title: Effect of dietary ascorbyl-2-phosphate on immune function after transport to a feeding facility.
abstract: Effects of dietary ascorbyl-2-phosphate on immune function after a 210-km trip were measured in 18 Holstein heifers. After transport on d 0, 10 g of ascorbyl-2-phosphate each were added to the diets of 10 heifers, whereas eight heifers were fed a control diet. Plasma cortisol concentrations increased by an average of 25.6 microgram/ml on d 0 following transport, but by d 7 after transport had decreased to pretransport levels. Average daily gain was lower in heifers fed ascorbyl-2-phosphate from d 28 to 49 d after transport, but did not differ over the entire study. Feeding ascorbyl-2-phosphate maintained plasma ascorbate concentrations on d 7 post-transport, which decreased in control heifers. Plasma keyhole limpet hemocyanin antibody titers were significantly higher in control heifers from d 7 to 49. Mononuclear leukocyte proliferation responses were decreased on d 0 in lymphocytes stimulated by mitogens, with pokeweed mitogen-stimulated cells showing less of a response than cells stimulated by the other mitogens. In the absence of mitogens, dietary ascorbyl-2-phosphate increased basal 3H-methyl thymidine incorporation by cultured lymphocytes. Across diets and mitogens, lymphocytes treated with cortisol showed decreased 3H-methyl thymidine incorporation. Transportation acted as a stressor, as evidenced by the increased plasma cortisol levels at d 0 immediately after transport, but immunological effects were not apparent by d 7. Feeding ascorbyl-2-phosphate maintained plasma ascorbate concentrations on d 7, but had negative effects on immune responses posttransport.
authors.affiliation: Department of Animal Sciences, Alabama Agricultural Experiment Station, Auburn University, AL 36849, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Tyler
authors.forename: K A
authors.initials: KA
authors.lastname: Cummins
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood; D001835:Body Weight; D002417:Cattle / Q000254:growth & development / Q000276:immunology* / Q000502:physiology; D002455:Cell Division; D002478:Cells, Cultured; D004032:Diet; D005260:Female; D006854:Hydrocortisone / Q000097:blood / Q000494:pharmacology; D007109:Immunity / Q000187:drug effects*; D007074:Immunoglobulin G / Q000097:blood; D007963:Leukocytes, Mononuclear / Q000166:cytology; D008214:Lymphocytes / Q000166:cytology; D008934:Mitogens / Q000494:pharmacology; D014186:Transportation; D015430:Weight Gain
chemical_list: D007074:Immunoglobulin G; D008934:Mitogens; C011669:ascorbate-2-phosphate; D001205:Ascorbic Acid; D006854:Hydrocortisone