204 An Investigation into the Role of Dietary Essential Fatty Acids Ratios and Linoleic Acid Level on Growth Performance and Inflammation of Grow-finish Pigs

Abstract

Abstract The objective was to investigate the effects of dietary linoleic acid level and the ratio of linoleic acid:linolenic acid (n6:n3) on the growth performance and inflammatory status of grow-finish pigs. A total of 300 growing pigs (BW = 41.1 ± 6.3 kg) were randomly assigned to either a high (30 g/kg; HLA) or low (15 g/kg; LLA) linoleic acid level with a high (20:1; HR), moderate (12:1; MR) or low (4:1; LR) n6:n3 in a 2 x 3 factorial design. Diets were fed across three 28-day phases and were balanced for dietary metabolizable energy. Pigs were housed 5 pigs per pen. Blood samples were collected on weeks 1, 3, 6, and 12, and synovial fluid was collected from the hock joint on weeks 1 and 12 for inflammatory marker analysis. Data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with initial body weight as a covariate, pen as the experimental unit, and linoleic acid level, ratio, and their interaction as fixed effects. Compared to HLA, LLA pigs had increased BW (P < 0.05) at d56 (103.2 vs. 101.3kg) and tended to have increased BW at d84 (P < 0.10; 129.1 vs. 127.8kg). Pigs receiving LR tended to have higher d84 BW compared to MR (P < 0.10; 129.1 vs. 127.3kg). There was no effect of linoleic acid ratio interaction for growth performance. In phase 2, pigs receiving LR had higher feed intake (P < 0.05) compared to MR. Pigs receiving HR performed intermediate of LR and MR. Overall, C-reactive protein was reduced in the plasma of pigs receiving HLA (P < 0.05; 19.3 vs. 26.2mg/mL). Across all treatments, CRP was reduced in synovial fluid and plasma in week 12 vs. week 1 (P < 0.05). In conclusion, LLA and a low ratio of n6:n3 improved final pig BW, and HLA is potentially beneficial in improving inflammation.