Horse Coat Color Calculator
Predict foal coat colors based on sire and dam genetics
Horse Coat Color Calculator
Input Mode
Sire (Father)
Dam (Mother)
Understanding Horse Coat Color Genetics
Horse coat color genetics is a fascinating field that combines science with the art of breeding beautiful horses. The Horse Coat Color Calculator uses proven genetic principles to predict the possible coat colors of foals based on their parents' genetics. Understanding these inheritance patterns helps breeders make informed decisions and set realistic expectations for their breeding programs. The basic coat colors in horses are controlled by just a few genes, making predictions surprisingly accurate when the parent genotypes are known.
The foundation of horse color genetics lies in two primary genes: Extension (E) and Agouti (A). The Extension gene controls whether a horse can produce black pigment, with 'ee' resulting in chestnut horses that produce only red pigment. Horses with at least one 'E' allele can produce black pigment. The Agouti gene then determines where black pigment appears - horses with at least one 'A' allele restrict black to the points (mane, tail, lower legs), creating bay horses, while 'aa' horses are black all over. This simple two-gene system creates the three base colors: chestnut, bay, and black.
Dilution genes add complexity and beauty to horse coat colors by modifying the base colors. The cream gene (Cr) is one of the most important dilution genes, creating popular colors like palomino and buckskin. One copy of the cream gene on a chestnut base creates palomino, while on a bay base it creates buckskin. Two copies create double dilutes: cremello from chestnut, perlino from bay, and smoky cream from black. These double dilute horses have pink skin and blue eyes, making them easily identifiable. Understanding cream gene inheritance is crucial for breeders seeking these valuable colors.
Predicting foal colors requires understanding basic Mendelian genetics and probability. Each parent contributes one allele for each gene to their offspring, with the combination determining the foal's color. For example, crossing two heterozygous bays (EeAa) can produce nine different genotype combinations, resulting in bay, black, and chestnut foals in predictable ratios. The calculator uses Punnett square principles to determine all possible combinations and their probabilities, giving breeders a scientific basis for their expectations.
Beyond the basic colors and cream dilution, horses can carry many other color genes including dun, champagne, silver, pearl, and various white patterns. While this calculator focuses on the fundamental Extension, Agouti, and Cream genes for simplicity, real-world breeding often involves multiple genes interacting. Advanced genetic testing can identify exactly which genes a horse carries, removing guesswork from breeding decisions. Many breed registries now accept or even require genetic testing for color genes, especially when registering horses with unusual colors.
Successful color breeding requires balancing color goals with other important traits like conformation, temperament, and performance ability. While this calculator helps predict color outcomes, responsible breeders never select horses based solely on color. The best breeding programs use color genetics as one tool among many, ensuring that beautiful colors come in sound, athletic packages. Understanding color genetics also helps breeders avoid unwanted surprises and market their foals more effectively by accurately predicting and describing possible outcomes to buyers.
Frequently Asked Questions
No, two chestnut horses (ee) can only produce chestnut foals. Chestnut horses have two copies of the recessive 'e' allele and cannot pass on the dominant 'E' allele needed for black pigment production. This makes chestnut x chestnut crosses 100% predictable for base color, though dilution genes can still create variations like palomino or cremello.
Buckskin and dun horses may look similar but are genetically different. Buckskin results from one cream gene on a bay base, creating a golden body with black points. Dun is caused by a different gene that dilutes the body color and adds primitive markings like a dorsal stripe, leg barring, and shoulder stripes. A horse can be both buckskin and dun (dunskin) if it carries both genes.
Predictions based on known genotypes for Extension, Agouti, and Cream genes are highly accurate for these specific colors. However, horses may carry other color genes not included in basic calculations. Genetic testing of parents provides the most accurate predictions. Additionally, some colors may change as foals mature - many bay foals are born looking chestnut and develop black points later.
A palomino (chestnut base with one cream gene) bred to a bay can produce chestnut, palomino, bay, or buckskin foals. The exact probabilities depend on whether the bay carries any recessive genes. If the bay is EeAa (heterozygous), you could get all four colors. If the bay is EEAA (homozygous), all foals will be bay or buckskin. Genetic testing can determine exactly what each parent carries.
No, double dilute horses are not albino. True albinism (complete lack of pigment) doesn't exist in horses. Cremellos, perlinos, and smoky creams have two cream genes that heavily dilute their color, resulting in pale coats and blue eyes, but they still have pigment. Their pink skin contains some pigment, and genetic testing shows they have normal color genes that are simply diluted by the double cream genes.