Rooting is a core motivated behaviour in pigs that cannot be suppressed without welfare cost. Scientific understanding of rooting drives advocacy for better substrate provision in commercial pig farming.
The scientific evidence is clear: pigs in systems without adequate rooting substrate experience significant frustration. This frustration manifests as redirected rooting onto pen mates and objects, stereotypic behaviour, and elevated stress indicators. The welfare cost is compounded by the fact that rooting motivation does not diminish over time — pigs remain motivated to root throughout their lives. Providing straw or other deep-litter substrate dramatically reduces these negative outcomes. The persistence of inadequate substrate provision in commercial pig farming represents one of the most well-documented and persistent welfare failures in the industry.