WASHINGTON, Feb. 18 (UPI) -- Agriculture officials say most of the beef covered by a current recall likely already has been eaten, much of it at schools across the United States.

The U.S. Department of Agriculture announced Sunday 143 million pounds of processed meat produced at a California slaughterhouse was being pulled off the market due to violation of rules on the handling of so-called downer cattle.

The Chino facility hasn't produced beef since Feb. 4. Rules state downer cattle may not be used for beef unless a veterinarian certifies that the animals were not sick.

The recall at the Hallmark/Westland Meat Packing Company goes back to 2006. The Los Angeles Times said Monday the USDA believes much of the beef produced within the recall's timeframe was eaten long ago either as fast-food fare or as tacos and burgers served up at school cafeterias.