Enrichment toys in pens are not only good for pigs, but also good for the bottom line, said a researcher with the Prairie Swine Centre.
Despite years of breeding and pigs living indoors, pigs need to have stimulation to satisfy their desire to chew, nest, wallow, root and explore their environment.
“The pigs that are on farms today still have the need for that behavior. Those behaviors are important for species survival,” Miranda Smit, told the Prairie Swine Centre producer meeting.
“We must cater to these needs. On commercial farms with limited space and a barren environment compared to nature, this can have negative behaviours.”
In a research study in a commercial barn and one at the centre’s own barn the number of pigs removed from pens, either dead, euthanized or moved to a sick pen, was higher when the pigs only had a chain for enrichment than pigs in pens with other enrichments, said Smit.
During the study, the pigs in the control group had only a hanging chain as enrichment. Another pen had hanging static toys that had narrow finger-like spikes or other interesting shapes hanging from the chain. The third group had renewable toys that the pigs could eat like cotton rope, cardboard rolls or wood.
“In the grow finish, especially the grower phase, the number of pigs removed in the chains group was higher than the other two groups.”
With medication use, the number of pigs treated was better for the toys group and not significantly different between chains and renewable enhancement group. Smit believes the pigs quickly chewed through the cardboard, wood or rope which left them with no enrichment.
“We think it only took a few days for the pigs to eat through the cardboard and the rope and they were only replaced once a week. The rest of the week they only had a chain in the pen. We think we didn’t replace it often enough to see that benefit.”
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If using renewable enhancements, Smit recommended these be replaced often to ensure the pigs always had enhancements in the pen. The renewable enrichments must also be size and age appropriate. Small pigs can’t get their mouths around large pieces of wood or rope, but separating a rope into its three braids allowed piglets to chew and manipulate the objects.
During the study with the commercial barn, the carcass weight was higher for the pigs in the chains group. Taken on its own, the information would make producers think the chain group was more effective, but Smit said the reason the chains group grew larger is because there were less pigs in the pen because more were removed because of death or sickness.
“If you were just to look at this data, clearly the chains group is growing faster. The thing is the reason the pigs grew better was because there were less pigs in the pen. We know they have more space, they just grow better.
When the weight from all the pigs were added, the toys group had significantly more weight because fewer pigs had been removed. “That is what you are getting paid on.”
In the commercial barn trial only one enrichment per 24 pigs was placed in the pen compared to one enrichment in nine pigs for the centre barn. In both cases the enriched pens improved medication use, but there was still some tail biting and skin lesions in the pen with more pigs per enrichment. Smit doesn’t know what the ideal amount of enrichment per pig is, but likely more than one in 24.
The Canadian Pork Council’s pig care program recommends there be two or more enrichments in pens at all stages of production. The Code of Practice recommends enrichments be provided to improve the welfare of animals, but both are vague on what the enrichments should be doing or not doing for the pigs.
With upcoming changes to the code of practice, Smit said any enrichments should be destructive, malleable or deformable.
“They love when they can change the shape of it. It needs to be chewable and needs to be edible, rootable, odorous. Pigs love things that have a smell to it. It needs to be novel and fresh and clean.”
When hanging objects, Smit said the object needs to be suspended low enough to allow the pigs to grab it with their mouths. “Some of the farms were hanging the enrichments too high. Think of the physiology of a pig’s neck. Pigs are meant to root, not meant to look up. If the enrichment is hanging higher and needs to lift their necks it won’t be as desirable to the pigs.” •
— By Mary MacArthur