The effect of reducing the ratio of omega-6 to omega-3 fatty acids to blood metabolites, reducing inflammation and modulating insulin resistance in dairy cows

The aim was to determine the effect of different dietary n-6/n-3 fatty acid (FA) ratio during the postpartum period on plasma haptoglobin, metabolic profile, and insulin resistance in Holstein dairy cows. 24 multiparous cows were randomly assigned to three treatments with a ratio of omega-6 fatty acids to omega-3: 2.5 to 1 (low ratio); 4.5 to 1 (average ratio); and 6.5 to 1 (high ratio) were distributed. Blood samples were collected on d 7, 14, 28, 42, 56 and 70 postpartum to determine blood metabolites and haptoglobin concentrations. Intravenous glucose tolerance tests and insulin challenges were performed on d 28 and 42 of experiment. Plasma concentrations of haptoglobin were significantly higher in the cows fed with high ratio than the other two treatments. The 42-day postpartum results of insulin challenge test indicates that the change in the ratio of fatty acids to moderate treatment causes an increase in the clearance rate and a decrease in the area under the curve of the insulin. The results of this study indicate that the moderate ratio of omega-6 to omega-3 fatty acids in dairy cows decreases insulin resistance by reducing inflammatory factors.