DIETARY SATURATED AND UNSATURATED FATTY ACIDS ON HEPATIC AND SUBCUTANEOUS TISSUES INTERMODULATION, GENE EXPRESSION IN TRANSITION DAIRY GOATS, AND INFLUENCE OF MATERNAL DIETS ON KIDS' IMMUNE RESPONSE

Peripartum is a critically important period for health and production of dairy ruminants that is characterized by marked changes in the endocrine status that can lead to an increase incidence of metabolic and production-related diseases (e.g. NEB) to accommodate parturition and lactogenesis. Some classical efforts to enhance the energy status during transition are relative to the optimization of pre-partum nutritional level by increasing energy density of the diets. The most common practices are partial replacement of grains or forages in the ration with fats sources. On the other hand, dietary fat have peculiar roles in lipid metabolism and organismal defense system. Fish oil has been supplemented in dairy animals often with the aim of enrich animal products with essential fatty acids considered healthy for human. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been able to modulate immune and inflammatory response as observed in vivo and in vitro studies. Also saturated fatty acids (C16:0 and C18:0) can affect lipid metabolism in dairy ruminants. Studies in dairy goats characterizing lipid metabolism in body tissues and the influence of different fat sources are still scant, but diet has effects on the transcription of the major genes involved in fatty acid uptake and de novo synthesis. About the influence of maternal lipid supplementation in diet on newborn animals, studies reported FO supplementing in milk replacer attenuated many aspects of the acute phase response and health in pre-weaned calves. Moreover, feeding calves colostrum from cows fed diets supplemented with saturated fatty acids (SFA) improved transfer of passive immunity. The purpose of the present work is to study the variations of lipid metabolism in periparturient dairy goats supplemented with polyunsaturated (FO) or saturated (ST) fatty acid (1st and 2nd experiment) and their kids’ immune-response (3rd experiment). The first study evaluates immune-metabolic adaptation in periparturient dairy goats fed saturated or unsaturated fat supplement throughout a biochemical and histological approach. Results suggest dietary SFA and PUFA are able to modulate the lipomobilizing machinery. In particular, FO could reduce lipomobilization but, on the other hand, it appeared to have slight more detrimental effects on liver. The second study shows that lipid inclusion in diet could modulate the expression of genes involved in fatty acid metabolism. Differences were found in liver tissue, for genes related to biosynthesis of monounsaturated fatty acids (SCD) and mRNA expression of genes encoding proteins associated with FA oxidation (ACOX1 and ACAA1). In adipose tissue LPIN1, gene involved in TAG synthesis was differentially expressed. The last study shows that fatty acids supplements in goats diet can influence the immune response in newborn kids. The FAs profile of kids’ plasma testifies a sure passage from diets into colostrum and milk. IgA and IgG content report a probably more reactive immune system in animals born from and fed by dams fed saturated fatty acids. Ig’s, neutrophils and monocytes plasma content support the idea that saturated fat dietary supplementation can have a positive effect on passive immunity transfer from goats to newborn kids, and can stimulate the immune system of offspring. Our results point out the importance of lipid supplementation in dairy goats diets on liver and adipose tissues intermodulation, mRNA expression of genes involved in FA oxidation in transition dairy goats and their role in the modulation of immune response in newborn kids.