Racehorse welfare across a training season.

Racehorse welfare is gaining increasing public attention, however scientific evidence in this area is lacking. In order to develop a better understanding of racehorse welfare, it must be measured and monitored. This is the first study to assess racehorse welfare using scientific objective methods across a training season. The aim of this study was threefold, firstly to investigate welfare measures which could be used in the first welfare assessment protocol for racehorses. Secondly, to understand the effect that a racing and training season had on individual racehorses and thirdly to identify risk factors for both good and poor welfare. Thirteen racehorse training yards were visited at the beginning and the peak of the racing season in England. Behavioral observations along with individual environmental and animal-based welfare measures were carried out on 353 horses in 13 training yards selected for variability. In our sample the horses were generally in good physical health: 94% of horses recorded as an ideal body condition score, no horses had signs of hoof neglect and 77.7% had no nasal discharge. The overall prevalence of external Mouth Corner Lesions was 12.9% and was significantly higher for Flat racing than Jump racing horses. The majority of horses (67.5%) showed positive horse human interactions. When stabled 54.1% horses had physical social contact and nasal discharge was not associated with increased physical contact. The training season significantly affected Human Reactivity Tests, Horse Grimace Scale scores and time spent resting and feeding. A total of 14.5% of horses displayed stereotypic behavior on at least two occasions. Horses with windows in their stables spent more time surveying their surroundings. Overall, in this population of racehorses, horses spent around a third of their daytime feeding (33.7%) followed by time spent standing resting (22.6%). The welfare assessment protocol used in this study is suitable for use in industry to collect welfare data on racehorses.

Does a high social status confer greater levels of trust from groupmates? An experimental study of leadership in domestic horses.

In collective movements, specific individuals may emerge as leaders. In this study on the domestic horse (Equus ferus caballus), we conducted experiments to establish if an individual is successfully followed due to its social status (including hierarchical rank and centrality). We first informed one horse about a hidden food location and recorded by how many it was followed when going back to this location. In this context, all horses lead their groupmates successfully. In a second step, we tested whether group members would trust some leaders more than others by removing the food before the informed individual led the group back to the food location. In addition, two control initiators with intermediate social status for which the food was not removed were tested. The results, confirmed by simulations, demonstrated that the proportions of followers for the unreliable initiator with highest social status are greater than the ones of the unreliable initiator with lowest social status. Our results suggest an existing relationship between having a high social status and a leadership role. Indeed, the status of a leader sometimes prevail at the detriment of the accuracy of the information, because an elevated social status apparently confers a high level of trust.

Measurement of Endurance of Untrained Five-Year-Old and Six-Year-Old Horses Raised in Multi-age Herds on Pasture.

The objective of this study was to explore how the endurance of five-year-old horses, kept out on pasture all their life and ridden for the first time well into their fifth year of age, developed within one year and compared to that of six-year-old horses raised under the same conditions and to other horses. Horses were submitted to a standardized exercise test (SET) to calculate their v4 (velocity run under defined conditions inducing 4 mmol/L of blood lactate concentration (LA)) and v180 (velocity run under defined conditions inducing a heart rate of 180 beats/min). The test consisted of up to five consecutive intervals at increasing speed until the blood LA of a horse increased above 4 mmol/L. The blood LA measured after each interval was plotted exponentially against running speed to derive v4 from the blood lactate-running speed relationship, and the mean heart rate during the intervals was plotted linearly against running speed to derive v180 from the heart rate-running speed relationship. The following were examined: (1) the development of v4 and v180 of five-year-old horses within one year through measurements in September and in the following July and September; the comparison of endurance variables (2) between five-year-olds and six-year-olds; (3) between six-year-olds on consecutive years; and 4) between six-year-olds and foreign horses. The results showed that: (1) there were no changes of either variable within one year (repeated measures ANOVA P > .05); (2) there were no significant differences between five-year-olds and six-year-olds (one-way ANOVA P > .05); (3) no significant differences between six-year-old groups (one-way ANOVA; P > 05); and (4) foreign horses had higher v4 and v180 values than six-year-olds (one-way ANOVA; P = .0001 and P = .003, respectively). There was no significant relationship between v4 and v180 (P > .05; r2 = 0.02). In conclusion, one additional year on pasture in multiage herds did not increase the endurance variables of five-year-old horses. Thus, the endurance appeared to be consolidated in these horses at the age of five years, and additional training seems to be necessary to increase it.

How does the expressiveness of leaders affect followership in domestic horses (Equus ferus caballus)?

In collective movements, some individuals are more effective and attractive leaders than others. Parameters such as social network, personality, and physiologic needs failed to explain why group members follow one leader more than another. In this study in the domestic horse, we propose to focus on the leader's attitude and its impact to the followers' recruitment during two conditions: spontaneous group departures or experimentally induced departures. We postulate that the expressiveness of the leader could enhance its attractiveness and thus produce a successful followership. We found that a high expressiveness level is associated with a high curiosity score and with a low social status. This propensity to initiate while being expressive was higher in the experimental condition than in the spontaneous condition which was expected, since the experimental procedure sought to increase the motivation of initiators with a highly appetent reward. Moreover, the more intense the leader's expressiveness is, the faster the followers will join the movement regardless of the condition. This positive and dynamic attitude can be perceived as an attractive feature by the followers. Finally, we evidenced collective arousal in followers initiated by the leader that could be essential for group cohesion. The present study is the first to investigate the expressiveness level in animals, and provides new insights into the emergence of leadership.

Stakeholder Perceptions of the Challenges to Racehorse Welfare.

The purpose of this paper is to highlight some of the key challenges to racehorse welfare as perceived by racing industry stakeholders. The paper draws upon statements and transcripts from 10 focus group discussions with 42 participants who were taking part in a larger study investigating stakeholders' perceptions of racehorse welfare, which participants recognised as maintaining the physical and mental well-being of a performance animal. Analysis of the 68 statements participants identified as challenges produced nine themes. Among these, 26% (18 statements) of the challenges were health related, whilst 41% (28 statements) focused on the effect staff shortages were having on the racing industry. Staff shortages were perceived as affecting standards of racehorse care and the opportunity to develop a human-horse relationship. Poor employee relations due to a lack of recognition, communication and respect were perceived as having a detrimental effect on employee attitudes, behaviour and staff retention which, in turn, can have a sequential effect on the welfare and health of horses in training. Although the number of challenges produced is small (68), they emphasise the perceptions of stakeholders closely associated with the racing industry.

Relationship between ranging behavior and spatial memory of free-range chickens.

Different personalities may lead to different ways of processing environmental information; however, the relationship between personality and cognition is not fully understood as studies on diverse species present contrasting results. As there is great within-flock variability of outdoor ranging behavior in free-range broiler chickens, we tested whether and how ranging behavior impacts on individual spatial memory abilities. The experiment was conducted on one flock (n = 200) reared in the same conditions throughout the study, to simulate on-farm situations. As the ranging behavior was stable over time, we compared two distinct groups of male chickens: one that visited the range more (High rangers) and one that was more prone to staying in the poultry house (Low rangers). To test the spatial memory, individuals (n = 30) went through two main phases in an arena with 8 cups. For the familiarization phase, individuals were submitted to one trial per day, for seven days, to a situation where all eight cups were baited with mealworms. Animals had to reach a criterion of 5 cups visited out of 8 to advance to the next phase. For the spatial test, only four cups were baited and systematically placed at the same location. This last phase comprised two trials per individual per day, for nine days. During these two phases, latency to visit cups and the number of visits and revisits of all cups were recorded. Low ranger chickens took less time to attain the pre-established threshold of visiting 5 cups out of 8, over the familiarization phase. During the spatial test, the latency to visit four cups decreased between the within-day trials for low ranger chickens and increased for high ranger chickens. Moreover, in the within-day trial analysis, low ranger chickens exhibited an improvement on spatial memory and better spatial memory compared to high ranger chickens. Different speed-accuracy trade-offs may explain these differences between low and high ranger chickens and the way individuals interact and solve the task. Our study strengthens the scientific evidence relating consistent individual differences in behavior, with the ranging behavior of free-range chickens, and cognitive performance during a spatial memory task.

Living the 'Best Life' or 'One Size Fits All'-Stakeholder Perceptions of Racehorse Welfare.

The purpose of the study was to explore the perceptions held by British racing industry stakeholders of factors influencing racehorse welfare. Ten focus groups were held across the UK with a total of 42 stakeholders from a range of roles within racehorse care including trainers, stable staff and veterinarians. Participants took part in three exercises. Firstly, to describe the scenarios of a 'best life' and the minimum welfare standards a horse in training could be living under. Secondly, to identify the main challenges for racehorse welfare and thirdly, to recall any innovative or uncommon practices to improve welfare they had witnessed. Using thematic analysis, eight themes emerged from the first exercise. Two strands, factors that contribute to maintaining health and the horse-human relationship ran through all eight themes. Across all themes horses living the 'best life' were perceived as being treated as individuals rather than being part of a 'one size fits all' life when kept under minimum welfare standards. Health was both perceived as the main challenge to welfare as well as one open to innovative practices such as improved veterinary treatments. Data obtained, informed by the knowledge and expertise of experienced stakeholders, combined with practical animal welfare science will be used to develop the first British racehorse welfare assessment protocol.

Emotional state and personality influence cognitive flexibility in horses (Equus caballus).

Emotions are recognized as strong modulators of cognitive capacities. However, studies have mainly focused on the effect of negative emotions, with few investigating positive emotions. Recent studies suggest that traits of personality can modulate the effects of emotion on cognitive performance. This study aimed to assess whether emotional states differing according to their valence influenced the ability to achieve instrumental conditioning and learning flexibility and to determine the influence of personality. After being tested for their personality, 55 mares underwent acquisition and extinction procedures of instrumental conditioning in a box previously associated with negative events (e.g., novel and sudden stimuli; E-), positive events (e.g., food reward; E+), or no particular event (E°). This contextual conditioning induced contrasting behavioral and physiological responses during acquisition, indicating that E- horses were in a negative and E+ horses were in a positive emotional state. Although acquisition performance did not differ between groups, E+ horses showed a greater flexibility in the extinction phase of instrumental learning than E- and E° horses. Furthermore, fearless personality was related to better acquisition and increased cognitive flexibility. This study demonstrates that horses were able to undergo contextual conditioning that induced negative or more positive emotional states and that this latter emotional state enhanced cognitive flexibility. (PsycINFO Database Record

Stress affects instrumental learning based on positive or negative reinforcement in interaction with personality in domestic horses.

The present study investigated how stress affects instrumental learning performance in horses (Equus caballus) depending on the type of reinforcement. Horses were assigned to four groups (N = 15 per group); each group received training with negative or positive reinforcement in the presence or absence of stressors unrelated to the learning task. The instrumental learning task consisted of the horse entering one of two compartments at the appearance of a visual signal given by the experimenter. In the absence of stressors unrelated to the task, learning performance did not differ between negative and positive reinforcements. The presence of stressors unrelated to the task (exposure to novel and sudden stimuli) impaired learning performance. Interestingly, this learning deficit was smaller when the negative reinforcement was used. The negative reinforcement, considered as a stressor related to the task, could have counterbalanced the impact of the extrinsic stressor by focusing attention toward the learning task. In addition, learning performance appears to differ between certain dimensions of personality depending on the presence of stressors and the type of reinforcement. These results suggest that when negative reinforcement is used (i.e. stressor related to the task), the most fearful horses may be the best performers in the absence of stressors but the worst performers when stressors are present. On the contrary, when positive reinforcement is used, the most fearful horses appear to be consistently the worst performers, with and without exposure to stressors unrelated to the learning task. This study is the first to demonstrate in ungulates that stress affects learning performance differentially according to the type of reinforcement and in interaction with personality. It provides fundamental and applied perspectives in the understanding of the relationships between personality and training abilities.

Behavioral and Transcriptomic Fingerprints of an Enriched Environment in Horses (Equus caballus).

The use of environmental enrichment (EE) has grown in popularity over decades, particularly because EE is known to promote cognitive functions and well-being. Nonetheless, little is known about how EE may affect personality and gene expression. To address this question in a domestic animal, 10-month-old horses were maintained in a controlled environment or EE for 12 weeks. The control horses (n = 9) lived in individual stalls on wood shaving bedding. They were turned out to individual paddocks three times a week and were fed three times a day with pellets or hay. EE-treated horses (n = 10) were housed in large individual stalls on straw bedding 7 hours per day and spent the remainder of the time together at pasture. They were fed three times a day with flavored pellets, hay, or fruits and were exposed daily to various objects, odors, and music. The EE modified three dimensions of personality: fearfulness, reactivity to humans, and sensory sensitivity. Some of these changes persisted >3 months after treatment. These changes are suggestive of a more positive perception of the environment and a higher level of curiosity in EE-treated horses, explaining partly why these horses showed better learning performance in a Go/No-Go task. Reduced expression of stress indicators indicated that the EE also improved well-being. Finally, whole-blood transcriptomic analysis showed that in addition to an effect on the cortisol level, the EE induced the expression of genes involved in cell growth and proliferation, while the control treatment activated genes related to apoptosis. Changes in both behavior and gene expression may constitute a psychobiological signature of the effects of enrichment and result in improved well-being. This study illustrates how the environment interacts with genetic information in shaping the individual at both the behavioral and molecular levels.

Dimensions of temperament modulate cue-controlled behavior: a study on Pavlovian to instrumental transfer in horses (Equus caballus).

Pavlovian to instrumental transfer (PIT) is a central factor in how cues influence animal behavior. PIT refers to the capacity of a Pavlovian cue that predicts a reward to elicit or increase a response intended to obtain the same reward. In the present study, using an equine model, we assessed whether PIT occurs in hoofed domestic animals and whether its efficacy can be modulated by temperamental dimensions. To study PIT, horses were submitted to Pavlovian conditioning whereby an auditory-visual stimulus was repeatedly followed by food delivery. Then, horses were submitted to instrumental conditioning during which they learned to touch with their noses an object signaled by the experimenter in order to obtain the same reward. During the PIT test, the Pavlovian conditioned stimulus was presented to the animal in the absence of reward. At the end of the experiment, a battery of behavioral tests was performed on all animals to assess five temperamental dimensions and investigate their relationships with instrumental performance. The results indicate that PIT can be observed in horses and that its efficacy is greatly modulated by individual temperament. Indeed, individuals with a specific pattern of temperamental dimensions (i.e., higher levels of gregariousness, fearfulness, and sensory sensitivity) exhibited the strongest PIT. The demonstration of the existence of PIT in domesticated animals (i.e., horses) is important for the optimization of its use by humans and the improvement of training methods. Moreover, because PIT may be implicated in psychological phenomena, including addictive behaviors, the observation of relationships between specific temperamental dimensions and PIT efficacy may aid in identifying predisposing temperamental attributes.

Characterization of long-term memory, resistance to extinction, and influence of temperament during two instrumental tasks in horses.

The present study investigated the influence of temperament on long-term recall and extinction of 2 instrumental tasks in 26 horses. In the first task (backward task), horses learned to walk backward, using commands given by an experimenter, in order to obtain a food reward. In the second task (active avoidance task), horses had to cross an obstacle after a bell rang in order to avoid emission of an air puff. Twenty-two months after acquisition, horses exhibited perfect recall performance in both tasks. Accordingly, no influence of temperament on recall performance could be observed for either task. In contrast, in the absence of positive or negative outcomes, the horses' ability to extinguish their response to either task was highly variable. Resistance to extinction was related to some indicators of temperament: The most fearful horses tended to be the most resistant to extinction in the backward task, while the least sensitive horses tended to be the most resistant to extinction in the active avoidance task. These findings reveal extensive long-term memory abilities in horses and suggest an influence of temperament on learning processes other than acquisition.

Stress modulates instrumental learning performances in horses (Equus caballus) in interaction with temperament.

The present study investigates how the temperament of the animal affects the influence of acute stress on the acquisition and reacquisition processes of a learning task. After temperament was assessed, horses were subjected to a stressor before or after the acquisition session of an instrumental task. Eight days later, horses were subjected to a reacquisition session without any stressor. Stress before acquisition tended to enhance the number of successes at the beginning of the acquisition session. Eight days later, during the reacquisition session, contrary to non-stressed animals, horses stressed after acquisition, and, to a lesser extent, horses stressed before acquisition, did not improve their performance between acquisition and reacquisition sessions. Temperament influenced learning performances in stressed horses only. Particularly, locomotor activity improved performances whereas fearfulness impaired them under stressful conditions. Results suggest that direct exposure to a stressor tended to increase acquisition performances, whereas a state of stress induced by the memory of a stressor, because it has been previously associated with the learning context, impaired reacquisition performances. The negative effect of a state of stress on reacquisition performances appeared to be stronger when exposure to the stressor occurred after rather than before the acquisition session. Temperament had an impact on both acquisition and reacquisition processes, but under stressful conditions only. These results suggest that stress is necessary to reveal the influence of temperament on cognitive performances.