Cheryl F. Nockels

Protection of Chicks Against E. coli Infection by Dietary Supplementation with Vitamin E

Summary Dietary supplementation of 150–300 mg vitamin E (dl-α-tocopheryl acetate)/kg gave increased protection against a relatively moderate (25–30% mortality) E. coli infection. A correlative 2-3-fold increase in log2 antibody titer against the E. coli indicates that increased chick survival was in part immunologic. We thank Hoffmann La Roche, Inc., for supplying the vitamin E and for the vitamin E assays of the diets.

Vitamin E, Immunity and Disease Resistance

The effect of vitamin E on immune responses and disease resistance is now well established and has been covered in recent reviews (Axelrod, 1978; Nockels, 1978; Sheffy and Schultz, 1979; Tengerdy, 1978). Predictably, vitamin E ([dl])-α-tocopheryl-acetate) deficiency leads to impaired immune response and disease protection (Axelrod, 1978). Large doses of vitamin E, much larger than the presently accepted recommended minimal daily allowance, on the other hand, enhance certain immune responses and can lead to increased disease resistance in a number of animal species against a variety of infectious agents. Table I. illustrates this point.

Antioxidants improve cattle immunity following stress

Abstract Free radical and nonfree radical oxidants can produce damaging effects in animal tissues if antioxidants are deficient. These oxidants are produced during metabolism and may be substantially increased by aerobic exercise, stress, tissue injury, infection, and detoxification of many compounds. Stress may precede an infectious episode in animals by decreasing antioxidants needed later by an active immune response. Antioxidant nutrients such as vitamin E, β-carotene and the trace elements selenium, copper, zinc and manganese in enzymes are very important in protecting an animals tissues from oxidative destruction. This protective benefit also results in an improved immune response which decreases mastitis in dairy cows and infectious disease incidences arising in stressed cattle following shipping. The amount of nutrients needed for immunoenhancement is higher than the suggested required amounts by NRC.

Effect of beta carotene on disease protection and humoral immunity in chickens.

The effect of beta carotene on disease protection and humoral immunity in chickens was investigated in comparison with the effect of other lipid-soluble antioxidant vitamins, vitamin E and A, which are both proven immunoenhancers and contributors to disease protection. Beta carotene alone was not as effective as either vitamin in protecting chickens from Escherichia coli infection, nor did it significantly enhance humoral immunity. In combination with vitamin E, however, beta carotene significantly increased disease protection and reduced hepatomegaly caused by E. coli infection.

THE EFFECT OF VITAMIN E ON PROSTAGLANDIN LEVELS IN THE IMMUNE ORGANS OF CHICKS DURING THE COURSE OF AN E COLI INFECTION

Abstract The effect of dietary vitamin E supplementation on prostaglandin levels in the bursa and spleen of E. coli infected chicks was studied in two separate but similar experiments. In the first experiment Single Comb White Leghorn chicks were fed either a control diet (adequate in vitamin E) or a supplemented diet (containing an additional 300 IU per kilogram) and sacrificed at 21 days at several time points after infection. Infection had its maximum effect on PGE 2 and PGF 2α at 1 to 4 h post infection in the spleen and 24 to 48 h in the bursa. Vitamin E reduced PGF 2α levels in bursa but not in the spleen. In the second experiment the use of broiler chicks provided enough tissue to also determine thromboxane B 2 and 6-keto PGF 1α levels. Broiler chick bursa levels of PGE 2 , PGF 2α , 6-keto PGF 1α and thromboxane B 2 were depressed by vitamin E supplementation whereas only PGF 2α was decreased in the spleen. Infection resulted in increased levels of PGE 2 , PGF 2α and thromboxane B 2 in the spleen but not in the bursa.

The Role of Vitamins in Modulating Disease Resistance

Many of the metabolic incursions resulting from stress and oxidative damage are detrimental to disease resistance. Vitamins A, E, and C and carotenoids are able to protect cells from free radical oxidation, reduce the detrimental effects of certain eicosanoids, and enhance humoral and cellular immune responses in disease. The regulation of cell differentiation by vitamin A in maintaining an epithelial barrier to pathogen entry and the differentiation of precursor cells to functional lymphocytes by 1,25-dihydroxycholecalciferol are essential to disease resistance. Nutritionists must redefine the levels of vitamins necessary to maximize health-supportive systems. The animals metabolism must constantly be adjusting to its environmental stress or disease and may require increased vitamins.

The Influence of Supplemental Vitamins A and E on Ovine Humoral Immune Response

These experiments determined if supplemental vitamins A and/or E would enhance ovine antibody responses. All-rac-α-tocopheryl acetate was fed to lambs approximately 6 months old (30 to 40 kg) at levels of 33 (controls), 121, 276, 396, and 476 mg/kg of feed (which are total vitamin E levels). Primary and secondary immunizations with 10 mg keyhole limpet hemocyanin (KLH) were given. A nonlinear dose response of serum antibody titers was observed and the 476 mg vitamin E/kg treatment significantly enhanced (P < 0.05) the peak primary response over controls. Retinyl acetate fed at five levels ranging from 7000 (the control level) to 97,400 IU/kg feed failed to influence antibody production to 10 mg KLH of lambs about 6 months old (29 to 41 kg). There was no detectable response to an ovalbumin antigen (100 mg). Neonatal lambs were injected with retinyl palmitate or the carrier of the injected vitamin. These lambs failed to raise antibody titers to either of the antigens administered (10 mg KLH, 100 mg ovalbumin). This was apparently due to a neonatal period of immune paralysis to certain antigens. A preliminary study showed that no KLH-specific antibodies are detectable in lambs immunized earlier than 7 weeks of age. Lambs in this age range were utilized in the last trial in which four treatments were applied: 3000 mg oral vitamin E, 400,000 IU injected vitamin A, 4 ml of the injectable vitamin A carrier, or no treatment. Half of the animals in each of these groups were immunized with 15 mg KLH and 1 ml Brucella ovis bacterin and the other half served as nonimmunized controls. No significant differences in titers to KLH were observed. Lambs receiving 3000 mg vitamin E or the carrier produced secondary peak anti-B. ovis titers higher (P < 0.05) than those of the untreated controls.

Starch digestion and digesta kinetics in the small intestine of steers fed on a maize grain and maize silage mixture

Abstract An attempt was made to overcome incomplete starch digestion in the small intestine of ruminants by exogenous amylase and/or sodium bicarbonate additions into the small intestine of steers fed on a diet of 60% cracked maize grain and 30% maize silage. Four Hereford × Angus steers were cannulated in the rumen, duodenum, jejunum and ileum. Ytterbium-marked maize was given daily and a liquid phase marker, Cr-EDTA, was infused into the rumen continuously. Treatments (amylase, bicarbonate, amylase plus bicarbonate or distilled water) were individually infused into the jejunal cannula at an average rate of 190 ml day−1 for four 7-day periods in a 4 × 4 Latin square design. Duodenal and ileal composite samples were analyzed for dry matter (DM), starch and marker contents to determine ruminal and small intestinal digestibility. Digesta kinetics for the small intestine indicated that the particulate and liquid phases flowed together with little separation. The pH of the duodenal, jejunal and ileal digesta prior to any treatment infusions averaged 2.5, 4.8 and 7.3, respectively. Starch flow to the small intestine averaged 1000 g day−1 with 350 g passing to the large intestine. Nutrient digestibility was not affected by the infusion treatments. The results were interpreted to suggest that amylase and probably digesta pH are not the first limiting factors in the digestion of maize starch in the small intestine of cattle adapted to starch diets.

The effect of age on water metabolism in hens.

Summary Kinetic parameters associated with the body water pool were studied in hens of two age brackets by Isotope Dilution Techniques using tritium-labeled water. The half-life of body water was found to be significantly longer (p < 0.05) in hens than in pullets. It is probable that the difference is due to an increased utilization of body water by the younger birds for their greater anabolic demands. Total body water, expressed as percent of body weight, was significantly higher (p < 0.01) in the pullets than in the hens. The lower water content of the hens appears to be due to a decrease in intra- and extracellular body water with age as previously suggested for mammals. Additionally, the greater fat mass of the older birds may be contributing to the results observed.

Body water kinetics in vitamin A-deficient chickens.

Summary The effect of mild vitamin A deficiency on kinetic parameters associated with the body water pool was studied in five-month-old pullets by isotope dilution techniques, using tritium-labeled water. The body water T 1/2 was significantly shorter (p < 0.01) and the flux through the body water pool greatly increased (p < 0.01) in the A-deficient chicks indicating that even under mild vitamin A deficiency, water turnover rates are significantly altered. These changes appear to be due to alterations in the stability and permeability of the cells involved in water transport in the A-deficient chicken, through mechanisms yet to be elucidated.