Behavioural and physiological responses of calves to dehorning by heat cauterization with or without local anaesthesia

Abstract Behavioural and physiological reactions to thermal dehorning were studied in separate groups of 4- to 6-week-old calves after injection of a local anaesthetic (A), after saline injection (S), and without any injection (C). To assess the physiological responses, blood was collected from a jugular catheter from each calf of the physiology groups A ( n =8), S ( n =8), and C ( n =7) prior to and for 4 h after injection and dehorning, which occurred 20 min after the injection. Behavioural reactions during dehorning were video-recorded. For the next 4 h thereafter, behavioural data were recorded by visual observations in the behaviour groups (A: n =10, S: n =10, C: n =10). Two days prior to the actual dehorning, the complete procedure was simulated in all calves. Compared to simulation, dehorning C-calves induced increased frequencies of tail wagging (3.5±0.5 [mean±SEM] vs. 1.5±0.5; P P P P P