involved is 5-7 years, meaning they were likely born long after a 1997 ban on ruminant feed, and that the incidence of BSE in U.S. cattle is "extremely rare."

"We do not know how much of this product is out there at this time. We do not feel this product presents a health risk of any significance," he said. "But the product was produced in non-compliance with our regulations, so therefore we do have to take this action."

About 37 million pounds of the meat went to school lunch programs and other federal nutrition programs since October 2006, said Ron Vogel, of the USDA's Food and Nutrition Service.