Sow housing has become a controversial welfare issue for pork producers. We cannot begin to implement costly alternative housing systems without scientific data that support these changes that could have an impact on sow well-being. The long-term objectives of this project was to design, optimize and implement sow housing and management systems that will enhance sow well-being while sustaining productivity and profitability of swine production (Continuation proposal was funded by NPB in 2009 and is in progress). In Exp. 1, a pilot study was conducted to determine the impact of a modified gestation stall, the FLEX stall—a prototype stall in which the width of the stall could be easily expanded while the length was fixed on sow performance, productivity, and behavior throughout gestation. A standard non-adjustable stall was used as the control (STALL). In Exp. 2, the impact of the FLEX, STALL, and Free Access system (FREE) were used to determine the impact that these 3 housing environments had on sow productivity, behavior and other physiological measures throughout gestation.
Data from Exp. 1 (STALL vs. novel gestation stall FLEX) indicate that sows in STALL perform more oral-nasal-facial (ONF), sham-chewing, drinking behavior than sows in FLEX stall. Sows in FLEX stall sat more often and had more lesions on right side of body than did sows kept in STALL. Sows in FLEX stall had more piglets born and a tendency for more piglets to be born alive than did sows in STALL. Data from Exp. 2 (STALL vs. FLEX vs. FREE (individual stall and pen area) indicate that sows kept in FREE had more lesions than did those sows in either STALL or FLEX stalls. Sows in FLEX and FREE had more male piglets than did sows in STALL. While sows kept in FLEX had greater piglet mortality than did sows in either STALL or FREE system, these sows also gave birth to more total piglets. Sows kept in FREE had greater cortisol response later in gestation than did either sows in STALL or FLEX. Both behavior and immune status were affected by gestation environment. Data specifically registered from sows kept in FREE indicate that sow preference as to where they spend their time (pen or stall) varies from sow-to-sow. Day of gestation also impacts sow preference as to where she spends her time with sows spending more time in stall as days of gestation increase. Cortisol response was impacted by gestation environment; increasing FLEX stall width reduced stress status (decrease cortisol) of sow within 24 h after expanding width.

These data indicate that housing components may impact productivity, behavior and physiological responses of the dry sow. Specifically, simple alterations to the physical aspect of the stall (width increase) resulted in changes in behavior, stress response and litter productivity among sows kept in that particular environment. This research implies that we must first determine impact of housing components on sow well-being and then optimize the best system before we implement housing systems that unwittingly compromise well-being.