Feb. 2 (Bloomberg) -- U.S. beef inspectors sometimes ignore rules for screening cattle that are intended to prevent mad-cow disease, putting the nation's meat supply at risk, the Agriculture Department's Inspector General said.

Twenty-nine head of cattle that couldn't walk were slaughtered over a 10-month period at two of 12 meatpacking plants reviewed in an audit, the IG said in a report. Of these, 20 were identified as ``downers,'' with no records of acute injury. Downer animals are considered the highest-risk for mad- cow disease. In one plant, auditors saw a forklift being used to transport a downer cow to slaughter, the IG said.

This violates USDA policy that excludes ``all non- ambulatory disabled cattle from the human food supply,'' the IG said as part of a 118-page review of how the department enforces rules meant to prevent mad-cow disease. The report, which said the USDA must also improve record-keeping, was released on the Inspector General's Web site. The U.S. slaughters about 35 million head of cattle a year.

The report was released at a delicate time in negotiations between the U.S. and Japan over the safety of U.S. beef. Japan, normally the biggest overseas customer for the meat, suspended imports on Jan. 20 after banned tissue was found in a shipment of veal. The Japanese government had only allowed imports to resume in December, following a two-year ban because of mad-cow disease.

Japan bought $1.7 billion in U.S. beef in 2003, before banning the meat, along with scores of other nations. Japan's purchases accounted for almost half of total U.S. beef shipments of $3.8 billion that year.

Preventing BSE

The USDA ordered that downer cattle be excluded from the human food supply after the first case of mad-cow disease, or bovine spongiform encephalopathy, was found in the U.S. in December 2003. Meatpackers were also ordered to remove tissue suspected of harboring the BSE-causing agent from carcasses of older animals. These specified risk materials, or SRMs, include brains, spinal cord tissue and parts of a cow's intestine.

In response to the IG's charge, the USDA's Food Safety and Inspection Service said it will clarify its policy for slaughtering downer cattle and issue new guidance to its more than 6,000 inspectors, possibly this month.

The FSIS said the animals in question were deemed healthy for slaughter by the agency's on-site veterinarians, and that they were determined to have suffered injuries while waiting to be slaughtered, not as a result of a nervous system disease consistent with BSE.

Fatal Human Form

Mad-cow disease is a brain-wasting livestock illness with a fatal human that has been blamed for more than 150 deaths in the U.K., where the disease first surfaced in the 1980s. The U.S. confirmed its second BSE case in June, in an animal born in Texas.

The Inspector General said its auditors found no instances of banned tissues entering the human food supply. Still, it said inadequate records meant that inspectors couldn't determine whether proper procedures were being followed in nine of 12 plants surveyed during the audit. The Food Safety and Inspection Service also doesn't have any system to identify and track violation trends, the IG said.

In August, the USDA said government inspectors cited meatpackers 1,036 times over a 17-month period for violating these rules. Many of the violations were related to paperwork mistakes, according to the American Meat Institute, which represents Tyson Foods Inc., Smithfield Foods Inc. and other large U.S. meatpackers.

To contact the reporter on this story: Daniel Goldstein in Washington at at dgoldstein1@bloomberg.net

Last Updated: February 2, 2006 18:06 EST