Provision Point-Source Materials Stimulates Play in Sows but Does Not Affect Aggression at Regrouping

Simple Summary In most intensive pig production systems, pigs are often mixed into new groups. Sows are important to a production system, as they are the driver behind the farms' productivity. The aggression that results from sows being mixed into new groups and formation of hierarchy can detrimentally affect production and welfare. This study aimed to determine the effect of providing access to materials on aggressive and play behaviors in gestating sows. Play behaviors were observed in the enhanced' pen and no play was observed in standard housing (without materials present). Aggression measures, salivary free cortisol concentrations, and injury counts were unaffected by treatment. The provision of point-source materials to sows at mixing had no impact on aggression; however, their presence maintained sow interest over the course of the experiment. Additionally, play behavior was observed in their presence, which may suggest that a more positive affect was induced when the materials were provided. Abstract When sows are mixed into groups, hierarchies form and resulting aggression and stress can affect production and welfare. This study determined the effect of providing point-source materials on aggressive and play behaviors in gestating sows. Large white cross Landrace sows were mixed after insemination; six pens of 12 sows were housed in standard' pens, and six pens of 12 sows were housed in enhanced' pens. The enhanced' pens each contained two rubber mats, eight strands of 24 mm-thick sisal rope and two yellow plastic disks, suspended from the roof. The sows remained in these pens until pregnancy confirmation. Salivary cortisol concentration, injury counts, and sow behaviors were recorded the day before mixing (day 1), mixing (day 0) and post-mixing day 1, day 4, day 7 and day 20. At farrowing, reproductive outcomes were obtained. Play was observed (including locomotor and object play) in the enhanced' pen, and percentage of time spent playing was greater on d4 (1.48 +/- 0.3 Square root transformed data (2.84% non-transformed adjusted mean)), d7 (1.43 +/- 0.3 (2.97%)) and d20 (1.64 +/- 0.3 (3.84%)), compared to d0 (0.56 +/- 0.3 (0.70%)) and d1 (0.87 +/- 0.3 (1.67%) (p < 0.05)). No play was observed in standard housing. Aggression, salivary free cortisol concentrations and injuries were unaffected (p > 0.05). The provision of materials had no impact on aggression, although their presence maintained sow interest and play behavior, suggesting a positive effect.