Studies were undertaken looking at effects of omega 6 and omega 3 ratios on pigs post weaning. When a pig is weaned it is a very stressful time in its life, this stress triggers an immune response. By altering the omega 6:omega 3 ratio researchers found there was varying immune responses from pigs on different diets. It is recommended that a feed ratio of no less than 5:1 (omega6:omega3) be used. Pigs given a ratio of 1:1 experienced a heightened immune response and higher body temperature which can be interpreted as a heightened occurrence of  fever and stress.