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Why Should I Care About Color
By Marsha Yzaguirre
©Voice, June 2007
Most of us have heard the saying that "a good horse is never a bad color." And usually, the horse's ability to do the job for which it was intended is the most important (for some, the only) standard by which it is judged. But most people, whether they admit it or not, are influenced by a horses color. So why should you care about color?
As an Owner, the colors on a horse’s registration papers provide visible proof of the horse’s identity. Correctly identifying a horse’s color and faithfully reproducing his body markings helps the owner to identify the animal if stolen or lost.
As a Breeder, color can influence the price you get when you sell a horse. With bloodlines, conformation, and temperament being equal a person is more likely to pay a little more for a horse with a color he or she prefers than for one whose color they don’t particularly like. Because of this, color can influence the market value of a horse so it is beneficial to breeders to understand how horses produce the colors that people prefer. We now know that color is caused by relatively few genes with the basic ones well understood. Because of the advances in identifying color genes, breeders can, if they chose, breed for a specific color.
As a Registry, accurate color classifications are critical for the integrity of the data. How we classify horse coat colors and markings is important in any horse registry in order to identify horses as individual animals. Basic, definable characteristics and uniform application of terminology are critical for the integrity of the registry’s information. The registry has to provide breeders and buyers with enough possible color options to make the desired accuracy possible. Using a scheme of coat color classification based on the effects of the genes currently understood provides the necessary rigor. Through training the scheme can be uniformly applied by anyone to accurately define most of the common colors encountered in horses.
TWHBEASM recognizes and records many coat colors and since most Tennessee Walking Horses are registered as foals between the ages of three to six months, it is sometimes difficult to determine the true color of the foal. Coat Color Testing is highly recommended where visual appearance is not enough to accurately predict the true color. The new color brochure, Coat Colors of TWHs, found on the TWHBEASM web site explains the genetic terminology used in defining horse coat colors. It also includes a Color Genetics Chart that gives the genetic color test results for color genes associated with different coat colors to help you to accurately describe your foal at registration and to assist you in correcting a wrong color choice made or to add another dilution and/or modifier that affects the foal coat color after the foal has been registered. You can contact TWHBEASM to request a full size brochure be mailed to you.
Testing for Color
Scientists continue to work on identifying genes associated with a horse’s color. All horses, regardless of their color or markings, have their coat color built on one of two possible base pigments; red or black. The final color, shade and/or pattern of a horses coat will be determined by other possible genes that act upon the base coat of the horse. Following is a brief explanation of color coat tests currently available.
Red factor determines if a horse’s base coat color is red or black. The red factor is recessive and the black factor is dominant. Thus, a horse carrying at least one copy of the black factor will have black pigment in its coat. Only horses with no black factor will have a red pigmented base coat.
Agouti gene restricts the black pigment to the points (mane, tail, ear rims and legs) and is useful for breeders interested in producing or avoiding horses with black points (bay, buckskin, perlino, amber champagne, etc.) There has to be black pigment available for this gene to have an effect so it has no effect on red based horses.
Cream Dilution gene is responsible for the dilution of chestnut horses to palomino and cremello, bay horses to buckskin and perlino, and black horses to smoky black and smoky cream.
Silver Dilution gene mutation is responsible for what is commonly known as the silver dapple coat color. When present, black-based horses will have a chocolate body with flaxen mane and tail. Bay-based horses (those with black points) will have lightened lower legs and flaxen mane and tail. Red-based horses are not altered.
Tobiano testing is used to determine if a horse is homozygous, heterozygous or negative for the Tobiano coat pattern.
Sabino 1- Sabino1 is a gene mutation that has been determined to be the cause of the Sabino coat pattern found in a number of breeds of horses including the Tennessee Walking Horse. However, there is more than one sabino gene so that a horse that appears to have the sabino pattern may test negative for the Sabino1 gene.
Lethal White Overo (LWO) - Genetic testing useful for breeders interested in the frame overo pattern but wanting to avoid possible lethal foals associated with homozygous positive LWO horses. This has not been reported in TWHs because the Overo pattern is rarely seen.
Research to identify the Champagne, Grey and Dun genes
is in progress.
The University of Kentucky is
offering color tests for Tennessee Walking Horses at a reduced rate using the same hair samples pulled for DNA parentage verification testing. The forms are with the DNA Kit.
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