The USDA said it released documents to the American Meat Institute and the consumer group Public Citizen showing that federal inspectors filed 1,036 noncompliance reports from January 2004 to May of this year involving the removal of the brain, skull, and spinal cord of cattle aged 30 months and older. The instances involved meat plants cutting corners or otherwise violating regulations that are meant to prevent the disease from spreading.
The materials are considered to carry the highest risk in spreading the brain disease, also known as bovine spongiform encephalopathy (BSE). The USDA banned them from the human food supply a few days after the December 2003 discovery of the first American case of mad cow disease in a Washington state dairy cow.
The nation's second confirmed case of BSE was discovered earlier this summer in a Texas beef cow.
Public Citizen said the documents showed cases in which American meat plants didn't distinguish between the age of animals, banned materials weren't removed, and tools were improperly cleaned.
Despite the meat industry disagreement, Tony Corbo, legislative representative for Public Citizen, expressed concerned that meat from an infected animal could still turn up in the food supply.
''Some groups will no doubt attempt to use this information as evidence of possible operational problems and even a food safety concern, when nothing is further from the truth," said Jim Hodges, president of the AMI Foundation.
AMI said the noncompliance reports represent just one-tenth of 1 percent of the 46 million cattle slaughtered nationwide during the 17-month period.
The USDA's Food Safety and Inspection Service said its federal meat inspectors strictly enforced regulations to keep BSE out of the human food supply.