Stalled females produce greater num

Stalled females produce greater numbers of pigs born alive than tethered sows (den Hartog, 1993; McGlone et al., 1994), but stalled females show more stereotypic behavior than tethered females (McGlone et al., 1994). Few studies have reported the factors related to female-to-female variation in the behavior of stalled females and the relation between behavior and reproductive performance on commercial farms, but several studies have reported on the welfare of pigs in stall housing systems (Friend et al., 1988; Curtis et al., 1989; Robert et al., 1993). In this study, we describe the behavior of stalled pregnant females on a commercial farm to investigate the relationships of their behavior with parity and gestation periods, and potential associations between their behavior and reproductive performance.