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

Abstract

Simple SummaryIn 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.AbstractWhen 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.

Short-Term Impact of Point-Source Enrichment on the Behavior of Gestating Sows Housed in Groups

“…Sows are more likely to remain interested in point-source enrichment if a rotation between objects of different natures is provided (Roy et al, 2019). However, sows' interest in the enrichment rebounded slightly after the second day of enrichment provision, a pattern consistent with another study in which sow play behaviors were highest 4, 7, and 20 days after the day of enrichment provision (Greenwood et al, 2018). Lower parity sows spent more time interacting with the enrichment object as indicated by an increase in the number of enrichment interaction bouts.…”

“…Indeed, higher levels of aggression between conspecifics have been observed upon enrichment provision (Stewart et al, 2008;Roy et al, 2019). In the present study and similarly to Greenwood et al (2018), neither provision nor removal of the point-source enrichment had any impact on expression of agonistic behavior among focal sows. However, this observation might be the result of the low prevalence of agonistic behaviors observed in the population studied.…”

Providing Effective Environmental Enrichment to Pigs: How Far Have We Come?

“…Limited access to valued enrichment can result in greater aggression towards subordinate sows and higher stress levels in those animals [27]. Other studies also found increased aggression [25], although, in some studies, aggression remained unchanged after the provision of enrichment [28].…”

Gut-Brain Axis: Probiotic,Bacillus subtilis, Prevents Aggression via the Modification of the Central Serotonergic System

“…Aggression within a group is to establish a dominance hierarchy when the animals are first brought together in a common environment [129][130][131]. From an evolutionary perspective, aggression is adaptive behaviors that are related to an individual's survival, growth, and reproductive success within a group [132,133].…”