1. White will cross the back between the withers and the dock of the tail. 2. Generally all four of the tobiano's legs are white, at least below the hocks and knees. 3. They will have face markings of a normal horse, such as a star, snip, strip, blaze or no marking at all on the face. 4. The spots are rounded or oval shapes and generally the dark color will extend down the neck, giving the appearence of a shield. It is typical for the dark color to cover at least one of the flank areas. 5. The tail often has two colors. 6. Tobiano horses can be predominantly dark or white in appearance.Tobiano Characteristics
The tobiano gene is dominant, meaning that if the horse has tobiano characteristics then the horse does have the tobiano gene. If the horse does not express the tobiano genetics then the horse does not have the tobiano gene.
A tobiano horse can be either "double gened or single gened" for this dominant trait. The double gened tobiano horses are referred to as homozygous and should produce 100% colored tobiano offspring. All of their foals will have the tobiano gene. On the other hand a single gened tobiano is heterozygous for the dominant gene. This horse will produce 50% colored tobiano offspring and 50% non-tobiano offspring when bred to non-tobiano mares. One of these two horses illustrated is homozygous for the tobiano gene, and one is not. There is a visual indicator, that is about 90% without having to look at the registration papers or the blood type results. Which one is homozygous and thus more valuable as a Paint sire?
3 comments:
Wade, there are two things about this that surprise me, since to my knowledge there is no visual indicator or blood test to distinguish heterozygous from homozygous gold tigers. I will hazard a guess that the homozygous or "double-gened" tobiano is the second one, the one on the bottom because of his bi-colored tail.
Mary Ann
Mary Ann,
Small little clusters of "spots" some where on the coat pattern, is a visual identifier for homozygous. And there is a visual identifier to distinguish heterozygous and homozygous gold tigers. Don't ask, as there has been enough damage done in the color breeding of tigers, and let's love and be thankful for what we have.
Wade
Wade, so it is the second horse, but not for the reason that I thought?
Mary Ann
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