Effect of knife castration on leukocyte cytokine expression and indicators of stress, pain, and inflammation in Korean cattle bull calves

Abstract

Objective: This study investigated the effects of surgical castration on behavior, physiological and inflammatory indicators, and leukocyte cytokine mRNA levels in Korean cattle bull calves.Methods: Nineteen Korean cattle bull calves (average body weight, 254.5 kg; average age, 8.2 months) were divided into two treatment groups: control (n = 9) and castration (n = 10). Surgical castration was performed using Newberry knives and a Henderson castrating tool. Blood was obtained just before castration (0 h) and at 0.5 h, 6 h, 1 d, 3 d, 7 d, and 14 d after castration. Plasma cortisol (PC), saliva cortisol (SC), plasma substance P, and plasma haptoglobin concentrations, and the leucocyte mRNA levels of the interleukin-1-alpha (<i>IL1A</i>), interleukin-1-beta (<i>IL1B</i>), interleukin-1 receptor antagonist (<i>IL1RN</i>), and interleukin-6 (<i>IL6</i>) genes were analyzed.Results: Castration decreased (p<0.01) the average daily gain and gain/feed ratio. Castration reduced the time spent eating (p<0.001) and the eating frequency (p<0.01) and increased (p<0.001) the lying frequency. Castration temporarily increased (p<0.05) circulating PC and SC concentrations at 0.5 h after castration. Castration temporarily increased (p<0.05) plasma substance P concentrations at 1 d after castration. Castration increased (p<0.05) plasma haptoglobin concentrations at 1 and 3 d after castration. Castration increased (p< 0.05) leukocyte mRNA levels of the <i>IL1A, IL1B, IL1RN</i>, and <i>IL6</i> genes at 6 h after castration.Conclusion: Castration temporarily induced stress and expression of leucocyte inflammatory cytokine genes in Korean cattle bull calves.