The relation between maternal fat intake and the immune system of the offspring has not been studied extensively in pigs. Therefore, this study was designed to determine the effect of different maternal dietary omega-3/omega-6 consumption on the composition of leukocyte populations, on leukocyte stimulatory capacity and the fatty acid status of their piglets.
4 gilts were fed a diet containing 3 % sunflower or seal oil from the onset of pregnancy and a diet containing 5 % seal or sunflower oil during lactation. Zootechnical performance was recorded, sows´ serum and colostrum/milk were analysed for fatty acids and the leukocyte populations were characterized by flow cytometry. Piglets were sampled after birth before colostral uptake, 24 hours post natum (p.n.), 10 and 19 days p.n.. Tissue samples were analysed for fatty acids and by flow cytometry (FCM) for phenotyping leukocytes. For the analyses of leukocyte populations three colour stainings with monoclonal antibodies against CD21, SWC3, and MHC II, as well as CD4 and CD8, were performed.
Additionally, lymphocytes were stimulated using Concanavalin A, Phytohaemagglutinin and Pokeweed mitogen in proliferation tests. ELISA technique was used for the estimation of macromolecule uptake by the piglets within the first 12 hours p.n..
No difference in birth weight and weight gain was recorded between the two groups. The serum and colostrum/milk fatty acid status of the sow was markedly influenced by the diet. The serum and liver as well as the lymphatic tissues of piglets born from sows fed seal oil had higher EPA, DPA and DHA concentrations. ARA was always lower in the serum and organs of piglets from sows fed seal oil but no enrichment of EPA at the expanses of ARA could be observed until the last third of the suckling period.
The composition of leukocyte populations was influenced by age but not by feeding. The proportion of CD21+ B cells, CD8+ T cells and the CD4+CD8+ T-lymphocyte subpopulation did increase whereas CD4+CD8- T cells decreased slightly with time. The high coexpression of MHCII on SWC3 positive cells was probably due to immunological experience with foreign antigens. Finally there was no difference in the lymphocyte proliferation test and the uptake of intact bovine serum albumin between piglets born to sows fed either seal oil or sunflower oil.