Effects of yarding and handling procedures on stress responses of red deer stags (Cervus elaphus)

The aim of the present study was to evaluate the relative stressfulness of different components of typical yarding and close handling procedures on red deer stags. Behavioural observations, remotely collected blood samples and heart rate measures were obtained from undisturbed animals at pasture, during one of three procedures involving yarding, handling and restraint, and after return to pasture, The 'Pen' group (six stags per group) was left undisturbed in an indoor pen for 12 min. The 'Draft' treatment required a handler to enter the pen (twice) and move the animals around. The 'Crush' procedure required animals to be drafted from the group and restrained in a pneumatic drop-floor crush for 2 min. Plasma cortisol, lactate and glucose levels were elevated relative to pre-handling levels after all three handling procedures, with the greatest increases following the Crush treatment. Heart rate and three haematological parameters (haematocrit, red blood cell number and haemoglobin) also increased as a result of the handling treatments, with increases following Draft and Crush being greater than after Pen. Behaviourally, animals exposed to the three handling procedures spent similar total amounts of time standing, walking, grazing and lying upon release back to pasture, but Crush animals began grazing 20-40 min later than the Pen and Draft groups. These data indicate that the three handling procedures examined resulted in perturbations (from levels in undisturbed animals) of measures which are indicators of stress responses. However, given that all measures rapidly returned to resting values, deer wellbeing does not appear to be unduly compromised by such handling practices. The present study again demonstrates the usefulness of remote blood sampling devices for collecting blood from free-ranging flighty animals by eliminating the confounding effects of stress associated with manual blood sampling techniques.