The Canadian Food Inspection Agency says it has found no evidence that bovine tuberculosis spread beyond an original six cases in an outbreak that shook Alberta's beef industry, resulting in 11,500 animals being killed and a further 50,000 being tested on 150 farms.

Six cases of the disease were tied to one Alberta ranch after an animal tested positive at a U.S. slaughterhouse more than a year ago.

A lead veterinarian with the agency told the Alberta Beef Producers at their annual general meeting Tuesday in Calgary that the CFIA's investigation is almost completed and there is no evidence the disease spread.

CFIA inspector Rick James-Davies says this is one of the largest investigations the agency has ever conducted.

"From an animal testing, number of farms we were on, number of producers we dealt with, this has certainly been one of the larger cattle diseases in Canada," he said. 

More than 300 CFIA staff were involved in the operation. It resulted in 11,500 animals being destroyed as a precaution and a further 50,000 cattle being tested on 150 farms.

The agency paid out $39 million in compensation to farmers whose animals were ordered destroyed.

James-Davies says the final phase of testing is expected to be complete by Christmas.

Encouraging signals

"So far, the signals are all really encouraging — that we're almost at the end, there's no evidence of spread," he said.

"No evidence that it's spread, no evidence of a residual source. There will continue to be some ongoing work."

The complexity of the investigation raised questions about the industry's ability to trace animals.

Rich Smith, executive director of the Alberta Beef Producers, says his group is working with the agency to change that.

"We have animal identification, we have movement tracking in Alberta through the manifest system. We have premise identification. But what we're not doing is catching animals when they move from one operation to another operation yet."

Smith says new federal regulations are expected in the spring.