Gray or grey is a coat color of horses characterized by progressive silvering of the colored hairs of the coat. Horses exhibit a diverse array of coat colors and distinctive markings. The horse ( Equus caballus) is a hoofed ( Ungulate) Mammal, one of eight living species of the family Equidae. [1] Most gray horses have black skin and dark eyes; unlike many depigmentation genes, gray does not affect skin or eye color[1] Their adult hair coat is white, dappled, or white intermingled with hairs of other colors. Gray horses may be born any base color, depending on other color genes present. White hairs begin to appear at or shortly after birth and become progressivly lighter as the horse ages. Graying can occur at different rates--very quickly on one horse and very slowly on another.
Gray horses appear in many breeds, though the color is most commonly seen in breeds descended from Arabian ancestors. Meyers b12 s0947bjpg|thumb|Heavy or draft horse breeds]] This page is a list of Horse and Pony breeds and also includes terms used to describe types of horses that are not The Arabian horse is a breed of Horse with a reputation for Intelligence, spirit and stamina Some breeds that have large numbers of gray-colored horses include the Thoroughbred, the Arabian, the American Quarter Horse, the Percheron, the Andalusian, the Welsh pony, and the most famous of all gray horse breedss, the Lipizzaner. The Thoroughbred is a horse breed The Arabian horse is a breed of Horse with a reputation for Intelligence, spirit and stamina The Lipizzan or Lipizzaner ( Slovene Lipicanec) is a breed of Horse closely associated with the Spanish Riding School
Many people who are unfamiliar with horses call gray horses "white. " However, a gray horse whose hair coat is completely "white" will still have black skin (except under markings that were white at birth) and dark eyes. Note This article is about individualized markings on any breed type or color of horse and does not discuss coat colors generally This is how most people can tell a gray horse from a white horse. White horses usually have pink skin and frequently have blue eyes. True Young horses with hair coats consisting of a mixture of colored and gray or white hairs are sometimes confused with roan. Roan is a coat color found in many animals notably Horses Cattle and Dogs It is defined generally as an even mixture of white and pigmented hairs that Some horses that carry dilution genes may also be confused with white or gray. Dilution gene is a popular term for any one of a number of Genes that act to create a lighter coat color in living creatures
While gray is commonly called a coat color by breed registries, genetically it may be more correct to call it a depigmentation pattern. A breed registry, also known as a stud book or register, in Animal husbandry and the Hobby of Animal fancy, is an official list of It is a dominant gene,[1] and thus a horse needs only one copy of the gray allele, that is, heterozygous, to be gray in color. An allele (ˈæliːl (UK /əˈliːl/ (US (from the Greek αλληλος allelos, meaning each other) is one member of a pair or series of different forms Zygosity refers to the genetic condition of a Zygote. In genetics zygosity describes the similarity or dissimilarity of DNA between Homologous A homozygous gray horse, one carrying two gray alleles, will always produce gray foals. Zygosity refers to the genetic condition of a Zygote. In genetics zygosity describes the similarity or dissimilarity of DNA between Homologous
Contents |
Prevalence
Gray is common in many breeds. The vast majority of Lipizzaners are gray, as are the majority of Andalusian horses. The Lipizzan or Lipizzaner ( Slovene Lipicanec) is a breed of Horse closely associated with the Spanish Riding School Many breeds of French draft horse such as the Percheron and Boulonnais are often gray as well. The Boulonnais, also known as the "White Gray is also found among Welsh Ponies, Thoroughbreds, and American Quarter Horses. The Thoroughbred is a horse breed All of these breeds have common ancestry in the Arabian horse. The Arabian horse is a breed of Horse with a reputation for Intelligence, spirit and stamina In particular, all gray Thoroughbreds descend from a horse named Alcock's Arabian, a gray born in 1700. [2] The gray coat color makes up about 3% of Thoroughbreds. [3]
Gray also occurs in spotted horses such as pintos or Appaloosas, but its effects wash out the contrast of the markings of these patterns. A Pinto horse has a coat color that consists of large patches of white and another color For this reason, some color breed registries refuse or cancel registration of gray horses. A color breed is a term that refers to Horses that are registered based primarily on their coat color regardless of the horse's actual breed or breed type
Changes in the color of gray horses
A gray foal may be born any color. A foal is a Horse that is one year old or younger More specific terms are colt for a Male foal and Filly for a Female foal However, bay, chestnut, or black base colors are most often seen. Bay is a hair coat color of Horses characterized by a reddish brown body color with a black Mane, Tail, ear edges and lower Chestnut is a hair coat color of Horses consisting of a reddish-to-brown coat with a mane and tail the same or lighter in color than the coat Black is a hair coat color of Horses in which the entire hair coat is black As the horse matures, white hairs begin to replace the base or birth color. Usually white hairs are first seen by the muzzle, eyes and flanks, occasionally at birth, and usually by the age of one year. Over time, white hairs replace the birth color and the horse changes slowly to either a rose gray, salt and pepper (or iron gray), or dapple gray. As the horse gets older, the coat continues to lightens further to a pure white or fleabitten gray hair coat. Thus, the many variations of gray coloring in horses are simply intermediate steps that a young horse takes while graying out from a birth color to a hair coat that is completely "white. "
Different breeds, and individuals within each breed, take differing amounts of time to gray out. Graying therefore cannot be used to approximate the age of a horse except in the broadest of terms: a very young horse will never have a white coat (unless it is a true white horse), while a horse in its teens usually is completely grayed out. True One must also be careful not to confuse the small amount of gray hairs that may appear on some older horses in their late teens or twenties, which do not reflect the gray gene and never cause a complete graying of the horse.
This change in hair color can be confusing. Many new horse owners, not understanding the workings of the gray gene, are disappointed to discover that their dapple gray horse turns completely white a few years later! Other times, people traveling with gray horses who have a pure white hair coat have run into problems with non-horse-oriented officials such as police officers or border guards who are confused over a horse who has papers saying it is "gray" when the horse is front of them appears white! When a black horse is born it will normally turn white or gray as it gets older, and frekles may apper.
Young gray horses
An intermediate stage in young horses that are in the early stages of turning gray is sometimes called "salt and pepper," "iron gray" or "steel gray. " This coloring occurs when white and black hairs are intermingled together on the body, usually seen in horses that are born black or dark bay. This is the most common intermediate form of gray, which can give a silvery look to the coat. "Rose gray" is a term used to describe this intermediate stage for horse born a chestnut or lighter bay color. While these colors are "graying out," both red and white hairs are often mixed together on the body. Thus rose gray horses have a slight pinkish tinge to their graying coat. These horses are sometimes confused with roan, but a gray continues to lighten with age, while a roan does not. Roan is a coat color found in many animals notably Horses Cattle and Dogs It is defined generally as an even mixture of white and pigmented hairs that
Dapple gray
"Dapple gray" is an intermediate stage not seen on all grays, but often considered highly attractive. It consists of a dark hair coat with "dapples," which are dark rings with lighter hairs on the inside of the ring, scattered over the entire body of the animal. It is another possible intermediate step in the graying process of the horse. Dappled grays should not be confused with the slight dappling "bloom" seen on horses that are very healthy or slightly overweight, as "bloom" dapples disappear should the horse lose condition.
The "flea-bitten" gray
A horse that has completely changed its base coat will either be pure white or "flea-bitten" gray. Fleabitten gray is a color consisting of a white hair coat with small speckles or "freckles" of red-colored hair throughout. Most horses who become fleabitten grays still go through a brief period when they are pure white.
The fleabitten pattern, like freckles on a human, can also vary: Some horses may appear almost pure white, with only a few speckles observed on close examination. Others may have so many speckles that they are occasionally mistaken for a roan or even a type of sabino. Sabino is a color spotting pattern in Horses that is usually recognized as a form of Pinto horse color One unique form of fleabitten gray is the "bloody shouldered" horse. This is an animal that is so heavily flea-bitten on certain parts of the body, usually the shoulder area, that it almost appears as if blood had been spilled on the horse, hence the name. In the traditions of the desert Bedouin people who bred the Arabian horse, the "bloody shoulder" was a prized trait in a war mare and much desired. The Bedouin, (from the Arabic (ar بدوي pl badū) are a desert-dwelling Arab Nomadic pastoralist, or previously The Arabian horse is a breed of Horse with a reputation for Intelligence, spirit and stamina In some cases, a "bloody shoulder" might in theory also be caused the sabino or rabicano gene acting in addition to a gray coat. Sabino is a color spotting pattern in Horses that is usually recognized as a form of Pinto horse color Rabicano, also called white ticking, is a Horse coat color characterized by limited roaning in a specific pattern interspersed white hairs most dense
The genetic process that causes the fleabitten color pattern is not well-understood at present.
The genetics of gray
- See also: Equine coat color genetics
The gray gene (G) is a dominant gene,[1] meaning in practical terms that a horse which has even one copy of the gray gene, even if it has a gene for another coloring, will always be gray. Equine coat color genetics determine a Horse 's coat color All horses begin genetically with a base coat of "red" ( chestnut) or "black If a gray horse is homozygous (GG), meaning that it has a gray allele from both parents, it will always produce gray offspring. Zygosity refers to the genetic condition of a Zygote. In genetics zygosity describes the similarity or dissimilarity of DNA between Homologous An allele (ˈæliːl (UK /əˈliːl/ (US (from the Greek αλληλος allelos, meaning each other) is one member of a pair or series of different forms However, if a gray horse is heterozygous (Gg), meaning it inherits one copy of the recessive gene (g), that animal may produce offspring who are not gray (depending on what color gene an offspring inherits from its other parent). Zygosity refers to the genetic condition of a Zygote. In genetics zygosity describes the similarity or dissimilarity of DNA between Homologous
Horse coat colors sometimes confused with gray
White Horses
Many people who are unfamiliar with horses refer to a gray horse as "white. True " However, most White horses have pink skin and frequently have blue eyes. True A horse with dark skin and dark eyes under a white hair coat is gray. In theory, a gray horse with an underlying cremello base color may be born and mature to have pink skin and white hair, but at present there is no DNA test for gray, so such horses are likely to be identified as white. Cremello is a Horse coat color consisting of a cream colored body with a cream or white mane and tail Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known
Roan
Some grays in intermediate stages of graying may be confused with a blue roan, strawberry roan or red roan. Roan is a coat color found in many animals notably Horses Cattle and Dogs It is defined generally as an even mixture of white and pigmented hairs that Some heavily fleabitten grays may also be confused with a red roan. However, roans are easily distinguishable from grays: roan consists of individual white hairs on a dark base coat, usually with the head and legs of the horse darker than the rest of the body. With gray horses, the head is often the first area to lighten, especially around the eyes and muzzle. Also, roans do not lighten with age, while grays always do.
The varnish roan is another unusual coloration, sometimes seen in Appaloosa horses, that, like gray, can change with age, but unlike gray, the horse does not become progressively lighter until it is pure white. Varnish roan describes an Appaloosa Horse with coloration similar to roan, but with some changes in color over the years though not to the extreme of a Varnish roans are thought to be linked to a gene complex within the Appaloosa breed and are seldom seen elsewhere.
Diluted colors
The dilution genes that create dun, cream, pearl, silver dapple and champagne coloring may occasionally result in confusion with gray. Dilution gene is a popular term for any one of a number of Genes that act to create a lighter coat color in living creatures
Some horses with a particular type of dun hair coat known as a "blue dun," grullo, or grulla, appear to be a solid gray. The dun gene is a Dilution gene that affects both red and black pigments in the coat color of a Horse. Grullo (also black dun, blue dun or lobo dun) is a color of Horses in the dun family characterized by smoky or mouse-colored However, this color is caused by the dun gene acting on a black base coat, and horses who are dun have all hairs the same color; there is no intermingling of white and dark hairs. The dun gene is a Dilution gene that affects both red and black pigments in the coat color of a Horse. Also, dun horses do not get lighter as they age. This particular color is most commonly seen in the American Quarter Horse, and because Quarter Horses can also be born gray or roan, there is sometimes a bit of confusion amongst aficionados of the breed.
Horses who are a light cream color are also not grays. These are usually cremello or perlino horses, colors produced by action of the cream gene. Cremello is a Horse coat color consisting of a cream colored body with a cream or white mane and tail Perlino is a color in Horses created by a Dilution gene, also known as the Creme gene acting on an underlying Bay coat color The cream gene is a Dilution gene expressed in Horses and produces lighter colors However, if a gray parent passes on the gene, the gray gene will be dominant over cremello. Another cream-colored dilition, the pearl gene or "barlink factor," may also create very light-coated horses. The Pearl gene, also known as the "Barlink factor" is a Dilution gene that somewhat resembles the Cream gene and the Champagne gene, but is neither
In spite of its name, the silver dapple gene has nothing to do with graying. The silver dapple ( Z) gene is a Dilution gene that affects the black base coat color. It is a dilution gene that acts only on a black coat, diluting the coat to a dark brown and the mane to a flaxen shade. Black is a hair coat color of Horses in which the entire hair coat is black Horses that express the silver dapple gene (and do not have the gray gene) are born with the color and it will not lighten. However, again, if one parent passes on the gray gene, the gray gene will again be dominant. Similarly, the champagne gene can lighten coat color, often producing dappling or light colors that can be confused with gray. The champagne gene is a gene that occurs in Horses that produces a golden coat color and other distinctive features
References
- ^ a b c d Locke, MM; MCT Penedo, SJ Brickker, LV Millon, JD Murray (2002). "Linkage of the grey coat colour locus to microsatellites on horse chromosome 25". Animal Genetics 33: 329-337. “The progressive loss of colour in the hair of grey horses is controlled by a dominantly inherited allele at the Grey locus (G^G). Foals are born any colour depending on the alleles present at other colour determining loci. ”
- ^ Swinburne, JE; A Hopkins, MM Binns. "Assignment of the horse grey coat colour gene to ECA25 using whole genome scanning". Animal Genetics 33: 338-342. “All grey Thoroughbred horses trace back to the Alcock’s Arabian (b1700). ”
- ^ Willett, P. (1989). The Classic Racehorse. London: Stanley Paul, 24.
- "Introduction to Coat Color Genetics" from Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis. Web Site accessed January 12, 2008
See also
Equine coat color genetics determine a Horse 's coat color All horses begin genetically with a base coat of "red" ( chestnut) or "black Horses exhibit a diverse array of coat colors and distinctive markings. True Albinism (from Latin albus, "white" see extended etymology) is a form of hypopigmentary Congenital disorder,Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic