Effects of the method of restraint for shearing on behaviour and heart rate variability in alpacas.

@enAlpacas are increasingly kept in Europe for different purposes including fibre production. Yearly shearing is necessary to harvest fibre and for welfare reasons. Different methods of restraint are used during shearing, which may affect the welfare of the animals differently. The aim of the study was to compare three common restraint methods: Standing, the animal is standing and held by hand; Ground, the animal is laid down and its legs are tied up and stretched out by ropes; Table, the animal is restrained on a special table, legs are tied up by ropes. We recorded behaviour continuously during restraint and, afterwards, at 10-min intervals from 30-120 min in alpacas sheared during restraint (ExpRS, 45 animals, 15 animals per treatment) or only restrained (ExpR, 15 animals, repeated measures). HRV and HR was measured in ExpR. Large individual variation was found, especially in ExpRS. One Standing animal in ExpRS could not be shorn due to strong defence reactions. During restraint, fewer Standing animals vocalised in ExpRS (p=0.07) and showed least flinching in both experiments (p < 0.05), but showed leg movements (such as stepping, kicking, leg twitches, escape attempts) more often (p < 0.001). After restraint, Standing animals showed or tended to show more lying, ruminating (ExpRS) or feeding (ExpR) and less agonistic (ExpRS) or affiliative interactions (ExpR) (p < 0.05 to p < 0.1 for all), although both tie up treatments did not always differ. Accordingly, HRV (SDNN) was higher in Standing compared to Table. Differences between Ground and Table were rare, in contrast to Ground all Table animals vocalised during shearing; in ExpR Table animals showed more often flinching during restraint (both p < 0.05) and tended to move legs and to vocalise more compared to Ground. In sum results indicate that Standing is the least aversive method with the shortest duration of the whole procedure and thus should be preferably used. However, shearing can induce strong reactions in some of the animals independent from treatment which may preclude shearing in those animals when standing. Habituation to handling procedures should be used to reduce stress and avoid the necessity for more invasive restraint. Effects of Ground and Table might depend on the exact body position which should be investigated further.

Veterinärmedizinische Universität Wien