Rooting is one of pigs most fundamental behavioral needs, and its frustration in bare commercial housing causes significant welfare compromise.
Rooting is as fundamental to pig welfare as swimming is to fish. The motivation to root and explore the substrate is independent of hunger and persists even in well-fed pigs. In natural conditions, pigs spend many hours daily investigating the ground with their highly sensitive snouts. In bare concrete housing, they redirect this drive to inappropriate substrates including pen mates and equipment, causing injuries and social conflict. Providing manipulable substrate like straw or compost almost eliminates redirected rooting behavior. Despite the clear evidence, most commercial pig housing provides no rooting substrate because of the additional labor required for management. Requiring substrate provision represents one of the most impactful single changes possible in commercial pig welfare.