The coordinated class-action lawsuits, filed in the provinces of Alberta, Saskatchewan, Ontario and Quebec, seek at least $5.7 billion, the industry's estimated losses to date, and another $81 million in punitive damages.
They claim the federal government introduced a regulation in 1990 that specifically allowed the feeding of cattle parts to other cattle, the method through which mad cow disease is transmitted.
That was a full two years after Great Britain had banned the practice because of the risk and about three years after Canada banned cattle imports from the United Kingdom and Ireland that were not from farms certified as free of the disease.
It was only in 1997 that Canada banned the practice of feeding cattle to other cattle.
"They were grossly negligent in not taking into account the common knowledge and scientific knowledge of how mad cow is transmitted," Montreal lawyer Gilles Gareau, who is leading the Quebec suit, said April 11. "The entire world knew about it."
In addition, the discovery of an infected cow in Alberta in May 2003 that prompted the United States to close its borders to Canadian cattle and precipitated the crisis can be directly traced to another act of federal negligence, the suit says.
In the 1980s, Canada imported 191 cows from the United Kingdom. In 1993, one was found to have BSE. Despite a federal monitoring program, the government lost track of 80 of the animals, which entered the food chain.
"It is in all likelihood, if not a certainty, the source of the contamination of the Alberta cow," Gareau said.
Elizabeth Whiting, a spokeswoman for Canadian Agriculture Minister Andy Mitchell, said the government could not comment "until there has been an opportunity to review the full statement and assess the issues."
Estimates are that the proposed class action would represent about 100,000 producers and others directly affected across the country.
Bill Sauer, a cattle producer near Niagara Falls, Ontario, and the lead plaintiff in Ontario, said he hoped the suit would help alleviate farmers' financial pain and prompt the federal government to act more carefully.
While issued in four provincial courts in early April, it's expected the four similar suits will be combined at some point in what would be the largest such action in Canadian history.
Canadian cattle and beef shipments continue to be banned by the United States. Two more Alberta cows tested positive for the disease in January.
The only U.S. cow confirmed to have BSE also came from Canada. It was found in December 2003 in Washington state.
BSE can cause a fatal brain disorder in humans called variant Creutzfeldt-Jakob disease.