The effect of rope and an activation ball on the performance of harmful social behaviors in pigs

Abstract: A widespread problem in the housing of captive animals is the occurrence and development of abnormal behaviors. In the pig breeding industry the abnormal behaviors causing the biggest welfare problems are stereotypies such as tail-biting, ear-biting, equipment-biting and belly-nosing. In this study a rope and an activation ball were tested as curative treatments to reduce the performance of these stereotypies by inducing the underlying innate behaviors. A total of 141 pigs spread over 18 pens were used as test-subjects. They were divided into three groups which were introduced to one of the two enrichments or no enrichment at all. Both the enrichments contained characteristics which mostly targeted exploratory and foraging needs and, if functional, were thought to mainly have an effect on tail-biting, ear-biting and equipment-biting. The pigs were observed both at initial contact with the enrichments and after having familiarized with them for three days, and the amount of registered enrichment interaction and performed stereotypies were used to evaluate the effect of the enrichment objects. In both enrichment treatments the enrichments occupied the pigs both on day one and after three days. The presence of equipment-biting was successfully reduced on both day one and day three while the presence of tail-biting and ear-biting only were initially reduced. No effect was found on belly-nosing in either enrichment treatment. This suggests that both enrichments are functional over time and efficient in reducing some types of harmful social behaviors. However, belly-nosing would need to be targeted with a different kind of object.