Effect of maternally supplied n-3 and n-6 oils on the fatty acid composition and mononuclear immune cell distribution of lymphatic tissue from the gastrointestinal tract of suckling piglets.

Fatty acids are essential for immune cell function. Maternal dietary fatty acid supply influences body fat composition of their offspring. As a first step to study immunonutritional interactions at an early age of pigs, four sows were fed a diet containing sunflower oil or oil from seal blubber during pregnancy and lactation. Corresponding piglets were sacrificed at three consecutive time points in the suckling period and their mesenteric lymph nodes and spleen were analysed by gas chromatography for levels of fatty acid. At the same time mononuclear cells of these organs and of the intestinal lymphoid tissue from the jejunum were isolated and subpopulations characterised by flow cytometry. Levels of fatty acids from the lymphatic organs of the piglets were significantly influenced by the maternal diet. The concentration of the fatty acids 20:5n-3, 22:5n-3 and 22:6n-3 were higher in the spleen and mesenteric lymph node of piglets suckled to sows of the test diet. Additionally, suckling time affected the levels of some long chain polyunsaturated fatty acids. Dietary effects were seen on some subpopulations including CD4-CD8alpha+ lymphocytes of the mesenteric lymph nodes and CD4+CD8alpha+ lymphocytes of the lamina propria, which were higher in the group fed seal blubber oil. The levels of CD21+ B-cells were higher in the group fed sunflower oil. The results indicate that the maternal diet and suckling time affect the fatty acid status of the investigated lymphatic tissues of piglets, but may have minor effects on the investigated lymphocyte subpopulations.

Phenotypic and functional aspects of the neonatal immune system as related to the maternal dietary fatty acid supply of sows.

The maternal-fetal transfer and subsequent uptake of sow milk enriched with n-6- or n-3-polyunsaturated fatty acids may not only influence neonatal body fat but may also have an impact on the immune function of newborn piglets. Sows were fed a diet containing sunflower oil as n-6-source or oil from seal blubber with long chain polyunsaturated n-3-fatty acids during pregnancy and lactation. Sow serum was investigated during pregnancy and serum and milk during lactation; piglet serum and liver were investigated in the suckling period until day 19. Piglet leukocyte subpopulations were characterised by flow cytometry and leukocyte proliferation was tested after stimulation with mitogens. No differences were noted in performance. The serum and milk fatty acid status of the sows was markedly influenced by the diet. Eicosapentaenoic acid (20:5n-3), 22:5n-3 and 22:6n-3 were higher (p < 0.001) in serum and liver of piglets delivered from sows fed the seal blubber oil. Piglets at birth had lower lymphocyte counts (p < 0.01) than piglets 19 days after birth. However, no influence of feeding the different oil sources was noted on lymphocyte phenotyping and leukocyte proliferation test. The results of the present study show that the maternal diet affected the fatty acid status of neonates, but much more in the sucking period. Immunological traits were not affected, probably as the mononuclear cell lineage is too immature around birth. Effects of PUFA n-3 might only be seen at a later time point or in the polymorphonuclear cell lineage as they were dominating right after birth.

Effects of feeding sunflower oil or seal blubber oil to horses with recurrent airway obstruction.

A crossover feeding trial was performed with 9 horses suffering from recurrent airway obstruction (RAO). The study aimed to determine whether ingestion of sunflower oil (SFO), rich in linoleic acid, or seal blubber oil (SBO), a source of long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFAs), changes the fatty acid (FA) ratios in plasma and leukocyte membrane phospholipids (PLs) or the leukocyte numbers or proportions of cell types in the airways. We also investigated diet-related changes in respiratory rate, maximum change in pleural pressure (deltaPpl(max)), dynamic compliance (C(dyn)), and pulmonary resistance (RL). Each animal was fed hay and oats supplemented with 320 mg/kg body weight (BW) of either SFO or SBO for 10 wk. Before and after the feeding periods, we performed FA analyses, cytologic testing of the pulmonary epithelial lining fluid (PELF), clinical scoring, and pulmonary function testing. The results demonstrated that supplementary FAs were readily ingested and incorporated into leukocyte cell membranes. The n-6:n-3 FA ratios in plasma and leukocyte PLs were reduced after SBO supplementation, as were the PELF leukocyte counts (P < 0.05). On the other hand, pulmonary function and clinical signs were not markedly changed by the different dietary FAs. These results indicate a possible influence of dietary n-3 PUFAs on the pulmonary inflammation of horses with RAO. Further studies are warranted to address effects on inflammatory mediators and clinical outcome.

High performance liquid chromatography-tandem mass spectrometry of phospholipid molecular species in eggs from hens fed diets enriched in seal blubber oil.

The total lipid fraction of eggs from hens fed diets enriched in seal blubber oil (1.25-5.0% SBO) was directly analysed with normal-phase high performance liquid chromatography coupled on-line with electrospray ionization ion-trap tandem mass spectrometry (HPLC-ESI-MS-MS) for the identification of the molecular species of phospholipids (PLs). The species of phosphatidylethanolamine (PE) and phosphatidylinositol (PI) were all detected as the [M-H](-) ions. The phosphatidylcholine (PC), sphingomyelin (Sph) and lysophosphatidylcholine (LPC) classes, were detected as formate adducts [M+HCOO](-). Tandem MS of PE and PI showed the loss of the carboxylate anions, and, for PI, also the loss of water and inositol. Product ion spectrum of PC, LPC and Sph contained only the [M-CH(3)](-) ion fragment. Feeding different levels of SBO for 5 weeks resulted in a significant increase of PE, PC and PI molecular species carrying eicosapentaenoic acid (C(20:5 omega3), EPA), docosapentaenoic acid (C(22:5 omega3), DPA) and docosahexaenoic acid (C(22:6 omega3), DHA), but not Sph nor LPC. The highest increase of the omega3/omega6 ratio occurred for PE and PC. On the contrary, PI was less affected by the increase of SBO in the diet.

Determination of the carbon deficiency in the flame ionization detector response of long-chain fatty acid methyl esters and dicarboxylic acid dimethyl esters.

Carbon deficiencies (CDs) of long-chain fatty acid methyl esters (FAMEs) and dicarboxylic acid dimethyl esters (DDMEs), which lead to decreased response in a flame ionization detection (FID) system, were determined by using full responding hydrocarbons (heptadecane, eicosane and alpha-cholestane) as references. For saturated FAMEs ranging from C12 to C22 and for DDMEs ranging from C4 to C10, CDs between 1.3+/-0.12 and 1.7+/-0.36 per ester group were recorded. All values were significantly (P < 0.05) greater than 1. Generally, response factors for gas-chromatographic analysis using FID have been calculated on the theory that the CD of FAMEs is 1 per ester group. However, this theory could not be confirmed experimentally for short-chain FAMEs of less than 8 carbons as CDs of around 1.5 were reported for C4 and C6 FAMEs. The study presented here contributes an approach to this problem by confirming the validity of response factors calculated from a CD of 1.5 per ester group as well as for long-chain FAMEs and DDMEs.