The investigation into Canada’s 19th case of BSE discovered last February said contaminated feed was the likely cause of infection.
“The carry-over of a small amount of residual contaminated feed associated with the earlier case on the same birth farm is the most plausible explanation for BSE case No. 19,” said the Canadian Food Inspection Agency report released Nov. 30.
A purebred black Angus cow born March 25, 2009, came from the same Alberta farm as a positive case in 2007. The two cows were not related.
The cow was born on a cow-calf operation with both purebred Angus and commercial beef cattle. There were about 290 breeding animals. The positive cow had been sold through an auction market to another farm where it became sick. It was euthanized and samples were sent for testing.
The case was considered unusual because it was born two years after Canada introduced stringent feed manufacturing rules that applied to animal feed, pet food and fertilizer production. It was also the first farm to have two cases.
The farm’s practices and feed companies were investigated to find potential pathways of infection. Investigators also traced 746 animals that could have been at risk.
The trace-out investigation located 132 live animals, 99 of which were on the original farm. All live animals, located on 14 different premises including the birth farm, have been placed under quarantine.