Here is an article from a couple of years ago when we were color testing all our mares.

Spanish Vision Farm Mares to be Color Tested...

picture of andalusian fillyNobleza D, Keberes D, Galadriel DD, and Galaxia DD are scheduled to be tested for "color" by the University of California at Davis Veterinary Genetics Laboratory (UCD VGL). The tests will include the Extension gene (red factor) and the Agouti gene (controls the distribution of black pigment). 

To understand color genetics in horses, we suggest you study the information available at UCD.  Although most Andalusian horses look "grey", they are actually a base color other than grey - such as red or black. To determine your gray horse's base color, genetic testing can be done for $40 (both red and agouti) per horse.

To sum up, "The basic coat colors of chestnut, bay, brown and black horses are controlled by the interaction between two genes: Extension (gene symbol E) and Agouti (gene symbol A). The Extension gene (red factor) controls the production of red and black pigment. Agouti controls the distribution of black pigment either to a points pattern (mane, tail, lower legs, ear rims) or uniformly over the body. The effects of approximately 10 other genes may modify these pigments to provide an array of colors in the domestic horse ranging from white to black.

The results of the genetics test will answer two important questions...

Does My Horse Carry Chestnut?

The Extension gene (red factor) has two alternative states (alleles). The dominant allele E produces black pigment in the coat. The recessive allele e produces red pigment. Red horses (chestnuts, sorrels, palominos and red duns, to name a few) are homozygous, that is they have two alleles, for the recessive red allele ee. Black pigmented horses (black, bay, brown, buckskin and grullo, to name a few) have at least one E allele. They can be homozygous EE or heterozygous Ee. A horse that is homozygous EE will not produce red offspring, regardless of the color of the mate.

Is My Horse Base Black or Can He Throw Black?

The Agouti gene controls the distribution of black pigment. The dominant allele A restricts black pigment to the points of the horse (mane, tail, lower legs and ear rims), as seen, for example, in bays and buckskins. The recessive allele "a" uniformly distributes black pigment over the entire body.

Breeders interested in producing black horses need to have breeding stock carrying the "a" allele, in addition to the E allele of the Extension gene. 

Can My Grey Horse Produce Color?

In order to produce color other than grey in your foals, your mares and stallions must be heterozygous for grey (Gg) or non-grey. If both parents are GG, homozygous for grey, then no matter what the base color of your foal is, the foal will eventually turn grey. There currently is NO TEST for grey in horses. However, if one parent of your horse is NOT GREY, then you can be 100% certain your horse is Gg. If both parents are grey, it depends whether they are Gg or GG. 

When both parents are heterozygous, then there is a 1 in 4 chance of getting non-grey (gg), 1 in 4 of getting homozygous grey (GG), and 1 in 2 chance of getting heterozygous grey foals (Gg). Heterozygous grey horses bred to a non-grey horse will throw color about 50% of the time.

Spanish Vision Farm Mares Color History

Currently, we know that both Keberes D and Nobleza D are heterozygous for grey (they are Gg). Keberes D has produced a non-grey foal (Adriano DD) and Nobleza has a bay parent and has also produced a non-grey foal (Basilio TFA). Galaxia DD and Galadriel DD have a 50/50 chance of being either GG or Gg. Their sire Remate is most likely GG because he has never produced color when bred to Gg greys or gg bays. Their dams are Gg. So they are either GG or Gg.

As for color, Keberes D has produced chestnut, so we know she carries at least one "e" gene for chestnut. She has produced foals that appear black, bay, and chestnut in base color. So most likely she is EeAa. Genetic testing will confirm. 

Nobleza has produced bay, so we know she carries at least one "E" gene for black base. Her foals have appeared bay and black in base color. Two of her foals have tested EeAa for color - so it's possible she also carries "e" or else that gene came from the sires of the foals. Most likely she is EEAa or EeAa. Genetic testing will confirm.

Galaxia DD appears as a  black bay or black base color. She has black, bay, and chestnut in her background. Galadriel DD appears bay in base color, she also has multiple colors in her background. Genetic testing will confirm.

What Will This Knowledge Tell Me?

By knowing the genetics of all 4 mares, I'll know if they can produce black, bay, and/or chestnut base colors when bred to certain colored stallions that have also been genetically tested. This information is especially valuable if you plan on paying higher stud fees to a black/bay or black stallion.

Skyhorse Ranch - Andalusian horse breeder in Texas with Andalusian horses for sale. Breeders of PRE Pura Raza Espanola horses with cartas from Spain. Selling black, grey, and bay Andalusians. Recommend Andalusian stallions at stud. Pictures, history, facts, and info. Spanish Andalusian horse farm. Bloodlines from Spain in the USA.

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