222 Late-Breaking: Evaluating gilts’ toy preference and the effect of their preferred toy on aggressive behaviors after mixing.

Abstract An increase in aggressive behaviors is observed when unfamiliar breeding-age gilts are mixed. High incidence of aggression can lead to injuries and ultimately affect gilts’ longevity, reproductive performance, and welfare. Research has found that environmental enrichment in the form of toys can help redirect undesired behaviors. However, gilts’ preference for enrichment toys of varying size, location, and food additives with the potential to reduce aggression when breeding-age gilts are mixed has not been thoroughly studied. The objective of this study was to assess breeding-age gilts’ preference for different enrichment objects. In Experiment 1 and 2, we evaluated gilts (N=32) preference for 3 different toys (Jolly Ball, Kong, Ring ball) at different locations (floor, hanging) and either alone or with a food additive (applesauce, peanut butter). Each combination of toy, location, and food was tested individually and in random order, and gilts’ behavior was recorded for 5 hours to measure interaction time. Experiment 1 showed gilts interacted significantly more with toys on the floor (4.9%, 95% CI [3.9%, 6.2%]) than hanging (3.1%, 95% CI [2.4%, 4.0%]) (p< 0.0001). The results also showed a statistical significant interaction where gilts interacted significantly more with Jolly Balls on the floor (5.3%, 95% CI [4.1%, 6.8%]), and Kongs on the floor (5.1%, 95% CI (4.0%, 6.5%]) and hanging (4.5%, 95% CI (3.5%, 5.8%]), than any other combination of toy and location (p<0.0001). A statistically significant 3-way interaction between location, toy, and food was observed in Experiment 2 (p=0.02). Overall, gilts interacted with the Jolly Ball on the floor filled with applesauce (7.9%, 95% CI [6.6%, 9.4%]) or peanut butter (8.9%, 95% CI [7.5%, 10.5%]) more than any other permutation of food, toy, and location. We are currently evaluating if providing the Jolly Ball filled with applesauce on the floor reduces the incidence of aggression when breeding-age gilts are mixed. Our work will provide insight as to enrichment that can be utilized to potentially reduce aggression in breeding-age gilts and thus improve gilt welfare and longevity.