Pigs behaving badly

Preventing behavioural problems in pigs

source: Philip Broomhead
Country Smallholding December 2003
starts p27, 3 pages long

Smallholders need to observe their pigs to understand normal behaviour, and be able to pick up on behavioural problems. Too much stress can cause problems, for example from bad weather for pigs kept outside, and not having an escape route for pigs kept indoors. A pig that is threatened by another pig may submit to being bitten, or fight back, if it cannot escape. Hierarchies may become more rigid if pigs do not have enough space. This can include one pig dominating a feeding trough, while, in contrast, outdoor pigs may have several feeding points. Very palatable food can also lead to conflict. Pigs foraging on harvested land are spread over a wide space, and eating more slowly, so are less likely to compete aggressively than pigs at a trough. Raised troughs may help reduce domination of the feeding space by a dominant pig. Providing escape routes and hiding places can also help to reduce conflict. Mixing strange pigs may create problems, for example at weaning. There may be fights to establish hierarchies. Fear may affect fertility, and infant mortality in pigs.

Stress thresholds are affected by routines, and pigs that have very controlled environments may become too vulnerable to change. Being handled and transported are more stressful for pigs unused to this. Pigs need some stimuli, such as noises, sights, and objects to investigate. Open pen arrangements allow pigs to see what is going on, and tyres and football can be offered as toys.

Chewing and tail biting may occur with indoor pigs, and rail chewing can be seen as stereotypical behaviour, due to lack of stimulation. Pigs also like social interaction. They learn from other pigs, are involved in more activities, gain reassurance from company, and their breeding patterns synchronise. Isolated pigs can become lethargic, and owners of single pigs can provide interactions with other species, such as sheep, to prevent this. Pigs may also interact with humans, and some people keep house pigs.