A "blood" bay horse. This is the classic bay coat color

Both of these horses are dark bays, sometimes called "Mahogany bay," "black bay" or "brown."

A dark bay like this horse can be distinguished from a black horse by the lighter hairs around the eye.

A black horse, even with a sun-bleached hair coat (as seen with the forelock of the black horse in this image) will have solid black hairs around the eye.

Bay is a hair coat color of horses, characterized by a reddish brown body color with a black mane, tail and lower legs. Bay is one of the most common coat colors in many horse breeds. Bay Horse is a sparsely populated hamlet in the English county of Lancashire. ... Image File history File linksMetadata BayMare. ... Image File history File linksMetadata BayMare. ... Image File history File links Size of this preview: 756 × 600 pixelsFull resolution‎ (2,089 × 1,657 pixels, file size: 817 KB, MIME type: image/jpeg) Caballos españoles Andalusian horses - moving backwards as presented on the german horsefair Equitana 02. ... Image File history File links Size of this preview: 756 × 600 pixelsFull resolution‎ (2,089 × 1,657 pixels, file size: 817 KB, MIME type: image/jpeg) Caballos españoles Andalusian horses - moving backwards as presented on the german horsefair Equitana 02. ... Image File history File links Metadata No higher resolution available. ... Image File history File links Metadata No higher resolution available. ... Image File history File links Metadata No higher resolution available. ... Image File history File links Metadata No higher resolution available. ... Wild horses on the range, showing a wide range of coat colors Horses exhibit a diverse array of coat colors and distinctive markings. ... Binomial name Equus caballus Linnaeus, 1758 The horse (Equus caballus, sometimes seen as a subspecies of the Wild Horse, Equus ferus caballus) is a large odd-toed ungulate mammal, one of ten modern species of the genus Equus. ... Look up mane in Wiktionary, the free dictionary. ... A scorpion tail The tail is the section at the rear end of an animals body; in general, the term refers to a distinct, flexible appendage to the torso. ...

The black areas of a bay horse's hair coat are called "black points." Black points always include the mane and tail, almost always include the lower legs (unless covered by white markings), and may also be found on the tips of the ears. Bay horses usually have black skin under their hair coat, except beneath white markings. These young horses, though all the same color, exhibit uniquely different markings, which can be used to identify individual horses Note: This article is about markings on any type or color of horse and does not discuss horse coat colors generally. ... These young horses, though all the same color, exhibit uniquely different markings, which can be used to identify individual horses Note: This article is about markings on any type or color of horse and does not discuss horse coat colors generally. ...

Color shade variations

Bay horses range in color from a light copper red, to a rich red blood bay (the best-known variety of bay horse) to a very dark red or brown called either dark bay, mahogany bay, black-bay, or simply brown. Some bay horses will exhibit dappling, a faint pattern of concentric rings within the coat, usually only appearing on a summer coat, considered a sign of a healthy horse in good condition, though the tendency to dapple may also be, to some extent, inborn, as many well-conditioned bay horses do not dapple.

Many light bays and blood bays have a two-toned hair shaft, which, if shaved too closely (such as when body-clipping for a horse show), may cause the horse to appear several shades lighter, a somewhat dull orange-gold, almost like a dun. However, as the hair grows out, it will darken again to the proper shade. This phenomenon is usually not seen in dark bays. A horse show is a judged exhibition of horses and ponies. ... Dun is a yellow-brown color, sometimes seen in the hair coats of horses, characterized by a body color ranging from sandy yellow to reddish-brown. ...

Other variations

A few bay horses may carry the rabicano gene, which can cause some white or cream hairs to appear in the mane or tail, sometimes creating a "skunk" effect. Some bay horses, particularly Clydesdales, may exhibit sabino traits and exhibit slight body spotting. Rabicano is a horse coat color that appears to be a type of partial roaning. ... Clydesdale draft horse at the Maryland State Fair The Clydesdale is a breed of draft horse named after and derived from hard-working farm horses of Clydesdale (now Lanarkshire), Scotland. ... This Clydesdale horse has classic Sabino belly spots, white above its hocks, a chin spot and wide white facial markings. ...

"Brown" horses

Some breed registries (including the Jockey Club Thoroughbred registry) use the term "brown" to describe dark bays, though genetically, bay and brown horses both have a black (E) gene suppressed into black points by the agouti (A) gene. However, "liver" chestnuts, horses with a red or brown mane and tail as well as a dark brownish body coat, are also sometimes called "brown." Therefore,"brown" is an ambiguous term for describing horse coat color. It is preferable to refer to dark-colored horses as dark bays or liver chestnuts. For the processor with the same codename , see Athlon. ... Chestnuts. ...

Colors that are not bay

For description of other coat colors, see Equine coat color.

• Buckskin horses have a black mane and tail, but instead of a red or brown coat, they have a cream or gold coat. Though once called a "Sandy" bay in some texts on horse color, the genetic distinction created by the cream gene is significant. Buckskins are seldom mistaken for bays because their coats are significantly lighter and have no hint of a red or orange tint.
• Chestnuts have a reddish body coat like a bay, but their manes and tails are the same shade as their body color or even a few shades lighter--never black.
• Black are occasionally confused with dark bays and liver chestnuts because some black horses "sunburn," that is, when kept out in the sun, they develop a bleached-out coat that looks brownish. However, a true black can be recognized by looking at the fine hairs around the muzzle and eyes. These hairs are always black on a black horse, but are reddish, brownish, or even a light gold on a bay or chestnut.
• Roan horses sometimes have a bay base coat, but the roan gene creates an effect of white hairs intermingled with the red body coat. Such horses are called bay roans or, less accurately, red roans, but they are not bay horses even though they have a predominantly red body coat with a black mane and tail.
• Pinto horses also may have a bay base coat overlaid by white spots. However, these horses are pinto, not bay. Sometimes the term Skewbald or "Tricolor" is used, especially in the UK, to refer to bay and white pintos.

Wild horses on the range, showing a wide range of coat colors Horses exhibit a diverse array of coat colors and distinctive markings. ... Buckskin New Forest pony A Buckskin Quarter Horse Mare Buckskin is a color of horses; it also refers to other things that are the color of a buckskin horse, such as the color of some breeds of dogs. ... The cream gene is a dilution gene expressed in horses, and produces lighter colors. ... Chestnuts. ... Friesian horses are one of the best-known breeds of black-colored horse Black is a relatively uncommon coat color in horses, though not so unusual as to be considered rare. ... A red roan horse Roan is a type of coat color in horses (and, occasionally, in other animals, such as dogs and cattle) that is a mixture of white hairs with a base coat of another color. ... Pinto is a horse coloring that consists of large patches of white and another color. ... The Skewbald horse has a coat made up of brown and grey patches, on top of either pink or black skin. ... A tri-coloured horse Tri-coloured (archaic: oddbald) refers to a horse with three different coat colours in a pinto spotting pattern of large white and dark patches, usually bay (a reddish colour with a black mane and tail) and white. ...

Genetics

See also: equine coat color genetics

Equine coat color genetics are complex, but a simple explanation of bay color begins with the understanding that "red" color, such as that of the chestnut horse, represented by the recessive "e" gene, and black color, represented by the somewhat more dominant "E" gene are the two most basic coat colors genes. All other equine colors are produced by the action of additional alleles acting on these two base colors. There are currently two theories of equine coat color genetics: Dr. Ann Bowlings and Dr. Phillip Sponenbergs. ... There are currently two theories of equine coat color genetics: Dr. Ann Bowlings and Dr. Phillip Sponenbergs. ... Chestnuts. ... In genetics, the term recessive gene refers to an allele that causes a phenotype (visible or detectable characteristic) that is only seen in a homozygous genotype (an organism that has two copies of the same allele). ... Friesian horses are one of the best-known breeds of black-colored horse Black is a relatively uncommon coat color in horses, though not so unusual as to be considered rare. ... The word dominant has several possible meanings: In music theory, the dominant or dominant note (second most important) of a key is that which is a perfect fifth above the tonic; in just intonation the note whose pitch is 1. ...

A bay horse carries both the Extension gene (E) and a suppression gene known as the agouti gene (A). The extension gene, also sometimes called the "black" gene, adds black color to the coat and the agouti gene, dominant over the black gene, limits or suppresses the black coloring to black points, allowing the underlying red coat color to come through. Unlike other types of "point" coloring, such as that seen in Siamese cats, the black points characteristic of bay coloring are not produced by a dilution or albinism gene. The Melanocortin-1 receptor (Mc1r) is one of the key proteins in hair colour production. ... The genetics of cat coat length and coloration is a complex subject, and many different genes are involved. ... There are currently two theories of equine coat color genetics: Dr. Ann Bowlings and Dr. Phillip Sponenbergs. ... Friesian horses are one of the best-known breeds of black-colored horse Black is a relatively uncommon coat color in horses, though not so unusual as to be considered rare. ... Point coloration refers to animal coat coloration with a pale body and relatively darker extremities, i. ... The Siamese is one of the first distinctly recognised breeds of Oriental cat. ... The genetics of cat coat length and coloration is a complex subject, and many different genes are involved. ... Albino redirects here. ... For other uses, see Gene (disambiguation). ...

Simply put, crossing two bay horses may produce bay, black or chestnut offspring, depending on the particular combination of alleles. If an offspring with the Extension (E) gene lacks the agouti (A) gene, it is completely black. If an offspring lacks the extension (or black) gene (E), it will be chestnut (also called "sorrel"). A chestnut may produce bays when bred to black or bay horses, and a black horse may produce bays when bred to bay or chestnut horses who carry the Agouti gene. Chestnuts. ... Sorrel is a coat color in horses, ranging from reddish-gold to deep burgundy. ... Friesian horses are one of the best-known breeds of black-colored horse Black is a relatively uncommon coat color in horses, though not so unusual as to be considered rare. ...

If a horse carrying the extension and agouti genes additionally has a dilution gene, such as the cream gene, or the dun gene, it will be buckskin or dun in color, which is similar to bay except that red or brown areas are lightened to a tan or gold shade. If the horse has a homozygous cream gene, it will have a perlino color, where the black points become reddish, and red areas appear nearly white. If it has assorted genes for spotting patterns, then white body markings may also be present. The genetics of cat coat length and coloration is a complex subject, and many different genes are involved. ... The cream gene is a dilution gene expressed in horses, and produces lighter colors. ... Dun coloring The dun gene is one of the dilution genes that affects both red and black pigments in a horses coat color. ... Buckskin New Forest pony A Buckskin Quarter Horse Mare Buckskin is a color of horses; it also refers to other things that are the color of a buckskin horse, such as the color of some breeds of dogs. ... Dun coloring The dun gene is one of the dilution genes that affects both red and black pigments in a horses coat color. ... Homozygote cells are diploid or polyploid and have the same alleles at a locus (position) on homologous chromosomes. ... Perlino is a color in horses created by a dilution gene, also known as the creme gene acting on an underlying Bay coat color. ...

Because the extension (E) gene and agouti (A) gene can be either heterozygous or homozygous, the extent to which a bay passes on its color varies widely from one horse to another depending on its genotype and that of its mate. All the combination of genes below are possible, making bay breedings hard to predict without a prior DNA blood test for color-related genes. The structure of part of a DNA double helix Deoxyribonucleic acid, or DNA, is a nucleic acid molecule that contains the genetic instructions used in the development and functioning of all known living organisms. ...

• Ee Aa bay × ee aa chestnut: 25% bay, 25% black, 50% chestnut
• Ee Aa bay × ee Aa chestnut: 50% bay, 25% black, 25% chestnut
• Ee Aa bay × Ee aa black: 37.5% bay, 37.5% black, 25% chestnut
• Ee Aa bay × EE aa black: 50% bay, 50% black
• Ee Aa bay × Ee Aa bay: 56.25% bay, 18.75% black, 25% chestnut
• Ee Aa bay × EE Aa bay: 75% bay, 25% black
• Ee Aa bay × Ee AA bay: 75% bay, 25% chestnut
• Ee Aa bay × EE AA bay: 100% bay
• Ee AA bay × Ee aa black: 75% bay, 25% chestnut
• Ee AA bay × EE aa black: 100% bay
• Ee AA bay × any chestnut: 50% bay, 50% chestnut
• EE Aa bay × EE AA bay: 100% bay
• EE Aa bay × EE Aa bay: 75% bay, 25% black
• EE Aa bay × ee Aa chestnut: 50% bay, 50% black
• EE Aa bay × ee aa chestnut: 100% bay
• EE Aa bay × any black: 75% bay, 25% black
• EE AA bay × any bay: 100% bay
• EE AA bay × any chestnut: 100% bay
• EE AA bay × any black: 100% bay

The above list does not explain when offspring will be homozygous or heterozygous for a given gene. Homozygote cells are diploid or polyploid and have the same alleles at a locus (position) on homologous chromosomes. ... Heterozygote cells are diploid or polyploid and have different alleles at a locus (position) on homologous chromosomes. ...

The following grid shows the two-gene Punnett square for a crossing of two Ee Aa bays, that demonstrates one of the many possibilities outlined above. Each of the sixteen squares is equally likely. Nine of the results carry both genes (bays), three carry extension but not agouti (blacks), and four do not carry extension (chestnuts): The Punnett square is a diagram designed by Reginald Punnett and used by biologists to determine the probability of an offspring having a particular genotype. ...

References

Bowling, Ann T. "Coat Color Genetics: Positive Horse Identification" from Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis. Web Site accessed February 9, 2007

See also

• Equine coat color genetics
• Equine coat color
• cream gene
• Perlino
• Buckskin

There are currently two theories of equine coat color genetics: Dr. Ann Bowlings and Dr. Phillip Sponenbergs. ... Wild horses on the range, showing a wide range of coat colors Horses exhibit a diverse array of coat colors and distinctive markings. ... The cream gene is a dilution gene expressed in horses, and produces lighter colors. ... Perlino is a color in horses created by a dilution gene, also known as the creme gene acting on an underlying Bay coat color. ... Buckskin is a color of horses; it also refers to other things that are the color of a buckskin horse, such as the color of some breeds of dogs. ...

External links

• List of coat colors with images and examples, from UC Davis