Effect of carprofen administration during banding or burdizzo castration of bulls on plasma cortisol, in vitro interferon-[gamma]/production, acute-phase proteins, feed intake, and growth

The objective of this study was to determine the effect of carprofen (C) administration before banding or burdizzo castration of bulls on cortisol, in vitro interferon-[gamma] (IFN-[gamma]) production, acute-phase proteins, feed intake, and growth. Fifty Holstein Friesian bulls (5.5 mo old; 191 [+ or -] 3.7 kg) were blocked by weight and assigned randomly to 1 of 5 treatments (n = 10/ treatment): 1) untreated control (2) banding castration at 0 min (Band); 3) Band following an i.v. injection of 1.4 mg/kg of BW of C at -20 min (Band+C); 4) Burdizzo castration at 0 min (Burd); or 5) Burd following 1.4 mg/ kg of BW of C at -20 min (Burd+C). Castration acutely increased plasma cortisol concentrations compared with control; no significant differences occurred in peak and interval to peak cortisol responses between Band and Band+C or Burd and Burd+C groups. The administration of C in Band+C reduced (P < 0.05) the cortisol concentration between 6 and 12 h postcastration compared with Band animals. Overall, the integrated cortisol response was greater (P < 0.05) in the castrates than in control, whereas C treatments tended to reduce this response compared with Band (P = 0.08) and Burd (P = 0.07), respectively. Plasma fibrinogen was elevated in Band animals on d 14 and in Burd animals on d 3 and 14. Carprofen administration reduced Band- and Burd-induced fibrinogen production on d 14 and 3, respectively. Plasma haptoglobin was elevated in Band animals on d 3 and 35 compared with control, and C adminstration was effective in reducing the haptoglobin elevation on d 35 in Band+C compared with Band. There were no differences among treatments in in vitro IFN-[gamma], production induced by concanavalin A and phytohemagglutinin on d 1 and 2. Overall from d-1 to 16, there were no DMI differences among treatments. From d-1 to 35, there were no ADG differences among treatments. In conclusion, banding and burdizzo castration increased plasma cortisol with no change in in vitro IFN-[gamma] production. Carprofen (1.4 mg/kg of BW) tended to reduce the integrated cortisol response, and it reduced cortisol secretion in banded animals between 6 and 12 h postcastration. There was an increased acute-phase protein production following castration; this response was effectively moderated by the administration of C before castration. Key words: acute-phase protein, carprofen, castration, cattle, interferon-[gamma], stress