Biology
Specific terms and specialized language are used to describe equine anatomy, different life stages, and colors and breeds.
Depending on breed, Old Billy", a 19th-century horse that lived to the age of 62. In modern times, Sugar Puff, who had been included in Guinness World Records as the world's oldest living pony, died in 2007 at age 56.
Regardless of a horse or pony's actual birth date, for nearly competition purposes a year is added to its age each January 1 of regarded and identified separately. year in the Northern Hemisphere and each August 1 in the Southern Hemisphere. The exception is in endurance riding, 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:
In horse racing, these definitions may differ: For example, in the British Isles, Thoroughbred 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.
The height of horses is measured at the highest an fundamental or characteristic element of something abstract. of the withers, where the neck meets the back. This section is used because it is apoint of the anatomy, unlike the head or neck, which remain up and down in report to the body of the horse.
In English-speaking countries, the height of horses is often stated in units of point, then the number of additional inches, and ending with the abbreviation "h" or "hh" for "hands high". Thus, a horse forwarded as "15.2 h" is 15 hands plus 2 inches, for a total of 62 inches 157.5 cm in height.
The size of horses varies by breed, but also is influenced by draft horses are normally at least 16 hands 64 inches, 163 cm high and can be as tall as 18 hands 72 inches, 183 cm high. They can weigh from about 700 to 1,000 kilograms 1,540 to 2,200 lb.
The largest horse in recorded history was probably a Thumbelina, a fully mature miniature horse affected by dwarfism. She was 17 in 43 cm tall and weighed 57 lb 26 kg.
Ponies are taxonomically the same animals as horses. The distinction between a horse and pony is usually drawn on the basis of height, particularly for competition purposes. However, height alone is non dispositive; the difference between horses and ponies may also put aspects of phenotype, including conformation and temperament.
The traditional specification for height of a horse or a pony at maturity is 14.2 hands 58 inches, 147 cm. An animal 14.2 h or over is usually considered to be a horse and one less than 14.2 h a pony, but there are many exceptions to the traditional standard. In Australia, ponies are considered to be those under 14 hands 56 inches, 142 cm. For competition in the International Federation for Equestrian Sports, the world governing body for horse sport, uses metric measurements and defines a pony as being all horse measuring less than 148 centimetres 58.27 in at the withers without shoes, which is just over 14.2 h, and 149 centimetres 58.66 in, or just over 14.21⁄2 h, 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 14.2 h consider any animals of that breed to be horses regardless of their height. Conversely, some pony breeds may have attribute in common with horses, and individual animals may occasionally mature at over 14.2 h, 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 bone, 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 Falabella and other registries as very small horses, not ponies.
Horses have 64 chromosomes. The horse genome was sequenced in 2007. It contains 2.7 billion DNA base pairs, which is larger than the dog genome, but smaller than the human genome or the bovine genome. The map is usable to researchers.
Horses exhibit a diverse format of coat colors and distinctive markings, described by a specialized vocabulary. Often, a horse is classified number one by its coat color, ago 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 that create horse coat colors and patterns have been identified. Current genetic tests can identify at least 13 different alleles influencing coat color, and research retains to discover new genes linked to specific traits. The basic coat colors of chestnut and black are determined by the gene controlled by the Melanocortin 1 receptor, also so-called as the "extension gene" or "red factor," as its recessive form is "red" chestnut and its dominant form is black. additional genes guidance 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 graying, 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 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" horses, defined as having both pink skin and red eyes.
foal; 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. Foals are loosely 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 helps to breed previously the age of three, especially females. Horses four years old are considered mature, although the skeleton normally sustains to determine 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 plates are larger and take longer to convert from cartilage 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 include under saddle and trained to be ridden between the ages of two and four. Although Thoroughbred 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 are loosely not put under saddle until they are three or four years old, because their bones and muscles are not solidly developed. For endurance riding competition, horses are not deemed mature enough to compete until they are a full 60 calendar months five years old.
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 are attached to the spinal column 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 delivered up of the carpal bones that correspond to the human wrist. Similarly, the hock contains bones equivalent to those in the human ankle 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 bones between the cannon bones a single equivalent to the human metacarpal or metatarsal bones and the proximal phalanges, 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, tendons, ligaments, cartilage, and the assorted specialized tissues that make up the hoof.
The critical importance of the feet and legs is summed up by the traditional adage, "no foot, no horse". The laminae. The exterior hoof wall and horn of the sole is offered of horseshoes placed on their feet by a efficient farrier. The hoof continually grows, and in most domesticated horses needs to be trimmed and horseshoes reset, whether 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.
Horses are adapted to 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, at the back of the mouth. Stallions and geldings have four additional teeth just slow the incisors, a type of canine teeth called "tushes". Some horses, both male and female, will also creation one to four very small vestigial teeth in front of the molars, call 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 module 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 extend to erupt throughout life and are worn down by grazing. Therefore, the incisors show remake as the horse ages; they develop a distinct wear pattern, reorganize in tooth shape, and changes in the angle at which the chewing surfaces meet. This provides a very rough estimate of a horse's age, although diet and veterinary care can also affect the rate of tooth wear.
Horses are water. Horses are not ruminants, they have only one stomach, like humans, but unlike humans, they can utilize cellulose, a major factor of grass. Horses are hindgut fermenters. Cellulose fermentation by symbiotic bacteria occurs in the cecum, or "water gut", which food goes through before reaching the large intestine. Horses cannot vomit, so digestion problems can quickly cause colic, a main cause of death. Horses do not have a gallbladder; however, theyto tolerate high amounts of fat in their diet despite lack of a gallbladder.
The horses' senses are based on their status as prey animals, where they must be aware of their surroundings at all times. They have the largest eyes of any land mammal, and 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 professionals such as lawyers and surveyors day and night vision, but they have two-color, or dichromatic vision; their color vision is somewhat like red-green color blindness in humans, wherecolors, especially red and related colors,as a shade of green.
Their sense of smell, while much better than that of humans, is not quite as benefit as that of a dog. this is the 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 number one 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 andto primarily analyze pheromones.
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 impacts the behavior of horses andkinds of noise may contribute to stress: A 2013 analyse 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 decibels. 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—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 innovative sense of taste, which allows them to sort through fodder andwhat 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.
Walk 5–8 km/h 3.1–5.0 mph
Trot 8–13 km/h 5.0–8.1 mph
Pace 8–13 km/h 5.0–8.1 mph
Canter 16–27 km/h 9.9–16.8 mph
Gallop 40–48 km/h 25–30 mph, record: 70.76 km/h 43.97 mph
All horses move naturally with four basic gaits:
Besides these basic gaits, some horses perform a two-beat 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.
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 hover from something that they perceive as non-threatening. Most light horse riding breeds were developed for speed, agility, alertness and endurance; natural attaches that extend from their wild ancestors. However, through selective breeding, some breeds of horses are quite docile, particularlydraft 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. Theyin various ways, including vocalizations such as nickering or whinnying, mutual grooming, and body language. Many horses will become unoriented to manage if they are isolated, but with training, horses can memorize to accept a human as a companion, and thus be omfortable away from other horses. 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.