Contaminated feed produced shortly after a ban on risk materials in cattle feed may have been the cause of a case of BSE confirmed in Canada on January 11, according to an investigation by the Canadian Food Inspection Agency.

“The feed component of the investigation determined that BSE may have been transmitted to the affected animal through feed produced shortly after the feed ban was introduced,” the agency said in a statement on the investigation’s findings.

Canada banned the Specified Risk Material which can contain BSE agents in 1997. “At that time it is likely that the feed ban was not immediately adopted uniformly across the feed industry,” the agency said. “Similar experiences have been observed in all countries with BSE that have implemented feed controls. The detection of an affected animal born after the feed ban was not unexpected.”

Canadian officials are conducting a review of how the ban is working, the agency said.