A color calculator for horses is a tool used to predict the possible coat colors of a foal based on the coat colors and genetic makeup of the parents. Coat color in horses is determined by a combination of multiple genes, and understanding the inheritance patterns of these genes can help in predicting the color of offspring.

Key Genes Involved in Horse Coat Color

1. Extension (E) Locus:

• Determines the presence of black pigment.
• E (dominant) = black pigment.
• e (recessive) = red pigment (chestnut/sorrel).

2. Agouti (A) Locus:

• Controls the distribution of black pigment.
• A (dominant) = restricts black to points (bay).
• a (recessive) = no restriction (solid black).

2. Agouti (A) Locus:

1. Controls the distribution of black pigment.
2. A (dominant) = restricts black to points (bay).
3. a (recessive) = no restriction (solid black).

3. Gray (G) Gene:

• Causes progressive graying of the coat.
• G (dominant) = grays out with age.
• g (recessive) = retains base color.

4. Cream (C) Dilution:

• Dilutes red and black pigments.
• CC = no dilution.
• CCr = single dilution (palomino, buckskin).
• CrCr = double dilution (cremello, perlino).

5. Dun (D) Gene:

• Dilutes body color and adds primitive markings.
• D (dominant) = dun dilution.
• d (recessive) = no dun dilution.

6. Roan (Rn) Gene:

• Mixed white hairs with base color.
• Rn (dominant) = roan.
• rn (recessive) = non-roan.

7. Other Modifiers:

• Various genes can cause spotting, white markings, and other patterns (e.g., Tobiano, Overo).

Using a Color Calculator

To use a horse color calculator, you typically input the genotypes or phenotypes of the parent horses. The calculator then uses Mendelian inheritance rules to predict the possible coat colors of the foal.

Here is a simple example of how this works:

Example here:

Parent 1: Bay (Ee Aa)

• E (black pigment) is present.
• A (bay pattern) is present.

Parent 2: Chestnut (ee aa)

• e (red pigment) is homozygous.
• a (no black restriction) is homozygous.

Potential Foal Colors

• (Black Bay)
• EE Aa
• Ee AA (Black Bay)
• Ee Aa (Black Bay)
• ee AA (Chestnut)
• ee Aa (Chestnut)
• ee aa (Chestnut)

From this example, we can see that all foals with at least one dominant E allele will have a black base color. The presence of the A allele will determine if the foal is bay.

Online Horse Color Calculators

There are several horse coat color calculator online tools that can help you calculate the colors of horse:

• Animal Genetics Horse Color Calculator – A comprehensive tool that allows input of various genetic markers.
• HorseColor.com – Another useful tool for calculating potential coat colors.

These calculators take into account the complex interactions between different genes and provide probabilities for each potential outcome.