The three base colors
Chestnut
A chestnut horse has red hair ranging from pale copper to very dark brown. Its mane and tail are red or lighter. Unlike a bay horse, a chestnut has no naturally black mane, tail or lower legs.
Chestnut: how the color works and is inherited
MC1R helps determine which pigments, the substances that color hair, a horse produces. In a chestnut horse, both inherited versions prevent black pigment production in the hair. Red pigment provides the coat’s color instead.
A foal inherits one MC1R version from its mother and one from its father. Two chestnut-based parents pass on a chestnut base. Another variant, such as Cream, can then lighten that color.
Chestnut: origins and the role of breeding
Chestnut comes from a naturally occurring change in DNA. Ancient DNA identifies chestnut horses living around 5,000 years ago. Chestnuts subsequently became more common among horses kept by people, particularly during the Bronze Age. The variant is therefore much older than today’s horse breeds.
Choosing two chestnut horses preserves the chestnut base in a breeding program. That choice combines variants already carried by the parents; it does not create a new color.
Chestnut: photographs of horses
Admire Main, a chestnut horse with copper-colored hair.
Red hair on a chestnut horse’s neck and mane.
A chestnut horse’s head, with reddish ears and mane.
A chestnut Highlander-type horse in a mountain landscape.
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A chestnut Aegidienberger resting in straw.
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A young chestnut filly with a broad white facial marking.
Photograph credits
Photographs have been resized. Photographs within scientific figures have been separated by cropping. Colors are preserved.
- Admire Main, a chestnut horse with copper-colored hair. — Goki · CC BY-SA 3.0
- Red hair on a chestnut horse’s neck and mane. — Acabashi · CC BY-SA 4.0
- A chestnut horse’s head, with reddish ears and mane. — Acabashi · CC BY-SA 4.0
- A chestnut Highlander-type horse in a mountain landscape. — Edciech · CC BY-SA 3.0
- A chestnut Aegidienberger resting in straw. — Ixitixel · CC BY-SA 3.0
- A young chestnut filly with a broad white facial marking. — BLM Nevada · Public domain
Chestnut: telling similar coats apart
A liver chestnut can look almost black. Look for red or brown tones in its mane and hair. A chestnut can also have a very pale mane without being palomino.