The transition from individual gestation stalls to group housing for pregnant sows has major welfare implications that require careful management to realize benefits.
The transition to group gestation housing represents a significant welfare improvement for sows when well-managed. Sows in group systems can move freely, lie in their preferred positions, engage in social interaction, and perform comfort behaviors. The welfare challenge is managing group aggression — particularly when sows are mixed at pregnancy confirmation. Space allocation, group composition, introduction management, and provision of resources including feeding stations and resting areas all significantly affect whether group housing delivers its welfare potential. Poorly managed group systems with overcrowding and insufficient resources may not provide welfare improvements over stalls in the short term, but good management consistently achieves far better outcomes than even well-managed stall confinement.