The gestation crate, which confines pregnant sows in individual stalls barely larger than their bodies for most of their pregnancy, has been the subject of significant welfare reform globally. The science firmly supports group housing as more welfare-positive when well managed.
The gestation crate subjected pregnant sows to one of the most severe movement restrictions applied to any farmed animal. The inability to turn around or engage in any natural behaviour for weeks represents a profound welfare compromise. The transition to group housing has been welfare-positive overall, though group systems introduce new management challenges. The remaining gap relates to the quality of group housing - well-designed, enriched group systems with individual feeding are substantially better than poorly managed minimal-space group pens.