Republican and Democratic lawmakers on Thursday scolded the U.S. Department of Agriculture for its performance in protecting consumers against mad cow disease after the agency admitted it allowed Canadian beef imports that went beyond previously announced restrictions.

The USDA said about 10 million pounds of beef were allowed into the United States from Canada since last summer, including hamburger, bone-in beef and processed beef. Last August, the USDA announced that it was only allowing boneless beef from young Canadian animals into the United States.

Boneless beef is thought to have the lowest risk of carrying mad cow disease, which was discovered in Canada last May.

Following a briefing by USDA officials on Capitol Hill, House Agriculture Committee Chairman Bob Goodlatte, a Virginia Republican, said the USDA admitted “mistakes were made” and products were allowed entry that were not on public lists.

Charles Stenholm, the Democratic leader on the farm panel, said USDA’s performance marked “a breakdown in the process.”

The controversy over USDA’s enforcement of mad cow safeguards came as the agency already was reeling over revelations that federal inspectors failed to test a sick cow in Texas last month. The animal showed possible central nervous system symptoms that could indicate mad cow disease.

The department’s Office of the Inspector General was investigating the Texas case.

Referring to the beef imports allowed from Canada, USDA spokeswoman Alisa Harrison said, “We should have made it more public and more clear” that additional types of Canadian beef were being approved for import.

A full accounting to Congress of the imports came after R-CALF United Stockgrowers of America said the USDA let in 33 million pounds of processed Canadian beef imports between August 2003 and February 2004. The cattle group said the USDA quietly approved special import permits for some companies.

Similarly, details of the sick Texas cow were only made public after reporters were alerted to a violation of standard testing procedures, which USDA has since admitted.

In both cases, USDA said no contaminated beef entered the human food supply.

But the U.S. beef industry is worried that USDA’s missteps could hurt efforts to reopen Japanese and other foreign markets to American beef that were closed in December, when the first U.S. case of mad cow disease was discovered.

Rep. Earl Pomeroy, a North Dakota Democrat, said the USDA declared in October that ground beef from Canada would not be allowed into the United States. Nevertheless, small amounts of ground beef have entered the country, the USDA confirmed. Pomeroy called USDA’s handling of Canadian imports “a very serious breach” of the public trust.

North Dakota Sen. Kent Conrad, a Democrat and frequent critic of Agriculture Secretary Ann Veneman, called for her resignation.

Rep. Randy Neugebauer, a Texas Republican on the House Agriculture panel, complained that the USDA was not “transparent” in identifying Canadian beef products entering the country.

The United States imposed a total ban on Canadian beef after a lone case of mad cow disease was discovered in Alberta one year ago.

USDA eased that ban last August after gaining confidence in Canada’s steps to stop the spread of the fatal animal illness. At the time, USDA floated a little-noticed statement that Canadian plants could request an exemption from the regulations and ship beef that would otherwise be prohibited.

Import permits were issued to Canadian plants deemed to have sufficient safeguards to prevent the spread of mad cow disease, according to USDA. Those steps included using only animals under 30 months of age and procedures to remove brain, spinal columns and other high-risk materials, an official said.

The USDA refused to say how many Canadian plants were granted the exemptions.

“We were shocked to learn that USDA had quietly relaxed our health and safety standards to allow these products in without notifying the public,” said Bill Bullard, chief executive of R-CALF.