title: Effects of suppressing cortisol following castration of bull calves on adrenocorticotropic hormone, in vitro interferon-gamma production, leukocytes, acute-phase proteins, growth, and feed intake.
abstract: The objective was to determine the effects of reducing the plasma cortisol rise in calves following castration on plasma ACTH concentrations, keyhole limpet hemocyanin (KLH)- and concanavalin A (Con A)-induced in vitro interferon (IFN)-gamma production, white blood cell (WBC) numbers, neutrophil:lymphocyte (N:L) ratio, plasma haptoglobin and fibrinogen concentrations, ADG, and ADFI. Forty 5-mo-old Friesian bull calves (169 +/- 1.7 kg) were assigned to four treatments: 1) control (CON); 2) oral metyrapone administration (MET); 3) surgical castration at 0 h on d 0 (SURG); and 4) oral metyrapone administration and surgical castration (MET+SURG). Cortisol, ACTH, IFN-gamma production, haptoglobin, fibrinogen, ADFI, and ADG were not different between CON and MET animals. The MET+SURG calves had lower (P < .001) peak and mean cortisol during .25 to 1.5 h than SURG animals, but area under the cortisol vs time curve from 0 to 12 h did not differ (P > .39) between SURG and MET+SURG calves. Peak ACTH concentrations and area under the ACTH vs time curve from 0 to 6 h were greater (P < .05) for MET+SURG than for SURG calves. There were no differences between MET+SURG and SURG animals in IFN-gamma production, WBC numbers, and ADFI. On d 1, MET+SURG and SURG animals had lower (P < .01) KLH- and Con A-induced IFN-gamma production and higher (P < .05) neutrophil numbers and N:L ratio compared with CON animals. Plasma haptoglobin on d 1 and 3 and fibrinogen concentrations on d 3 and 7 were elevated (P < .05) for MET+SURG and SURG compared with CON animals, whereas SURG animals had greater (P < .05) haptoglobin and fibrinogen concentrations than MET+SURG animals on d 7. The ADG of SURG calves was lower (P < .05) than that of MET+SURG calves during d 0 to 7. Metyrapone treatment partially suppressed cortisol and increased ACTH in castrated calves but did not alter the castration-induced suppression of IFN-gamma and increases in neutrophil numbers and the N:L ratio.
authors.affiliation: Teagasc, Grange Research Centre, Dunsany, Co. Meath, Ireland.
authors.forename: A D
authors.initials: AD
authors.lastname: Fisher
authors.forename: M A
authors.initials: MA
authors.lastname: Crowe
authors.forename: E M
authors.initials: EM
authors.lastname: O'Nualláin
authors.forename: M L
authors.initials: ML
authors.lastname: Monaghan
authors.forename: D J
authors.initials: DJ
authors.lastname: Prendiville
authors.forename: P
authors.initials: P
authors.lastname: O'Kiely
authors.forename: W J
authors.initials: WJ
authors.lastname: Enright
mesh_terms: D000209:Acute-Phase Proteins / Q000032:analysis / Q000378:metabolism*; D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000704:Analysis of Variance; D000818:Animals; D002417:Cattle / Q000097:blood* / Q000254:growth & development / Q000502:physiology; D003208:Concanavalin A / Q000494:pharmacology; D004435:Eating / Q000502:physiology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary; D005340:Fibrinogen / Q000032:analysis / Q000378:metabolism; D006242:Haptoglobins / Q000032:analysis / Q000378:metabolism; D006433:Hemocyanins / Q000276:immunology / Q000378:metabolism; D006854:Hydrocortisone / Q000097:blood* / Q000502:physiology; D007371:Interferon-gamma / Q000097:blood*; D007958:Leukocyte Count / Q000662:veterinary; D007962:Leukocytes / Q000166:cytology*; D008297:Male; D008797:Metyrapone / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology; D009919:Orchiectomy / Q000009:adverse effects / Q000662:veterinary; D013997:Time Factors
chemical_list: D000209:Acute-Phase Proteins; D000276:Adjuvants, Immunologic; D006242:Haptoglobins; D003208:Concanavalin A; D007371:Interferon-gamma; D005340:Fibrinogen; D000324:Adrenocorticotropic Hormone; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin; D006854:Hydrocortisone; D008797:Metyrapone