Placing together male and female groups of pigs in one house could reduce aggressive behaviour at finishing, according to Sabine Conte, Queens University, Belfast in UK.

At the British Society of Animal Science Conference, Conte said, "when looking at single sex male groups compared to mixed sexed groups with high or low within-group weight variation, we found housing entire male pigs in all-male groups led to an increase in injuries when weight variation within the group was low.

"Reducing weight variation within groups at the start of the finishing period also lead to reduced variation in slaughter and carcass weight," she said.

All male groups also had high levels of mounting, which Conte suggested could have a negative impact on welfare. "This suggests entire male pigs should be housed in mixed sexed groups. To reduce variability in the final product, housing pigs with similar weights together could also help," she added.