Enrichment in the Sucker and Weaner Phase Altered the Performance of Pigs in Three Behavioural Tests

SIMPLE SUMMARY: Two important questions about the intensive housing of pigs concern whether young pigs require environmental enrichment to enhance their welfare, and from what age should enrichment be provided to pigs to achieve the benefit? We provided sucker and weaner pigs with enrichment in the form of blocks, which they could push around the floor of the pen, compared to no blocks (‘barren’ control). Behavioural and physiological responses of the pigs were then measured in a series of standard tests used to assess fear response, learning, and cognitive ability. Enrichment blocks modified the behavioural responses of pigs in the different tests, suggesting enriched pigs were more willing to explore novel environments and they had increased ability to learn. However, our enrichment treatment did not alter the pigs’ cortisol response, suggesting any differences due to enrichment were subtle. In contrast, the altered behavioural responses probably indicate that although pigs readily learned complex tasks and modify their behaviour to suit the current situation, there may be some potential benefits from enrichment when applied during the early weeks of a pig’s life that might have life-long benefits for the animal and its welfare. ABSTRACT: We tested the hypothesis that provision of enrichment in the form of enrichment blocks during the sucker and weaner phases would affect the behaviour of pigs. We measured the performance of pigs in an open field/novel object test, a maze test, an executive function test and the cortisol response of the pigs after exposure to an open field test. The provision of enrichment blocks altered the behaviour of the pigs in all three tests and these changes suggest an increased willingness to explore and possibly an increased ability to learn. The behavioural tests highlighted that young pigs have the capacity to learn complex tasks. Our findings support the notion that the benefits of enrichment cannot be evaluated by measuring the interactions the animal has with the enrichments in the home pen and it may simply be beneficial to live in a more complex environment. We have highlighted that the early rearing environment is important and that the management and husbandry at an early age can have long-term implications for pigs. The enrichment we used in this study was very simple, an enrichment block, and we provide evidence suggesting the provision of enrichment effected pig behavioural responses. Even the simplest of enrichments may have benefits for the welfare and development of young pigs and there is merit in developing enrichment devices that are suitable for use in pig production.