Group gestation housing systems for pregnant sows offer welfare improvements over individual stalls but require careful design and management to prevent dominance-related welfare problems.
Group gestation housing represents genuine welfare progress compared to individual stall confinement, but welfare quality varies enormously between group systems. Well-designed systems with adequate space, ESF for individual feeding, and static group composition achieve good welfare outcomes with low aggression and adequate body condition in all sows. Poorly designed group systems with insufficient space, inadequate feed access, or frequent mixing can create chronic welfare problems for subordinate animals who cannot avoid aggression or access adequate feed. The transition to group systems without adequate design and management attention can shift welfare problems rather than solving them.