WHAT MAKES BLACK (E)
What Makes Black (E)
Possible Color Genotypes/Black & Black-to-Grey
Possible Color Genotypes/Bay & Bay-to-Grey
Possible Color Genotypes/Chestnut & Chestnut-to-Grey
Glossary of Terms Conclusion Return to HOME
The color of black is quite rare in Arabian horses. However, with the DNA test called the RED FACTOR test, it is becoming easier to breed for this color. The presence of the Extension (E) allele is known because the horse will have black hair either all over the body of a black or at the points (mane/tail, ears, knees/ hocks and lower leg areas) of a bay.
If the horse is black, then it will have at least one, and maybe both, dominant E alleles and only has recessive g and a alleles (no dominant A allele).
If a black horses gets sweaty and spends time in the sun, it is not uncommon for the salt in their sweat to discolor/sunburn some of their black hair, especially in the late summer or in the early spring before they shed the old coat and get in the new coat. (This is sometimes referred to as fading and does not have anything to do with whether the horse is homozygous black or heterozygous black--all horses of this color can fade if exposed to these conditions. To keep a black horse from fading, it can be kept out of the sun and sweat washed off.) However, a black horse will never have reddish/ brownish hair around its muzzle.
-------------------------------------------------------------------------------------------------------------------
Special Note: If the horse is chestnut, then it has two recessive e genes and will not have any black hair--just red hair--and it will be impossible to tell by LOOKING at the horse's coat to determine which A/a alleles are present. A bay horse must have at least one dominant E allele and at least one dominant A allele--with black hair being restricted to the points only. (More discussion of this follows in the the Bay & Chestnut section.)
-------------------------------------------------------------------------------------------------------------------
What Makes Black (E)
Possible Color Genotypes/Black & Black-to-Grey
Possible Color Genotypes/Bay & Bay-to-Grey