It was unclear how much support the new Senate resolution would have in both chambers.

The Senate measure was authored by Kent Conrad, a North Dakota Democrat, who questioned whether Canada has adequate safeguards against mad cow disease because two new cases were recently found in Alberta. Other sponsors included Senate Democratic Leader Harry Reid of Nevada and New Mexico Republican Pete Domenici.

US imports of Canadian cattle, which are mostly purchased by American meatpacking plants, were halted in May 2003 after Canada discovered its first native case of bovine spongiform encephalopathy (BSE).

In late December, the USDA announced it would reopen the border to shipments of young Canadian cattle, which are considered least likely to carry mad cow disease.

"It is outrageous for USDA to continue pushing forward with this decision to reopen cattle trade with Canada, a country known to have mad cow in its herd and a record of failure in its attempt to ban illegal feed," said Conrad.

Rep. Earl Pomeroy, a North Dakota Democrat, said an attempt for a House vote on the issue would come after Senate action built momentum against the USDA trade rule.