Chestnut Sorrel Horse Color
Chestnut Sorrel Horse Color
Chestnut/Sorrel Horse Color
Also known as sorrel, chestnut is the most recessive equine color. Different shades of chestnut may be given different names in different parts of the world or in different breeds, but since every red horse has the same genetic makeup, we will stick to one term: Chestnut.
Every chestnut has these two genes: ee. This allele of the Extension gene makes the horse produce red pigments, instead of black (E produces black). All chestnuts are homozygous-- they have two e genes. This is why a chestnut crossed with a chestnut will always produce a chestnut.
Since this basic rule is understood by almost all breed associations, non-chestnut foals from two chestnut parents are not given recognition... it's obvious someone was mistaken as to the foal's parents, or one of the parents was misidentified as a chestnut.
While breeding two chestnuts always produces chestnuts, this is not the only way to produce a chestnut horse. Other colors, such as bay, black, palomino, buckskin, and brown, can also produce Chestnut foals.
There is one very rare exception to the chestnut x chestnut rule... theoretically, two chestnuts can produce a white if both parents carry the sabino-white gene. This gene is seen in solid horses and only shows through as facial or leg markings. However, this is not really an exception, because the white foal will still be a chestnut, only he will have the white gene masking his chestnut color. You'll read more about the Sabino-white gene in the "other" section.
If two non-chestnuts produce a chestnut foal, then this is proof that both parents carry the 'e' gene. Each parent gave their e gene, resulting in a foal that is ee-- chestnut.
The different shades of chestnut are many and varied. They can range from an intense red to palomino-colored, to almost black.
All attempts to classify the shades of chestnut by their genotype has failed. It is sometimes difficult to classify a horse by his phenotype because of changes in color due to season, nutrition, or other factors. However, you can get a pretty good idea of what shade your horse is and pick the term you best suits him-- usually horses are evaluted when they are well-groomed and in summer coat.
Here are some terms commonly used to describe different chestnut shades:
Light chestnut (or sorrel): Body is a light golden-red, mane and tail are light
Honey Chestnut: A very light yellow color, close to palomino.
Flaxen Chestnut: Any chestnut body color with a flaxen mane and tail.
Cherry Chestnut: A bright cherry-red color.
Standard Chestnut: A medium reddish-orange color.
Liver Chestnut: A dark red or chocolate color.
Black Chestnut: Nearly black or very dark chocolate color.
The shade of chestnut is also influenced by the F gene (flaxen), which makes the horse's mane and tail ligher, and may lighten the legs or entire body. The Pangarè gene will also lighten a chestnut's muzzle/flanks. The Sty (sooty) gene may scatter dark hairs throughout the horse, making him darker, giving him dapples, or seasonally changing him to a false liver chestnut.