J.C. Pollard

Effects of isolation and mixing of social groups on heart rate and behaviour of red deer stags

The effects of visual and spatial isolation from other deer (Experiment 1), and of mixing with unfamiliar deer (Experiment 2) on the behaviour and heart rate of 16 yearling red deer stags were measured. In each experiment, the deer were initially confined in an indoor pen for 1 min in the presence of two handlers and two familiar stags (Stage I), then given two successive treatments for 1 min (Stages II and III). In Experiment 1, treatments in Stages II and III were confinement in isolation from deer and humans (Treatment IS), and confinement with the two familiar stags (Treatment GP). Eight deer received Treatment IS then Treatment GP and eight received Treatment GP then Treatment IS. Heart rate was higher during Treatment IS than Treatment GP, and deer made more steps, nosed and made head movements at the perimeters of the enclosure more frequently than during Treatment GP (P < 0.05). In Experiment 2, treatments in Stages II and III were confinement in the presence of five familiar stags (Treatment F) and confinement in the presence of five unfamiliar stags (Treatment S; five yearling stags or five 2-year-old castrated stags). Heart rate was higher during Treatment S than Treatment F, and the deer stepped and nosed enclosure perimeters more during Treatment S. In addition, deer received or instigated aggressive interactions more frequently during Treatment S than Treatment F, and groomed themselves less (P < 0.05). The increases in heart rate and changes in behaviour indicated that social isolation and mixing with unfamiliar deer were stress-ful to red deer. The responses to the acute social stimuli used in the study could be useful in identifying other social stressors experienced by deer during handling.

Quantification of temperament in weaned deer calves of two genotypes (Cervus elaphus and Cervus elaphus × Elaphurus davidianus hybrids)

Two experiments were carried out on farmed deer calves at weaning (at 3–4 months of age) to compare individual temperament. In Experiment 1, 30 male red deer calves were confined indoors in groups of 15. On Days 1–27 following weaning they were subjected to the following tests: time taken to feed in the presence of a human (n=15 trials); time taken to sniff a novel object (n=5 trials); drafting order (n=8 trials); aggression during feeding (n=3 trials); isolation in a novel pen with and without a human; individual confinement (n=5 trials). Individual rangkings within groups within the same type of test revealed some consistency in individual behaviour. Principal components analysis indicated behavioural variability in fear of humans and exploratory behaviour. In Experiment 2, 22 red deer×Pere David deer and 34 red deer calves were tested in pairs of the same genotype, on either Day 1 or Day 2 after weaning. Each pair was confined for 20 min in an unfamiliar pen, with a stationary human in the pen during the last 10 min of the test. Hybrid calves showed a tendency to avoid the human more and to be less active in the presence of the human compared with red deer calves. This tendency was significant for nosing activities directed at the walls and floor of the pen (P<0.05). Principal components analysis indicated that the genotypes differed most in their nosing frequency and mobility within the pen, with hybrid calves nosing less than red deer at the same level of mobility. Thus both experiments indicated variability in the degree to which deer calves avoided humans and exhibited exploratory behaviour in new surroundings.

Behaviour and weight change of red deer calves during different weaning procedures

Two studies were carried out to examine the effectiveness of confinement indoors and the presence of adult hinds in reducing stress in farmed red deer calves separated from their dams for weaning at 3–4 months of age. In a preliminary pilot trial, 30 male and 30 female calves were weighed and randomly allocated to five groups of 12 animals (six males and six females). Each group was assigned to a different treatment: not weaned, or weaned and then confined in a paddock or indoors for 7 days, with or without two hand-reared hinds added to the group of calves during confinement. Activities observed over 5 days following weaning differed between the groups. The unweaned group spent the most time lying in sternal recumbency, indoor groups spent the most time standing and eating, and the outdoor group without hinds spent the most time pacing the fenceline. Analysis of variance revealed that both confinement indoors and the presence of hinds improved weight gain over the 7-day period following weaning. In an experiment carried out to determine how the presence of hinds might reduce weaning stress, 90 calves were allocated randomly to 15 groups of six. The distance maintained by the calves from: (a) a human, and (b) a novel object was tested, with either no adult hind (n=5 groups), or one of two hinds (n=10 groups) added to the group. Groups with a hind present showed less fear of the human and the novel object, and the behaviour of the groups varied according to the particular hind they were tested with. It was concluded from the two experiments that both confinement indoors and the presence of a hind were effective methods of reducing weaning stress, and that the hind reduced fear responses in the calves.

Responses of red deer to restraint in a y-maze preference test

To determine whether a y-maze could be used to assess the relative aversiveness of handling treatments used for red deer and how the treatments could most effectively be presented, 24 castrated stags were subjected to two simple treatments. In one arm of a y-maze deer were briefly restrained in a mechanical crush (Crush treatment), while they were allowed to walk through the opposite arm of the maze without restraint (No Crush treatment). The deer were tested in periods of three runs, over a total of 5 days. For each run, successive individuals were drafted down a handling race into the maze. Half of the deer (Group 1) were allowed to choose between entering either arm during every run. Group 2 were forced to enter one arm of the maze on Run 1, the opposite arm on Run 2 and then allowed to choose between arms on Run 3. This regime was repeated four times and there-after testing was as for Group 1. Runs were continued until individuals had chosen to receive the same (‘preferred’) treatment in the maze 12 times in succession, or for a maximum of 25 runs. No significant preference was shown by Group 1 (of 11 deer which chose a treatment 12 times in succession, eight preferred No Crush and three preferred Crush). Group 2 preferred No Crush (of 11 deer which preferred a treatment, ten preferred No Crush; P<0.01); this was evident during the first choice run (P<0.05). Discrimination between treatments by Group 2 was also evident in transit times through the handling area, as after the first period the deer took longer to be forced into the arm where they had received Crush treatment than the arm where they had received No Crush treatment (P<0.05). It was concluded that a y-maze may be useful in comparing the relative aversiveness of pairs of handling treatments used in deer husbandry and that giving individuals a forced run through each arm of the maze followed by a choice was an effective means of presenting the treatments.

Behavioural effects of light conditions on red deer in a holding pen

Abstract To investigate the possibility that fear-related behaviour of red deer in an unfamiliar holding pen was reduced by darkening the pen, eight groups of 10 yearling hinds were confined for 7 min on two occasions in a 4 m×6 m indoor enclosure, with a grid of 12 zones painted on the floor. On one occasion the enclosure was well lit (200 lux) and on the other occasion the enclosure was dark (0–1 lux), with the order of treatments reversed for half of the groups. During the first 5 min of each test the group was alone in the pen and for the last 2 min a stationary human was at the front of the pen. Before the arrival of the human, deer in the dark showed more ambulatory activity (mean number of lines crossed per 30 s interval were 28.5 in the dark compared with 21.9 in the light; SED=2.52) and were more dispersed throughout the pen (occupied more zones, and spent more time in the nearest and furthest zones with respect to the front of the pen; P P

Effects of social isolation and restraint on heart rate and behaviour of alpacas

Heart rate and behaviour of 16 yearling male alpacas were measured during spatial and visual isolation from other alpacas (Treatment I) and when a pair of familiar alpacas was present (Treatment G). In Experiment 1, subjects were free to move in a 2.4 m2 wire pen while in Experiment 2, subjects were held under manual restraint in the pen. In Experiment 1, Treatment I was associated with increased heart rate, movement around the pen, vertical or horizontal head movements at the wall and door of the pen, nosing of the pen, and resting in sternal recumbency, as well as decreased eating, compared with Treatment G (P < 0.05). In Experiment 2, there was a decrease in heart rate when restraint commenced but no response to Treatment I. It was concluded that providing social companions was likely to reduce acute stress during handling procedures, although whether this includes procedures carried out under restraint was not apparent, and that the responses observed in isolated alpacas in Experiment 1 might be useful indicators of acute stress in further studies on social environment in this species.

Effects of management at weaning on behaviour and weight gain of farmed red deer calves.

Two studies were performed to determine whether there were behavioural or productive differences arising from two contrasting weaning practices for red deer; proximate vs. distant separation of dams and calves. In Experiment 1, 80 calves across two replicates were used. For each replicate, calves were separated from their mothers, weighed and allocated to one of two treatments (n=20 calves), either confinement in an unfamiliar paddock 100 m from their mothers for 2 weeks following weaning (treatment N), or transportation 2 km to a different farm (treatment F). Groups were observed during the following 6 days and weighed 14 days after weaning. In Experiment 2, the same procedure was performed out on two commercial farms, but using 40 calves per treatment group, without replication or weight recording. In Experiment 1 running, fenceline pacing and vocalising declined following weaning, with steeper declines for F than N calves for running and vocalising (P<0.01). Similar trends, with an indication of less vocalising and movement overall, were seen in Experiment 2. In contrast, mean post-weaning weight gains for N calves were higher than for F calves (3.0 compared with 2.4 kg, SED 0.48 kg; P<0.05). Weather variables (cloud, temperature and wind) were associated with behaviour in both studies (P<0.05), with a trend for pacing, calling and running to increase as conditions deteriorated (cloud cover and wind speed increased, and temperature decreased). It was concluded that distant separation appeared beneficial to the calves but more research was required to determine optimal weaning management. The study supported previous evidence that weaning should be carried out in good weather.