Effects of different dietary n-6:n-3 PUFA ratios on growth performance, blood lipid profiles, fatty acid composition of pork, carcass traits and meat quality in finishing pigs

A total of 72 crossbred pigs [(Landrace × Yorkshire) × Duroc] with an average initial BW of 51.59±1.59 kg were used in this 10-wk feeding trial to investigate the effects of different dietary n-6:n-3 polyunsaturated fatty acids (PUFA) ratios in finishing pigs. Pigs were randomly allotted to 3 dietary treatments (each n=24) with 6 replications and 4 pigs per pen (2 barrows and 2 gilts). Pigs were fed a corn-soybean meal-based diets formulated by replacing soybean oil with linseed oil to achieve n-6:n-3 close to 5:1, 10:1 and 15:1, respectively. The growth performance, carcass traits and meat quality parameters (meat color, sensory evaluation, cooking loss, drip loss, pH, longissimus muscle area and water holding capacity) were not influenced (P>0.10) by various dietary n-6:n-3 ratios. Pigs fed dietary n-6:n-3 PUFA ratios of 5:1 had a lower (P<0.05) serum total cholesterol, LDL cholesterol and triglyceride levels. The concentrations of n-3 PUFA , including C18:3n-3, C22:5n-3 and C22:6n-3 were improved (P<0.05) in the longissimus dorsi muscles of pigs fed dietary n-6:n-3 PUFA ratios of 5:1. Furthermore, pigs fed dietary n-6:n-3 PUFA ratio of 5:1 decreased (P<0.05) the n-6 concentrations (C18:2n-6 and C20:4n-6) of longissimus dorsi muscles. In conclusion, lowering the dietary n-6:n-3 ratios to 5:1 could be beneficial for the blood lipid profiles, and improve the nutritional value of pork, without adverse effect on growth performance and meat quality parameters that are related to the consumer acceptance.