The behavioural and physiological responses of farmed red deer ( Cervus elaphus) penned adjacent to other species

The experiment describes the implications of red deer ( Cervus elaphus) being kept in pens in close proximity to other species as may occur during abattoir lairage. Twenty groups of five male yearling red deer were used to study behavioural and physiological responses over a 2-h period to one of five treatments: red deer penned adjacent to either an empty pen, unfamiliar red deer, cattle or pigs, and red deer which had previously been exposed to cattle (previously grazed adjacent to cattle) penned adjacent to cattle. Alert behaviour was significantly affected by treatment and groups of red deer penned next to cattle spent more time being alert than when next to unfamiliar red deer (0.68 vs. 0.32 scans; P < 0.05). Red deer next to cattle or pigs tended to spend less time idling than when next to an empty pen and engaged in more agonistic interactions over a 2-h period (15.6 and 22.8 vs. 6.1 interactions per deer respectively; P < 0.001). When next to cattle or pigs, less lying was observed than when next to unfamiliar red deer and red deer were less dispersed in the test pen, spending more time in areas furthest away from the alternative species than in areas closest to them ( P < 0.001). Heart rates of red deer penned next to cattle (70.3 beats per min (bpm)), pigs (77.5 bpm) and unfamiliar red deer (72.1 bpm) were not significantly different. Red deer previously exposed to cattle and penned next to cattle and red deer penned next to pigs had higher heart rates than those penned next to an empty pen (79.1 and 77.5 vs. 67.3 bpm; P < 0.01 and P < 0.05 respectively). Plasma cortisol concentrations in samples collected at 20-min intervals, using a remote blood sampling system (two replicate groups of five deer per treatment), were higher in red deer penned next to unfamiliar red deer (69.8 nmol l −1) than in the other treatments (mean values between 33.0 and 53.1 nmol l −1; P < 0.001). Total lactate dehydrogenase activity was significantly affected by treatment P < 0.01) and was greatest in red deer next to unfamiliar red deer (599 IU l −1) but there was no treatment effect on LDH5 isoenzyme activity. It was concluded that there was some evidence to suggest that previous exposure to cattle made red deer exhibit more aversion to cattle when subsequently penned adjacent to them and that pigs appeared to be more aversive to the red deer than cattle.