Abstract: The horse's temperament, including its manageability and reactivity and/or fearfulness, is of importance as it can result in problems and can render horses unsuitable for inexperienced riders. Early experience, including handling during infancy, may influence the horse's adult behaviour and reduce its fear of humans and other potentially frigthening situations. In the various species studied, handling has generally been undertaken during the neonatal period. The aim of the present study was to test the effects of handling young horses around the time of weaning, a period which has been demonstrated to be effective in increasing ease of handling in cattle and goats. Sixteen Anglo-Arab foals were handled for 12 days either immediately following weaning (early handled: EH) or 21 days later (late handled: LH); eight additional non-handled foals served as controls (C). Handling consisted of haltering, gently petting all parts of the body, picking up feet and leading the foal over 120 m. During handling sessions, EH were easier to handle than LH: time taken to fit them with a halter, to pick up feet, and “walk-ratio” (time walking under constraint/total time walking) were significantly lower for EH. During subsequent tests conducted over 2 days, 4, and 7 months, as well as 10 months and to some extent 18 months after the end of handling period, EH and LH were easier to handle and less reactive than controls, although differences diminished with time. The period following weaning can therefore be qualified as an “optimal period” for handling. Some of the effects persist for at least 18 months.

Abstract: The aim of this study was to test the existence of a “reactivity-to-humans” trait which is stable over time and across situations. For this purpose, four test situations were repeated on the same animals at 8 months, 1.5 years (N = 110 horses) and 2.5 years of age (N = 54 horses). These situations involved a “familiar passive human test” during which a familiar person stayed motionless in the test pen, a “familiar active human test” and an “unfamiliar active human test” during which a familiar or unfamiliar person attempted to touch the horse, and a “halter-fitting and heart-rate measurement test”, during which the horse was haltered and equipped with a surcingle and then had its heart-rate measured. Many behavioural variables were recorded during the tests, and correlations between ages and variables measured during other situations were investigated. When correlations were found, we concluded that the variables corresponded to temperament traits which are stable over time and across situations. The horses tested were divided into four groups according to breed (Anglo-Arab and Welsh) and year of birth (2001 and 2002). Data for each group were analysed separately with Spearman rank correlations. Regarding stability over time, there was a strong correlation between ages in the frequency of licking/nibbling the passive human, the time taken by a familiar or unfamiliar person to touch the horse, and the time taken to fit a halter (e.g. the time taken to touch the horse's muzzle was significantly correlated between ages in 7 out of the 8 possible cases: 0.40 <= R <= 0.67). Regarding stability across situations, results indicate that the more frequently a horse sniffed, licked or nibbled a passive human, the easier it was for either a familiar or unfamiliar active human to touch and halter it. Moreover, a horse which could be touched easily by a familiar human could also be touched and haltered easily by an unfamiliar human. These behaviours, which are linked directly to humans, therefore indicate good stability over time and across situations. In conclusion, this stability suggests the existence of a “reactivity-to-humans” temperament trait, whether the human is passive or active, familiar or unfamiliar. When the animals do not have frequent contact with humans, this reactivity is stable over time and can be measured as early as 8 months of age using the behavioural variables cited above.

Abstract: The purpose of this study was to test the existence of a “fearfulness” trait in horses, by testing the stability across situations and over time of the responses to different fear-eliciting situations. It was also to identify which behavioural parameters are the best indicators of this trait. Sixty-six Welsh ponies and 44 Anglo-Arab horses were successively tested at 8 months and 1.5 years of age. Of these, 33 Welsh ponies and 21 Anglo-Arabs were also tested at 2.5 years of age. At each age, they were subjected to four test situations. The first test involved the introduction of a novel object in the test pen (novel object test). In the second test, a novel area was placed in the pen between the horse and a bucket of food, to determine the time the horse took to cross the area (novel area test). Finally, the third test consisted in suddenly opening an umbrella in front of the horse while it was eating (surprise test). During these tests, many behavioural parameters were recorded. A fourth test consisted of a surprise test during which the horse was held by a handler while its heart rate was measured. Spearman correlations were used to identify links between behavioural parameters measured during different tests and between different ages. Reactions to the first three tests showed consistency between them and over time. Among all the behavioural parameters measured during these tests, some presented high stability over time and were well correlated with behaviours expressed during other tests, indicating they are the best indicators of a fearfulness trait: the frequency of licking/nibbling the novel object, the time to put one foot on the novel area and to eat from a bucket placed just behind it, and the flight distance and the time to eat under the opened umbrella. The stability across responses expressed in various fear-eliciting events and over time from 8 months to 2.5 years of age suggests the existence of a [`]fearfulness' trait in horses. The different indexes of heart rate measured or calculated during the surprise effect present limited stability over time and almost no correlation with the behavioural parameters measured during the other three tests. We conclude that, in contrast to the previously mentioned behaviours, these are not reliable measures of a temperament trait. From a practical point of view, this study shows that it is possible to identify a horse's level of fearfulness as early as 8 months of age using the first three tests.

Abstract: Learning performances are influenced by many factors, not only breed, age and sex, but also temperament. The purpose of this study was to understand how different temperamental dimensions affect the learning performance of horses, Equus caballus. First, we carried out a series of behavioural tests on 36 Welsh ponies aged 5-7 years to measure five temperamental dimensions: fearfulness (novel area test and surprise test), gregariousness (social isolation test), reactivity to humans (passive human test), tactile sensitivity (von Frey filament test) and activity level (evaluation of locomotor activity during all the tests). We then presented them with two learning tasks (avoidance and backwards-forwards tasks). In the avoidance task they had to learn to jump over a fence when they heard a sound associated with an aversive stimulus (puff of air). In the backwards-forwards task they had to walk forwards or move backwards in response to a tactile or vocal command to obtain a food reward. There was no correlation between performances on the two learning tasks, indicating that learning ability is task-dependent. However, correlations were found between temperamental data and learning performance (Spearman correlations). The ponies that performed the avoidance task best were the most fearful and the most active ones. For instance, the number of trials required to perform 5 consecutive correct responses (learning criterion) was correlated with the variables aimed at measuring fearfulness (way of crossing a novel area: rs = -0.41, P = 0.01 and time to start eating again after a surprise effect: rs = -0.33, P = 0.05) and activity level (frequency of trotting during all the tests: rs = -0.40, P = 0.02). The animals that performed the backwards-forwards task best were the ones that were the least fearful and the most sensitive. For instance, the learning criterion (corresponding to the number of trials taken to achieve five consecutive correct responses) was correlated with the variables aimed at measuring fearfulness (latency to put one foot on the area: rs = 0.43, P = 0.01; way of crossing a novel area: rs = 0.31, P = 0.06; and time to start eating again after a surprise effect: rs = 0.43, P = 0.009) and tactile sensitivity (response to von Frey filaments: rs = -0.44, P = 0.008). This study revealed significant links between temperament and learning abilities that are highly task-dependent.

Abstract: Changes in social hierarchy were evaluated in a herd of 3-year-old Hanoverian geldings. One group (n = 5) was exposed to a training programme, the other (n = 5) remained untrained. After 6 months, the groups were reversed. Hierarchical positions were evaluated by field observations and/or paired-feeding tests at the beginning, the middle, the end of the first and at the end of the second training period. Both methods yielded identical results. Almost all horses changed position in only one direction: either up or down. Neither increase in aggression nor mutual injuries were recorded during the whole experiment. No statistically verified differences in dominance ranking occurred between trained and untrained groups, but apparent differences were consistent. Thus, if horses are kept in the same group for a longer period of time, exercise induced changes in hierarchy are probably of minor importance and are unlikely to increase the incidence of injuries. This may have implications for the promotion of group-housing for sport horses.