Abstract: The effect of dietary ω6/ω3 polyunsaturated fatty acid (PUFA) ratio on longissimus dorsi fatty acid composition of and serum antioxidant parameters were investigated in finishing pigs with body weight of approximately 70 kg. ω6/ω3 PUFA ratios of 26:1; 19:1; 12:1; 8:1; 6:1 and 3:1 were obtained by replacing corn oil with the same amount of linseed oil. Ninety finishing Duroc × Landrace × York shine pigs of similar body weight (approximately 70 kg) were divided randomly into 6 groups of 15 pigs (5 replicates in each group, 3 pigs per replicate). The contents of ω3 PUFAs such as ALA (C18:3), EPA (C20:5) in longissimus dorsi significantly increased (P＜0.05), and DHA (C22:6) content increased but not significantly (P＞0.05) as the dietary ω6/ω3 PUFA ratio decreased. However, the contents of ω6 PUFAs such as LA (C18:2), C20:4 and C22:4 significantly decreased (P＜0.05) and ω6/ω3 PUFA ratio in longissimus dorsi also showed a significant downward trend. In contrast, MDA content in porcine serum tended to gradually increase. There were no significant changes in serum GSH-Px or T-AOC activities (P＞0.05). A significantly higher level of serum SOD activity was obtained at an ω6/ω3 PUFA ratio of 19:1 compared to 12:1, 8:1, 6:1 and 3:1 (P＜0.05). These results indicated that dietary ω6/ω3 PUFA ratio could modify the fatty acid composition of pork longissimus dorsi and affect serum antioxidant parameters to a certain extent.

Key words: ω6/ω3, finishing pigs, fatty acids composition, antioxidant parameters