Abstract: Horses are known to show fear reactions when confronted with novelty and this can be a considerable hindrance in the context of working situations such as riding, dressage or racing. The aim of the present study was to measure the potential effects of a synthetic analogue of the Equine Appeasing Pheromone on saddled horses when subjected to a stressful situation using a double-blinded, placebo controlled study design. A group of 40 horses was analyzed during this study and horses were divided by sex, breed and reactivity into two homogenized groups. The test, which consisted of walking the horse through a fringed curtain, was selected from a range of tests which are used to assess behaviour for the selection of French breeding stock. Horses that could have been subjected to the test on a previous occasion, and therefore be familiar with it, were not included. Behavioural and physiological parameters were both taken into account with measures of time to go through the curtain, fear related typical behavioural patterns, based on available literature detailed in the bibliography, and heart rate being recorded. Parameters were analyzed by means of Mann-Whitney U-test. Significant differences were noticed between the two groups concerning heart rate data during the test (UMeanHR = 100.5, pMeanHR = 0.02; UMaxHR = 75, pMaxHR = 0.001) and during the whole measured period (UMeanHR = 67, pMeanHR = 0.005; UMaxHR = 58, pMaxHR = 0.002). Observation of the animals also revealed less behavioural items characteristic of fear within the treated group. As a result, horses performed the test with a better time performance when they received the pheromone analogue (U = 62, p = 0.002). The main parameter, area under the HR graph, is based on heart rate measure and performance. Differences noticed (U = 74, p = 0.002) for this parameter lead to the conclusion that horses who received EAP underwent less stress related consequences in terms of their cardiac physiology. As horses are subjected to a number of foreseeable stressful events this study suggests that the use of Equine Appeasing Pheromone could be a significant factor in improving the welfare of this species.

Abstract: The paper offers a detailed quantitative descripition of the distribution of agonistic activities over the members of two groups of Java-monkeys (Macaca fascicularis). These groups lived in captivity and were well-established: i.e. they had an extensive network of genealogical relationships. The study pays special attention to agonistic interactions with three or more participants. Its main purpose is an analysis of the way dyadic agonistic relations (e.g. dominance relations) are affected by third group members and the relations among these. The paper presents data on the ontogeny of 'dependent dominance', the 'control role' of the alpha-male, and the functions of different types of alliances.

Abstract: Habituation to frightening stimuli plays an important role in horse training. To investigate the extent to which horses generalise between different visual objects, 2-year-old stallions were habituated to feeding from a container placed inside a test arena and assigned as TEST (n=12) or REFERENCE horses (n=12). In Experiment 1, TEST horses were habituated to six objects (ball, barrel, board, box, cone, cylinder) presented in sequence in a balanced order. The objects were of similar size but different colour. Each object was placed 0.5m in front of the feed container, forcing the horses to pass the object to get to the food. TEST horses received as many 2min exposures to each object as required to meet a habituation criterion. We recorded behavioural reactions to the object, latency to feed, total eating time, and heart rate (HR) during all exposures. There was no significant decrease in initial responses towards a novel object with increasing object number, indicating that habituation was stimulus-specific. REFERENCE horses were exposed to the test arena without objects in the same period, and reactions of TEST and REFERENCE horses were subsequently compared in a fear-test (2m2.5m rubber mat placed under the feed container, forcing the horses to step on the mat to get food). There were no significant differences between the treatment groups, i.e. previous habituation of TEST horses to six visual objects did not reduce responses in a fear-test involving visual and tactile stimulation. Due to the lack of generalisation in Experiment 1, we designed a supplemental experiment (Experiment 2), in which REFERENCE horses were exposed to the same six objects except that object colour was kept constant. We found a significant reduction in response (behaviour and HR) with increasing object number, indicating that horses generalise between similarly coloured objects of varying shape. We conclude that a high degree of object similarity, e.g. identical colouring, appears to be crucial for object generalisation in horses.

Abstract: Horses frequently react nervously when passing animal production farms and other places with distinctive smells, leading riders to believe that horses are innately frightened by certain odours. In three experiments, we investigated how horses respond to (1) urine from wolves and lions, (2) blood from slaughtered conspecifics and fur-derived wolf odour, and (3) a sudden auditory stimulus in either presence or absence of fur-derived wolf odour. The experiments were carried out under standardised conditions using a total of 45 naive, 2-year-old horses. In the first two experiments we found that horses showed significant changes in behaviour (Experiments 1 and 2: increased sniffing; Experiment 2 only: increased vigilance, decreased eating, and more behavioural shifts), but no increase in heart rate compared to controls when exposed to predator odours and conspecific blood in a known test environment. However, the third experiment showed that exposure to a combination of wolf odour and a sudden stimulus (sound of a moving plastic bag) caused significantly increased heart rate responses and a tendency to a longer latency to resume feeding, compared to control horses exposed to the sudden stimulus without the wolf odour. The results indicate that predator odour per se does not frighten horses but it may cause an increased level of vigilance. The presence of predator odour may, however, cause an increased heart rate response if horses are presented to an additional fear-eliciting stimulus. This strategy may be adaptive in the wild where equids share habitats with their predators, and have to trade-off time and energy spent on anti-predation responses against time allocated to essential non-defensive activities.

Abstract: The ability of horses to learn and remember new tasks is fundamentally important for their use by humans. Fearfulness may, however, interfere with learning, because stimuli in the environment can overshadow signals from the rider or handler. In addition, prolonged high levels of stress hormones can affect neurons within the hippocampus; a brain region central to learning and memory. In a series of experiments, we aimed to investigate the link between performance in two learning tests, the baseline level of stress hormones, measured as faecal cortisol metabolites (FCM), fearfulness, and social rank. Twenty-five geldings (2 or 3 years old) pastured in one group were included in the study. The learning tests were performed by professional trainers and included a number of predefined stages during which the horses were gradually trained to perform exercises, using either negative (NR) or positive reinforcement (PR). Each of the learning tests lasted 3 days; 7min/horse/day. The NR test was repeated in a novel environment. Performance, measured as final stage in the training programme, and heart rate (HR) were recorded. Faeces were collected on four separate days where the horses had been undisturbed at pasture for 48h. Social rank was determined through observations of social interactions during feeding. The fear test was a novel object test during which behaviour and HR were recorded. Performance in the NR and PR learning tests did not correlate. In the NR test, there was a significant, negative correlation between performance and HR in the novel environment (rS=-0.66, P<0.001, i.e. nervous horses had reduced performance), whereas there was no such correlation in the home environment (both NR and PR). Behavioural reactions in the fear test correlated significantly with performance in the NR test in the novel environment (e.g. object alertness and final stage: rS=-0.43, P=0.04), suggesting that performance under unfamiliar, stressful conditions may be predicted by behavioural responses in a fear test. There was a negative correlation between social rank and baseline stress hormones (rS=-0.43, P=0.04), i.e. high rank corresponded to low FCM concentrations, whereas neither rank nor FCM correlated with fearfulness or learning performance. We conclude that performance under stressful conditions is affected by activation of the sympathetic nervous system during training and related to behavioural responses in a standardised fear test. Learning performance in the home environment, however, appears unrelated to fearfulness, social rank and baseline FCM levels.