Behaviour of red deer following antler removal with two methods of analgesia

Abstract

This study examined the effect of two different methods of analgesia on behavioural responses to velvet antler removal in red deer. Specifically, behaviour during the first 7 h after antler removal using compression (C, latex band around the pedicle) or lignocaine (L, 2% lignocaine hydrochloride) analgesia was compared with controls (R, restraint only). The frequencies of ear flicking, tongue flicking, yawning, head shaking, grooming and scratching were all higher following antler removal (C + L) than restraint only ( P < 0.05). The only overall difference between analgesia methods was for head rubbing which was higher after antler removal with L than with C ( P = 0.05). There were differences between compression and lignocaine in the hourly pattern of behavioural changes following antler removal. On an hourly basis, ear flicking was higher in C than L at hour two ( P = 0.006) then higher in L than C at hours six and seven ( P < 0.01). Tongue flicking was higher in C than L at hour one ( P < 0.05). Grooming and yawning were higher in L than C at hour one ( P < 0.05) and head rubbing was higher in L than C at hour six ( P < 0.01). Agonistic behaviour was higher in R at hour three ( P < 0.05). There were no differences in scratching, standing, walking, stepping, running, eating and lying between groups, however; all showed a time trend ( P < 0.01). Eating peaked at 3 h, lying showed the main increase throughout the period, although there was also an increase in running in the last 2 h. Panting, standing, stepping and walking all decreased with time. In summary, behavioural indications of pain or irritation increased following antler removal with analgesia and had mostly disappeared by 7 h. The hourly pattern of behavioural changes following antler removal indicate differences in the time course of pain or irritation between methods of analgesia. Overall behavioural differences between animals receiving either compression or lignocaine analgesia provide little evidence for a difference in post-surgical welfare between these two methods.