Effect of fatty acid composition of the sows’ diet on selected immune parameters of the piglets after weaning S. Millet1, S. Tanghe2, V. Melkebeek3, S. De Smet2, E. Cox3 ¹ILVO (Institute of Agricultural and Fisheries Research), Animal Sciences Unit, 2Laboratory for Animal Nutrition and Animal Product Quality, Department of Animal Production, Faculty of Bioscience Engineering, Ghent University, 3 Laboratory of Immunology, Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University [email protected] Introduction: Environmental exposures early in life are important for health and disease later in life. Nutrition during pregnancy may have a fundamental influence on post natal development. Studies in mice suggest perinatal programming effects of the fatty acid composition of the maternal diet on their offspring's immune response, although different studies yield contradictory results (Lauritzen et al., 2011; van Vlies et al., 2011). Knowledge on the effect of the sows’ perinatal diet on the piglets immunity post-weaning is limited. Therefore, this study aimed to investigate if the immunocompetence of piglets at weaning was modulated by including different sources of n-3 polyunsaturated fatty acids (PUFA) in the gestation and lactation feed of the sow. Animals, material and methods: Thirty-two pregnant sows divided over two weaning groups were fed a palm oil diet or a diet including 1% linseed oil, echium oil or fish oil from day 73 of gestation until weaning at four weeks. All diets were formulated to contain a similar amount of linoleic acid (C18:2n-6; 14 g/kg) and were supplemented with vitamin E (75 mg/kg). Piglets were fed a conventional diet without added n-3 PUFA from weaning until day 35 post-weaning. At weaning and 21 days post-weaning, four piglets per litter were immunized with bovine thyroglobulin. Consequently, thyroglobulin-specific antibodies, and serum amyloid A (SAA) concentration were determined in piglets’ blood at selected time points. Data were analysed with repeated measurements analysis. All experimental procedures involving animals were approved by ILVO’s Ethical Committee. Results and discussion: The onset of the thyroglobulin-specific IgM response differed between dietary groups, with a delay in response for piglets from sows fed the fish oil diet. No significant diet effects were observed on the thyroglobulin-specific IgG and IgA titers. However, in comparison with the echium oil diet, a tendency for lower IgA titers (P=0.08) was observed on the linseed oil treatment. A tendency (P=0.10) to a lower IgG titer was observed for the piglets from the sows fed the linseed oil diet, compared to the palm oil diet. The measured immune responses differed to a larger extent between weaning groups than between dietary treatment groups. Therefore, the observed changes may not be relevant in view of other environmental factors affecting immunity. SAA concentration was highest one day after weaning. It was higher on day 22 than on day 21. It was not possible to observe an effect of maternal diet on SAA concentration (P=0.12). Conclusion: Including n-3 PUFA in the maternal diet at the concentrations used in the present study had no major effects on the measured immune parameters of the piglets after weaning. Other environmental factors may have a larger impact on the adaptive and innate immunity. References: Lauritzen, L., et al. 2011. Maternal intake of fish oil but not of linseed oil reduces the antibody response in neonatal mice. Lipids 46, 171-178. van Vlies, N., et al. 2011. Perinatal programming of murine immune responses by polyunsaturated fatty acids. Journal of Developmental Origins of Health and Disease 2, 112-123.