Dietary linoleic acid divergently affects immune responsiveness of growing layer hens

Health and Reproduction Group, Wageningen Institute of Animal Sciences, Wageningen Agricultural University, The Netherlands. john.sijben@genr.vh.wau.nl

The effects of linoleic (LA)- and linolenic acid (LNA)-enriched diets on humoral and in vivo cellular immune responses to keyhole limpet hemocyanin (KLH)-dinitrophenyl (DNP) and Mycobacterium butyricum were studied in growing layer hens. Pullets were fed one of three diets: a control, LA enriched, or LNA enriched. Pullets were assigned to one of three immunization treatments: KLH-DNP, M. butyricum, or PBS. The LA-enriched diet enhanced the antibody response to KLH in pullets immunized with KLH-DNP. On the other hand, the antibody response to M. butyricum in M. butyricum-immunized birds was decreased by feeding an LA-enriched diet. In vitro lymphocyte proliferation in the presence of Concanavalin A was affected by the interaction between diet and immunization. Neither cutaneous hypersensitivity to KLH nor to M. butyricum was affected by the diet. The BW gain before immunization was not affected by the diet, but after immunization, the LA-enriched diet enhanced growth in birds immunized with M. butyricum. Diets had various effects on organ weights. We concluded that dietary linoleic acid enrichment of the diet has an antigen-dependent divergent effect on the antibody response. The dietary LNA effect on the antibody response is less pronounced and is opposite to that of the LA effect.