The effectiveness of the most important U.S. safeguard against mad cow disease was questioned on Monday when a government report accused the Food and Drug Administration of “overstating” feed mill compliance with a ban on cattle remains in animal feed.

The Government Accountability Office report was released as many U.S. lawmakers seek to prevent Canadian cattle from entering the United States because of concerns that its neighbor is not effectively enforcing its own animal feed ban.

In 1997, the United States and Canada both outlawed the use of cattle remains as a protein supplement for cattle, goats and sheep to prevent the spread of mad cow disease, or bovine spongiform encephalopathy (BSE).

Canada found two more cases of mad cow disease as 2005 began and both cases are believed due to infected feed. So far, the United States has found only one case of mad cow disease, in a Washington state cow imported from Canada.

The GAO said the FDA, which regulates livestock feed, cannot pinpoint how many plants comply with the 1997 feed ban.

“We believe FDA is overstating industry’s compliance with the animal feed ban and understating the potential risk of BSE for U.S. cattle in its reports to Congress and the American people,” the GAO report said.

The FDA has repeatedly claimed that the industry has a 99-percent compliance rate with the 1997 ban.

Iowa Sen. Tom Harkin, the ranking Democrat on the Senate Agriculture Committee who requested the GAO report, criticized the FDA for not testing livestock feed. “Common sense tells us the best way to measure compliance is to sample feed to make sure it does not contain ruminant byproducts,” Harkin said.

An FDA spokeswoman was not available for comment.

However, the GAO report said the FDA was provided a draft of its report and responded that its enforcement of the feed ban did not “place U.S. cattle at risk of spreading BSE.”

The FDA said in a letter it agreed with GAO’s call for uniform procedures to identify businesses subject to the feed ban. The agency also said it concurred with GAO recommendations to collect test results from states that sample feed and to tighten controls on feed destined for export.

CANADA BEEF TRADE UNCERTAIN

Although the GAO report examined only U.S. enforcement of livestock feed regulations, it was made public at a time when some American lawmakers and farm groups have raised questions about Canada’s enforcement of a virtually identical ban.

Earlier this month, Harkin and a majority of U.S. senators voted to keep Canadian cattle out of the United States, saying they were concerned Canada may not be adequately enforcing its feed ban. The United States halted trade in May 2003 after Canada found its first native case of mad cow disease.

A federal judge in Montana separately agreed to a request by R-CALF USA, a cattle group, to block a U.S. government plan to lift the ban on March 7. That decision is being appealed by National Meat Association members, who want access to Canadian cattle to keep their slaughter plants running efficiently.

The GAO, the investigative arm of Congress, said it examined 404 inspection reports by the FDA in 2003-2004 to assess how effectively the agency is enforcing its feed ban. The report said it found about 2,800 entities that make or handle livestock feed had not been inspected since 1999 or earlier.

In one instance, the GAO said an inspector discovered a firm inadvertently allowed banned material into cattle feed for nearly a year. The firm issued a voluntary recall, but the FDA did not alert the USDA. USDA officials told GAO investigators they would have tracked the animals and tested them for mad cow disease had they known about the recall.

The GAO said FDA improved its oversight of the feed ban rule, but added, “Program weaknesses continue to limit the effectiveness of the ban and place U.S. cattle at risk of spreading BSE.” Specifically, the FDA lacks a uniform way to identify cattle feed manufacturers, transporters and others beyond the 14,800 firms already inspected.

About 19 percent of feed companies have not been inspected in five years or more, and “several hundred are potentially high risk,” the GAO said.