Research in behavioral genetics is important for pig welfare. Consequences of the ongoing selection for high production on pigs’ behavior need to be studied, as well as possibilities to select directly for changed behavior. The Farm Animal Welfare Council’s definition of welfare is based on five freedoms related to hunger and thirst, discomfort, pain, injury or disease, fear and distress and normal behavior. All these freedoms are associated with pig behavior. Maternal behavior related to piglet survival and aggressive behavior of pigs kept in groups are especially important for welfare. Pig breeding programs could be further developed by including behavioral traits relevant for welfare.

Breeding for behavioural traits may improve pig welfare and breeding for high production may decrease pig welfare. Maternal behaviours important for piglet production includes savaging, crushing and nursing. Behaviours of importance for production of pigs for slaughter includes feeding behaviour, tail biting and aggressive behaviour. These are complex traits and large amounts of data are needed for accurate genetic evaluation and selection.