As part of a series of studies to evaluate the value omega-6 and omega-3 fatty acids, researchers with Prairie Swine Centre compared the performance of newly weaned piglets fed a tallow-based control diet low in unsaturated fatty acids, three plant-based diets containing a 10 to 1, a 5 to 1 or a 1 to 1 omega-6 to omega-3 fatty acid ratio or a 1 to 1 fish-oil based diet.

Laura Eastwood, a University of Saskatchewan Ph.D. Student, explains six days after weaning half of the piglets were injected with lipopolysaccharide to elicit an immune response and half were injected with saline as a control.

Laura Eastwood-University of Saskatchewan:

For sure our immune model worked.

All of the animals that were injected with LPS had a clear spike in body temperature for a 12-hour period before they returned back to normal plus we were able to measure some blood pro-inflammatory cytokines which are molecules which are increased in production when an animal is undergoing an immune response.

We looked at four different ones specifically and saw clear increases in all four of those so we know that our LPS model is able to illicit an immune response in these animals.

We did not find any significant differences between pigs fed the different diets in this case.

In a previous study where we had looked at feeding sows the diets and then weaning the pigs onto a common diet and running the same study we found that a 1 to 1 fatty acid ratio, the pigs actually had an increased immune response, higher body temperature and higher IL-8 production, where as in when we feed the piglets we did not see that.

Ms Eastwood says researchers are now working to identify the optimal omega-6 to omega-3 fatty acid ratio for newly weaned pigs and plan to examine the longer term immune response in the animals.