Increased number of skin lesions as a measure of aggression following the mixing of slaughter boars from western Canada assembled for export.

A preliminary observational study was conducted to evaluate the animal welfare impacts of holding and mixing on boars; specifically, the need to tusk trim on arrival at assembly. Cull boars assembled in Manitoba from 3 western Canadian provinces were observed without intervention. Although aggression among boars was common, significant physical injury to boars from handling and other boars was rare. Tusk trimming was widely practised in mature boars prior to transport in the population studied. Length of time assembled, number of boars in a pen, temperature, size of boar, and presence of tusk were not associated with change in the skin score of new boars introduced into a pen. Holding groups of previously unfamiliar boars en route to slaughter did not appear to be a significant risk for increased skin lesions in the population studied. Further research is required into the methods and welfare implications to boars subjected to tusk trimming.