Research conducted by the Saskatoon-based Prairie Swine Centre shows, given the choice, not all sows will choose to leave their stalls.
Several packers and producers have indicated a desire to transition from stall housing to group housing over the next decade. The Prairie Swine Centre has completed a study which examined free space utilization by sows in free access stalls to determine the number, size and parity of sows that use the free space. Dr. Harold Gonyou, a research scientist in animal behavior, explains researchers tracked the amount of time sows spent inside their stalls and in the free access area.
Researchers found that the sows did spend a fair amount of time within the stalls, that they would eat and then many of them would lie down within the stalls. The study found that 95 percent of the sows at some point would leave their stall during their gestation.
Over a 24 hour period, approximately 40 percent of the sows spent less than two percent of the time outside the stalls throughout the day but there were also some that would spend 80 or 90 percent out. Thus, approximately 20 percent of the sows were outside of the stalls at any time during the day but it was very skewed in terms of who was outside and who was inside the stalls.
Dr. Gonyou observed that the sows that were outside tended to be the larger, older sows and this raises two questions: 1)Are the younger sows staying in the stall and not using the free access space because they want to avoid these other larger sows, or 2) maybe the 26 inch wide stalls used in this study are not adequate to provide a comfortable lying space for the older sows and so they chose to get out and lie somewhere else.
Dr. Gonyou says further research is needed to identify the issue and to come up with ways to even out the use of the free access space.
Source: Farmscape.ca, Episode #3386