Effect of dietary fatty acids on antibody production and fatty acid composition of lymphoid organs in broiler chicks.

This study examined the effect of increasing amounts of dietary polyunsaturated fatty acids on antibody production in vivo and fatty acid composition of plasma and lymphoid tissues in the broiler. Chicks were fed four diets containing 12% added fat made up of different proportions of palm oil and soybean oil and immunized against bovine serum albumin at 14 to 16 d of age. Blood samples were taken every 4 to 5 d for 30 d; then the chicks were killed and liver, spleen, thymus, bursa of Fabricius, and bone marrow were sampled. Fatty acid composition in serum and tissues reflected the composition of the diets, although amounts of saturated fatty acids were tissue-specific. Arachidonic acid concentration was not changed by dietary fatty acid content. Antibody production developed more rapidly, reached a higher level, and was more persistent in the chicks fed lower levels of linoleic acid. A quadratic relationship was found between tissue linoleic acid or total polyunsaturated fatty acid concentrations and antibody production at 11 and 14 d after challenge. No correlation was found with arachidonic acid. It is concluded that dietary fatty acid composition can influence immune response in broilers.