Canada has concluded on-farm testing for bovine tuberculosis after the fall 2016 outbreak in 
Alberta. The TB investigation has been underway since September of last year, when Canadian officials got notice from the U.S. Department of Agriculture that a cow from Alberta had tested TB-positive at a U.S. slaughter plant, and later found six confirmed cases.
The Canadian Food Inspection Agency reported this week it has completed on-farm testing of those “trace-in” herds, which include about 15,000 animals in all.
AgCanada reports that testing of “trace-out” animals, any animals that left the infected index herd in the past five years, is also “largely complete with no additional cases to date.”
Genetic analysis of the TB strains in the six infected animals showed they were all infected with the same strain, but that it wasn’t the same as any strain ever previously detected in Canadian domestic livestock or wildlife or people. Officials say it’s possible that a source for the confirmed infections won’t ever be found.
From the National Association of Farm Broadcasting News Service.