Pig enrichment research has identified key principles including novelty, complexity, and substrate variety that determine whether enrichment effectively improves welfare, moving beyond token provision to evidence-based programs.
Pig enrichment science has progressed beyond establishing that enrichment helps to identifying what kinds of enrichment help, for how long, and for which behavioral needs. The practical implication is that a single rubber toy hanging in a pen is legally compliant in some jurisdictions but provides minimal welfare benefit due to rapid habituation. Effective enrichment programs require rotation, destructibility, and root substrate that allows pigs to express highly motivated foraging behaviors. Welfare audits should assess enrichment quality and behavioral engagement rather than mere presence, as the difference between token and effective enrichment is significant for pig welfare.