The Canadian Food Inspection Agency announced Wednesday that the cow discovered with bovine spongiform encephalopathy earlier this month was born in March 2009.
Paul Mayers, a CFIA vice-president, said the agency is working to determine the source of the feed used at the birth farm in Alberta and assess any potential risk factors to other animals.
"The enhanced feed ban was put in place to accelerate Canada's progress toward the reduction of the disease," Mayers said in Ottawa.
"As this progression continues, the detection of a small number of cases among the 30,000 samples tested yearly as part of our BSE surveillance program is not unexpected."
The farm where the cow was born and the farm where it was discovered to have BSE are both in the Edmonton area.
Mayers said the case has been reported to the World Organisation for Animal Health and won't affect Canada's official beef trade status.
He said Canada expects its trading partners not to restrict market access to Canadian beef.
But since the discovery of the cow earlier this month, South Korea has suspended imports of Canadian beef and Indonesia has suspended imports of non-edible bone meal.
David Solverson, president of the Canadian Cattlemen's Association, said he was disappointed to hear the cow was born after the feed ban.
He said Canada has good safeguards against BSE but there is always the possibility of new cases.
"It takes such a minute amount of infected feed. There could have been a residue," said Solverson, who has a cattle ranch and feedlot near Camrose, southeast of Edmonton.
Producers will be watching for the results of the CFIA investigation into this BSE case, he said.
"They will be checking through the records as to any possible herdmates that could also be infected. Those are the kinds of things that we are waiting for."
Canada is currently listed as having a "controlled BSE risk" by the World Organisation for Animal Health.
CFIA officials said Canada was planning to apply this year for "negligible BSE risk" status, the same designation as the United States and some other beef producing countries.
To apply for the change, Canada needs to have no cattle born with BSE for 11 years.
The birth date of this new BSE cow means Canada will not be able to apply for "negligible" status until 2020, said Dr. Martine Duboc, a CFIA vice-president.
"It is unfortunate right now, but this is one of the important criteria that is part of the BSE evaluation status," she said.
The federal government brought in tougher cattle feed rules in 2007 following the 2003 BSE outbreak that devastated Canada's beef industry.
About 40 markets immediately closed their borders to Canadian cattle and beef products, although most of those markets have since reopened.
The enhanced feed ban prohibits the use of cattle tissues that can transmit BSE, such as brains and spinal cords, from use in animal feeds, pet foods and fertilizers.
The goal at the time was to prevent more than 99 per cent of potential BSE infection from entering the feed system.
Mayer said Canada's program has been working well and cases of mad cow disease are extremely rare. The last reported case was four years ago.
He said the investigation will provide insight into what contributed to the development of the disease in this animal.
"It's birth after the enhanced feed ban will be a consideration that we take into account in investigating," he said.
"No system we recognize to be perfect, and our experience here is no different."