Behavioural and heart rate responses to velvet antler removal in red deer

Abstract

Heart rate and behaviour during and following velvet antler removal were monitored in yearling red deer stags to determine the extent to which this procedure was perceived by the deer to be aversive. Nine stags normally kept at pasture were habituated over 5 weeks to the following daily handling procedure. Each deer was fitted with a harness containing a heart rate monitor. It was then allowed to run through a fixed course in a deer yard, restrained for 40 s in a mechanical deer crush, and then confined for 3.5 h with the remainder of the group of stags in an indoor pen containing food and water. In Week 6, the deer were subjected to either restraint for 6 minutes (the control treatment) or removal of one velvet antler under local anaesthesia. Each velvet antler was removed on separate occasions, either on Days 1 and 2 (five deer) or Days 3 and 4 (four deer). The control treatment was applied to all deer when velvet antler was not being removed, and on Day 5. Heart rate and behaviour (time taken to enter the treatment area, and number of struggles made during restraint) were measured before and during treatment, and post-treatment activities were recorded at 0, 1 and 3 h (indoors), and at 6 and 9 h (at pasture). Heart rate was higher during the second velvet antler removal treatment than during the first, but lower during the second control treatment than the first (P<0.05). During velvet antler removal, stags struggled more, and after the treatment flicked their ears, shook their heads, and groomed themselves more than control stags (P<0.05). Stags whose velvet antler had been removed spent less time eating than control stags, and spent progressively more time sitting during the 3.5 h of confinement (P<0.05). However, during the paddock observation at 9 h post-treatment, stags which had had their velvet antler removed grazed more than control stags (P<0.05). The increase in heart rate over the two velvet antler removal treatments and the greater amount of struggling during velvet antler removal indicated that it was more aversive than the control treatment. Post-treatment differences in behaviour may have been due to pain following velvet antler removal.

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

“…Reduced eating and increased lying found in animals kept indoors following velvet removal (Pollard et al, 1992b) were not seen in the present study however. A possible explanation for this difference is that in the present study, animals were released immediately to pasture, as is normal practice.…”

Comparison of analgesic techniques for antler removal in halothane-anaesthetized red deer (Cervus elaphus): electroencephalographic responses

“…1992). Stags respond to painful stimuli applied to velvet antler (Pollard et al. 1992) and scientific evaluation of techniques for antler removal clearly indicates the need for analgesia (Wilson 1989; Matthews et al.…”

Genetics and Behavior During Handling, Restraint, and Herding

“…Parsons and Helphinstine (1969) used a dark box for handling cattle, and Pollard and Littlejohn (1994) and Pollard et al (1992) used a dark room for deer. Deer in a dark room lose their flight zone and can be touched by people.…”