Biological effects of short-term salmon oil administration, using distinct salmon oil sources in healthy dogs.

OBJECTIVES: To assess the short-term effects of feeding distinct salmon oil sources in healthy dogs. METHODS: A diet containing chicken fat as major fat source was fed to 17 dogs for 14 days. For the next 14 days, dogs received one of two diets, both with 1% of chicken fat exchanged for 1% salmon oil; Norwegian or Scottish salmon oil, harvested using a distinct procedure. Finally, all dogs were fed chicken fat again for 14 days. RESULTS: Salmon oil increased serum phospholipid total n-3 polyunsaturated fatty acids, eicosapentaenoic and docosahexaenoic acid and decreased total n-6 polyunsaturated fatty acids and n-6:n-3. The phospholipid fatty acid profile returned to initial values within 2 weeks of discontinuing salmon oil administration. Blood coagulation, acute phase response and plasma immunoglobulin concentrations were not affected by salmon oil and no differences were detected for the measured indices between the two salmon oils. CLINICAL SIGNIFICANCE: Low-dose salmon oil administration alters serum phospholipid fatty acid profile within 2 weeks, but without affecting selected immunologic and coagulation indices. Salmon oil sources from different sources and harvested using a distinct procedure did not induce different effects, most probably because of their similar fatty acid profiles.

The effect of vitamin C supplementation in healthy dogs on antioxidative capacity and immune parameters.

The aim of the study was to investigate the ability of vitamin C to increase the antioxidative and immunomodulating potential in healthy dogs. Fifteen dogs were tested for the effects of orally administered vitamin E (60 mg dl-alpha tocopheryl acetate) in combination with vitamin C (0, 30 or 60 mg ascorbic acid crystalline). Three treatments (0, 30, 60 mg vitamin C) were tested in a 3 x 3 cross-over study in three periods of 36 days. Pre-prandial blood samples were taken for analysis of vitamins C, E, A, retinyl palmitate and stearate, antioxidant status [Thiobarbituric acid reactive substances (TBARS) and uric acid], biochemical and haematological analysis. Subpopulations of lymphocytes, mitogen-induced peripheral blood mononuclear cell proliferation (PBMC) and serum IgA and IgG concentrations were determined. There was a trend (p = 0.056) for an increased plasma vitamin C concentration by vitamin C supplementation. There was no evidence that dietary treatment altered neither the other plasma vitamin concentrations nor TBARS and uric acid concentrations nor the subpopulations of the lymphocytes except for the number of CD4+ lymphocytes that increased with vitamin C supplementation. There was no effect of vitamin C on serum IgA and IgG concentration. A significant time x treatment interaction was demonstrated on PBMC's to pokeweed, with an increase observed by 30 mg vitamin C supplementation but a decrease by 60 mg vitamin C supplementation. There was no clear evidence for an effect of dietary vitamin C on antioxidative capacity in healthy dogs fed a diet with vitamin E concentrations well above the recommendations. Yet, a limited number of immunological parameters were slightly affected.

In vitro effects of alpha toxin from Clostridium perfringens on the electrophysiological parameters of jejunal tissues from laying hens preincubated with inulin and N-acetyl-L-cysteine.

The present report demonstrates the effect of alpha toxin from Clostridium perfringens on electrophysiological indexes of jejunal mucosa from laying hens pretreated with inulin and N-acetyl-l-cysteine (ACC), a mucolytic agent. In a first set of experiments, the effect of alpha toxin with or without pretreatment with ACC on the electrophysiological parameters was determined when jejunal tissues from laying hens were mounted in Ussing chambers. The short-circuit current remained unchanged when alpha toxin was added mucosally in the tissues whether pretreated with ACC or not. The change in the transmural tissue conductance (DeltaGt) was higher (P = 0.18) after 90 min exposure of toxin independent of pretreament with ACC. The effect of alpha toxin on DeltaGt became significant (P < or = 0.05) after 120 min of incubation. In the second set of experiments, the effect of alpha toxin on the jejunal tissues preincubated with inulin (0.1%) was investigated. The effect of toxin was also time dependent, and DeltaGt became significantly higher (P < or = 0.05) after 120 min of incubation independent of preinubation with inulin. Inulin did not influence the DeltaGt during the experimental period when compared with control tissues. In conclusion, alpha toxin from C. perfringens can impair the intestinal mucosal barrier. The effect is obviously not dependent on the presence of a mucolytic agent nor can it be affected by direct addition of inulin under in vitro conditions. Whether there is an effect of inulin after long-term supplementation in feeding trials or it is due to fermentation bacterial metabolites remains an open question.

Effect of oregano (O. majorana x O. vulgare) on performance and antioxidative capacity of quails fed a diet rich in omega3 fatty acids.

Oregano possesses high antioxidant activity and could therefore be used to enhance oxidative stability of eggs high in omega3 fatty acids. In this study, 20 female quails were fed a diet containing 4% linseed oil. They were divided into two groups, one receiving oregano, and the other grass meal as control (2% respectively). Cholesterol oxidation products were analysed in fresh eggs, in stored eggs and in the livers. Trolox equivalent antioxidative capacity of plasma was measured. No significant differences were seen between the groups.

Effects of dietary inulin on the intestinal short chain fatty acids and microbial ecology in broiler chickens as revealed by denaturing gradient gel electrophoresis.

Inulin can stimulate the growth of the intestinal bacteria as well as alter the ratio among various short chain fatty acids (SCFA) produced. In the present study, we analyzed the effect of dietary inulin on the intestinal bacterial community as determined by denaturing gradient gel electrophoresis analysis of universal 16S rDNA after amplication with PCR and SCFA profile. Broilers were fed a diet primarily composed of corn-soybean meal or same diet with 1% inulin for 42 d. The relative weight of digesta-filled ceca of the inulin-fed group was higher (P<0.01) than in the control group. Amongst SCFA, only acetate could be detected in the jejunal digesta, which tended to be higher (P=0.09) in inulin-fed group compared with the control group. Inulin did not affect the total concentration of SCFA in the cecal digesta. The relative proportion of n-butyrate was elevated (P=0.05) with a concomitant decrease in the concentration of n-valerate (P<0.05) in the inulin-fed group compared with the control group. Dietary inulin did not affect the number of PCR-denaturing gradient gel electrophoresis bands nor their diversity in the jejunal and cecal digesta. Intragroup similarities were not different between the groups, nor were any differences between intra-and intergroup similarities in the jejunal and cecal samples. In conclusion, inulin altered the cecal microbial metabolic activity without any major impact on the composition of intestinal bacterial communities as measured by the present techniques.