Coat Color Genetics

There is a very nicely programmed CoatColorCalculator by Animal Genetics Inc. The tool is professionally set up and the results are reliable. As the tool is not focussed on Quarter Horses they use slightly different terms but with a consistent and logic use.

For Smoker as a Sire please use “Smoky Grullo” and then select “Red Carrier Ee” and “Heterozygous Dun Dd”. The more you know about your mare from former offspring or pedigree the more exactly the results can be calculated.

If you need help, please contact us.

A short introduction to coat color genetics adapted for the Quarter Horse breed.
Recommended literature is the book of Ann T. Bowling “Horse Genetics” , CAB International 1996.

Basic Colors: black, bay, sorrel

The basic horse colors are determined by the two genes extension (E) and agouti (A).
The extension gene controls the amount of black pigment in skin and hair (EE or Ee) or only in the skin (ee).
The agouti gene controls the distribution pattern of black pigment and is only active in the presence of E.
The dominant inherited allele A restricts the pigment to the points.
 

Phenotype (color of horse):

Alleles:

Genotype:

Black

EE or Ee with aa

EEaa or Eeaa

Bay or Brown

EE or Ee with AA or Aa

EEAA, EeAA, EEAa, EeAa

Sorrel

ee with AA or Aa or aa

eeAA, eeAa, eeaa

Color Diluting Genes: cream, dun, roan and champagne (tests available)

The cream gene (C^cr) dilutes mainly red pigment while black pigment is not or minimal diluted. The dun gene (D) dilutes both red and black pigment but does not dilute either pigment in hair on the points. While two copies of the cream gene do have a double dilute impact on the coat color, two copies of the dun gene can not be recognized by the phenotype of the horse. The roan (Rn) dilution spreads white hairs all over the body but is only seen in the summer coat. They change their color with every season. It can’t be phenotypically determined if a horse is homozygous or heterozygous roan. The champagne dilution (Ch) dilutes red pigment more than black pigment and behaves like the dun gene: there is no phenotypical difference in horses with one copy or two copies of the champagne gene.

If a horse carries another dilution plus the roan and/or champagne gene, the term for the other dilution is used first and at the end the term “roan” and/or “champagne” is added, for example: Red Dun Roan, Palomino Roan, Buckskin Champagne, Dunalino Champagne or Grullo Roan Champagne.
 

Basic Color:

Dilution:

Term of use for Phenotype:

Black

CC^cr

Smoky Black

Black

C^crC^cr

Smoky Cream

Bay or Brown

CC^cr

Buckskin

Bay or Brown

C^crC^cr

Perlino

Sorrel

CC^cr

Palomino

Sorrel

C^crC^cr

Cremello

Black

Dd or DD

Grulla/Grullo

Bay or Brown

Dd or DD

Dun

Sorrel

Dd or DD

Red Dun

Black

Rnrn or RnRn

Blue Roan

Bay or Brown

Rnrn or RnRn

Bay Roan

Sorrel

Rnrn or RnRn

Red Roan (also Strawberry Roan)

Black

Chch or ChCh

Classic Champagne

Bay or Brown

Chch or ChCh

Amber Champagne

Sorrel

Chch or ChCh

Gold Champagne

Black

CC^cr with Dd or DD

Silver (Smoky) Grulla/Grullo

Black

C^crC^cr with Dd or DD

Smoky Cream Dun

Bay or Brown

CC^cr with Dd or DD

Buttermilk (Smoky) Dun

Bay or Brown

C^crC^cr with Dd or DD

Perlino Dun

Sorrel

CC^cr with Dd or DD

Dunalino

Sorrel

C^crC^cr with Dd or DD

Cremello Dun

Pedigree Information:

The cream and the dun gene are rather widely spread and definitely found their impact into the performance horse industry mainly through Hollywood Dun It. The roan gene is less common but found its way into the industry through Peptoboonsmal. The Champagne gene is still extremely rare and the stallions with probably the highest impact into the performance horse industry are Cougarand (cutting) and My Skip Vanzi (halter) but their number of offspring is small. Most often the Gold Champagne is seen, there are a few Amber Champagnes around and the Classic Champagnes are considered rare.

More Color Diluting Genes: Silver Dapple and “Flax”

The Silver Dapple is very rare in the Quarter Horse breed but “Bar U Champ Binder” was shown to have it - now a corresponding test is available as well.

The “Flax” gene is something with hardly any information about it. It seems though that the trait is only seen if it is homozygous.