As gestation crates are phased out in favour of group housing for pregnant sows, enrichment provision becomes essential for managing stress, preventing aggression, and meeting the behavioural needs of highly intelligent animals.
Group housing with enrichment represents a meaningful welfare improvement over gestation crates, but the improvement is contingent on management quality. Poorly managed group housing can result in worse welfare outcomes than well-managed crates if aggression at feeding, inadequate enrichment, and frequent regrouping create chronic stress. The key welfare-positive elements of group housing are freedom of movement, ability to perform natural behaviours including rooting, and appropriate social interactions. Enrichment provision — particularly straw or other rooting substrates — is not optional in group housing; it is essential for preventing the frustration-driven aggression that undermines welfare and productivity. Sow welfare assessment in group systems should include aggression scoring, body condition monitoring, and lameness checks.