title: Arginine supplementation increases weight gain, depresses antibody production, and alters circulating leukocyte profiles in preruminant calves without affecting plasma growth hormone concentrations.
abstract: The hypothesis that dietary L-arginine (L-Arg) supplementation would increase growth hormone (GH) secretion and antibody production in preruminant calves was tested. Sixteen newborn calves were randomly assigned to either Arg+ or Arg- treatment groups. Both groups were fed a single dose of Colostrx within 6 h after birth followed by milk replacer twice daily until weaning. Beginning with the Colostrx feeding, calves in the Arg+ group were supplemented with L-arginine at 500 mg kg x BW(-1) x d(-1), and the Arg- group received equivalent, but unsupplemented, diets. All calves were immunized against keyhole limpet hemocyanin (KLH) on d 4 and received a booster vaccination on d 14. The Arg+ treatment increased (P < .05) plasma L-Arg and urea concentrations an average of 2.8-fold and 26%, respectively, during the 4-wk supplementation period. Average daily gain (ADG) of Arg+ calves was increased (P < .10) during wk 1, 3, and 5 of life. The Arg+ treatment depressed (P < .05) total and KLH-specific IgG concentrations in plasma and caused a decrease (P < .01) in circulating leukocyte numbers. Differential counts revealed that the decrease in circulating leukocyte numbers was due to decreases in absolute numbers of lymphocytes, monocytes, and neutrophils. The Arg+ diet did not affect mean plasma GH concentrations during the first 3 wk of life, but GH mean concentrations were decreased (P < .01) during wk 4 due to depressed (P < .10) pulse amplitudes. The decrease in GH mean concentrations during wk 4 was paralleled by lower (P < .10) plasma IGF binding protein-3 concentrations. These data show that supplementary L-Arg does not increase plasma GH concentrations, but it increases ADG, depresses KLH antibody production, and alters circulating leukocyte populations in preruminant calves.
authors.affiliation: Department of Dairy and Animal Science, The Pennsylvania State University, University Park 16802, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Fligger
authors.forename: C A
authors.initials: CA
authors.lastname: Gibson
authors.forename: L M
authors.initials: LM
authors.lastname: Sordillo
authors.forename: C R
authors.initials: CR
authors.lastname: Baumrucker
mesh_terms: D000375:Aging / Q000097:blood / Q000276:immunology / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn / Q000097:blood / Q000254:growth & development* / Q000276:immunology; D000917:Antibody Formation / Q000187:drug effects* / Q000502:physiology; D001120:Arginine / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D002417:Cattle / Q000097:blood / Q000254:growth & development* / Q000276:immunology; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D013006:Growth Hormone / Q000097:blood*; D006433:Hemocyanins / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007962:Leukocytes / Q000166:cytology* / Q000187:drug effects; D008297:Male; D009584:Nitrogen / Q000097:blood; D011863:Radioimmunoassay / Q000379:methods / Q000662:veterinary; D011897:Random Allocation; D014508:Urea / Q000097:blood; D015430:Weight Gain / Q000187:drug effects* / Q000502:physiology
chemical_list: D007074:Immunoglobulin G; D018972:Insulin-Like Growth Factor Binding Protein 3; D014508:Urea; D013006:Growth Hormone; D006433:Hemocyanins; D001120:Arginine; C032808:keyhole-limpet hemocyanin; D009584:Nitrogen