There is some concern among Irish producers converting from stall to loose housing for pregnant sows that sows will be unable to adapt to these systems having spent several parities in stalls. The objective of the 2 experiments referred to in the current paper was to assess the welfare of sows previously housed in stalls when changed to group housing. In the 1st experiment housing constraints meant that it was not possible to measure sow welfare in the loose housing treatment for more than one month. With the advent of additional loose pens it was decided to conduct a second experiment whereby sow welfare was measured up to the end of the gestation-housing period. The current paper presents the findings from both experiments on responses of sows to an ACTH challenge at different stages.