Horse coats come in a wonderful array of shades and patterns, all beautiful in their own right, but a blood bay horse color is one of the most stunning. What makes this striking color? What horses can produce it if you are breeding?
Bay is one of the most common horse colors. However, the bay is a broad term, as there are many shades that fall into this category. Even though the bay has several shades, there are always certain factors that a bay horse has.
The shades of bay range from very dark, commonly known as dark bay, to blood bay, to light bay. A dark bay horse can look almost black, especially with its winter coat. When trying to distinguish if a horse is a dark bay or black, take a good look at the hair.
A bay horse will always have some traces of reddish or brown tint. This is easiest to find around the muzzle or eyes. It is also easier to spot when a horse has its summer coat.
A light bay horse is often easily confused with brown. However, these horses have a lot of red in their coat, some even look chestnut, but the black mane and tail give away that they are bay. Blood bay is one of the richest coat colors.
Another shade of bay, sandy bay, is often mistakenly thought of as buckskin. The main coat color of the two is very similar.
These horses are quite dark, but lighter than a dark bay. They have a deep red, almost blood-like tones throughout their coat. Similar to blood bay is copper.
The copper bay is a bit lighter than a blood bay. They also have a slightly orange tint to their hair. Finally, bay coloring can turn up in other types of coats.
Bay Horse Coat Patterns
Skewbald is a horse with a pattern of white and bay, or white and chestnut. You will mostly hear the term Skewbald in the UK and Ireland. In the United States, you will usually hear the word, pinto, to describe this coat pattern.
Another coat pattern that can contain bay is an Appaloosa. These horses are mostly white with many bay spots. Or bay with a white blanket and bay spots.
Facts About Bay Horses
All bay horses have a black mane and tail. They also all have blackleg points. If a horse has a coat that looks like it is a shade of bay without black, then it is not bay. It is common for bay horses to have white socks and white face markings.
Every horse breed has a bay in its genetics. It is a dominant color but not a true base. There are only two true base colors black and chestnut. Researchers believe that light bay has existed for thousands of years and is one of the ancient horse colors, along with dun.
Horses with white markings against a bay horse are very flashy. Another way to describe these horses is that they have a lot of chrome. White socks look quite striking against the blackleg points.
Bay Coloured Horse
The hair on bay horses often has two tones. This is one reason why there is such a variety of shades. It is also one reason why bay horses can look much dark with their winter coats.
If your body clips a bay horse, you will notice that some look much lighter. As the hair regrows, the shade darkens again. Genetics determine the shades a bay horse appears in.
There are two genes that determine if a horse is a bay and also the specific shade you see. In addition to genetics, the environment the horse is in influences that shade. Nutrition, care, and the time of year also influence changes in shade.
Now that you have a basic understanding of the variety of bay coats you will see, let’s take a look at genetics. This is where things can get confusing, so let’s go back to one basic we already mentioned. There are only two color pigments for horses, red and black.
These are based pigments. The base pigments are then influenced by other genes, which bring to life a variety of horse colors. Of the two base pigments, red is recessive. All color genes pass to a foal from its sire and dam.
The influencing genes include the gene that dilutes the coat, giving us some of the more unusual horse coat colors. Coats with black points include bay, buckskin, dun, brown, and grulla. Whereas coats without black points include chestnut, palomino, red dun, and cremello.
You then have further genes that influence the coat pattern of Appaloosas, pintos, and roans, on top of the base colors. When breeding, a cross between a bay and any other color can produce a bay foal.
Bay Color Genetics
The agouti gene is the main influencer for bay coat colors. Within agouti, there are two alleles, ‘A’, which is dominant, and ‘a’, which is recessive. It is ‘A’ that determines if a horse is a bay. A horse that has A/A genetics, will always pass the dominant ‘A’ to its offspring.
If a horse has A/a genetics, it will pass on the dominant ‘A’ fifty percent of the time and the recessive ‘a’ fifty percent of the time. If a horse ends up with two a/a genes, it will have a full black coat, not just points.
Essentially the agouti gene only has an effect on horses with a black base color. The ‘A’ will restrict the black to the points you see on the legs, plus the mane and tail. The ‘a’ is not capable of restricting black, hence why you get a black coat.
The gene for black base color is ‘E’. Even with all the shades of bay, the majority of horses with this color will have one of four genetic combinations – EeAa, EEAA, EEAa, and EeAA. However, there are other rarer combinations.
For example, ABCee is often found in the genetic makeup of red bay horses. The ‘A’ gene is the wild pattern gene that helps to provide camouflage and is a version of the ancient ‘A’ gene.
For a good introduction to horse coat color genetics, check out this video.
A blood bay horse color means that the horse has rich red tones in its coat. Sometimes these horses can even have a purple tint in their coat. In the domestic horse population, a bay coat does not give any benefit over other colors.
Many years ago, in the wild, blood bay or any shade of this color allows the horse to blend into its surroundings better. However, today, wanting a bay horse is purely a personal preference.