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Biomedical subjects

C Y Davis

Publications and source records attributed to C Y Davis.

4 recordsLinked to original sources
PubMed1989

Immunoglobulin concentrations in serum and tissues of vitamin A-deficient broiler chicks after Newcastle disease virus vaccination.

The effect of all-trans retinol and retinoic acid (RA) on the local and systemic immune system of broiler chicks was examined. Chicks fed diets supplemented with .2 micrograms retinol/g of diet had significantly greater serum immunoglobulin IgG, IgM, and IgA concentrations 5 wk after primary vaccination with live B1 strain of Newcastle disease virus (NDV) than did chicks fed 2 micrograms retinol/g of diet. Eight days after a second vaccination with an inactivated La Sota strain of NDV, serum, intestinal, and tracheal IgG and IgM concentrations were higher in chicks fed a diet without retinol or retinoic acid (RA) than in chicks fed either 2 micrograms of retinol or RA/g of diet, respectively. Despite an increase in serum immunoglobulin concentration, serum antibody titer in response to the second NDV vaccination was significantly lower in chicks fed a vitamin A-deficient diet than in chicks fed adequate retinol and RA-supplemented diets. Eight days after revaccination, IgA concentrations in bile were also significantly lower in vitamin A-deficient chicks than in controls. Serum IgG, IgM, IgA, biliary IgA, and antibody responses were greater in chicks fed diets supplemented with 2 micrograms of RA/g of diet than in chicks fed an equivalent amount of vitamin A in the form of retinol.

Animals↗
PubMed1986

Influence of cottonseed meal on vanadium toxicity and 48vanadium distribution in body tissues of laying hens.

Hens of two commercial White Leghorn strains were fed diets representing a complete factorial arrangement of 0, 3, or 6 ppm vanadium (V) from dicalcium phosphate and 0 or 5% cottonseed meal (CSM). Test diets were fed for 4 consecutive weeks beginning when hens were 25, 40, 62, or 76 weeks old. After each 4-week treatment period, all hens were fed a diet containing no added V or CSM. Albumen quality (Haugh units) was determined on eggs produced on Days 6 and 7 of each week of feeding the test diets. Three ppm V caused a slight decrease in Haugh units, while 6 ppm V reduced Haugh unit score (HU) by 6 to 15 units when fed to hens 29, 44, or 80 weeks old. The relative influence of V on HU of eggs from 66-week-old hens was less pronounced. The inclusion of 5% CSM in the diet counteracted most of the adverse effects of V on egg quality, irrespective of strain of hens. Egg production and egg weight were not affected by V or CSM. In a second experiment, hens fed diets containing no V + no CSM, 6 ppm V + no CSM, no V + 5% CSM, or 6 ppm V + 5% CSM were given 110 microCi of 48V by oral capsule. Greatest concentrations of 48V were found in bone, kidney, liver, and magnum. Little 48V was detected in whites, and none was found in yolks of eggs produced 2 days after 48V dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1983

Effect of all-trans retinol and retinoic acid nutriture on the immune system of chicks.

The effects of all-trans retinol and retinoic acid (RA) on the humoral and cell-mediated immune response and on lymphoid organ weights of broiler chicks were examined. Chicks were fed diets supplemented with retinol or RA at 0, 0.2 and 2.0 micrograms/g diet. The diets were fed continuously from day of hatch or after depletion of hepatic vitamin A reserves. Rapid vitamin A deficiency was induced in chicks by initially feeding the diet containing 2.0 micrograms RA/g diet and subsequently feeding diets containing 0 or 0.2 microgram RA/g diet. Serum antibody hemagglutination titers, in response to intravenous injection of human serum albumin (HSA), were not affected by level or chemical form of vitamin A supplemented in diets. In vitamin A-deficient chicks, there was an inverse relationship observed between the number of peripheral blood lymphocytes obtained per milliliter of blood and their ability to proliferate in response to mitogenic stimulation. Growth of the bursa of Fabricius and the thymus was impaired in chicks fed a vitamin A-free diet. A partial deficiency of vitamin A adversely affected relative bursa weight but not that of thymus. In general, RA was inferior to retinol in maintenance of lymphoid tissue.

Animals↗