Recent interest in environmental enrichment stems from the National Farm Animal Care Council’s 2014 update to the Canadian Code of Practice for the Care and Handling of Pigs which states that all pigs must have “multiple forms of enrichment that aim to improve the welfare of the animals through the enhancement of their physical and social environments.” The lack of enrichment can lead to problematic behaviours such as tail-biting and belly-nosing and there is a need for practical and cost-effective solutions that producers can implement.
Research that has been done found that piglets given enrichment had increased play and exploratory behaviours and decreased aggression, tail-biting, and belly-nosing. There is also some evidence of improved growth and meat quality when pigs are given enrichment, so there is potential for enrichment to benefit production as well as welfare.
Unfortunately, most previous research on enrichment for pigs has been done using substrates such as straw. While straw is effective and attractive to pigs, it isn’t feasible for most Canadian barns because of biosecurity risks and slatted flooring systems. The project therefore looked at enrichment alternatives such as commercially available pig toys hung from chains, segments of PVC pipe, hanging knotted cotton rope, rubber mats, and hay cubes. To help maintain pigs’ interest, three or four objects were provided at once, and the set of enrichments was rotated twice per week.
Thirty litters were used for the experiment: ten litters received enrichment only in the nursery (from 4-8 weeks of age), ten received enrichment both pre-weaning and in the nursery, and ten received no enrichment. All piglets were weighed shortly after birth, at weaning (approximately 28 days of age), and at 8 weeks. Video cameras were used to record piglet behaviour in their nursery pens at weaning, two weeks post-weaning, and four weeks post-weaning. Skin lesions were recorded before weaning, 24 hours post-weaning, and four weeks post-weaning. Finally, the pigs’ fear of humans was assessed by measuring their latency to approach and contact a human.
Results showed that piglets given enrichment before weaning showed less pen-mate manipulation (tail-biting, ear-biting, belly-nosing, etc.) and tended to fight less at weaning than the other pigs. This is important because weaning is stressful for piglets, so anything that can help to reduce weaning stress has the potential to benefit their health, welfare, and productivity throughout the nursery and beyond.

Similarly, piglets that were given enrichment only in the nursery had fewer head and shoulder lesions at four weeks post-weaning than the other groups, indicating that they fought less towards the end of the nursery phase.
Additionally, pigs with enrichment spent more time exploring their pens at three weeks post-weaning, indicating that they were more engaged with their surroundings. Pigs enriched post-weaning also showed reduced fear of humans, which has implications for both welfare and ease of handling.
No difference in growth between the groups was found, however previous research indicates that the effects of early enrichment on growth are be greater later in the pigs’ lives. Pigs in this trial were not followed after 8 weeks of age. Therefore, more research should be carried out regarding the long-term growth and welfare effects of enrichment.
Of the objects used, the hanging knotted cotton rope was the most popular. Pigs are known to prefer malleable objects that they can chew and destroy because these qualities allow them to express their instinctive rooting and foraging behaviours. The attractiveness of the rope and its low cost make it a viable alternative to substrates such as straw. However, the drawback of destructible enrichments such as rope is the fact that they need to be replaced regularly, which may make them more labour intensive than something that can be used for a longer period of time. If a more durable option is desired, commercial pig toys hanging from chains were also attractive to the piglets and required significantly less labour, however they involve a higher initial cost. Both the rope and the pig toys had the advantage of being suspended off the ground and were not soiled by feces, unlike the rubber mat and PVC pipe which were placed on the floor of the pen.
This study indicated that for producers looking to implement physical enrichment in their barns, a rotation of several inexpensive objects can be effective to increase exploration and reduce manipulation of pen-mates among piglets. Environmental enrichment for piglets is an exciting area of research because it also has potential to improve pig health, productivity, and public perception of the swine industry as a whole. •
— By Hayley Bowling,
Western College of Veterinary Medicine, and Jennifer Brown, Prairie Swine Centre

This research project was funded by an NSERC Undergraduate Student Research Award and by Prairie Swine Centre.