Chestnut (coat)

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. Chestnut is characterized by the absolute absence of true black hairs. It is one of the most common horse coat colors, seen in almost every breed of horse.

Chestnut is a very common coat color but the wide range of shades can cause confusion. The lightest chestnuts may be mistaken for palominos, while the darkest shades can be so dark they appear black. Chestnuts have dark brown eyes and black skin, and typically are some shade of red or reddish brown. The mane, tail, and legs may be lighter or darker than the body coat, but unlike the bay they are never truly black. Like any other color of horse, chestnuts may have pink skin with white hair where there are white markings, and if such white markings include one or both eyes, the eyes may be blue.

Chestnut is produced by a recessive gene. Unlike many coat colors, chestnut can be true-breeding; that is, assuming they carry no recessive modifiers like champagne or mushroom, the mating between two chestnuts will produce chestnut offspring every time. This can be seen in breeds such as the Suffolk Punch and Haflinger, which are exclusively chestnut. Other breeds including the Belgian and Budyonny are predominantly chestnut. However, a chestnut horse need not have two chestnut parents. This is especially apparent in breeds like the Friesian horse and Ariegeois pony which have been selected for many years to be uniformly black, but on rare occasions still produce chestnut foals.

Chestnut
Pottok2
A chestnut horse
Other namesRed, sorrel, chesnut
VariantsFlaxen, Liver chestnut
Genotype
Base colorRecessive extension "e"
Modifying genesnone
Descriptionreddish-brown color uniform over entire body other than markings
Phenotype
Bodyreddish-brown
Head and Legssame as body, occasionally lighter
Mane and tailflaxen to brown
SkinUsually black, may be lighter at birth in some breeds
EyesBrown, eyes may be lighter at birth

Visual identification

Avenger - Westphalian horse
A chestnut horse with white markings.

Chestnuts can vary widely in shade and different terms are sometimes used to describe these shades, even though they are genetically indistinguishable. Collectively, these coat colors are usually called "red" by geneticists.

  • A basic chestnut or "red" horse has a solid copper-reddish coat, with a mane and tail that is close to the same shade as the body coat.
  • Sorrel is a term used by American stock horse registries to describe red horses with manes and tails the same shade or lighter than the body coat color. In these registries, chestnut describes the darker shades of red-based coats.[1] Colloquially, in the American west, almost all copper-red chestnuts are called "sorrel." In other parts of the English-speaking world, some consider a "sorrel" to be a light chestnut with a flaxen mane and tail.
Tori horse universal
The lower legs of this liver chestnut horse are distinctly red, even underneath the white markings.
  • Liver chestnut or dark chestnut are not a separate genetic color, but a descriptive term. The genetic controls for the depth of shade are not presently understood. Liver chestnuts are a very dark-reddish brown. Liver chestnuts are included in the term "dark chestnut." The darkest chestnuts, particularly common in the Morgan horse, may be indistinguishable from true black without very careful inspection. Often confusingly called "black chestnuts," they may be identified by small amounts of reddish hair on the lower legs, mane and tail, or by DNA or pedigree testing. Recently, it has been suggested that the trait or traits that produce certain darker shades of chestnut and bay, referred to as "sooty" coloration follow a recessive mode of inheritance.[2]
  • Flaxen chestnut and blond chestnut are terms that describe manes and/or tails that are flaxen, or significantly lighter than the body color. Sometimes this difference is only a shade or two, but other flaxen chestnuts have near-white or silverish manes and tails. Haflingers are exclusively of this shade. It is considered desirable in other breeds, though the genetic mechanism is not fully understood. Some flaxen chestnuts can be mistaken for palominos and have been registered in palomino color registries.
Halflinger 3607
This light, flaxen, mealy chestnut Haflinger might be mistaken for a palomino
  • Pangare or mealy is thought to be controlled by a single gene, unrelated to chestnut color, and produces distinct characteristics common to wild equids: pale hairs around the eyes and muzzle and a pale underside. Haflingers and Belgians are examples of mealy chestnuts. The flaxen characteristic is sometimes associated with pangare, but not always.

Chestnut family colors

Chestnut is considered a "base color" in the discussion of equine coat color genetics. Additional coat colors based on chestnut are often described in terms of their relationship to chestnut:

  • Palominos have a chestnut base coat color that is genetically modified to a golden shade by a single copy of the incomplete dominant cream gene. Palominos can be distinguished from chestnuts by the lack of true red tones in the coat; even the palest chestnuts have slight red tints to their hair rather than gold. The eyes of chestnuts are usually dark brown, while those of a palomino are sometimes a slightly lighter amber.[3] Some color breed registries that promote palomino coloring have accepted flaxen chestnuts because registration is based on a physical description rather than a genetic identity.
  • Cremellos have a chestnut base coat and homozygous (two copies) for the cream gene. They have a cream-colored coat, blue eyes and lightly pigmented pink skin.
IslandFuchsfalbe
A red dun has a light reddish- tan body and dark red primitive markings and points.
  • Red duns have a chestnut base coat with the dun gene (one or two copies). Their body color is pale, dusty tan shade that resembles the light undercoat color of a body-clipped chestnut but with a bold, dark dorsal stripe in dark red, a red mane, tail and legs. They may have additional primitive markings, which distinguish a red dun from a light or body-clipped chestnut.
  • Gold champagnes have a chestnut base coat with the champagne gene (one or two copies). They resemble a palomino, or they may be an all-over apricot shade, but can be distinguished from other colors by amber or green eyes and lightened skin color with freckling.
  • Red or "strawberry" roans have a chestnut base coat with the classic roan gene (one or two copies).
  • A skewbald, "chestnut pinto" or "sorrel Paint" is a pinto horse with chestnut and white patches.

Combinations of multiple dilution genes do not always have consistent names. For example, "dunalinos" are chestnuts with both the dun gene and one copy of the cream gene.

Chestnut mimics

Pernod Al Ariba 0046b
Bay horses have a red body but black "points"
  • Bay horses also have reddish coats, but they have a black mane, tail, legs and other "points". The presence of true black points, even if obscured by white markings, means that a horse is not chestnut.
  • Seal brown or dark bay horses are not chestnut but may be confused with a liver chestnut. Those unfamiliar with horse coat color terminology often call most horses "brown". including chestnuts. Brown, which may be difficult to distinguish visually from dark bay, is always accompanied by black points. Liver chestnuts, in particular, are mistakenly called brown or "seal brown".
  • Silver bay horses typically have chocolate- to red-brown bodies with silvered mane, tail, and legs. The flat reddish-brown color and lack of easily identified black points can confuse even knowledgeable horse persons. Silver dapple horses usually hint at black or dark gray pigment at the roots of the mane and tail, and where their silver points end on the legs. Silvers look a bit "off"-chestnut. To further confuse matters, some flaxen chestnuts have silverish streaks in their manes and tails. However, genetic testing can clarify matters.

Inheritance and expression

Feromoni Kuu
A young chestnut foal, showing slight lightening of skin, possibly related to the pheomelaninistic characteristics of chestnut genetics. The skin will darken as the foal becomes older. Skin depigmentation is not always seen in chestnut foals.

The chestnut color, called "red" by geneticists, is created by an allele that is a mutation from the wildtype and is genetically the most recessive coat color that exists in modern horses. The gene for "red" color is designated as "e". This is because the presence or absence of red color in horses is determined by the equine melanocortin 1 receptor (MC1R), a protein positioned on chromosome 3 (ECA3) at the Extension locus. The wild type version of the gene encoding MC1R is the E allele (colloquially, though imprecisely, called the "Extension gene"), and is part of the genetic pathway that allows melanocytes to produce eumelanin, or black pigment.[4] When the "E" allele is not present, no eumelanin is produced, but the "e" allele still allows melanin to be produced in the form of pheomelanin, or red pigment, creating a chestnut or red-based coat color. In general, alleles that create fully functional MC1R proteins are inherited dominantly and result in a black-based coat color ("E"), while mutated alleles that create "dysfunctional" MC1R are recessive and result in a lighter coat color ("e").

Red hair color in horses ("e") is created by a missense mutation in the code for MC1R, which results in a protein that cannot bind to the Melanocyte-stimulating hormone (MSH),[5] which is released by the pituitary gland,[4] and stimulates the production and release of melanin in skin and hair. So long as one functional copy ("E") is present, the protein is formed normally and black pigment is produced. However, when only mutant copies ("e) of the gene are available, non-functional MC1R proteins are produced. As a result, no black pigment is deposited into the hair and the entire coat is red-based. However, the skin of chestnut horses is still generally black, unless affected by other genes. Some chestnut foals are also born with lighter eyes and lightened skin, which darken not long after birth. This is not the same as the blue eyes and pink skin seen at birth in foals carrying the champagne gene. It is a genetic mechanism not fully understood, but may be related to the pheomelanistic characteristics of "e".

Chestnut foal
A chestnut foal with body-clipped head and neck, showing two-toned hair shaft, lighter at the roots

The recessive nature the chestnut or "red" coat in horses occurs because a single copy of the E allele is dominant over the e allele. Therefore, for example, bay and black horses may be heterozygous for e and if so, could produce a chestnut foal when bred to another horse with at least one copy of "e". However, all chestnut horses are homozygous for the "e" allele and thus breeding a chestnut to another chestnut will always produce a chestnut foal. Thus, unlike many coat colors, chestnut can be true-breeding; if any color other than chestnut occurs, then one of the parents was not chestnut.

Red can occur in horses that carry "E" when other genes influence its expression. In some cases, MC1R exists but is locally antagonized by the agouti signalling peptide (ASIP), or "agouti gene", which "suppresses" black color and allows some red pigment to be formed. This results in localized regions of black-rich or red-rich pigmentation, as seen in bay horses.

See also

References

  1. ^ "General Glossary". American Quarter Horse Association. Archived from the original on 2011-07-07. Retrieved 2010-12-25.
  2. ^ Henner, J; PA Poncet; L Aebi; C Hagger; G Stranzinger; S Rieder (August 2002). "Horse breeding: genetic tests for the coat colors chestnut, bay and black. Results from a preliminary study in the Swiss Freiberger horse breed". Schweizer Archiv für Tierheilkunde. 144 (8): 405–412. The statistical analysis of 1369 offspring from five stallions indicate, that darker shades of basic color phenotypes (dark chestnut, dark bay) follow a recessive mode of inheritance in the Franches-Montagnes horse breed.
  3. ^ Locke, MM; LS Ruth; LV Millon; MCT Penedo; JC Murray; AT Bowling (2001). "The cream dilution gene, responsible for the palomino and buckskin coat colors, mapes to horse chromosome 21". Animal Genetics. 32 (6): 340–343. doi:10.1046/j.1365-2052.2001.00806.x. PMID 11736803. The eyes and skin of palominos and buckskins are often slightly lighter than their non-dilute equivalents.
  4. ^ a b Online Mendelian Inheritance in Man, OMIM (TM). Johns Hopkins University, Baltimore, MD. MIM Number: 155555: 15 Feb. 2008: [1]
  5. ^ Marklund, L.; M. Johansson Moller; K. Sandberg; L. Andersson (1996). "A missense mutation in the gene for melanocyte-stimulating hormone receptor (MC1R) is associated with the chestnut coat color in horses". Mammalian Genome. 7 (12): 895–899. doi:10.1007/s003359900264. PMID 8995760.

External links

2018 Melbourne Cup

The 2018 Melbourne Cup (known commercially as 2018 Lexus Melbourne Cup) was the 158th running of the Melbourne Cup, a prestigious Australian Thoroughbred horse race. The race was run over 3,200 metres (1.988 mi) on 6 November 2018 at Flemington Racecourse in Melbourne.

Lexus commenced a five year naming rights sponsorship deal, taking over from Emirates. It was the last Melbourne Cup broadcast by the Seven Network before Network Ten takes over in 2019.The race was won by Cross Counter, ridden by Kerrin McEvoy and trained by Charlie Appleby.

Amelanism

Amelanism (also known as amelanosis) is a pigmentation abnormality characterized by the lack of pigments called melanins, commonly associated with a genetic loss of tyrosinase function. Amelanism can affect fish, amphibians, reptiles, birds, and mammals including humans. The appearance of an amelanistic animal depends on the remaining non-melanin pigments. The opposite of amelanism is melanism, a higher percentage of melanin.

A similar condition, albinism, is a hereditary condition characterised in animals by the absence of pigment in the eyes, skin, hair, scales, feathers or cuticle. This results in an all white animal, usually with pink or red eyes.

Baulking Green

Baulking Green was a chestnut gelding British steeplechaser, sired by Coup de Myth out of Nicotine Nelly by Irish Trout. He was foaled in 1952, and throughout his racing career in the 1960s he was owned by Jim Reade. He was usually ridden by George Small, and after the 1962 season was trained by Tim Forster. He raced in point-to-points and hunter 'chases; to be eligible for these races, he was qualified with the Old Berkshire Hunt. During his career, Baulking Green drew attention to the tiny village of Baulking, Oxfordshire (until 1974 part of Berkshire).

Bend Or

Bend Or (1877–1903) was a British Thoroughbred racehorse who won the 1880 Epsom Derby. His regular jockey Fred Archer, winner of thirteen consecutive British jockey titles, said Bend Or was probably the greatest horse he had ever ridden.

Blueskin (horse)

Blueskin was a gray horse ridden by George Washington. He was one of Washington's two primary mounts during the American Revolutionary War. The horse was a half-Arabian, sired by the stallion "Ranger", also known as "Lindsay's Arabian", said to have been obtained from the Sultan of Morocco. Blueskin was a gift to Washington from Colonel Benjamin Tasker Dulany (c. 1752–1816) of Maryland. Dulany married Elizabeth French, a ward of Washington's, who gave her away at her wedding to Dulany on February 10, 1773.Blueskin, due to his white hair coat, was the horse most often portrayed in artwork depicting Washington on a horse. Washington's other primary riding horse was Nelson, a chestnut gelding said to be calmer under fire than Blueskin. Both horses were retired after the Revolutionary War. Blueskin lived at Mount Vernon, until he was returned to Mrs. Dulany in November 1785 with the following note:

General Washington presents his best respects to Mrs Dulany with the horse blueskin; which he wishes was better worth her acceptance. Marks of antiquity have supplied the place of those beauties with which this horse abounded—in his better days. Nothing but the recollection of which, & of his having been the favourite of Mr Dulany in the days of his Court ship, can reconcile her to the meagre appearance he now makes.

Champagne gene

The champagne gene is a simple dominant allele responsible for a number of rare horse coat colors. The most distinctive traits of horses with the champagne gene are the hazel eyes and pinkish, freckled skin, which are bright blue and bright pink at birth, respectively. The coat color is also affected: any hairs that would have been red are gold, and any hairs that would have been black are chocolate brown. If a horse inherits the champagne gene from either or both parents, a coat that would otherwise be chestnut is instead gold champagne, with bay corresponding to amber champagne, seal brown to sable champagne, and black to classic champagne. A horse must have at least one champagne parent to inherit the champagne gene, for which there is now a DNA test.

Unlike the genes underlying tobiano, dominant white, frame overo spotting and the Leopard complex common to the Appaloosa, the champagne gene does not affect the location of pigment-producing cells in the skin. Nor does the champagne gene remove all pigment from the skin and hair, as in albinism. Instead, the champagne gene produces traits known as hypomelanism, or dilution. Champagne is not associated with any health defects. Other dilution genes in horses include the Cream gene, Dun gene, Pearl gene and Silver dapple gene. Horses affected by these genes can sometimes be confused with champagnes, but champagnes are genetically distinct. Champagnes are not palominos, buckskins, or grullos, nor does the word champagne indicate that a horse is a shiny or light shade of another coat color.

This gene and the associated coat colors are only known in American breeds, especially the American Cream Draft, Tennessee Walker, American Saddlebred and Missouri Fox Trotter.

Chestnut (color)

Chestnut is a colour, a medium reddish shade of brown (displayed right), and is named after the nut of the chestnut tree. An alternate name for the colour is badious.Indian red is a similar but separate and distinct colour from chestnut.

Chestnut is also a very dark tan that almost appears brown.

Dun gene

The dun gene is a dilution gene that affects both red and black pigments in the coat color of a horse. The dun gene lightens most of the body while leaving the mane, tail, legs, and primitive markings the shade of the undiluted base coat color. A dun horse always has a dark dorsal stripe down the middle of its back, usually has a darker face and legs, and may have transverse striping across the shoulders or horizontal striping on the back of the forelegs. Body color depends on the underlying coat color genetics. A classic "bay dun" is a gray-gold or tan, characterized by a body color ranging from sandy yellow to reddish brown. Duns with a chestnut base may appear a light tan shade, and those with black base coloration are a steel gray. Manes, tails, primitive markings, and other dark areas are usually the shade of the undiluted base coat color. The dun gene may interact with all other coat color alleles.

Equine coat color

Horses exhibit a diverse array of coat colors and distinctive markings. A specialized vocabulary has evolved to describe them.

While most horses remain the same color throughout life, a few, over the course of several years, will develop a different coat color from that with which they were born. Most white markings are present at birth, and the underlying skin color of a horse does not change, absent disease.

The basic outline of equine coat color genetics has largely been resolved, and DNA tests to determine the likelihood that a horse will have offspring of a given color have been developed for some colors. Discussion, research, and even controversy continues about some of the details, particularly those surrounding spotting patterns, color sub-shades such as "sooty" or "flaxen", and markings.

Flaxen gene

The flaxen gene is a trait which causes the mane and tail of chestnut-colored horses to be noticeably lighter than the body coat color, often a golden blonde shade. Manes and tails can also be a mixture of darker and lighter hairs. Certain horse breeds such as the Haflinger carry flaxen chestnut coloration as a breed trait. It is seen in chestnut-colored animals of other horse breeds that may not be exclusively chestnut.The degree of expression of the trait is highly variable, with some chestnuts being only slightly flaxen while others are more so. Flaxen was once thought to be produced by a recessive allele, based on preliminary studies, proposed as Ff for flaxen. However, more recently it is thought that it may actually be polygenic, influenced by multiple genes.Some chestnut horses that do not exhibit much flaxen may nonetheless produce strongly flaxen offspring. Studies on Morgan horses have indicated that the flaxen trait is inherited. One found that flaxen chestnut horses mated with other flaxen chestnut horses consistently produce only flaxen chestnuts, which, if Mendelian inheritance is assumed, would make it a recessive gene. Flaxen does not affect black or bay horses, only chestnuts. However, as there are examples of flaxen chestnuts born to parents that are black or bay, it may be masked in darker-colored horses but still passed on to their offspring.

Floyd (horse)

Floyd (foaled 1980, died 7 January 1993) was an English bred and English trained National Hunt racehorse sired by Relko. The horse was named after the English progressive rock band Pink Floyd.

David Elsworth-trained Floyd was the first horse to win the Long Walk Hurdle when it was upgraded to Grade One status in 1990.Only five horses have done the double of winning the Imperial Cup with a follow-up win at the same year’s Cheltenham Festival, with Floyd being the first in 1985 when he completed the double by winning the County Hurdle.19 wins, £196,234: 3 wins at 3 and 5 years and £10,872; also 16

wins over hurdles

Furioso II

Furioso II (1965–1986) is one of the most influential sires in sport horse history. His offspring have performed well in all disciplines of show jumping, including at the Barcelona and Sydney Olympics.

Horse chestnut (disambiguation)

Horse chestnut may refer to:

Horse-chestnut tree or Aesculus hippocastanum, a species of large deciduous tree

Horse chestnuts, Eurasian species of the genus Aesculus

Horse Chestnut (horse), a South African Thoroughbred racehorse

Chestnut (coat), a common coat color in horses

Chestnut (horse anatomy), the callous on the leg of a horse

Liver (color)

At right is displayed the color traditionally called liver.

The first recorded use of liver as a color name in English was in 1686.The source of this color is: ISCC-NBS Dictionary of Color Names (1955)--Color Sample of Liver (color sample #36).

Liver may also refer to a group of certain types of dark brown color in dogs and horses. Said nomenclature may also refer to the color of the organ.

Old Tobe

Old Tobe was the foundation sire of the Rocky Mountain Horse breed. He was owned by Sam Tuttle, and used as a trail horse in Kentucky's Natural Bridge State Park. Old Tobe was gaited, and passed the trait to his offspring.

Russian Rhythm

Russian Rhythm is a retired Thoroughbred racehorse and active broodmare who was bred in the United States but trained in the United Kingdom. During a racing career which lasted from June 2002 until May 2004 she ran ten times and won seven races. In 2003 her wins included the Classic 1000 Guineas, the Coronation Stakes and the Nassau Stakes and at the end of the season she was voted European Champion Three-Year-Old Filly at the Cartier Racing Awards. After winning the Lockinge Stakes on her only race in 2003 her racing career was ended by injury and she retired to become a broodmare.

Ten Point

Ten Point (テンポイント) was a racehorse registered by the Japan Racing Association. Ten Point, Tosho Boy, and Green Grass were a group of Thoroughbred horses refereed to as TTG.

Ten Point debuted in August 1975 as a racehorse. He gathered attention in a classic race in Kansai and was named "Young Youth of the Falling Star" due to his facial features and chestnut coat. He did not win the classic race, but he managed to win the Tenno Sho and the Arima Kinen at the age of four. His match race with Tosho Boy in the 1977 Arima Kinen race remains the most famous in horse racing history. In January 1978, Ten Point had a bone fracture in the middle of the Japanese Economy New Year Cup and died after 43 days of treatment.

Ten Point won the JRA Award for Best Two-Year-Old Colt in 1975 and the JRA Award for Best Older Male Horse in 1977. He was elected to the Japan Racing Association Hall of Fame in 1990. Akira Shikato was Ten Point's jockey.

West Caucasian tur

The West Caucasian tur (Capra caucasica syn Capra caucasica caucasica) is a mountain-dwelling goat-antelope found only in the western half of the Caucasus Mountains range.

West Caucasian turs stand up to 1 m (3.3 ft) tall at the shoulder and weigh around 65 kg (143 lb). They have large but narrow bodies and short legs. West Caucasian turs have a chestnut coat with a yellow underbelly and darker legs. Their horns are scimitar-shaped and heavily ridged. In males, these horns are around 70 cm (28 in), while in females they are much smaller.

West Caucasian turs live in rough mountainous terrain between 800 and 4,000 m (2,600 and 13,100 ft) above sea level, where they eat mainly grasses and leaves and are preyed upon by wolves and lynxes. They are nocturnal, eating in the open at night and sheltering during the day. Females live in herds of around 10 individuals, while males are solitary.

The wild population is estimated to be between 5,000 and 6,000 individuals.

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