An Introduction to Horse Genetics
Horses have played an important part in human history. After we domesticated them, their characteristics helped to propel civilizations. Their speed assisted in quick delivery of messages across long distances and their strength helped in the cultivation of large tracts of land in short periods of time. As such, horse husbandry became an important activity to perform. Interacting with horses helped to change the lives and living conditions for human beings. It also changed the lives of horses through crossbreeding and genetics.
History of Horses and Entry of Genetic Differentiation
The earliest horses were wild and they lived on the Eurasian Steppes 5,500 years ago. After domestication, horses were initially used for agricultural activity. Over time, they were adapted and crossbred so as to bring out different characteristics. This activity resulted in specialized breeds and types of horses that we have today.
Some horses are lean and perform as racehorses. Examples of these are the American Quarter Horse, Arabian and the Standardbred. On the other hand, others are strong and stocky. They perform as workhorses with examples being the Clydesdale, Tennessee Walking Horse, Morgan Horse and the Friesian Horse.
Genetic effects on the horse coat colors
The genetic modification that has been implemented over time is also visible in colors of the horses’ coats. The color of a horse’s coat is a qualitative trait, actually determined by relatively few genes. These can be identified phenotypically.
The base colors for horse coats include:
Bay. This is a brown, reddish or dark brown color with black points. A deep, dark bay can actually be confused with black. In such a case, red undertones distinguish the color as Bay.
Black. The black coat is characterized by a black color with black points. Interestingly, many black horses have white skin. A black horse with black skin is referred to as a True Black.
Brown. In this coat, the horse is brown in color with no black points. It is more chocolate than red in color. If a brown horse is very dark, he can be confused to be black.
Chestnut. This color is basically red. It may be light or dark in color. Chestnut horses do not have dark points. A dark Chestnut is referred to as Liver Chestnut. With this type of coat, the horse has a reddish mane and tail. These features distinguish it as a Liver Chestnut.
Other horse colors. Supplementary horse colors include Sorrel, Palomino, Dun, Cream, Gray, Grullo and the Blue Roan. Some more of these include the Appaloosa, Red Roan, Pinto and Paint. These colors are mixes and shades of the original, base coat colors. Patterns, stripes and dapple may appear on the coat depending on the most dominant genetic traits.
Genetics behind speed in horses
Modern racehorses are also referred to as Thoroughbreds. They were bred over many decades purely for speed and endurance. These horses may have one or more legendary ancestors that lived and performed in the last 100 years. An example of such is Eclipse. This was a British Thoroughbred from the 18th century who won 18 races. This elegant, powerful horse appears in the pedigree of many modern winning race horses.
Today, scientists have found the specific gene responsible for the speed and strength of racehorses. It is known as the myostatin gene (MSTN). Every horse has a unique version of this gene. MSTN is responsible for muscle growth. Horses that have strong versions of this gene are able to grow more muscle faster than those with weaker versions of the gene. Geneticists have found ways to change the sequence of this gene so as to adjust the muscle-mass growth potential of a horse. By doing so, geneticists are able to create faster, stronger and more powerful racing horses.
Horses have helped us to create many civilizations and today are used for racing and other gallant activities. Genetics have played a huge role in transforming the original wild horses into modern thoroughbreds. With growing interest in healthier and faster horses, the role of genetics in the lives of horses is far from over.