An animal will choose an open space versus a confined one every time — or so the theory goes. But animals don’t always perform like some people would expect. They have minds of their own and have different needs and environmental interpretations than humans do.
The Saskatoon-based Prairie Swine Center recently completed a study looking at utilization by sows in free-access stalls. The goal was to determine the number, size and parity of sows that use the free space. Among the results, researchers found that, given the choice, not all sows will abandon their stalls. In fact, some spend a fair amount of time there.
Harold Gonyou, the center’s research scientist in animal behavior, points out that the study tracked the amount of time sows spent inside their stalls as well as in the free-access area. Researchers found that after the sows would eat, many returned to their stalls to lie down. The study did show that 95 percent of the sows would leave their stalls at some point during gestation.
In a 24-hour period, approximately 40 percent of the sows spent less than 2 percent of their time out of the stall. At the same time, some would spend 80 percent or 90 percent of the time way from their stall. At any given point, about 20 percent of the sows would be out of their stalls, but which ones were out and which were in stalls was quite skewed.
Gonyou observed that sows choosing the open area tended to be larger, older sows. This presents two questions:
Do younger sows stay in the stall and not use the free-access space because they want to avoid the other larger sows?
Perhaps the 26-inch-wide stalls used in the study didn’t provide a comfortable lying space for the older, larger sows, so they chose to get out and lie somewhere else?
Gonyou says additional research is needed to clarify what’s occurring as well as to develop options for balancing out the use of the free-access space.