Housing Pregnant Sows in Turnaround Stalls During Gestation Impacts Behavior, Immune and Well-Being

This study aimed to determine the effects of housing gestating multiparous sows in alternative turn-around stalls on selective measures of well-being. Sows were randomly assigned to either a Turn-Around Stall (TAS) or standard Straight Stall (STS) from gestational day 6 until 110. Behavior was registered on days 6, 30, 45, 65, 90 and 110 of gestation and immune and cortisol on days 30 and 90. Social rank and directional orientation of the sow's head (forward or backward) was only determined for sows housed in the TAS. On gestational days 6 and 30, duration of stand and oral-nasal-facial behaviors were greater (p<0.05) for sows in TAS compared to sows in STS. Regardless of gestational day, sows in TAS spent more (p<0.01) time standing and eating than sows in STS. Plasma cortisol and B-cell induced proliferative index and neutrophil chemotaxis were greater (p<0.05) for sows in TAS, whereas, natural killer cell cytotoxicity (p<0.05) and lymphocytes (p=0.07) were greater for sows in STS. Lesion scores were more (p<0.0001) severe and backfat depth less (p<0.001) for sows in TAS compared to those in STS. Moreover, sows in TAS were facing forward 70% of the time on days 6 and 110, but facing backward 50 to 60% of the time on all other days (p<0.05). Socially, dominant sows in the TAS were more aggressive, won more encounters and shoved the gate more often (p<0.05) and had heavier litters (p<0.05) when compared to their submissive counterparts. These data imply that housing sows in turn-around stalls during gestation can positively and negatively impact measures of well-being including behavior and immune function. The behavioral and physiological responses found indicate there may be a cost associated with turning and that sow social rank may affect the outcome.