According to Canadian officials the dairy cow which is the country's latest suspected case of mad cow disease was heavily pregnant.
The Canadian Food Inspection Agency (CFIA) is now trying to establish whether it had delivered other calves over the past two years.
The Agency says the cow was heavily pregnant, so its 2006 calf was not born.
George Lutenbach, a CFIA veterinarian says the investigation is still in its very preliminary stages and they will be checking out if the cow had calves in 2004 and 2005.
The Alberta cow's age suggests it would have been exposed to the BSE agent after the 1997 introduction of Canada's feed ban, possibly during its first year of life.
Lutenbach says it is not uncommon to have traces of BSE-infected products in the feed system after the 1997 ban.
The CFIA is running tests in Winnipeg on the the 50-month-old cow following it's death on an Alberta farm.
It was singled out through a surveillance program for bovine spongiform encephalopathy (BSE), known as mad cow disease.
Preliminary tests were apparently unable to rule out BSE.
The animals on the farm are now under quarantine says Lutenbach.
Should tests prove positive for the brain-wasting disease, this will be Canada's seventh case since 2003, and the second in the last week.
The agency confirmed last week that a cow in Manitoba died of BSE.
Lutenbach says that no part of the carcass entered the human food or animal feed systems but nevertheless there remains opposition in the U.S. to accepting Canadian beef.
CFIA has tested 115,000 cows since Canada's first case of Mad Cow disease was discovered.
The federal government recently extended its feed ban and under the new rules, no animal feed, pet food or fertilizer can contain cattle parts that are susceptible to BSE.