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The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family
Equidae Equidae (commonly known as the horse family) is the Taxonomy (biology), taxonomic Family (biology), family of Wild horse, horses and related animals, including Asinus, asses, zebra, zebras, and many extinct species known only from fossils. The fa ...
and is one of two
extant Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Exta ...
subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...
of ''Equus ferus''. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature, '' Eohippus'', into the large, single-toed animal of today. Humans began domesticating horses around 4000 BCE in Central Asia, and their
domestication Domestication is a multi-generational Mutualism (biology), mutualistic relationship in which an animal species, such as humans or leafcutter ants, takes over control and care of another species, such as sheep or fungi, to obtain from them a st ...
is believed to have been widespread by 3000 BCE. Horses in the subspecies ''caballus'' are domesticated, although some domesticated populations live in the wild as feral horses. These feral populations are not true wild horses, which are horses that have never been domesticated. There is an extensive, specialized vocabulary used to describe equine-related concepts, covering everything from
anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...
to life stages, size, colors, markings,
breeds A breed is a specific group of breedable domestic animals having homogeneous appearance (phenotype), homogeneous behavior, and/or other characteristics that distinguish it from other organisms of the same species. In literature, there exist seve ...
, locomotion, and behavior. Horses are adapted to run, allowing them to quickly escape predators, and possess a good sense of balance and a strong fight-or-flight response. Related to this need to flee from predators in the wild is an unusual trait: horses are able to sleep both standing up and lying down, with younger horses tending to sleep significantly more than adults. Female horses, called
mare A mare is an adult female horse or other equidae, equine. In most cases, a mare is a female horse over the age of three, and a filly is a female horse three and younger. In Thoroughbred horse racing, a mare is defined as a female horse more th ...
s, carry their young for approximately 11 months and a young horse, called a
foal A foal is an equine up to one year old; this term is used mainly for horses, but can be used for donkeys. More specific terms are colt (horse), colt for a male foal and filly for a female foal, and are used until the horse is three or four. Whe ...
, can stand and run shortly following birth. Most domesticated horses begin training under a
saddle A saddle is a supportive structure for a rider of an animal, fastened to an animal's back by a girth. The most common type is equestrian. However, specialized saddles have been created for oxen, camels and other animals. It is not know ...
or in a harness between the ages of two and four. They reach full adult development by age five, and have an average lifespan of between 25 and 30 years. Horse breeds are loosely divided into three categories based on general temperament: spirited "hot bloods" with speed and endurance; "cold bloods", such as
draft horse A draft horse (US) or draught horse (UK), also known as dray horse, carthorse, work horse or heavy horse, is a large horse bred to be a working animal hauling freight and doing heavy agricultural tasks such as plowing. There are a number o ...
s and some ponies, suitable for slow, heavy work; and "
warmblood Warmbloods are a group of middle-weight horse types and breeds primarily originating in Europe and registered with organizations that are characterized by open studbook policy, studbook selection, and the aim of breeding for equestrian sp ...
s", developed from crosses between hot bloods and cold bloods, often focusing on creating breeds for specific riding purposes, particularly in Europe. There are more than 300 breeds of horse in the world today, developed for many different uses. Horses and humans interact in a wide variety of sport competitions and non-competitive recreational pursuits as well as in working activities such as police work,
agriculture Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created ...
, entertainment, and
therapy A therapy or medical treatment is the attempted remediation of a health problem, usually following a medical diagnosis. Both words, ''treatment'' and ''therapy'', are often abbreviated tx, Tx, or Tx. As a rule, each therapy has indications a ...
. Horses were historically used in warfare, from which a wide variety of riding and
driving Driving is the controlled operation and movement of a land vehicle, including cars, motorcycles, trucks, and buses. A driver's permission to drive on public highways is granted based on a set of conditions being met, and drivers are required to ...
techniques developed, using many different styles of
equipment Equipment most commonly refers to a set of tool A tool is an Physical object, object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many Tool use by ...
and methods of control. Many products are derived from horses, including
meat Meat is animal Tissue (biology), tissue, often muscle, that is eaten as food. Humans have hunted and farmed other animals for meat since prehistory. The Neolithic Revolution allowed the domestication of vertebrates, including chickens, sheep, ...
,
milk Milk is a white liquid food produced by the mammary glands of lactating mammals. It is the primary source of nutrition for young mammals (including breastfeeding, breastfed human infants) before they are able to digestion, digest solid food. ...
, hide,
hair Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals. The human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and ...
, bone, and pharmaceuticals extracted from the urine of pregnant mares.


Lifespan and life stages

Depending on breed,
management Management (or managing) is the administration of organizations, whether businesses, nonprofit organizations, or a Government agency, government bodies through business administration, Nonprofit studies, nonprofit management, or the political s ...
and environment, the modern domestic horse has a life expectancy of 25 to 30 years. Uncommonly, a few animals live into their 40s and, occasionally, beyond. The oldest verifiable record was " Old Billy", a 19th-century horse that lived to the age of 62. In modern times, Sugar Puff, who had been listed in ''
Guinness World Records ''Guinness World Records'', known from its inception in 1955 until 1999 as ''The Guinness Book of Records'' and in previous United States editions as ''The Guinness Book of World Records'', is a British reference book published annually, list ...
'' as the world's oldest living pony, died in 2007 at age 56. Regardless of a horse or pony's actual birth date, for most competition purposes a year is added to its age each January 1 of each year in the Northern Hemisphere and each August 1 in the Southern Hemisphere. The exception is in
endurance riding Endurance riding is an equestrian sport based on controlled long-distance races. It is one of the international competitions recognized by the FEI. There are endurance rides worldwide. Endurance rides can be any distance, though they are rar ...
, where the minimum age to compete is based on the animal's actual calendar age. The following terminology is used to describe horses of various ages: ;
Foal A foal is an equine up to one year old; this term is used mainly for horses, but can be used for donkeys. More specific terms are colt (horse), colt for a male foal and filly for a female foal, and are used until the horse is three or four. Whe ...
: A horse of either sex less than one year old. A nursing foal is sometimes called a ''suckling'', and a foal that has been weaned is called a ''weanling''. Ensminger, p. 418 Most domesticated foals are weaned at five to seven months of age, although foals can be weaned at four months with no adverse physical effects. ; Yearling : A horse of either sex that is between one and two years old. ; Colt : A male horse under the age of four. A common terminology error is to call any young horse a "colt", when the term actually only refers to young male horses. ;
Filly A filly is a female horse that is too young to be called a mare. There are two specific definitions in use: *In most cases, a ''filly'' is a female horse under four years old. *In some nations, such as the United Kingdom and the United States ...
: A female horse under the age of four. ;
Mare A mare is an adult female horse or other equidae, equine. In most cases, a mare is a female horse over the age of three, and a filly is a female horse three and younger. In Thoroughbred horse racing, a mare is defined as a female horse more th ...
: A female horse four years old and older. ; Stallion : A non-castrated male horse four years old and older. The term "horse" is sometimes used colloquially to refer specifically to a stallion. Ensminger, p. 420 ;
Gelding A gelding (Help:IPA/English, /ˈɡɛldɪŋ/) is a castration, castrated male horse or other equine, such as a pony, donkey or a mule. The term is also used with certain other animals and livestock, such as domesticated Camelidae, camels. By compa ...
: A castrated male horse of any age. In
horse racing Horse racing is an equestrian performance activity, typically involving two or more horses ridden by jockeys (or sometimes driven without riders) over a set distance for competition. It is one of the most ancient of all sports, as its bas ...
, these definitions may differ: For example, in the British Isles,
Thoroughbred The Thoroughbred is a list of horse breeds, horse breed developed for Thoroughbred racing, horse racing. Although the word ''thoroughbred'' is sometimes used to refer to any breed of purebred horse, it technically refers only to the Thorough ...
horse racing defines colts and fillies as less than five years old. However, Australian Thoroughbred racing defines colts and fillies as less than four years old.


Size and measurement

The height of horses is measured at the highest point of the
withers Withers are the ridge between the shoulder blades of an animal, typically a quadruped. In many species, this ridge is the tallest point of the body. In horses and dogs, it is the standard place to measure the animal's height. In contrast, catt ...
, where the neck meets the back. Whitaker, p. 77 This point is used because it is a stable point of the anatomy, unlike the head or neck, which move up and down in relation to the body of the horse. In English-speaking countries, the height of horses is often stated in units of hands and inches: one hand is equal to . The height is expressed as the number of full hands, followed by a point, then the number of additional inches, and ending with the abbreviation "h" or "hh" (for "hands high"). Thus, a horse described as "15.2 h" is 15 hands plus 2 inches, for a total of in height. Ensminger, p. 51 The size of horses varies by breed, but also is influenced by
nutrition Nutrition is the biochemistry, biochemical and physiology, physiological process by which an organism uses food and water to support its life. The intake of these substances provides organisms with nutrients (divided into Macronutrient, macro- ...
. Light-riding horses usually range in height from and can weigh from . Larger-riding horses usually start at about and often are as tall as , weighing from . Heavy or
draft horse A draft horse (US) or draught horse (UK), also known as dray horse, carthorse, work horse or heavy horse, is a large horse bred to be a working animal hauling freight and doing heavy agricultural tasks such as plowing. There are a number o ...
s are usually at least high and can be as tall as high. They can weigh from about . The largest horse in recorded history was probably a Shire horse named
Mammoth A mammoth is any species of the extinct elephantid genus ''Mammuthus.'' They lived from the late Miocene epoch (from around 6.2 million years ago) into the Holocene until about 4,000 years ago, with mammoth species at various times inhabi ...
, who was born in 1848. He stood high and his peak weight was estimated at . Whitaker, p. 60 The record holder for the smallest horse ever is
Thumbelina Thumbelina (; ) is a literary fairy tale written by Danish author Hans Christian Andersen. It was first published by C. A. Reitzel on 16 December 1835 in Copenhagen, Denmark, with "The Naughty Boy" and "The Travelling Companion" in the se ...
, a fully mature miniature horse affected by
dwarfism Dwarfism is a condition of people and animals marked by unusually small size or short stature. In humans, it is sometimes defined as an adult height of less than , regardless of sex; the average adult height among people with dwarfism is . '' ...
. She was tall and weighed .


Ponies

Ponies are taxonomically the same animals as horses. The distinction between a horse and pony is commonly drawn on the basis of height, especially for competition purposes. However, height alone is not dispositive; the difference between horses and ponies may also include aspects of
phenotype In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology (physical form and structure), its developmental processes, its biochemical and physiological propert ...
, including conformation and temperament. The traditional standard for height of a horse or a pony at maturity is . An animal or over is usually considered to be a horse and one less than a pony, but there are many exceptions to the traditional standard. In Australia, ponies are considered to be those under . For competition in the Western division of the
United States Equestrian Federation The United States Equestrian Federation (USEF or US Equestrian) is the national Sport governing body, governing body for most Equestrianism, equestrian sports in the United States. It began on January 20, 1917, as the Association of American Hor ...
, the cutoff is . The
International Federation for Equestrian Sports The International Federation for Equestrian Sports (, FEI) is the international sport governing body, governing body of equestrianism, equestrian sports. The FEI came into being following the Olympic Congress in Lausanne (SUI) in 1921 from May ...
, the world governing body for horse sport, uses metric measurements and defines a pony as being any horse measuring less than at the withers without shoes, which is just over , and , with shoes. Height is not the sole criterion for distinguishing horses from ponies. Breed registries for horses that typically produce individuals both under and over consider all animals of that breed to be horses regardless of their height. Conversely, some pony breeds may have features in common with horses, and individual animals may occasionally mature at over , but are still considered to be ponies. Ponies often exhibit thicker manes, tails, and overall coat. They also have proportionally shorter legs, wider barrels, heavier , shorter and thicker necks, and short heads with broad foreheads. They may have calmer temperaments than horses and also a high level of intelligence that may or may not be used to cooperate with human handlers. Small size, by itself, is not an exclusive determinant. For example, the Shetland pony which averages , is considered a pony.Conversely, breeds such as the Falabella and other miniature horses, which can be no taller than , are classified by their registries as very small horses, not ponies.


Genetics

Horses have 64
chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...
s. The horse genome was sequenced in 2007. It contains 2.7 billion DNA
base pair A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...
s, which is larger than the dog genome, but smaller than the
human genome The human genome is a complete set of nucleic acid sequences for humans, encoded as the DNA within each of the 23 distinct chromosomes in the cell nucleus. A small DNA molecule is found within individual Mitochondrial DNA, mitochondria. These ar ...
or the bovine genome. The map is available to researchers.


Colors and markings

Horses exhibit a diverse array of coat colors and distinctive markings, described by a specialized vocabulary. Often, a horse is classified first by its coat color, before breed or sex. Horses of the same color may be distinguished from one another by white markings, which, along with various spotting patterns, are inherited separately from coat color. Many
genes In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
that create horse coat colors and patterns have been identified. Current genetic tests can identify at least 13 different
allele An allele is a variant of the sequence of nucleotides at a particular location, or Locus (genetics), locus, on a DNA molecule. Alleles can differ at a single position through Single-nucleotide polymorphism, single nucleotide polymorphisms (SNP), ...
s influencing coat color, and research continues to discover new genes linked to specific traits. The basic coat colors of chestnut and
black Black is a color that results from the absence or complete absorption of visible light. It is an achromatic color, without chroma, like white and grey. It is often used symbolically or figuratively to represent darkness.Eva Heller, ''P ...
are determined by the
gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
controlled by the Melanocortin 1 receptor, also known as the "extension gene" or "red factor". Its recessive form is "red" (chestnut) and its dominant form is black. Additional
gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
s control suppression of black color to point coloration that results in a bay, spotting patterns such as pinto or leopard, dilution genes such as palomino or dun, as well as greying, and all the other factors that create the many possible coat colors found in horses. Horses that have a white coat color are often mislabeled; a horse that looks "white" is usually a middle-aged or older gray. Grays are born a darker shade, get lighter as they age, but usually keep black skin underneath their white hair coat (with the exception of pink skin under white markings). The only horses properly called
white White is the lightest color and is achromatic (having no chroma). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully (or almost fully) reflect and scatter all the visible wa ...
are born with a predominantly white hair coat and pink skin, a fairly rare occurrence. Different and unrelated genetic factors can produce white coat colors in horses, including several different alleles of dominant white and the sabino-1 gene. However, there are no "
albino Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and reddish pink or blue eyes. Individuals with the condition are referred to as albinos. Varied use and interpretation of ...
" horses, defined as having both pink skin and red eyes.


Reproduction and development

Gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregn ...
lasts approximately 340 days, with an average range 320–370 days, Ensminger, p. 156 and usually results in one
foal A foal is an equine up to one year old; this term is used mainly for horses, but can be used for donkeys. More specific terms are colt (horse), colt for a male foal and filly for a female foal, and are used until the horse is three or four. Whe ...
; twins are rare. Horses are a precocial species, and foals are capable of standing and running within a short time following birth. Foals are usually born in the spring. The estrous cycle of a mare occurs roughly every 19–22 days and occurs from early spring into autumn. Most mares enter an ''anestrus'' period during the winter and thus do not cycle in this period. Ensminger, p. 150 Foals are generally weaned from their mothers between four and six months of age. Horses, particularly colts, are sometimes physically capable of reproduction at about 18 months, but domesticated horses are rarely allowed to breed before the age of three, especially females. Horses four years old are considered mature, although the skeleton normally continues to develop until the age of six; maturation also depends on the horse's size, breed, sex, and quality of care. Larger horses have larger bones; therefore, not only do the bones take longer to form bone tissue, but the
epiphyseal plate The epiphyseal plate, epiphysial plate, physis, or growth plate is a hyaline cartilage plate in the metaphysis at each end of a long bone. It is the part of a long bone where new bone growth takes place; that is, the whole bone is alive, with ma ...
s are larger and take longer to convert from
cartilage Cartilage is a resilient and smooth type of connective tissue. Semi-transparent and non-porous, it is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints ...
to bone. These plates convert after the other parts of the bones, and are crucial to development. Depending on maturity, breed, and work expected, horses are usually put under saddle and trained to be ridden between the ages of two and four. Although
Thoroughbred The Thoroughbred is a list of horse breeds, horse breed developed for Thoroughbred racing, horse racing. Although the word ''thoroughbred'' is sometimes used to refer to any breed of purebred horse, it technically refers only to the Thorough ...
race horses are put on the track as young as the age of two in some countries, horses specifically bred for sports such as
dressage Dressage ( or ; , most commonly translated as "training") is a form of horse riding performed in exhibition and competition, as well as an art sometimes pursued solely for the sake of mastery. As an equestrianism, equestrian sport defined by th ...
are generally not put under saddle until they are three or four years old, because their bones and muscles are not solidly developed. For
endurance riding Endurance riding is an equestrian sport based on controlled long-distance races. It is one of the international competitions recognized by the FEI. There are endurance rides worldwide. Endurance rides can be any distance, though they are rar ...
competition, horses are not deemed mature enough to compete until they are a full 60 calendar months (five years) old.


Anatomy


Skeletal system

The horse skeleton averages 205 bones. A significant difference between the horse skeleton and that of a human is the lack of a collarbone—the horse's
forelimbs A forelimb or front limb is one of the paired articulated appendages ( limbs) attached on the cranial (anterior) end of a terrestrial tetrapod vertebrate's torso. With reference to quadrupeds, the term foreleg or front leg is often used inst ...
are attached to the
spinal column The spinal column, also known as the vertebral column, spine or backbone, is the core part of the axial skeleton in vertebrates. The vertebral column is the defining and eponymous characteristic of the vertebrate. The spinal column is a segmen ...
by a powerful set of muscles, tendons, and ligaments that attach the shoulder blade to the torso. The horse's four legs and hooves are also unique structures. Their leg bones are proportioned differently from those of a human. For example, the body part that is called a horse's "knee" is actually made up of the
carpal bones The carpal bones are the eight small bones that make up the wrist (carpus) that connects the hand to the forearm. The terms "carpus" and "carpal" are derived from the Latin wikt:carpus#Latin, carpus and the Greek language, Greek wikt:καρπός ...
that correspond to the human
wrist In human anatomy, the wrist is variously defined as (1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; "The wrist contains eight bones, roughly aligned in two rows, known as the carpal ...
. Similarly, the hock contains bones equivalent to those in the human
ankle The ankle, the talocrural region or the jumping bone (informal) is the area where the foot and the leg meet. The ankle includes three joints: the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular joint. The ...
and heel. The lower leg bones of a horse correspond to the bones of the human hand or foot, and the fetlock (incorrectly called the "ankle") is actually the proximal
sesamoid bone In anatomy, a sesamoid bone () is a bone embedded within a tendon or a muscle. Its name is derived from the Greek word for 'sesame seed', indicating the small size of most sesamoids. Often, these bones form in response to strain, or can be presen ...
s between the
cannon A cannon is a large-caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder during th ...
bones (a single equivalent to the human metacarpal or metatarsal bones) and the
proximal phalanges The phalanges (: phalanx ) are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges while the other digits have three phalanges. The phalanges are classed as long bones. Struct ...
, located where one finds the "knuckles" of a human. A horse also has no muscles in its legs below the knees and hocks, only skin, hair, bone,
tendon A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...
s,
ligament A ligament is a type of fibrous connective tissue in the body that connects bones to other bones. It also connects flight feathers to bones, in dinosaurs and birds. All 30,000 species of amniotes (land animals with internal bones) have liga ...
s,
cartilage Cartilage is a resilient and smooth type of connective tissue. Semi-transparent and non-porous, it is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints ...
, and the assorted specialized tissues that make up the hoof. Ensminger, pp. 21–25


Hooves

The critical importance of the feet and legs is summed up by the traditional adage, "no foot, no horse". Ensminger, p. 367 The horse hoof begins with the distal phalanges, the equivalent of the human fingertip or tip of the toe, surrounded by
cartilage Cartilage is a resilient and smooth type of connective tissue. Semi-transparent and non-porous, it is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints ...
and other specialized, blood-rich soft tissues such as the laminae. The exterior hoof wall and horn of the sole is made of keratin, the same material as a human fingernail. The result is that a horse, weighing on average , travels on the same bones as would a human on tiptoe. For the protection of the hoof under certain conditions, some horses have horseshoes placed on their feet by a professional farrier. The hoof continually grows, and in most domesticated horses needs to be trimmed (and horseshoes reset, if used) every five to eight weeks, though the hooves of horses in the wild wear down and regrow at a rate suitable for their terrain.


Teeth

Horses are adapted to
grazing In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to free range (roam around) and consume wild vegetations in order to feed conversion ratio, convert the otherwise indigestible (by human diges ...
. In an adult horse, there are 12  incisors at the front of the mouth, adapted to biting off the grass or other vegetation. There are 24 teeth adapted for chewing, the premolars and
molars The molars or molar teeth are large, flat tooth, teeth at the back of the mouth. They are more developed in mammal, mammals. They are used primarily to comminution, grind food during mastication, chewing. The name ''molar'' derives from Latin, '' ...
, at the back of the mouth. Stallions and geldings have four additional teeth just behind the incisors, a type of canine teeth called "tushes". Some horses, both male and female, will also develop one to four very small vestigial teeth in front of the molars, known as "wolf" teeth, which are generally removed because they can interfere with the bit. There is an empty interdental space between the incisors and the molars where the bit rests directly on the gums, or "bars" of the horse's mouth when the horse is bridled. An estimate of a horse's age can be made from looking at its teeth. The teeth continue to erupt throughout life and are worn down by grazing. Therefore, the incisors show changes as the horse ages; they develop a distinct wear pattern, changes in tooth shape, and changes in the angle at which the chewing surfaces meet. This allows a very rough estimate of a horse's age, although diet and veterinary care can also affect the rate of tooth wear. Ensminger, pp. 46–50


Digestion

Horses are
herbivore A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...
s with a digestive system adapted to a forage diet of grasses and other plant material, consumed steadily throughout the day. Therefore, compared to humans, they have a relatively small stomach but very long intestines to facilitate a steady flow of nutrients. A horse will eat of food per day and, under normal use, drink of
water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...
. Horses are not
ruminant Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microb ...
s, having only one stomach, like humans. But unlike humans, they can digest
cellulose Cellulose is an organic compound with the chemical formula, formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of glycosidic bond, β(1→4) linked glucose, D-glucose units. Cellulose is an important s ...
, a major component of grass, through the process of hindgut fermentation. Cellulose fermentation by symbiotic bacteria and other microbes occurs in the
cecum The cecum ( caecum, ; plural ceca or caeca, ) is a pouch within the peritoneum that is considered to be the beginning of the large intestine. It is typically located on the right side of the body (the same side of the body as the appendix (a ...
and the
large intestine The large intestine, also known as the large bowel, is the last part of the gastrointestinal tract and of the Digestion, digestive system in tetrapods. Water is absorbed here and the remaining waste material is stored in the rectum as feces befor ...
. Horses cannot vomit, so digestion problems can quickly cause colic, a leading cause of death. Although horses do not have a gallbladder, they tolerate high amounts of fat in their diet.


Senses

The horses' senses are based on their status as prey animals, where they must be aware of their surroundings at all times. Ensminger, pp. 309–310 The equine eye is one of the largest of any land mammal. Horses are lateral-eyed, meaning that their eyes are positioned on the sides of their heads. This means that horses have a range of vision of more than 350°, with approximately 65° of this being binocular vision and the remaining 285° monocular vision. Horses have excellent day and
night vision Night vision is the ability to see in low-light conditions, either naturally with scotopic vision or through a night-vision device. Night vision requires both sufficient spectral range and sufficient intensity range. Humans have poor night v ...
, but they have two-color, or dichromatic vision; their color vision is somewhat like red-green
color blindness Color blindness, color vision deficiency (CVD) or color deficiency is the decreased ability to color vision, see color or differences in color. The severity of color blindness ranges from mostly unnoticeable to full absence of color percept ...
in humans, where certain colors, especially red and related colors, appear as a shade of green. Their sense of smell, while much better than that of humans, is not quite as good as that of a dog. It is believed to play a key role in the social interactions of horses as well as detecting other key scents in the environment. Horses have two olfactory centers. The first system is in the nostrils and nasal cavity, which analyze a wide range of odors. The second, located under the nasal cavity, are the vomeronasal organs, also called Jacobson's organs. These have a separate nerve pathway to the brain and appear to primarily analyze
pheromone A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...
s. A horse's hearing is good, and the pinna of each ear can rotate up to 180°, giving the potential for 360° hearing without having to move the head. Noise affects the behavior of horses and certain kinds of noise may contribute to stress—a 2013 study in the UK indicated that stabled horses were calmest in a quiet setting, or if listening to country or classical music, but displayed signs of nervousness when listening to jazz or rock music. This study also recommended keeping music under a volume of 21
decibel The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a Power, root-power, and field quantities, power or root-power quantity on a logarithmic scale. Two signals whos ...
s. An Australian study found that stabled racehorses listening to talk radio had a higher rate of gastric ulcers than horses listening to music, and racehorses stabled where a radio was played had a higher overall rate of ulceration than horses stabled where there was no radio playing. Horses have a great sense of balance, due partly to their ability to feel their footing and partly to highly developed
proprioception Proprioception ( ) is the sense of self-movement, force, and body position. Proprioception is mediated by proprioceptors, a type of sensory receptor, located within muscles, tendons, and joints. Most animals possess multiple subtypes of propri ...
—the unconscious sense of where the body and limbs are at all times. A horse's sense of touch is well-developed. The most sensitive areas are around the eyes, ears, and nose. Horses are able to sense contact as subtle as an insect landing anywhere on the body. Horses have an advanced sense of taste, which allows them to sort through
fodder Fodder (), also called provender (), is any agriculture, agricultural foodstuff used specifically to feed domesticated livestock, such as cattle, domestic rabbit, rabbits, sheep, horses, chickens and pigs. "Fodder" refers particularly to food ...
and choose what they would most like to eat, and their prehensile lips can easily sort even small grains. Horses generally will not eat poisonous plants, however, there are exceptions; horses will occasionally eat toxic amounts of poisonous plants even when there is adequate healthy food.


Movement

All horses move naturally with four basic gaits: Harris, p. 32 *the four-beat walk, which averages ; *the two-beat trot or jog at (faster for harness racing horses); *the canter or lope, a three-beat gait that is ; *the gallop, which averages , Harris, pp. 47–49 but the world record for a horse galloping over a short, sprint distance is . Besides these basic gaits, some horses perform a two-beat pace, instead of the trot. Harris, p. 50 There also are several four-beat ' ambling' gaits that are approximately the speed of a trot or pace, though smoother to ride. These include the lateral rack, running walk, and tölt as well as the diagonal fox trot. Ambling gaits are often genetic in some breeds, known collectively as gaited horses. These horses replace the trot with one of the ambling gaits. Harris, pp. 50–55 File:Muybridge horse walking animated.gif, ''Walk'' File:Trot animated.gif, ''Trot'' File:Muybridge_horse_pacing_animated.gif, ''Pace'' File:Canter animated.gif, ''Canter'' File:Muybridge race horse animated.gif, ''Gallop'' , record:


Behavior

Horses are prey animals with a strong fight-or-flight response. Their first reaction to a threat is to startle and usually flee, although they will stand their ground and defend themselves when flight is impossible or if their young are threatened. They also tend to be curious; when startled, they will often hesitate an instant to ascertain the cause of their fright, and may not always flee from something that they perceive as non-threatening. Most light horse riding breeds were developed for speed, agility, alertness, and endurance, natural qualities that extend from their wild ancestors. However, through selective breeding, some breeds of horses are quite docile, particularly certain draft horses. Horses are herd animals, with a clear hierarchy of rank, led by a dominant individual, usually a mare. They are also social creatures that are able to form companionship attachments to their own species and to other animals, including humans. They communicate in various ways, including vocalizations such as nickering or whinnying, mutual grooming, and
body language Body language is a type of nonverbal communication in which physical behaviors, as opposed to words, are used to express or convey information. Such behavior includes facial expressions, body posture, gestures, eye movement, touch and the use o ...
. Many horses will become difficult to manage if they are isolated, but with training, horses can learn to accept a human as a companion, and thus be comfortable away from other horses. Ensminger, pp. 305–309 However, when confined with insufficient companionship, exercise, or stimulation, individuals may develop stable vices, an assortment of bad habits, mostly stereotypies of psychological origin, that include wood chewing, wall kicking, "weaving" (rocking back and forth), and other problems.


Intelligence and learning

Studies have indicated that horses perform a number of cognitive tasks on a daily basis, meeting mental challenges that include food procurement and identification of individuals within a
social system In sociology, a social system is the patterned network of relationships constituting a coherent whole that exist between individuals, groups, and institutions. It is the formal Social structure, structure of role and status that can form in a smal ...
. They also have good spatial discrimination abilities. They are naturally curious and apt to investigate things they have not seen before. Studies have assessed equine intelligence in areas such as
problem solving Problem solving is the process of achieving a goal by overcoming obstacles, a frequent part of most activities. Problems in need of solutions range from simple personal tasks (e.g. how to turn on an appliance) to complex issues in business an ...
, speed of learning, and
memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembe ...
. Horses excel at simple learning, but also are able to use more advanced cognitive abilities that involve
categorization Classification is the activity of assigning objects to some pre-existing classes or categories. This is distinct from the task of establishing the classes themselves (for example through cluster analysis). Examples include diagnostic tests, identi ...
and
concept learning Concept learning, also known as category learning, concept attainment, and concept formation, is defined by Jerome Bruner, Bruner, Goodnow, & Austin (1956) as "the search for and testing of attributes that can be used to distinguish exemplars fro ...
. They can learn using
habituation Habituation is a form of non-associative learning in which an organism’s non-reinforced response to an inconsequential stimulus decreases after repeated or prolonged presentations of that stimulus. For example, organisms may habituate to re ...
, desensitization,
classical conditioning Classical conditioning (also respondent conditioning and Pavlovian conditioning) is a behavioral procedure in which a biologically potent Stimulus (physiology), stimulus (e.g. food, a puff of air on the eye, a potential rival) is paired with a n ...
,
operant conditioning Operant conditioning, also called instrumental conditioning, is a learning process in which voluntary behaviors are modified by association with the addition (or removal) of reward or aversive stimuli. The frequency or duration of the behavior ma ...
, and positive and negative reinforcement. One study has indicated that horses can differentiate between "more or less" if the quantity involved is less than four. Domesticated horses may face greater mental challenges than wild horses, because they live in artificial environments that prevent
instinct Instinct is the inherent inclination of a living organism towards a particular complex behaviour, containing innate (inborn) elements. The simplest example of an instinctive behaviour is a fixed action pattern (FAP), in which a very short to me ...
ive behavior whilst also learning tasks that are not natural. Horses are animals of habit that respond well to regimentation, and respond best when the same routines and techniques are used consistently. One trainer believes that "intelligent" horses are reflections of intelligent trainers who effectively use response conditioning techniques and positive reinforcement to train in the style that best fits with an individual animal's natural inclinations.


Temperament

Horses are
mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...
s. As such, they are warm-blooded, or endothermic creatures, as opposed to cold-blooded, or poikilothermic animals. However, these words have developed a separate meaning in the context of equine terminology, used to describe temperament, not body temperature. For example, the " hot-bloods", such as many race horses, exhibit more sensitivity and energy, Belknap, p. 255 while the "cold-bloods", such as most draft breeds, are quieter and calmer. Belknap, p. 112 Sometimes "hot-bloods" are classified as "light horses" or "riding horses", Ensminger, pp. 71–73 with the "cold-bloods" classified as "draft horses" or "work horses". Ensminger, p. 84 "Hot blooded" breeds include " oriental horses" such as the Akhal-Teke,
Arabian horse The Arabian or Arab horse ( , DIN 31635, DMG ''al-ḥiṣān al-ʿarabī'') is a horse breed, breed of horse with historic roots on the Arabian Peninsula. With a distinctive head shape and high tail carriage, the Arabian is one of the most easi ...
,
Barb Barb or the BARBs or ''variation'' may refer to: People * Barb (name), a list of people and fictional characters with the given name or surname * Barb, a term used by fans of Nicki Minaj to refer to themselves * The Barbs, a band Places * Barb, ...
, and now-extinct Turkoman horse, as well as the
Thoroughbred The Thoroughbred is a list of horse breeds, horse breed developed for Thoroughbred racing, horse racing. Although the word ''thoroughbred'' is sometimes used to refer to any breed of purebred horse, it technically refers only to the Thorough ...
, a breed developed in England from the older oriental breeds. Hot bloods tend to be spirited, bold, and learn quickly. They are bred for agility and speed. They tend to be physically refined—thin-skinned, slim, and long-legged. The original oriental breeds were brought to Europe from the Middle East and North Africa when European breeders wished to infuse these traits into racing and light
cavalry Historically, cavalry (from the French word ''cavalerie'', itself derived from ''cheval'' meaning "horse") are groups of soldiers or warriors who Horses in warfare, fight mounted on horseback. Until the 20th century, cavalry were the most mob ...
horses. Whitaker, p. 43 Whitaker, pp. 194–197 Muscular, heavy
draft horse A draft horse (US) or draught horse (UK), also known as dray horse, carthorse, work horse or heavy horse, is a large horse bred to be a working animal hauling freight and doing heavy agricultural tasks such as plowing. There are a number o ...
s are known as "cold bloods", as they are bred not only for strength, but also to have the calm, patient temperament needed to pull a plow or a heavy carriage full of people. They are sometimes nicknamed "gentle giants".
Price A price is the (usually not negative) quantity of payment or compensation expected, required, or given by one party to another in return for goods or services. In some situations, especially when the product is a service rather than a ph ...
, p. 15
Well-known draft breeds include the Belgian and the Clydesdale. Some, like the
Percheron The Percheron is a horse breed, breed of draft horse that originated in the Huisne river valley in western France, part of the former Perche province, from which the breed takes its name. Usually gray (horse), gray or black (horse), black in col ...
, are lighter and livelier, developed to pull carriages or to plow large fields in drier climates. Bongianni, entry 87 Others, such as the
Shire Shire () is a traditional term for an administrative division of land in Great Britain and some other English-speaking countries. It is generally synonymous with county (such as Cheshire and Worcestershire). British counties are among the oldes ...
, are slower and more powerful, bred to plow fields with heavy, clay-based soils. Ensminger, pp. 124–125 The cold-blooded group also includes some pony breeds. "
Warmblood Warmbloods are a group of middle-weight horse types and breeds primarily originating in Europe and registered with organizations that are characterized by open studbook policy, studbook selection, and the aim of breeding for equestrian sp ...
" breeds, such as the Trakehner or Hanoverian, developed when European carriage and war horses were crossed with Arabians or Thoroughbreds, producing a riding horse with more refinement than a draft horse, but greater size and milder temperament than a lighter breed. Certain
pony A pony is a type of small horse, usually measured under a specified height at maturity. Ponies often have thicker coats, manes and tails, compared to larger horses, and proportionally shorter legs, wider barrels, heavier , thicker necks and s ...
breeds with warmblood characteristics have been developed for smaller riders. Warmbloods are considered a "light horse" or "riding horse". Today, the term "Warmblood" refers to a specific subset of sport horse breeds that are used for competition in
dressage Dressage ( or ; , most commonly translated as "training") is a form of horse riding performed in exhibition and competition, as well as an art sometimes pursued solely for the sake of mastery. As an equestrianism, equestrian sport defined by th ...
and show jumping. Strictly speaking, the term " warm blood" refers to any
cross A cross is a religious symbol consisting of two Intersection (set theory), intersecting Line (geometry), lines, usually perpendicular to each other. The lines usually run vertically and horizontally. A cross of oblique lines, in the shape of t ...
between cold-blooded and hot-blooded breeds. Belknap, p. 523 Examples include breeds such as the Irish Draught or the Cleveland Bay. The term was once used to refer to breeds of light riding horse other than Thoroughbreds or Arabians, such as the Morgan horse.
Price A price is the (usually not negative) quantity of payment or compensation expected, required, or given by one party to another in return for goods or services. In some situations, especially when the product is a service rather than a ph ...
, p. 18


Sleep patterns

Horses are able to sleep both standing up and lying down. In an adaptation from life in the wild, horses are able to enter light sleep by using a " stay apparatus" in their legs, allowing them to doze without collapsing. Horses sleep better when in groups because some animals will sleep while others stand guard to watch for predators. A horse kept alone will not sleep well because its
instinct Instinct is the inherent inclination of a living organism towards a particular complex behaviour, containing innate (inborn) elements. The simplest example of an instinctive behaviour is a fixed action pattern (FAP), in which a very short to me ...
s are to keep a constant eye out for danger. Unlike humans, horses do not sleep in a solid, unbroken period of time, but take many short periods of rest. Horses spend four to fifteen hours a day in standing rest, and from a few minutes to several hours lying down. Total sleep time in a 24-hour period may range from several minutes to a couple of hours, mostly in short intervals of about 15 minutes each. Ensminger, p. 310. The average sleep time of a domestic horse is said to be 2.9 hours per day. Horses must lie down to reach REM sleep. They only have to lie down for an hour or two every few days to meet their minimum REM sleep requirements. However, if a horse is never allowed to lie down, after several days it will become sleep-deprived, and in rare cases may suddenly collapse because it slips, involuntarily, into REM sleep while still standing. This condition differs from narcolepsy, although horses may also suffer from that disorder.


Taxonomy and evolution

The horse adapted to survive in areas of wide-open terrain with sparse vegetation, surviving in an
ecosystem An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...
where other large grazing animals, especially
ruminant Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microb ...
s, could not. Horses and other equids are odd-toed ungulates of the order Perissodactyla, a group of mammals dominant during the Tertiary. In the past, this order contained 14  families, but only three—
Equidae Equidae (commonly known as the horse family) is the Taxonomy (biology), taxonomic Family (biology), family of Wild horse, horses and related animals, including Asinus, asses, zebra, zebras, and many extinct species known only from fossils. The fa ...
(the horse and related species), Tapiridae (the
tapir Tapirs ( ) are large, herbivorous mammals belonging to the family Tapiridae. They are similar in shape to a Suidae, pig, with a short, prehensile nose trunk (proboscis). Tapirs inhabit jungle and forest regions of South America, South and Centr ...
), and Rhinocerotidae (the
rhinoceros A rhinoceros ( ; ; ; : rhinoceros or rhinoceroses), commonly abbreviated to rhino, is a member of any of the five extant taxon, extant species (or numerous extinct species) of odd-toed ungulates (perissodactyls) in the family (biology), famil ...
es)—have survived to the present day. The earliest known member of the family Equidae was the '' Hyracotherium'', which lived between 45 and 55 million years ago, during the
Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
period. It had 4 toes on each front foot, and 3 toes on each back foot. The extra toe on the front feet soon disappeared with the '' Mesohippus'', which lived 32 to 37 million years ago. Over time, the extra side toes shrank in size until they vanished. All that remains of them in modern horses is a set of small vestigial bones on the leg below the knee, known informally as splint bones. Their legs also lengthened as their toes disappeared until they were a hooved animal capable of running at great speed. By about 5 million years ago, the modern ''Equus'' had evolved. Equid teeth also evolved from browsing on soft, tropical plants to adapt to browsing of drier plant material, then to grazing of tougher plains grasses. Thus proto-horses changed from leaf-eating forest-dwellers to grass-eating inhabitants of semi-arid regions worldwide, including the steppes of Eurasia and the
Great Plains The Great Plains is a broad expanse of plain, flatland in North America. The region stretches east of the Rocky Mountains, much of it covered in prairie, steppe, and grassland. They are the western part of the Interior Plains, which include th ...
of North America. By about 15,000 years ago, ''Equus ferus'' was a widespread
holarctic The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical reg ...
species. Horse bones from this time period, the late
Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...
, are found in Europe, Eurasia, Beringia, and North America. Yet between 10,000 and 7,600 years ago, the horse became extinct in North America. The reasons for this extinction are not fully known, but one theory notes that extinction in North America paralleled human arrival. Another theory points to
climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...
, noting that approximately 12,500 years ago, the grasses characteristic of a steppe ecosystem gave way to shrub
tundra In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic ...
, which was covered with unpalatable plants.


Wild species surviving into modern times

A truly wild horse is a species or subspecies with no ancestors that were ever successfully domesticated. Therefore, most "wild" horses today are actually feral horses, animals that escaped or were turned loose from domestic herds and the descendants of those animals. Only two wild subspecies, the tarpan and the
Przewalski's horse Przewalski's horse (''Equus ferus przewalskii'' or ''Equus przewalskii''), also called the takhi, Mongolian wild horse or Dzungarian horse, is a rare and endangered wild horse originally native to the steppes of Central Asia. It is named after t ...
, survived into recorded history and only the latter survives today. The
Przewalski's horse Przewalski's horse (''Equus ferus przewalskii'' or ''Equus przewalskii''), also called the takhi, Mongolian wild horse or Dzungarian horse, is a rare and endangered wild horse originally native to the steppes of Central Asia. It is named after t ...
(''Equus ferus przewalskii''), named after the Russian explorer Nikolai Przhevalsky, is a rare Asian animal. It is also known as the Mongolian wild horse;
Mongolia Mongolia is a landlocked country in East Asia, bordered by Russia to the north and China to the south and southeast. It covers an area of , with a population of 3.5 million, making it the world's List of countries and dependencies by po ...
n people know it as the ''taki'', and the
Kyrgyz people The Kyrgyz people (also spelled Kyrghyz, Kirgiz, and Kirghiz; or ) are a Turkic peoples, Turkic ethnic group native to Central Asia. They primarily reside in Kyrgyzstan, Uzbekistan, and China. A Kyrgyz diaspora is also found in Russia, Tajik ...
call it a ''kirtag''. The subspecies was presumed extinct in the wild between 1969 and 1992, while a small breeding population survived in zoos around the world. In 1992, it was reestablished in the wild by the conservation efforts of numerous zoos. Today, a small wild breeding population exists in Mongolia. Dohner, pp. 298–299 There are additional animals still maintained at zoos throughout the world. Their status as a truly wild horse was called into question when domestic horses of the 5,000-year-old Botai culture of Central Asia were found to be more closely related to Przewalski's horses than to ''E. f. caballus''. The study raised the possibility that modern Przewalski's horses could be the feral descendants of the domestic Botai horses. The study concluded that the Botai animals appear to have been an independent domestication attempt and apparently unsuccessful in terms of genetic markers carrying through to modern domesticated equines. However, the question of whether all Przewalski's horses descend from this population is also unresolved, as only one of seven modern Przewalski’s horses in the study shared this ancestry. It may also be that both the Botai horses and the modern Przewalski's horses descend separately from the same ancient wild Przewalski's horse population. The tarpan or European wild horse (''Equus ferus ferus'') was found in Europe and much of Asia. It survived into the historical era, but became
extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...
in 1909, when the last captive died in a Russian zoo. Dohner, p. 300 Thus, the genetic line was lost. Attempts have been made to recreate the tarpan, which resulted in horses with outward physical similarities, but nonetheless descended from domesticated ancestors and not true wild horses. Periodically, populations of horses in isolated areas are speculated to be relict populations of wild horses, but generally have been proven to be feral or domestic. For example, the Riwoche horse of Tibet was proposed as such, but testing did not reveal genetic differences from domesticated horses. Similarly, the Sorraia of Portugal was proposed as a direct descendant of the Tarpan on the basis of shared characteristics, Edwards, pp. 104–105 but genetic studies have shown that the Sorraia is more closely related to other horse breeds, and that the outward similarity is an unreliable measure of relatedness.


Other modern equids

Besides the horse, there are six other species of
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''Equus'' in the Equidae
family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
. These are the ass or
donkey The donkey or ass is a domesticated equine. It derives from the African wild ass, ''Equus africanus'', and may be classified either as a subspecies thereof, ''Equus africanus asinus'', or as a separate species, ''Equus asinus''. It was domes ...
, ''Equus asinus''; the mountain zebra, ''Equus zebra'';
plains zebra The plains zebra (''Equus quagga'', formerly ''Equus burchellii'') is the most common and geographically widespread species of zebra. Its range is fragmented, but spans much of southern and eastern Africa south of the Sahara. Six or seven subspec ...
, ''Equus quagga''; Grévy's zebra, ''Equus grevyi''; the kiang, ''Equus kiang''; and the onager, ''Equus hemionus''. Horses can crossbreed with other members of their genus. The most common hybrid is the
mule The mule is a domestic equine hybrid between a donkey, and a horse. It is the offspring of a male donkey (a jack) and a female horse (a mare). The horse and the donkey are different species, with different numbers of chromosomes; of the two ...
, a cross between a "jack" (male donkey) and a
mare A mare is an adult female horse or other equidae, equine. In most cases, a mare is a female horse over the age of three, and a filly is a female horse three and younger. In Thoroughbred horse racing, a mare is defined as a female horse more th ...
. A related hybrid, a hinny, is a cross between a stallion and a "jenny" (female donkey). Other hybrids include the zorse, a cross between a zebra and a horse. With rare exceptions, most hybrids are sterile and cannot reproduce.


Domestication and history

Domestication of the horse most likely took place in central Asia prior to 3500 BCE. Two major sources of information are used to determine where and when the horse was first domesticated and how the domesticated horse spread around the world. The first source is based on palaeological and archaeological discoveries; the second source is a comparison of DNA obtained from modern horses to that from bones and teeth of ancient horse remains. The earliest archaeological evidence for attempted
domestication of the horse It is not entirely clear how, when or where the domestication of the horse took place. Although horses appeared in Paleolithic cave art as early as 30,000 BCE, these were wild horses and were probably hunted for meat. The clearest evidence o ...
comes from sites in
Ukraine Ukraine is a country in Eastern Europe. It is the List of European countries by area, second-largest country in Europe after Russia, which Russia–Ukraine border, borders it to the east and northeast. Ukraine also borders Belarus to the nor ...
and
Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a landlocked country primarily in Central Asia, with a European Kazakhstan, small portion in Eastern Europe. It borders Russia to the Kazakhstan–Russia border, north and west, China to th ...
, dating to approximately 4000–3500 BCE. However the horses domesticated at the Botai culture in Kazakhstan were Przewalski's horses and not the ancestors of modern horses. By 3000 BCE, the horse was completely domesticated and by 2000 BCE there was a sharp increase in the number of horse bones found in human settlements in northwestern Europe, indicating the spread of domesticated horses throughout the continent. The most recent, but most irrefutable evidence of domestication comes from sites where horse remains were interred with chariots in graves of the Indo-European Sintashta and Petrovka cultures 2100 BCE. A 2021 genetic study suggested that most modern domestic horses descend from the lower Volga-Don region. Ancient horse genomes indicate that these populations influenced almost all local populations as they expanded rapidly throughout
Eurasia Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...
, beginning about 4,200 years ago. It also shows that certain adaptations were strongly selected due to riding, and that equestrian material culture, including Sintashta, spoke-wheeled chariots, spread with the horse itself. Domestication is also studied by using the genetic material of present-day horses and comparing it with the genetic material present in the bones and teeth of horse remains found in archaeological and palaeological excavations. The variation in the genetic material shows that very few wild stallions contributed to the domestic horse, while many mares were part of early domesticated herds. This is reflected in the difference in genetic variation between the DNA that is passed on along the paternal, or sire line ( Y-chromosome) versus that passed on along the maternal, or dam line (
mitochondrial DNA Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondrion, mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the D ...
). There are very low levels of Y-chromosome variability, but a great deal of genetic variation in mitochondrial DNA. There is also regional variation in mitochondrial DNA due to the inclusion of wild mares in domestic herds. Another characteristic of domestication is an increase in coat color variation. In horses, this increased dramatically between 5000 and 3000 BCE. Before the availability of DNA techniques to resolve the questions related to the domestication of the horse, various hypotheses were proposed. One classification was based on body types and conformation, suggesting the presence of four basic prototypes that had adapted to their environment prior to domestication. Another hypothesis held that the four prototypes originated from a single wild species and that all different body types were entirely a result of selective breeding after domestication. However, the lack of a detectable substructure in the horse has resulted in a rejection of both hypotheses.


Feral populations

Feral horses are born and live in the wild, but are descended from domesticated animals. Many populations of feral horses exist throughout the world. Studies of feral herds have provided useful insights into the behavior of prehistoric horses, as well as greater understanding of the instincts and behaviors that drive horses that live in domesticated conditions. There are also semi-feral horses in many parts of the world, such as Dartmoor and the
New Forest The New Forest is one of the largest remaining tracts of unenclosed pasture land, heathland and forest in Southern England, covering southwest Hampshire and southeast Wiltshire. It was proclaimed a royal forest by William the Conqueror, featu ...
in the UK, where the animals are all privately owned but live for significant amounts of time in "wild" conditions on undeveloped, often public, lands. Owners of such animals often pay a fee for grazing rights.


Breeds

The concept of purebred bloodstock and a controlled, written
breed registry A breed registry, also known as a herdbook, studbook or register, in animal husbandry, the hobby of animal fancy, is an official list of animals within a specific breed whose parents are known. Animals are usually registered by their breeders w ...
has come to be particularly significant and important in modern times. Sometimes purebred horses are incorrectly or inaccurately called "thoroughbreds".
Thoroughbred The Thoroughbred is a list of horse breeds, horse breed developed for Thoroughbred racing, horse racing. Although the word ''thoroughbred'' is sometimes used to refer to any breed of purebred horse, it technically refers only to the Thorough ...
is a specific breed of horse, while a "purebred" is a horse (or any other animal) with a defined pedigree recognized by a breed registry. Ensminger, p. 424 Horse breeds are groups of horses with distinctive characteristics that are transmitted consistently to their offspring, such as conformation, color, performance ability, or disposition. These inherited traits result from a combination of natural crosses and
artificial selection Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant ...
methods. Horses have been selectively bred since their
domestication Domestication is a multi-generational Mutualism (biology), mutualistic relationship in which an animal species, such as humans or leafcutter ants, takes over control and care of another species, such as sheep or fungi, to obtain from them a st ...
. An early example of people who practiced selective
horse breeding Horse breeding is reproduction in horses, and particularly the human-directed process of selective breeding of animals, particularly purebred horses of a given Horse breed, breed. Planned matings can be used to produce specifically desired chara ...
were the
Bedouin The Bedouin, Beduin, or Bedu ( ; , singular ) are pastorally nomadic Arab tribes who have historically inhabited the desert regions in the Arabian Peninsula, North Africa, the Levant, and Mesopotamia (Iraq). The Bedouin originated in the Sy ...
, who had a reputation for careful practices, keeping extensive pedigrees of their
Arabian horse The Arabian or Arab horse ( , DIN 31635, DMG ''al-ḥiṣān al-ʿarabī'') is a horse breed, breed of horse with historic roots on the Arabian Peninsula. With a distinctive head shape and high tail carriage, the Arabian is one of the most easi ...
s and placing great value upon pure bloodlines. These pedigrees were originally transmitted via an
oral tradition Oral tradition, or oral lore, is a form of human communication in which knowledge, art, ideas and culture are received, preserved, and transmitted orally from one generation to another.Jan Vansina, Vansina, Jan: ''Oral Tradition as History'' (19 ...
. Breeds developed due to a need for "form to function", the necessity to develop certain characteristics in order to perform a particular type of work. Sponenberg, p. 155 Thus, a powerful but refined breed such as the Andalusian developed as riding horses with an aptitude for
dressage Dressage ( or ; , most commonly translated as "training") is a form of horse riding performed in exhibition and competition, as well as an art sometimes pursued solely for the sake of mastery. As an equestrianism, equestrian sport defined by th ...
. Heavy draft horses were developed out of a need to perform demanding
farm A farm (also called an agricultural holding) is an area of land that is devoted primarily to agricultural processes with the primary objective of producing food and other crops; it is the basic facility in food production. The name is used fo ...
work and pull heavy wagons. Other horse breeds had been developed specifically for light agricultural work, carriage and road work, various sport disciplines, or simply as pets. Sponenberg, p. 162 Some breeds developed through centuries of crossing other breeds, while others descended from a single foundation sire, or other limited or restricted foundation bloodstock. One of the earliest formal registries was General Stud Book for Thoroughbreds, which began in 1791 and traced back to the foundation bloodstock for the breed. There are more than 300 horse breeds in the world today.


Interaction with humans

Worldwide, horses play a role within human cultures and have done so for millennia. Horses are used for leisure activities, sports, and working purposes. The
Food and Agriculture Organization The Food and Agriculture Organization of the United Nations; . (FAO) is a specialized agency of the United Nations that leads international efforts to defeat hunger and improve nutrition and food security. Its Latin motto, , translates ...
(FAO) estimates that in 2008, there were almost 59,000,000 horses in the world, with around 33,500,000 in the Americas, 13,800,000 in Asia and 6,300,000 in Europe and smaller portions in Africa and Oceania. There are estimated to be 9,500,000 horses in the United States alone. The American Horse Council estimates that horse-related activities have a direct impact on the economy of the United States of over $39 billion, and when indirect spending is considered, the impact is over $102 billion. In a 2004 "poll" conducted by Animal Planet, more than 50,000 viewers from 73 countries voted for the horse as the world's 4th favorite animal. Communication between human and horse is paramount in any equestrian activity; to aid this process horses are usually ridden with a
saddle A saddle is a supportive structure for a rider of an animal, fastened to an animal's back by a girth. The most common type is equestrian. However, specialized saddles have been created for oxen, camels and other animals. It is not know ...
on their backs to assist the rider with balance and positioning, and a bridle or related headgear to assist the rider in maintaining control. Sometimes horses are ridden without a saddle, and occasionally, horses are trained to perform without a bridle or other headgear. Many horses are also driven, which requires a harness, bridle, and some type of
vehicle A vehicle () is a machine designed for self-propulsion, usually to transport people, cargo, or both. The term "vehicle" typically refers to land vehicles such as human-powered land vehicle, human-powered vehicles (e.g. bicycles, tricycles, velo ...
.


Sport

Historically, equestrians honed their skills through games and races. Equestrian sports provided entertainment for crowds and honed the excellent horsemanship that was needed in battle. Many sports, such as
dressage Dressage ( or ; , most commonly translated as "training") is a form of horse riding performed in exhibition and competition, as well as an art sometimes pursued solely for the sake of mastery. As an equestrianism, equestrian sport defined by th ...
, eventing, and show jumping, have origins in military training, which were focused on control and balance of both horse and rider. Other sports, such as
rodeo Rodeo () is a competitive equestrian sport that arose out of the working practices of cattle herding in Spain and Mexico, expanding throughout the Americas and to other nations. It was originally based on the skills required of the working vaqu ...
, developed from practical skills such as those needed on working
ranch A ranch (from /Mexican Spanish) is an area of landscape, land, including various structures, given primarily to ranching, the practice of raising grazing livestock such as cattle and sheep. It is a subtype of farm. These terms are most often ap ...
es and stations. Sport hunting from horseback evolved from earlier practical hunting techniques.
Horse racing Horse racing is an equestrian performance activity, typically involving two or more horses ridden by jockeys (or sometimes driven without riders) over a set distance for competition. It is one of the most ancient of all sports, as its bas ...
of all types evolved from impromptu competitions between riders or drivers. All forms of competition, requiring demanding and specialized skills from both horse and rider, resulted in the systematic development of specialized breeds and equipment for each sport. The popularity of equestrian sports through the centuries has resulted in the preservation of skills that would otherwise have disappeared after horses stopped being used in combat. Horses are trained to be ridden or driven in a variety of sporting competitions. Examples include show jumping,
dressage Dressage ( or ; , most commonly translated as "training") is a form of horse riding performed in exhibition and competition, as well as an art sometimes pursued solely for the sake of mastery. As an equestrianism, equestrian sport defined by th ...
, three-day eventing, competitive driving,
endurance riding Endurance riding is an equestrian sport based on controlled long-distance races. It is one of the international competitions recognized by the FEI. There are endurance rides worldwide. Endurance rides can be any distance, though they are rar ...
, gymkhana,
rodeo Rodeo () is a competitive equestrian sport that arose out of the working practices of cattle herding in Spain and Mexico, expanding throughout the Americas and to other nations. It was originally based on the skills required of the working vaqu ...
s, and
fox hunting Fox hunting is an activity involving the tracking, chase and, if caught, the killing of a fox, normally a red fox, by trained foxhounds or other scent hounds. A group of unarmed followers, led by a "master of foxhounds" (or "master of hounds" ...
.
Horse show A horse show is a judged exhibition of horses and pony, ponies. Many different horse breeds and equestrianism, equestrian disciplines hold competitions worldwide, from local to the international levels. Most horse shows run from one to three days ...
s, which have their origins in medieval European fairs, are held around the world. They host a huge range of classes, covering all of the mounted and harness disciplines, as well as "In-hand" classes where the horses are led, rather than ridden, to be evaluated on their conformation. The method of judging varies with the discipline, but winning usually depends on style and ability of both horse and rider. Sports such as polo do not judge the horse itself, but rather use the horse as a partner for human competitors as a necessary part of the game. Although the horse requires specialized training to participate, the details of its performance are not judged, only the result of the rider's actions—be it getting a ball through a goal or some other task. Edwards, p. 360 Examples of these sports of partnership between human and horse include
jousting Jousting is a medieval and renaissance martial game or hastilude between two combatants either on horse or on foot. The joust became an iconic characteristic of the knight in Romantic medievalism. The term is derived from Old French , ultim ...
, in which the main goal is for one rider to unseat the other, and buzkashi, a team game played throughout
Central Asia Central Asia is a region of Asia consisting of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The countries as a group are also colloquially referred to as the "-stans" as all have names ending with the Persian language, Pers ...
, the aim being to capture a goat carcass while on horseback.
Horse racing Horse racing is an equestrian performance activity, typically involving two or more horses ridden by jockeys (or sometimes driven without riders) over a set distance for competition. It is one of the most ancient of all sports, as its bas ...
is an equestrian sport and major international industry, watched in almost every nation of the world. There are three types: "flat" racing; steeplechasing, i.e. racing over jumps; and harness racing, where horses trot or pace while pulling a driver in a small, light cart known as a sulky. A major part of horse racing's economic importance lies in the
gambling Gambling (also known as betting or gaming) is the wagering of something of Value (economics), value ("the stakes") on a Event (probability theory), random event with the intent of winning something else of value, where instances of strategy (ga ...
associated with it.


Work

There are certain jobs that horses do very well, and no technology has yet developed to fully replace them. For example,
mounted police Mounted police are police who patrol on horseback or camelback. Their day-to-day function is typically picturesque or ceremonial, but they are also employed in crowd control because of their mobile mass and height advantage and increasingly in th ...
horses are still effective for certain types of patrol duties and crowd control. Cattle
ranch A ranch (from /Mexican Spanish) is an area of landscape, land, including various structures, given primarily to ranching, the practice of raising grazing livestock such as cattle and sheep. It is a subtype of farm. These terms are most often ap ...
es still require riders on horseback to round up cattle that are scattered across remote, rugged terrain.
Search and rescue Search and rescue (SAR) is the search for and provision of aid to people who are in distress or imminent danger. The general field of search and rescue includes many specialty sub-fields, typically determined by the type of terrain the search ...
organizations in some countries depend upon mounted teams to locate people, particularly hikers and children, and to provide disaster relief assistance. Horses can also be used in areas where it is necessary to avoid vehicular disruption to delicate soil, such as nature reserves. They may also be the only form of transport allowed in
wilderness area Wilderness or wildlands (usually in the plural) are Earth's natural environments that have not been significantly modified by human activity, or any nonurbanized land not under extensive agricultural cultivation. The term has traditionally ...
s. Horses are quieter than motorized vehicles. Law enforcement officers such as
park ranger A ranger, park ranger, park warden, field ranger, or forest ranger is a person entrusted with protecting and preserving parklands and Protected area, protected areas – private, national, state, provincial, or local parks. Their duties include ( ...
s or
game warden A conservation officer is a law enforcement officer who protects wildlife and the environment. A conservation officer may also be referred to as an environmental technician/technologist, game warden, park ranger, forest watcher, forest guar ...
s may use horses for patrols, and horses or mules may also be used for clearing trails or other work in areas of rough terrain where vehicles are less effective. Although machinery has replaced horses in many parts of the world, an estimated 100 million horses, donkeys and mules are still used for agriculture and transportation in less developed areas. This number includes around 27 million working animals in Africa alone. Some land management practices such as cultivating and logging can be efficiently performed with horses. In agriculture, less fossil fuel is used and increased environmental conservation occurs over time with the use of draft animals such as horses. Logging with horses can result in reduced damage to soil structure and less damage to trees due to more selective logging.


Warfare

Horses have been used in warfare for most of recorded history. The first archaeological evidence of horses used in warfare dates to between 4000 and 3000 BCE, and the use of horses in warfare was widespread by the end of the
Bronze Age The Bronze Age () was a historical period characterised principally by the use of bronze tools and the development of complex urban societies, as well as the adoption of writing in some areas. The Bronze Age is the middle principal period of ...
. Whitaker, pp. 30–31 Although mechanization has largely replaced the horse as a weapon of war, horses are still seen today in limited military uses, mostly for ceremonial purposes, or for reconnaissance and transport activities in areas of rough terrain where motorized vehicles are ineffective. Horses have been used in the 21st century by the
Janjaweed The Janjaweed () are an Sudanese Arabs, Arab nomad militia group operating in the Sahel, Sahel region, specifically in Sudan, particularly in Darfur and eastern Chad. They have also been speculated to be active in Yemen. According to the United ...
militias in the
War in Darfur The War in Darfur, also nicknamed the Land Cruiser War, was a major armed conflict in the Darfur region of Sudan that began in February 2003 when the Sudan Liberation Movement/Army, Sudan Liberation Movement (SLM) and the Justice and Equalit ...
.


Entertainment and culture

Modern horses are often used to reenact many of their historical work purposes. Horses are used, complete with equipment that is authentic or a meticulously recreated replica, in various live action historical reenactments of specific periods of history, especially recreations of famous battles. Horses are also used to preserve cultural traditions and for ceremonial purposes. Countries such as the United Kingdom still use horse-drawn carriages to convey royalty and other VIPs to and from certain culturally significant events. Public exhibitions are another example, such as the Budweiser Clydesdales, seen in parades and other public settings, a team of
draft horse A draft horse (US) or draught horse (UK), also known as dray horse, carthorse, work horse or heavy horse, is a large horse bred to be a working animal hauling freight and doing heavy agricultural tasks such as plowing. There are a number o ...
s that pull a beer wagon similar to that used before the invention of the modern motorized truck. Horses are frequently used in television, films and literature. They are sometimes featured as a major character in films about particular animals, but also used as visual elements that assure the accuracy of historical stories. Both live horses and iconic images of horses are used in
advertising Advertising is the practice and techniques employed to bring attention to a Product (business), product or Service (economics), service. Advertising aims to present a product or service in terms of utility, advantages, and qualities of int ...
to promote a variety of products. The horse frequently appears in coats of arms in
heraldry Heraldry is a discipline relating to the design, display and study of armorial bearings (known as armory), as well as related disciplines, such as vexillology, together with the study of ceremony, Imperial, royal and noble ranks, rank and genealo ...
, in a variety of poses and equipment. The
mythologies Myth is a genre of folklore consisting primarily of narratives that play a fundamental role in a society. For scholars, this is very different from the vernacular usage of the term "myth" that refers to a belief that is not true. Instead, the ...
of many cultures, including Greco-Roman,
Hindu Hindus (; ; also known as Sanātanīs) are people who religiously adhere to Hinduism, also known by its endonym Sanātana Dharma. Jeffery D. Long (2007), A Vision for Hinduism, IB Tauris, , pp. 35–37 Historically, the term has also be ...
,
Islamic Islam is an Abrahamic religions, Abrahamic monotheistic religion based on the Quran, and the teachings of Muhammad. Adherents of Islam are called Muslims, who are estimated to number Islam by country, 2 billion worldwide and are the world ...
, and Germanic, include references to both normal horses and those with wings or additional limbs, and multiple myths also call upon the horse to draw the chariots of the Moon and Sun. The horse also appears in the 12-year cycle of animals in the Chinese zodiac related to the
Chinese calendar The traditional Chinese calendar, dating back to the Han dynasty, is a lunisolar calendar that blends solar, lunar, and other cycles for social and agricultural purposes. While modern China primarily uses the Gregorian calendar for officia ...
. Horses serve as the inspiration for many modern automobile names and logos, including the Ford Pinto,
Ford Bronco The Ford Bronco is a model line of SUV, SUVs manufactured and marketed by Ford Motor Company, Ford. The first SUV model developed by the company, five generations of the Bronco were sold from the 1966 to 1996 model years. A sixth generation of ...
, Ford Mustang, Hyundai Equus, Hyundai Pony, Mitsubishi Starion, Subaru Brumby, Mitsubishi Colt/ Dodge Colt, Pinzgauer, Steyr-Puch Haflinger, Pegaso, Porsche, Rolls-Royce Camargue,
Ferrari Ferrari S.p.A. (; ) is an Italian luxury sports car manufacturer based in Maranello. Founded in 1939 by Enzo Ferrari (1898–1988), the company built Auto Avio Costruzioni 815, its first car in 1940, adopted its current name in 1945, and be ...
, Carlsson, Kamaz, Corre La Licorne, Iran Khodro, Eicher, and Baojun. Indian TVS Motor Company also uses a horse on their motorcycles & scooters.


Therapeutic use

People of all ages with physical and mental disabilities obtain beneficial results from an association with horses. Therapeutic riding is used to mentally and physically stimulate disabled persons and help them improve their lives through improved balance and coordination, increased self-confidence, and a greater feeling of freedom and independence. The benefits of equestrian activity for people with disabilities has also been recognized with the addition of equestrian events to the
Paralympic Games The Paralympic Games or Paralympics is a periodic series of international multisport events involving athletes with a range of disability, disabilities. There are Winter Paralympic Games, Winter and Summer Paralympic Games, which since the 1988 ...
and recognition of para-equestrian events by the
International Federation for Equestrian Sports The International Federation for Equestrian Sports (, FEI) is the international sport governing body, governing body of equestrianism, equestrian sports. The FEI came into being following the Olympic Congress in Lausanne (SUI) in 1921 from May ...
(FEI). Hippotherapy and therapeutic horseback riding are names for different physical, occupational, and speech therapy treatment strategies that use equine movement. In hippotherapy, a therapist uses the horse's movement to improve their patient's cognitive, coordination, balance, and fine motor skills, whereas therapeutic horseback riding uses specific riding skills. Horses also provide psychological benefits to people whether they actually ride or not. "Equine-assisted" or "equine-facilitated" therapy is a form of experiential
psychotherapy Psychotherapy (also psychological therapy, talk therapy, or talking therapy) is the use of Psychology, psychological methods, particularly when based on regular Conversation, personal interaction, to help a person change behavior, increase hap ...
that uses horses as companion animals to assist people with mental illness, including anxiety disorders, psychotic disorders, mood disorders, behavioral difficulties, and those who are going through major life changes. There are also experimental programs using horses in
prison A prison, also known as a jail, gaol, penitentiary, detention center, correction center, correctional facility, or remand center, is a facility where Prisoner, people are Imprisonment, imprisoned under the authority of the State (polity), state ...
settings. Exposure to horses appears to improve the behavior of inmates and help reduce
recidivism Recidivism (; from 'recurring', derived from 'again' and 'to fall') is the act of a person repeating an undesirable behavior after they have experienced negative consequences of that behavior, or have been trained to Extinction (psycholo ...
when they leave.


Products

Horses are raw material for many products made by humans throughout history, including byproducts from the slaughter of horses as well as materials collected from living horses. Products collected from living horses include mare's milk, used by people with large horse herds, such as the
Mongols Mongols are an East Asian ethnic group native to Mongolia, China ( Inner Mongolia and other 11 autonomous territories), as well as the republics of Buryatia and Kalmykia in Russia. The Mongols are the principal member of the large family o ...
, who let it ferment to produce
kumis ''Kumis'' ( , ), alternatively spelled ''coumis'' or ''kumyz'', also known as ''airag'' ( ), is a traditional Fermented milk products, fermented dairy product made from mare milk. The drink is important to the peoples of the Central and East ...
. Horse blood was once used as food by the Mongols and other nomadic tribes, who found it a convenient source of nutrition when traveling. Drinking their own horses' blood allowed the Mongols to ride for extended periods of time without stopping to eat. The drug Premarin is a mixture of
estrogen Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three ...
s extracted from the urine of pregnant mares (pregnant mares' urine), and was previously a widely used drug for hormone replacement therapy. The tail hair of horses can be used for making bows for
string instrument In musical instrument classification, string instruments, or chordophones, are musical instruments that produce sound from vibrating strings when a performer strums, plucks, strikes or sounds the strings in varying manners. Musicians play some ...
s such as the
violin The violin, sometimes referred to as a fiddle, is a wooden chordophone, and is the smallest, and thus highest-pitched instrument (soprano) in regular use in the violin family. Smaller violin-type instruments exist, including the violino picc ...
, viola,
cello The violoncello ( , ), commonly abbreviated as cello ( ), is a middle pitched bowed (sometimes pizzicato, plucked and occasionally col legno, hit) string instrument of the violin family. Its four strings are usually intonation (music), tuned i ...
, and
double bass The double bass (), also known as the upright bass, the acoustic bass, the bull fiddle, or simply the bass, is the largest and lowest-pitched string instrument, chordophone in the modern orchestra, symphony orchestra (excluding rare additions ...
. Horse meat has been used as food for humans and carnivorous animals throughout the ages. Approximately 5 million horses are slaughtered each year for meat worldwide. It is eaten in many parts of the world, though consumption is
taboo A taboo is a social group's ban, prohibition or avoidance of something (usually an utterance or behavior) based on the group's sense that it is excessively repulsive, offensive, sacred or allowed only for certain people.''Encyclopædia Britannica ...
in some cultures, and a subject of political controversy in others. Horsehide leather has been used for boots, gloves,
jackets A jacket is a garment for the upper body, usually extending below the hips. A jacket typically has sleeves and fastens in the front or slightly on the side. Jackets without sleeves are vests. A jacket is generally lighter, tighter-fitting, and l ...
, baseballs, and baseball gloves. Horse hooves can also be used to produce
animal glue Animal glue is an adhesive that is created by prolonged boiling of animal connective tissue in a process called Rendering (animal products), rendering. In addition to being used as an adhesive, it is used for coating and sizing, in decorative co ...
. Horse bones can be used to make implements. Specifically, in Italian cuisine, the horse
tibia The tibia (; : tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two Leg bones, bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outsi ...
is sharpened into a probe called a ''spinto'', which is used to test the readiness of a (pig) ham as it cures. In Asia, the ''saba'' is a horsehide vessel used in the production of
kumis ''Kumis'' ( , ), alternatively spelled ''coumis'' or ''kumyz'', also known as ''airag'' ( ), is a traditional Fermented milk products, fermented dairy product made from mare milk. The drink is important to the peoples of the Central and East ...
.


Care

Horses are
grazing In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to free range (roam around) and consume wild vegetations in order to feed conversion ratio, convert the otherwise indigestible (by human diges ...
animals, and their major source of nutrients is good-quality forage from hay or pasture. They can consume approximately 2% to 2.5% of their body weight in dry feed each day. Therefore, a adult horse could eat up to of food. Sometimes, concentrated feed such as
grain A grain is a small, hard, dry fruit (caryopsis) – with or without an attached husk, hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and ...
is fed in addition to pasture or hay, especially when the animal is very active. When grain is fed, equine nutritionists recommend that 50% or more of the animal's diet by weight should still be forage. Horses require a plentiful supply of clean water, a minimum of per day. Although horses are adapted to live outside, they require shelter from the wind and
precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...
, which can range from a simple shed or shelter to an elaborate stable. Horses require routine hoof care from a farrier, as well as
vaccination Vaccination is the administration of a vaccine to help the immune system develop immunity from a disease. Vaccines contain a microorganism or virus in a weakened, live or killed state, or proteins or toxins from the organism. In stimulating ...
s to protect against various diseases, and dental examinations from a
veterinarian A veterinarian (vet) or veterinary surgeon is a medical professional who practices veterinary medicine. They manage a wide range of health conditions and injuries in non-human animals. Along with this, veterinarians also play a role in animal r ...
or a specialized equine dentist. If horses are kept inside in a barn, they require regular daily exercise for their physical health and mental well-being. When turned outside, they require well-maintained, sturdy fences to be safely contained. Regular grooming is also helpful to help the horse maintain good health of the hair coat and underlying skin. Giffin, p. 90


Climate change


See also

*
Glossary of equestrian terms This is a basic glossary of equestrian terms that includes both technical terminology and jargon developed over the centuries for horses and other equidae, as well as various horse-related concepts. Where noted, some terms are used only in Americ ...
* List of films about horse racing * List of films about horses * List of historical horses * Lists of horse-related topics


References


Sources

* * * * * * * * * * * *


Further reading

* * Doniger, Wendy, "The Rise and Fall of Warhorses" (review of David Chaffetz, ''Raiders, Rulers, and Traders: The Horse and the Rise of Empires'', Norton, 2024, 424 pp.), ''
The New York Review of Books ''The New York Review of Books'' (or ''NYREV'' or ''NYRB'') is a semi-monthly magazine with articles on literature, culture, economics, science and current affairs. Published in New York City, it is inspired by the idea that the discussion of ...
'', vol. LXXII, no. 6 (10 April 2025), pp. 17–19.


External links


"Ancient horse bone yields oldest DNA sequence"
* *
Genome of ''Equus caballus''
via Ensembl
Genome of ''Equus caballus'' (version EquCab3.0/equCab3)
via UCSC Genome Browser
Data of the genome of ''Equus caballus''
via NCBI
Data of the genome assembly of ''Equus caballus'' (versión EquCab3.0/equCab3)
via NCBI {{Authority control Animal-powered transport Equus (genus) Herbivorous mammals Horse subspecies Livestock Mammals described in 1758 National symbols of Burkina Faso National symbols of Lesotho National symbols of Mongolia National symbols of Nigeria National symbols of Turkmenistan Pack animals Symbols of New Jersey Taxa named by Carl Linnaeus