Repetitive oral behaviours including bar biting, rooting on pen floors and chewing non-food objects in pigs indicate frustrated natural behaviour and are important welfare indicators in commercial systems.
Oral stereotypies in pigs are not quirky habits but indicators of a welfare system that has failed to accommodate fundamental behavioural needs. Pigs evolved to spend 6-8 hours daily rooting and foraging; barren concrete or slatted floor environments provide no outlet for this motivation. The resulting frustration and thwarted motivation is expressed through repetitive compensatory behaviours. The difficulty of eliminating established stereotypies even after enrichment provision suggests lasting neurological consequences of early deprivation. Prevention through appropriate enrichment from birth is far more effective than treatment after stereotypies develop.