Effect Of Different Dietary Ratios Of N-6/n-3 PUFA On The Immune Functions In Chicken

Polyunsaturated Fatty Acids (PUFAs) have functions in immune regulation, as shown by animal research and from human clinical medicine.Two experiments were conducted to evaluate the effects of different dietary ratios of n-6/n-3 PUFA on the immune performance of Arbor Acre (AA) broilers and their effects, in vitro, on the transformation function of peripheral blood lymphocytes.1 Effects of different dietary ratios of n-6/n-3 PUFA on the immune performance of AA broilers .A total of ninty newly-hatched AA broiler were distributed to five groups of 18 chicks each, which were fed five different diets supplemented with corn oil and canola oil to achieve approximate n-6/n-3 ratios of 30:1, 20:1, 10:1, 5:1 and 2.5:1. On 56d, chicks in each dietary treatment were divided into control (6) and test (12) groups. Controls were given a single intraperitoneal injection of saline while test birds received lipopolysaccharide(LPS) (500μg/kg body weight for 3d). Immune performance was assessed every second day for 7d. Results: All following results concern differences between the dietary treatments.①Differences (P<0.05) were found in Bursal and Spleen indices;②The significant difference in the Heterophil/Lymphocyte ratio(H/L)ratio occurred on d 1, 3, and 7;③Significant differences were found in plasma concentrations of cortisone on d 7;④Differences were found in the concentration of serm albumin (Alb) on d 1, 3, or 7;⑤The antibody titer against Newcastle Disease virus (NDV) was significantly different(P<0.05) on d 1;⑥Differences(P<0.05) in the proportion of CD4+ and the ratio CD4+/CD8+ at d 7 were significant⑦Concentration of IL-1 on d 5 and 7 were significantly different(P<0.05). Conclusion: Immune performance of AA broilers was influenced by manipulation of the ratios of n-6/n-3 PUFA in the diet. The proportion of CD4+ lymphocytes and CD4+/CD8+ in the 10:1 treatment were higher than the others. The immuno-organ indices, concentration of IL-1, the antibody titre of ND were all highest in the 2.5:1 treatment while the ratio of H/L was lowest. The results demonstrated that immune function of AA broilers was influenced by the dietary supplements with different n-6/n-3 PUFA ratios. As the ratios of n-6/n-3 PUFA was decreased, the immune function of the chicken was enchanced.2 Efects of different ratios of n-6/ n-3 PUFA, added in vitro,on the transformation function of peripheral blood lymphocytes In order to study the immune regulation of the PUFA,different amounts of linoleic acid (n-6 PUFA) andα-linolenic acid (n-3 PUFA), making n-6/n-3 ratios of approximately 30:1,20:1,10:1,5:1 and 2.5:1,were added to culture medium used for the lymphocytic transformation test.The proliferative response to various concentrations of LPS or concanavalin A (ConA) was tested in media with various n-6/n-3 ratios. The results showed that the proliferation of lymphocytes varied with different n-6/n-3 ratios, and with concentrations of LPS or ConA. Lymphocytic transformation decreased significantly (P<0.05),as n-6/n-3 decreased.The optimal concentration of either ConA or LPS depended upon the ratio of n-6/n-3 PUFA in the medium.