Effects of changing omega-6 to omega-3 fatty acid ratios in corn-soybean meal-based diet on performance, serum lipid profile and colostrum and milk composition of sows and performance of piglets

This study aimed to test the effects of changing omega-6 to omega-3 fatty acid (FA) ratios in corn-soybean meal-based diet on performance, serum lipid profile and colostrum and milk nutrient contents of lactating sows as well as performance of suckling piglets. In total, 32 multiparous sows (Landrace x Yorkshire) were randomly allocated into one of four dietary treatments with eight replicates per treatment. The treatment diets were fed 7 days before farrowing until weaning. The omega-3 FA used in the experiment was from linseed oil and was coated using a spray-drying method. The dietary treatments consisted of control (CON, corn-soybean meal-based basal diet with omega-6:omega-3 FA ratios of 25:1), and basal diets (CON) containing omega-6: omega-3 FA ratios at 20:1, 15:1 and 10:1 levels. Inclusion of omega-6 and omega-3 FA at different ratios in the feed did not affect (P > 0.05) the performance, nutrient digestibility and milk nutrient composition of sows. The concentrations of high-density lipid cholesterol (HDL-C) increased (P < 0.05) and the low-density lipid cholesterol (LDL-C) tended to be reduced (P = 0.08) at weaning for sows fed 10:1 omega 6:omega-3 ratio diet. The bodyweights (BW) and average daily gains (ADG) of piglets born from sows fed 10:1 omega-6:omega-3 FA diet were greater (P < 0.05) at Week 3 and overall respectively. The BW of piglets raised from sows fed all treatment diets were heavier (P < 0.05) at Week 4 (weaning) than those in the CON. Positive correlations between dietary omega-6:omega-3 FA ratio and serum HDL-C concentrations and a negative correlations between dietary omega-6:omega-3 FA ratio and serum LDL-C concentrations for sows at weaning were observed. In addition, a positive correlation between omega-6:omega-3 FA in the diet and ADG in piglets was also observed. In conclusion, inclusion of omega-6:omega-3 FA at different ratios in different proportions did not affect sow performance, while increasing HDL-C and tending to reduce LDL-C in serum lipids. However, the piglets born to sows fed 10:1 diets benefitted, with increased BW and ADG.