Rooting is a fundamental behavioural need in pigs, driven by foraging instincts, and its deprivation on bare concrete floors causes chronic frustration.
Deprivation of rooting opportunities is a fundamental welfare failure causing chronic frustration and redirected behaviours including aggression and belly nosing. Providing adequate substrate is low-cost relative to its welfare benefit. High-welfare pig systems incorporating deep straw or outdoor access deliver dramatically better welfare outcomes for this core need.