Changes in delayed type hypersensitivity, egg antibody content and immune cell fatty acid composition of layer birds fed conjugated linoleic acid, n-6 or n-3 fatty acids

Abstract

The effects of polyunsaturated fatty acids on delayed type hypersensitivity (DTH), egg yolk antibody content, immune tissue fatty acid profile and lipid oxidation products of layer birds were investigated. One hundred and twenty layer birds were fed diets containing conjugated linoleic acid (CLA) + animal fat (Diet I), sunflower oil (Diet II), canola + flax oil (Diet III) or fish oil (Diet IV). The total added lipid content of the diet was 3%. Birds fed Diets III and IV had higher content of n-3 fatty acids in lymphocyte and splenocytes. Thiobarbituric reactive substances were higher (P < 0.05) in the breast and thigh muscle of Diet IV fed birds. Serum and yolk anti-BSA antibody contents were higher (P < 0.05) in birds fed Diets III and IV. DTH was decreased (P < 0.05) in birds fed Diets IV and III. The number of lymphocyte CD4+ and CD8+ cells and spleen mononuclear cell CD4+, CD8+ and IgM+ cells did not differ (P > 0.05) between treatment groups. Feeding n-3 fatty acids increased antibody-mediated immune response, while n-6 fatty acids and CLA increased cell-mediated immune response. Key words: Conjugated linoleic acid, polyunsaturated fatty acids, delayed type hypersensitivity, immunoglobulins