Information on the web from UC Davis provides easily understood genetic information regarding the coat color tests currently available. Previously, the silver dilution was distinguished by the red-factor test to determine if the horse was black-based. Therefore, there is a new genetic test for the Silver. The gene responsible for the Silver dilution (Z) was recently identified by researchers in Sweden and reported in 2006. The color is known to occur in Rocky Mountain Horses, Icelandic, Morgan Horses, Miniatures, and other breeds. Also, the effects of other modifiers such as grey, roan, or pinto would combine with the Silver and change the appearance of the Silver on a given horse.Īlthough quite rare, Silver can be found in a few Tennessee Walking Horses. A Chestnut can pass the gene to the next generation, therefore appearing as if the gene skips a generation. A Chestnut may carry the silver gene but does not display the modifier. The Silver Gene does not act on red pigment. Dark skin at birth may be a sign of the silver gene. Foals can be distinguished from chestnut foals by the color of the skin with chestnut foals having pink or pinkish skin. The mane and tail display as platinum blonde to a flaxen color, with a silvery color rather than a golden-hued flaxen color. The black on the legs will be diluted but will show darker than a chestnut, ranging from near black to pewter to chocolate brown with lighter hair close to the hooves. The Silver Gene can also act on a bay base color with the red pigment of the body unaffected. A light chocolate silver with dapples is considered more classic and is often called, ‘silver dapple,’ and can be confused with a chestnut, but again, the horse will lack red tones. A ‘black silver,’ or darker expression of the silver, can be confused with a flaxen dark chestnut although the silver will not have reddish tones. Cappie’s color is considered a medium expression of the chocolate silver. His mane has an intermixture of dark and light areas which is also very typical of the silver color. His base coat is black but the silver dilute makes his body a rich chocolate and his mane and tail white. This picture is “ Starbucks Iced Cappuccino” ( Cappie). Common names for this color on a black horse are ‘classic silver dapple,’ ‘chocolate silver,’ or ‘black silver.’ Silver foals usually have distinct striping patterns in their hooves and white eyelashes. Also, the silver dilution results in light hair on the lower legs, lightest closer to the hooves. Often the Silver will give a bluish cast rather than a reddish undertone. It is sometimes difficult to tell horses displaying the Silver gene from a red-based horse like a dark liver chestnut. When a horse gets the Z gene any black pigment may be diluted. In other words, one parent must have the gene in order to pass it on to the foal. The Silver dilution is a simple dominant in that only one Z gene is necessary to give the color trait. The gene tends to dilute the mane and tail much more strongly than the body, often resulting in a silvery-white color, sometimes showing darker roots. A solid black horse presenting this gene will be chocolate colored, ranging in shade from taupe to a rich chocolate brown. The Silver gene (Z) dilutes only black pigment and will display in some form or other on any horse with black points including black, brown, bay, dun, grullo, and buckskin. You may have heard of this same color as ‘silver dapple.’ Below is found a simple description of the effects of the Silver gene on horse color and new information regarding the testing for the silver gene. Although called ‘taffy’ in Australia, some breeds use the term ‘chocolate’ to describe the color. Originally thought to only apply to Shetland Ponies, the gene has been found in a number of other breeds, including the Tennessee Walking Horse, and is becoming more understood. The Silver gene is a rare color-modifying gene that is pigment-specific.
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