Another case of mad-cow disease has turned up in Alberta, this time in an animal born after feeding restrictions designed to halt the spread of BSE were introduced.

The Canadian Food Inspection Agency said Tuesday that it believes that the animal "most likely" became infected by eating feed produced before the ban went into effect.

Confronted with the news during a major speech unrelated to agriculture, Alberta Premier Ralph Klein said that the ability of inspectors to find infected animals such as these is good news, in that it shows that the surveillance program is working properly.

Mr. Klein conceded, though, that feeding regulations can easily be circumvented and he pleaded with farmers to obey the law.

"You can't stop people from, you know, not playing by the rules unfortunately," said Mr. Klein, who was widely criticized late in 2003 when he said that any "self-respecting" rancher would shoot and secretly bury a sick animal

"I would say to farmers and ranchers, for god's sakes, this is so serious now, and it has ... cost the industry so much money, play by the rules."

The federal government on Tuesday asked its regulators to launch an urgent investigation into feed restrictions, hoping to demonstrate the strength of the system before the United States relaxes import restrictions in early March.

"We continue to have confidence in the integrity of our current feed ban and that it protects animal an human health," Agriculture Minister Andy Mitchell told a televised press conference from Ottawa.

"However, it is important to demonstrate this to Canadians and others. I have asked the CFIA to undertake a review of our feed controls involving experts from interested third countries to clearly demonstrate to Canadians and the world the strength of the ban and the job it is intended to do."

The Alberta beef cow was born in March, 1998, about seven months after the ban on feeding protein made from cattle and other ruminants to Canadian herds went into effect. The 1997 Ruminant Ingredient Feed Ban prohibited feeding a ruminant animal with material that originated from a mink or ruminant. Milk, blood, gelatin, rendered fats and their products were exempt.

Charlie Angus, the New Democratic agriculture critic, attacked the government Tuesday, saying that the latest case raises his suspicions about the ability of the federal government to deal with BSE.

"Canada continues to lag behind the standards set in other regions that have dealt with BSE," Mr. Angus said in a statement. "Still, the Agriculture Minister is scrambling to prove that the status quo is good enough."

The case represents the third known incidence of the brain-wasting disease found in Canada in two years. The first case occurred in the spring of 2003 and caused a crisis in the cattle industry, with borders slamming shut and markets drying up. The more recent case was confirmed barely a week ago.

Both of the other cows were born before the feed ban.

The CFIA said after the previous cow was diagnosed that a small number of new cases were possible and should not affect export rules.

The United States recently announced that remaining beef import restrictions would be relaxed as early as March. They maintained that position even after news emerged several weeks ago of the second cow, noting that a cattle industry as big as Canada's could have up to a dozen cases annually and still keep it's so-called "minimal risk" status.