Fraser's The Behaviour and Welfare of the Horse

Christopher B Riley, Sharon E Cregier, Andrew Fraser, Christopher B Riley, Sharon E Cregier, Andrew Fraser

• Publisher: CAB International
• Year: 2022
• ISBN:
  9781789242133
• Edition: 3
• Topic: Medicine
• Subtopic: Equine Veterinary Science

This book continues to provide a comprehensive overview of equine behaviour and an outline of current advances in our understanding, as well as offering insights into contemporary and future challenges for improving horse welfare and safety.Completely updated and revised, a new, international, expert editorial team builds on Andrew Fraser's decades of work as an ethologist, veterinarian, historian, horseman, breeder, trainer, conservationist, and field scientist, sharing essential knowledge to improve horse behaviour and welfare. A range of international experts and key opinion leaders have updated this edition to include the effects of noise on the horse's welfare, husbandry and grazing management including the identification of harmful plants and issues of climate change on pasture. New illustrations and examples bring the book to life and further help to explain equine behaviour in a whole range of different situations, including road transport and horse safety during transport. The text covers key issues concerning equipment and the horse's mouth. It gives new insights into genetics, temperament and horse vocalisations and what these indicate. Welfare assessment models are outlined and the challenges presented in different equestrian sports debated. Difficult topics such as euthanasia are also covered. This classic text remains an essential resource for veterinarians, animal scientists, equine professionals and horse owners.

1 Development and Assessment of Equine Behaviour

NATALIE K. WARAN PHD^1*, GEMMA PEARSON BVMS, MSCR, MRCVS² AND ANDREW F. FRASER MVSC, MRCVS³

¹Eastern Institute of Technology, Hawke’s Bay, New Zealand; ²The University of Edinburgh, Midlothian, Scotland, UK; ³Carbonear, Newfoundland, Canada

The Process of Evolution

Innate Behavioural Patterns and Environment

Changes in Form or Type

Initial Learning

Domestication

Inherent Capability in Learning

Homeostasis and Survival

Appraisal of Behaviour in Horses

Methods for Appraising Behaviour

Open-field tests

Specific behavioural tests used in veterinary studies

Critical Appraisal of Behaviour

Behaviours Associated with Clinical Conditions

Locomotory Behaviour

Ontogeny of Behaviour: Instinct

Instinctive behaviour

Release of innate responses

Sensitive periods and imprinting

Early Experience

Ontogeny of Behaviour: Learning

Classical conditioning

Operant conditioning

Non-associative learning: habituation and desensitisation

Motivation, Reinforcement and Punishment

Emotionality and Intelligence

Cognitive Bias

Behaviour and Equine Welfare

One welfare

References

The Process of Evolution

When the behaviour of the domestic horse is studied, both objectively and realistically, ethology is being applied to a subject that is not entirely a product of natural selection. Variations have been used in the creation of breeds by generations of horse breeders. Nevertheless, this animal’s great inheritance is its natural past, which deserves appreciation because that is the source of much of its behaviour today (Clutton-Brock, 1999).

Darwin concluded that the evolution of a species occurred through selective processes (Jones, 2001). These determine which individuals are most able to survive and reproduce, and consequently to participate in the continuation of the species. The norms of horse behaviour today are the natural heritage of a long history of evolution before human control. Horses were subjected to nature’s control for some 8 million years before their domestication. During those times there was natural selection, in which some individuals were ultimately more successful at living and breeding than others, depending on their genes. This is the process of differential reproduction, whereby evolution occurs as a result. Ethology has an interest in natural selection. Behavioural and physical (i.e. visible) characteristics of a living thing (phenotype) must be distinguished from its genetic make-up (genotype). The evolutionary process produces changes if phenotype and genotype are both involved and adaptations, or differences in traits, increase the fitness of its carrier.

What is selected is the whole make-up of the living organism, including its variations and genes, and its behavioural fit into its ecological niche. The state of overall fitness is achieved through behaviour, structure and niche, and their constant interaction with each other. Applied ethology is interested in the animal’s dynamic wholeness. The applied ethological perspective of evolution is both holistic and traditional. It recognises that behaviour and structure have their own environmental needs and motivational components for survival (Lorenz, 1965).

Innate Behavioural Patterns and Environment

Horses are born equipped with ‘ingrained’ or, more accurately, instinctive responses that provide them with survival advantages. These are fixed action patterns of behaviour carried through generations in the species’ genetic code. These inherited behavioural attributes are common to all individuals in a species, although there may be differences in how these are expressed within individuals. Fixed behaviour patterns are not variations but are ‘fixed’ in the given species – possibly as endpoints of evolution, serving as cornerstones in the long-term support of the species. They are not learned and consist of certain complex responses usually triggered by a simple sensory signal. An example of this is the foal’s responses immediately after being born, such as standing, teat-seeking and sucking from the teat, and then when on its feet, following the dam. All are triggered by simple sign stimuli such as the feel of the mare licking it, the attraction the foal has to the smell of the inguinal wax (hence the term ‘waxing up’) between the teats and a heightened sensitivity to the temperature gradient that will attract them to the right place for milk. Once near the teat, the foal is instinctively attracted to objects of the ‘right’ shape. Once on the teat, the ‘suck reflex’ ensures that the foal gets colostrum quickly to aid his survival. The foal is also born with an instinctive attraction for large moving objects (usually the mare) and will follow her once able to move independently. This means that under natural circumstances, the mare and foal can very quickly re-join the herd.

Table 1.1. Classification of equine species.

Classification	Species	Common names
Order Perissodactyla (odd-toed ungulates)	Equus caballus	Horse (domestic)
Suborder Hippomorpha	Equus asinus	African wild ass (and domestic donkey)
Superfamily Equoidea Family Equidae	Equus burchelli	Common zebra

Changes in Form or Type

Novel features in a species can arise from genetic changes, such as mutations, occurring during cell division in the reproductive process. Such a variety might or might not be suited to the parental niche. If forced to move to a new niche, where it becomes geographically isolated, the mutant character would be perpetuated in homozygous form. This would allow a new form of the species to continue to reproduce unchanged. This phenomenon occurs in many species, including Equidae (see Table 1.1). The present array of horse types suggests that this has occurred periodically, resulting in phenotypic differences, including for example, ponies, heavy horses and the so-called ‘hot-blooded’ horse breeds (see Fig. 1.1 for varietal extremes). Through mutation, the latter type of horse, notably the Arabian, became more reactive and more athletic compared with the ‘cold-blooded’ type. Archetypal characters (both physical and behavioural) are retained and persist in a mutant. This genetic inheritance contributes to the success of the mutant form as a derivative with archetypal attributes. The origin of archetypal behavioural attributes lies in the phenomenon of epigenesis, whereby fixed designs are accurately and actively able to continue their developmental functions through successive generations. For example, a newborn foal, transferred suddenly from an intrauterine environment to a completely new environment to which it must quickly adapt, is equipped with ‘fixed’ action patterns, such as standing and finding the teat, both being essential instinctive behaviours for foal survival (Robinson, 2007).

Fig. 1.1. Varietal extremes. Young American miniature horse. Photo: C.B. Riley.

Initial Learning

During the early development phase, the mare and her newborn react to one another instinctively and reciprocally. The birthing process triggers the onset of maternal behaviour, and the smell and taste of the uterine membranes and fluids attract the parturient mare to lick the foal clear of membranes and clean of fluids. While doing so, the sensorium of the foal is being ‘imprinted’ with the mare’s details. Thereafter, it efficiently recognizes and remembers significant details about her. Similarly, the mare quickly identifies her progeny and accepts it as something to be protected. The evolved and innate abilities to learn quickly are thereby well illustrated in both neonate and adult.

Evolutionary processes dictate that parents care only for their own offspring, and reproduction occurs only between members of the same species. Such attachments in horses depend on the critical timing of first impressions in the neonatal foal (Bateson and Horn, 1994). The timing of the sensitive period during which the mother–offspring bond is formed is closely matched to the period when the possibility of error is very small, such as before the newborn has a chance to meet members of any species other than that of the mother.

The neonate foal relates to its mother not as a complex organism but as a unitary stimulus. Parturient mares usually isolate themselves from the herd before giving birth. This means that the first large moving object seen by the newborn will be its own dam. Although the foal can be quite easily confused by other large moving objects, it also receives, through touch, ‘thigmotaxic’ stimuli that enable it to recognize its dam. Through the contact of its muzzle with the ventral surfaces of the dam’s body, it learns the identity and location of this vitally important region and eventually finds the dam’s udder and food (see Fig. 1.2). The mare’s behaviour becomes gradually modified through experience to increase the efficiency of her task of watching over the foal, thus granting her reproductive success (see Fig. 1.3).

Fig. 1.2. Tactile exploration of the newborn foal by the mare. Reciprocity by the foal will follow once she is standing. Photo: C.B. Riley.

Fig. 1.3. Mare with reproductive success. Anonymous artist.

Domestication

Variation through selection as a result of domestication leads to the realization that many genetic mutations are non-adaptive in the evolutionary sense. Breeds with non-adaptive characters have appeared and have been kept true by continuous human selection for specific useful attributes, with the possessors of such mutations being complemented by human agency so that they can survive and reproduce. There are many non-adaptive phenotypic variations, such as coat colour, that play no essential part in the survival of the domesticated species. The true unit is the species as a whole, including variations, as well as the environmental niche and incidental factors within that niche.

For the complete success of the species, behavioural development in relation to environmental pressures play a central role in ensuring that the animal is able to adapt during its own lifetime. Environmental features provided by the husbandry system exert influences that determine whether the horse can adapt behaviourally to the system. Various environmental circumstances have been studied. Changes in behaviour, and ultimately in physical conditions, result directly or indirectly from environmental adaptation. The adaptive mechanisms of horses living under various environmental conditions have shown differences in response to housing, enclosure and the immediate environment. Some responses are maladaptive, and some vary between breeds and individuals. Adaptation is evident in respect of thermoregulation and ingestion (Herdt, 2007).

The temperature at which the so-called cold-blooded type of horse maintains a normal body surface temperature (the thermo-neutral zone) seems to be roughly from −10 to +20 °C, whereas warm-blooded horses can tolerate higher temperatures up to +30 °C. Ranges will be affected by other external factors such as wind and rain. Under extremes of temperature, horses use behavioural methods in attempting to control their temperatures. The most easily recognizable evidence of adaptive behaviour in horses is the movements directed towards thermoregulation and related aspects of body care. These include sheltering, shade-seeking, inactivity, etc. An early behavioural adaptive change during high temperatures is a reduction in food intake. This may arise not only from the shade-seeking activities of the animal but also from a reduced desire for food. Consequent results are an alteration in grazing behaviour and a general decline in all activity. Such an alteration in behaviour may indicate a welfare problem (Dawkins, 2004).

Taste and imitation play important parts in grazing behaviour, and this ensures that the requisite elements are consumed by a horse in appropriate quantities and suitable type to maintain health (McGreevy, 2004). Adaptive seasonal changes in eating indicate that grass palatability has been altered. Seasonal palatability varies markedly on ‘unimproved’ pasture. Horses generally prefer grass that is high in leafiness, greenness and nitrogen content. Sugar, organic acids and fats are preferred, whereas tannins and alkaloids are avoided. Variation in food choice by ponies is explained by the abundance of plant species at different stages of the growing season. As a rule, a drop in the percentage of time spent feeding on a species of grass can be attributed to a dearth of that grass or to the growth of a preferred one. The exceptions to this rule occur in summer and autumn, when certain leaves, such as beech (in the Northern Hemisphere), are increasingly consumed by horses. In the Camargue, in southern France, a long-term study of horses has shown a marked seasonality in ...