Burdizzo castration of calves less than 1-week old with and without local anaesthesia: Short-term behavioural responses and plasma cortisol levels

Castration of calves over 3 weeks of age is considered a painful procedure. It is less clear whether and how much pain is caused by this procedure in very young calves. The aim of the present study was to determine the short-term pain response of 30 calves less than 1-week of age to Burdizzo castration with and without local anaesthesia. The Burdizzo technique is considered to be the most humane method of castration in calves.Twenty minutes before castration, 10 ml lidocaine (n = 10), bupivacaine (n = 10) or saline solution (n = 10) was injected into both spermatic cords and distributed subcutaneously in the scrotal neck. Behaviour of the calves and response to local palpation was assessed on the day before and after castration during 8 h periods. Plasma cortisol levels were determined on the day of castration.The struggling behaviour exhibited by the calves during castration and their response to local palpation of the spermatic cords indicated that the procedure was painful. Nevertheless, postures and behavioural elements thought to be associated with pain were not readily apparent after castration in the majority of calves. The pain caused by injection of the anaesthetic was considered minimal. Local anaesthesia reduced the immediate pain response during castration as evidenced by less struggling during castration and lower cortisol levels. However, some calves struggled during the procedure and had distinct pain-indicating signs afterward. There was no apparent difference between the analgesia afforded by lidocaine and bupivacaine.