Rooting is a fundamental pig behaviour driven by strong innate motivation. Denial of rooting opportunities in concrete-floored systems causes frustration and stereotypies.
The deprivation of rooting substrate is one of the most significant welfare issues in intensive pig production. When pigs cannot perform this highly motivated behaviour, frustration leads to belly nosing, flank biting, and ear chewing directed at pen-mates. Deep straw bedding satisfies rooting motivation most effectively, but even suspended chains or root boards reduce harmful redirection.