The Head of the University of Plymouth's Food, Nutrition and Health Research Group is encouraging swine producers to consider increasing the bulk density of diets fed to gestating sows as a way of improving behavior.
Professor Peter Brooks says we've only become aware of the huge effect food has on behavior in the last 20 years, since we've started putting sows in stalls and feeding them limited amounts of food.
He suggests producers need to consider feed requirements as opposed to just nutrient requirements.
"If we think about nutrient requirements all we're doing is simply saying 'are we giving the animal enough nutrients to do things that we specifically want the animal to do like put on weight, like carry a pregnancy that might produce milk.'
If we talk about feed requirements we're also asking some other questions. We're saying 'is this enough to satisfy the animal, does this satisfy its need for foraging behavior, does this enable it to feel comfortable, to feel satisfied and therefor not indulge in stereotypic behavior.
When we were housing sows in groups usually they were on bedded systems and, as a consequence, they were able to consume bedding to supplement the diet that we gave them and that allowed them to satisfy their requirement for gut fill.
Once you put a sow in a sow stall, you're condemning her to only have that food which you choose to put in front of her.
She doesn't have any opportunity to alleviate her boredom, to alleviate her hunger by eating other substrates like bedding.
Anybody who's been on a diet will know that, when you're on a diet for any length of time, the worst thing is that you want something to make you feel full. It's often easier to eat one big meal a day and at least feel full once a day than to have little and often."
Professor Brooks says, by increasing the bulk density of the diet and allowing the sows to get filled up, producers can dramatically reduce stereotypic behavior such as bar biting and excessive water consumption.