The debate over gestation-sow stalls is not likely to disappear anytime soon. Meanwhile, researchers continue to look for answers. A University of Minnesota study looked at the wellbeing status of 25 pregnant sows housed in gestation stalls. Specifically, the team studied cortisol concentrations, behavior responses and injury scores for the sows.

Data were collected during the sows’ gestation period on the following days: 5, 56 and 108. The researchers used time-lapse video to record sows for 24-hour periods. The point was to observe the animal’s behavior at each data point. Cortisol concentrations were assessed via the saliva. Injuries were scored individually and added to provide a total injury score.

As for the results, researchers found that cortisol concentrations were lower on gestation day-56 than on other days, and the total injury score was higher on day-108 than on the other days measured. Time spent lying also was highest as sows reached their farrowing date. Sows were more active and spent more time exploring on the 56th day than either of the other two monitored days.

Time needed to transition from sitting to lying was greater on day-108 than on day-56. Concerning overall postural change, standing or sitting to lying and lying to sitting were highest on the 5th day. Body weight was negatively correlated with the animal's time spent on exploration, active behavior and standing, and it was positively correlated with time spent lying.

The researchers concluded that the wellbeing of sows in gestation stalls appears to be more compromised during the early and late gestation periods. Providing larger sows with larger stalls might improve overall wellbeing, they said.