Utilization of enrichment objects by growing pigs in a commercial facility and the impact on behavior and skin lesions

Abstract

Environmental enrichment is a way to provide growing pigs with a complex environment to explore and occupy themselves as they grow. Single point enrichment can provide some complexity to the environment while not having the drawbacks of substrate enrichment, including labor, biosecurity, and lack of infrastructure. To expand our knowledge into the type of point enrichments that pigs engage with, as well as the effects the objects have on lesion counts and behavior, a single point enrichment object was placed into each of the 129 pens, containing 27.1 ± 2.9 pigs per pen, in a conventional fully slatted wean-to-finish facility. The nine treatments included AllBite™ blocks, Bite-Rite™, chains, branched chains, Green Apple Porcichews®, Yellow Vanilla Porcichews®, cotton rope, EasyFix® Luna, and nothing. Interactions with the objects and activity level were monitored by scan sampling and skin lesions were measured by direct enumeration of scratches. Behavioral observation was conducted using the focal follow technique with an ethogram encompassing fighting, scampering, floor nosing, belly nosing, biting, and tail biting. Data collection took place in the 50 days after placement of enrichment objects. The proportion of pigs interacting with the enrichment object was lowest for chain (1.95 ± 0.13%) and highest for rope (6.63 ± 0.41%) (P < 0.011). A significant object-by-day interaction was observed for pigs at the objects (P <.001) with popularity of objects waning over time. There was a significant object by day interaction on the proportion of pigs in a pen that were standing (P <.001). There was also a significant object by day interaction for skin lesions (P<.001) with skin lesions leveling out by the end of the study but objects generally decreasing lesion counts in the first third of the study. Enrichment objects showed no significant effect on the observed behaviors. These findings suggest that the choice of point enrichment object can influence the level of interaction, level of interest over time, activity level, and skin lesions in growing pigs. Future work should investigate the practicality of these objects and farmer willingness and ability to provide them.