Environmental enrichment is legally required for pigs in many countries, but the type and quality varies enormously. Evidence-based enrichment significantly improves pig welfare.
Pig enrichment legislation requires materials that are manipulable and investigable, but compliance often involves minimal provision of hanging chains that fail to meet pigs' actual behavioural needs. Rooting, the most fundamental pig behavioural need, cannot be met without appropriate substrate. Pigs are highly motivated to explore and root in naturalistic substrates. Effective enrichment programmes provide rooting substrate, hanging objects, and puzzle feeders. Novel materials presented regularly maintain interest. Enrichment reduces harmful behaviours including tail biting by providing positive behavioural outlets.