Repetitive oral behaviours in pigs including bar-chewing and rooting on concrete are indicators of environmental deprivation and frustrated behavioural needs.
Oral stereotypies in pigs are behavioural scars of environmental deprivation — repetitive, functionless movements that develop when animals cannot perform behaviours they are strongly motivated to express. Rooting and foraging are deeply embedded in pig behavioural repertoire, and when a concrete floor prevents any rooting and bare walls offer nothing to investigate, the motivation is redirected into repetitive bar-biting or air-rooting. Once established, these behaviours become fixed and persist even when enrichment is subsequently provided, representing lasting welfare damage. The high prevalence of oral stereotypies in commercial pig systems across many countries is a direct indicator of the scale of environmental deprivation experienced. Preventing stereotypy development requires providing enrichment from the earliest age, before the motivation becomes permanently redirected.