Age-Related Changes in the Behaviour of Domestic Horses as Reported by Owners

Embedding research and enquiry in Australian DVM curriculum

Research and enquiry (R&E) is an integral part of veterinary training. It is a foundation of evidence-based practice. In the University of Sydney Doctor of Veterinary Medicine degree R&E culminates in a cap-stone experience in Year 3: a 'professionally focused project', a student-driven and academic supported individual research project. The project provides an authentic experience within a veterinary discipline. Students work with an academic advisor who provides guidance for developing and achieving meaningful educational and professional goals. Successful advising depends upon a shared understanding of, and commitment to, the advising process by students, advisors and the university. The R&E mission can be broadly defined as - veterinarians recognise that evidence-based approach to practice, which is based on the scientific method, leads to the generation of new knowledge that underpins the veterinary medical profession.

The Behavioral Cost of Care: Changes in Maintenance Behavior during Equine-Assisted Interventions

This study examined human-animal symbiosis in an animal-assisted intervention through observations of animal maintenance behaviors. The rise of psychotherapy, learning, and recreation incorporating animals warrants exploration of the welfare of the animals involved in these interventions. The analysis of welfare in multispecies engagements can be discussed in terms of symbiosis. Regarding an intervention's animal provider (e.g., therapy horse) and human recipient (psychotherapy client), the balance of cost and benefit is important. Research describing human and animal interactive behavior during interventions is limited, whether focusing on client outcomes or animal welfare. The present study adapted ethological methods to study humans and animals in an equine-assisted intervention, observing equine maintenance behaviors and equid-human interactive behavior. Maintenance behaviors were recorded before, during, and after equine-assisted (psychosocial) learning sessions with youth, providing 1600 observations. Equine alertness, eating behavior, and ambulation varied significantly before, during, and after the equine-assisted sessions. Such interruptions of typical behavior are an important aspect of welfare and unit of analysis when examining symbiotic relationships. A total of 267 sequences of equid-human approach-response behavior were also recorded, indicating that human-animal interaction was predominantly from humans toward equids. Equids' dominant response to human approach was no response, followed by avoidance, while humans' dominant response to equid approach was reciprocation. The findings are discussed in terms of symbiosis and animal welfare.

Phenotypic and Genetic Study of the Presence of Hair Whorls in Pura Raza Español Horses

Hair whorls are a hereditary feature in horses that may be associated with temperament and coat color. Hair whorls are described as changes in the hair pattern and may take various forms, such as circular and linear whorls. We first carried out a frequency analysis of hair whorls (circular and linear). Next, a Generalized Non-Linear Model was computed to assess the significance of some potential influencing factors, and a genetic parameter estimation was performed. ENDOG software v4.8 was used to estimate the inbreeding coefficient of all the animals analyzed. It was more common to find horses with circular hair whorls than with linear whorls. The heritability ranges obtained were, in general, medium-high for both circular whorls (0.20 to 0.90) and linear whorls (0.44 to 0.84). High positive correlations were found on the between left and right positions, indicating a tendency to symmetry in certain locations. The laterality of hair whorls was also evidenced, with the biggest concentration on the left-hand side, particularly in gray horses, showing circular whorls below the central line of eyes, which has been associated in a previous paper with a calmer and more docile temperament.

Does social motivation mitigate fear caused by a sudden sound in horses?

Living in a herd has multiple advantages for social species and is a primary survival strategy for prey. The presence of conspecifics, identified as a social buffer, may mitigate the individual stress response. Social isolation is, therefore, particularly stressful for horses, which are gregarious animals. However, they are not equally vulnerable to separation from the group. We tested whether more and less socially dependent horses and independent individuals would differ in their responses to novel and sudden sounds occurring in two contexts: non-social and social motivation. Twenty warmblood horses were first exposed to two social tests: to evaluate the level of social dependence (rate of restless behaviour; social isolation) and the quantity and the quality of interactions in which they were involved (stay on a paddock). Two fear audio tests were then performed to compare the responses to sudden sounds while feeding (non-social motivation; control trial) and while moving towards the herd (social motivation; experimental trial). Socially dependent horses showed more pronounced avoidance behaviour and needed much more time to resume feeding during the control trial. Hence, dependent individuals appeared to be more fearful. However, during an experimental trial, horses of both groups tended to ignore the sound or paid only limited attention to the stimulus, continuing to move forward towards their conspecifics. Thus, social motivation may mitigate fear caused by a frightening stimulus and make fearful and dependent horses more prone to face a potentially stressful event. This finding should be taken into account in horse training and management.

Identification of Personality-Related Candidate Genes in Thoroughbred Racehorses Using a Bioinformatics-Based Approach Involving Functionally Annotated Human Genes

Considering the personality traits of racehorses (e.g., flightiness, anxiety, and affability) is considered essential to improve training efficiency and decrease accident frequency, especially when retraining for a second career that may involve contact with inexperienced personnel after retiring from racing. Studies on human personality-related genes are frequently conducted; however, such studies are rare in horses because a consistent methodology for personality evaluation is lacking. Using the recently published whole genome variant database of 101 Thoroughbred horses, we compared horse genes orthologous to human genes related to the Big Five personality traits, and identified 18 personality-related candidate genes in horses. These genes include 55 variants that involve non-synonymous substitutions that highly impact the encoded protein. Moreover, we evaluated the allele frequencies and functional impact on the proteins in terms of the difference in molecular weights and hydrophobicity levels between reference and altered amino acids. We identified 15 newly discovered genes that may affect equine personality, but their associations with personality are still unclear. Although more studies are required to compare genetic and behavioral information to validate this approach, it may be useful under limited conditions for personality evaluation.

Basal Reactivity Evaluated by Infrared Thermography in the "Caballo de Deporte Español" Horse Breed According to Its Coat Color

Horses have been valued for their diversity of coat color since prehistoric times. In particular, the pleiotropic effect that coat color genes have on behavior determines the way the horse perceives and reacts to its environment. The primary aim of this study was to evaluate the influence of coat color on basal reactivity assessed with infrared thermography as eye temperature at rest (ETR), determine their relation with the results obtained by these horses in Show Jumping competitions and to estimate the genetic parameters for this variable to test its suitability for genetic selection. A General Linear Model (GLM) and Duncan post-hoc analysis indicated differences in ETR due to coat color, sex, age, location, and breed-group factors. A Spearman’s rank correlation of 0.11 (p < 0.05) was found with ranking, indicating that less reactive horses were more likely to achieve better rankings. Heritability values ranged from 0.17 to 0.22 and were computed with a model with genetic groups and a model with residual variance heterogeneity. Breeding values were higher with the last genetic model, thus demonstrating the pleiotropic effect of coat color. These results indicate that ETR has a suitable genetic basis to be used in the breeding program to select for basal reactivity due to coat color.

New animal-based measures to assess welfare in dromedary camels

Reliable and measurable animal-based measures (ABMs) are essential for assessing animal welfare. This study aimed at proposing ABMs for dromedary camels identifying their possible associations with management. Data were collected at a permanent camel market; a total of 76 pens and 528 camels were evaluated. ABMs were collected for each welfare principle (i.e., good feeding, good housing, good health, appropriate behavior), while resources or management-based measures were collected at three levels of investigations (animal, herd, or caretakers). Associations were calculated by generalized linear models. Body condition score and thirst index (ABMs of good feeding) resulted negatively associated with short caretaker's experience, dirty bedding, limited shaded space, feeding and water space, and space allowance (P < 0.05). Resting behaviors and restricted movements (ABMs of good housing) were associated with short caretaker's experience, dirty bedding and water, rationed water distribution, water points in the sun, and presence of hobbles (P < 0.05). Disease, injury, and pain induced by management procedures (ABMs of good health) were negatively associated with short caretaker's experience, presence of hobbles, limited space allowance and shaded space, dirty bedding, and feeding and watering practices (e.g., frequency of distribution, resource quality, location of the troughs; P < 0.05). Response to approaching test and aggressivity (ABMs of Appropriate behavior) were negatively associated with limited space allowance, shaded, feeding and water space, and rationed water distribution (P < 0.05). Overall, the proposed ABMs seems to be appropriate indicators of welfare consequences in camels being able to identify factors related to housing and management practices that may impair or improve camel welfare.

Behavioural and Physiological Changes in a Herd of Arabian Mares after the Separation of Individuals Differently Ranked within the Dominance Hierarchy

Simple Summary

There are many situations in riding facilities and studs in which horses have to be separated out of a group, for example, when they are needed for a riding lesson, training purposes or veterinary treatments. Such a group may form a social herd in which a dominance hierarchy with dominant and submissive members is established. In the study, we investigated how mares respond to a short separation of some of the herd members and whether the response differs according to the rank order of the mares separated. The response was determined with rates of different behaviours showing agitation or calmness, times of locomotion and physiological parameters. The results of the experiment show that the separation of some mares increases the agitation in the remaining herd. In spite of the fact that such situations are constantly repeated in practice, they are stressful for the horses. The reaction of the remaining herd does not depend strictly on the composition of the mares separated regarding their rank in the dominance hierarchy, i.e., it does not differ consistently when a dominant, mixed or submissive group of mares is separated.

Abstract

Horses in a herd develop and maintain a dominance hierarchy between all individuals. There are many situations in riding facilities and studs in which horses have to be separated out of a group. The aim of the study was to determine the rate of behaviours, level of locomotor activity and cardiac activity variables in a herd of horses during a short social separation of individuals differently ranked in the dominance hierarchy. Twelve adult Arabian mares were involved. A behavioural test had been performed before the main experiment to determine the rank order of the mares in this social herd. Three tests were performed when a dominant, mixed and submissive three-member group of mares was separated for 10 min. The response of the remaining herd was determined by a rate of behaviours, time of locomotor activity and cardiac parameters. The results of the experiment reveal evident changes towards emotional arousal in the social herd elicited by a short separation of some conspecifics. The herd created by humans preserves the sensitivity to a temporary loss of its members. The response of the remaining herd does not depend strictly on the composition of the separated mares regarding their rank in the dominance hierarchy.

The Impact of the Sex of Handlers and Riders on the Reported Social Confidence, Compliance and Touch Sensitivity of Horses in Their Care

Simple Summary

Any influence of the sex of the human partner in human–horse interactions on the behaviour of horses is currently largely anecdotal. Associations between the sex of humans and equine behaviour may have welfare implications. Our study investigates observations of ridden and non-ridden horse behaviour, as reported by respondents (n = 1420) to the Equine Behaviour and Research Questionnaire (E-BARQ). Results reveal some human sex-related differences between horses handled and ridden by male and female humans. Horses ridden or handled by male humans were more likely to be difficult to catch and defensive when approached, but less likely to pull on the reins/brace the neck or toss their head. The study revealed the importance of considering the sex of the rider or handler when investigating equine behaviour.

Abstract

Current evidence of how human sex-related differences in riders and handlers may influence horse behaviour is limited. The Equine Behaviour Assessment and Research Questionnaire (E-BARQ) was used to collect demographic data on riders and handlers (n = 1420) and behavioural data on their horses. It includes demographic items about the sex of the respondent and how frequently the horse has been ridden or handled by male and female humans. The questionnaire then gathers observations on the horse’s behaviour on the ground and under saddle or when driven. Using E-BARQ’s battery of 97 questions, the current study showed differences in ridden and non-ridden horse behaviour that were related to the sex of the rider or handler. Data were evaluated using multivariate analysis and revealed that horses handled by male humans were significantly more difficult to catch (t-value = −3.11; p = 0.002) and significantly more defensive when approached (t-value = −2.104; p = 0.035), but significantly less likely to pull on the reins/brace the neck or toss their head (t-value 1.980; p = 0.048) than horses handled more frequently by female humans. The differences found between male and female horse handlers suggest that sex is an important factor to consider when understanding equine behaviour. Our study explored reported differences in confidence, handling and working compliance and touch sensitivity among horses ridden and handled by male and female humans and suggested further research into how these differences are gendered.