We keep pigs, sheep, chickens, ducks and guineas together. The only incident was once our boar mistook one of the sheep for one of his ladies and tried to have his way with it. Unfortunately this dislocated both rear legs of the sheep and it had to be put into the freezer. I've not seen any preditory behavior from my pigs towards any of the other animals. They are kept on pasture, in large paddocks.
