“Sows have changed,” says Janeen Salak-Johnson, University of Illinois associate professor of animal sciences. “We need to change with them. Our research shows that modifications of stall design may have a positive effect on sow behavior and well-being.”

In an effort to establish welfare-friendly guidelines on how to effectively manage gestating sows, a team of researchers is studying the impact of stall design on sow behavior and well-being. The National Pork Board funded the research, which involved Ashley DeDecker and Salak-Johnson from the University of Illinois, and Paul Walker and Andrea Hanson of Illinois State University.

Sows were evaluated in a standard gestation stall and a turn-around gestation stall, which pairs two sows with a shared divider that allows one sow to turn around at a time. Researchers compared the behavioral differences of housing sows in the two stalls for 30 days before placing some sows in group pens and leaving others in stalls to complete gestation.

Preliminary findings show that slight modifications to the stall design can impact measures of the animal’s well-being, particularly behavior and immune status. “Sometimes behavior is the best adjustment an animal can make in a stressful situation,” Salak-Johnson notes. “Making modifications to the gestation stall may allow sows to adapt more easily to stressful situations without experiencing negative consequences.”

From a behavior standpoint, researchers observed that stall design modifications also resulted in differences between sow groups.  Sows in standard stalls sat more, while sows in turn-around stalls lay more. Oral-nasal-facial activity — or ONF — increased in sows in turn-around stalls as they approached gestation. However, sows in standard stalls engaged in less ONF overall and remained consistent in the amount they displayed throughout the gestation period.

In previous studies, immune status has been affected more by the day of gestation rather than actual treatment. However, this study indicates the stall design treatment may impact sow immune status, with sows in turn-around stalls having more lymphocyte activity which indicated a more stimulated immune response compared to sows in the standard stall.

“This is one of the first sets of data that has shown an immune response to stall types,” Salak-Johnson says. “The next step is to figure out what these differences mean and which response is better for the sow.” An activated immune system could imply either a sow’s biological defense to stress or a sow’s readiness to fight off infection if challenged with a pathogen.

Salak-Johnson and the team are interested in discovering the positive physical components of each stall type to assist in housing recommendations.“If you want to find the best option, you need to see research results that prove one housing option is better than the other,” she adds. “Right now, that information doesn’t exist. People want to throw sows in group pens to avoid certain behaviors such as ONF. However, ONF may actually be better for the sow.”

Researchers also are detecting differences between sows housed in standard stalls before moving to group housing and sows housed in turn-around stalls before that move. While there are no differences in ONF, researchers have observed differences in two maintenance behaviors — lying down and standing.

More results from the stall design study  will be relesased in the future.