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.

The objective of this study was to determine the effects of castration, with its presumed pain and inflammatory effects, including increased cortisol, and elevated cortisol per se on in vitro interferon-gamma (IFN-gamma) production, ADG, ADFI, and plasma haptoglobin and fibrinogen. Thirty Friesian bull calves (174 +/- 3.8 kg) were assigned to three treatments (given on d 0): 1) control (CON); 2) i.v. cortisol administration to mimic castration-induced increases in cortisol (CORT); and 3) surgical castration (SURG). Blood samples were collected for 12 h on d 0 and at 24 and 72 h after treatment for cortisol determination. Keyhole limpet hemocyanin (KLH)- and concanavalin A (Con A)-induced in vitro IFN-gamma production in blood, and plasma haptoglobin and fibrinogen were measured in blood samples taken before treatment on d 0 and on d 1 and 3. On d 0, CORT and SURG animals had higher peak cortisol (P < .001) and area under the cortisol curve (P < .001) than CON animals. There were no differences (P > .05) between CON, CORT, and SURG animals in cortisol at 24 and 72 h. There were no differences (P > .05) between CON and CORT animals in IFN-gamma production, haptoglobin, fibrinogen, ADG, and ADFI. Compared with CON animals, SURG animals had lower (P < .05) KLH-induced IFN-gamma on d 1 and CON A-induced IFN-gamma on d 1 and 3. Haptoglobin concentrations were greater (P < .05) for SURG than for CON animals on d 1 and 3. Fibrinogen concentrations were greater (P < .001) for SURG than for CON animals on d 3. The SURG animals had lower (P < .01) ADG and ADFI during d 0 to 7 than CON animals. In conclusion, castration decreased IFN-gamma production, ADG, and ADFI and increased haptoglobin and fibrinogen, and these effects seemed to be independent of plasma cortisol concentrations.

No abstract

No abstract

No abstract