Basic Color Genetics for Horses

We've begun our search for a second miniature stallion.  Our mini herd sire is 15 years old this year and we will eventually need a younger stallion.  While quality is the number one thing for us, we also breed for not-as-common colors.  Buckskin pintos are a favorite of ours.  Most of our miniature mares are homozygous for tobiano pinto, which means they will always produce a pinto colored foal, no matter what the color of the stallion is.  To give us a higher percentage chance of also producing buckskin, we would like to find another buckskin or even a perlino, show quality stallion.

I always find it interesting, that many people do not understand basic horse color genetics.  If you're breeding for color or selling a horse "of a different color", I think it's necessary to understand this.  If you are selling an animal, it's important to advertise that animal as honestly as you can, which includes providing the prospective buyer with the correct color genetics for that animal!

True story.....when we purchased our first mini driving mare, the seller advertised her as a buckskin.  Well of course, that was right up our alley, so we drove several hours to see her.  This lovely bay mare comes out and is nuzzling us and stealing her way into our hearts.  I ask where the buckskin is and the seller points to this little mare and says that's her!  Now folks, this mare is the most normal color of bay you'll ever hope to see!  How you could call her a buckskin, is beyond me!  The seller was an experienced horse person too.  She knew better.  I called her on the color and she sheepishly admitted that she knew the mare was a bay, but went on to say (and I quote), "Doesn't buckskin just sound better though?"

This is the mini mare we bought.....truly a bay, not a buckskin by any stretch of the imagination!

I think you'll now understand why the correct color is such a huge pet peeve of mine!  Now there CAN be various shades of both bay and buckskin, some being lighter, some being darker, some buckskins more cream based while others are more of a yellow base, but there is usually an obvious "cream" color of some nature, to the buckskin.  Here are a couple of our horses, to show a basic bay and a basic buckskin (the buckskin is also a pinto).



Basic bay.  Reddish-brownish body color with black points (mane, tail, lower legs black).

Basic, medium cream color, buckskin.  Cream (or yellow) colored body with black points (mane, tail, lower legs black).  He's also a pinto, which is what creates the white spots on his body/mane/tail and he has 4 white stockings, which is why his legs aren't black.



So let's go to the beginning of horse colors and genetics.  Every foal inherits one chromosome of a genetic pair, from each parent.  There are many different genetic pairs that are present, but the parent will only pass on ONE of the chromosomes from each pair to it's offspring.  A horse carries 32 genetic pairs.  You could easily make a lifetime study of genetics!  Here's a nice website to help start making sense of a lot of the color genetics for horses. 

https://www.vgl.ucdavis.edu/services/coatcolor.php


For a stripped down, basic introduction to this subject, we'll start here.  There are basically two base colors of horses.....either red or black.  All other color variations stem from these two base colors.

A chestnut (red) pinto miniature mare.

A black egyptian arabian stallion, Amir Ibn Inshalla.

There is an allele called AGOUTI. You can think of this as the "bay gene".  Agouti will only affect a black based horse.  If it is present in a black based horse's genetic make-up, it will ALWAYS present itself.  Meaning, it won't hide....it will always affect the black horse's coat color.  A red horse can carry it and can pass it on to it's offspring, but the agouti doesn't present itself visually on a red horse, so it doesn't change the red horse's coat color.  On a black based horse however, the agouti will restrict the black color to the "points" of the horse (the legs, the mane, the tail and the ear tips).  This is how you get a bay horse.

There is also a gene called the cream gene.  This affects both red and black based horses.  If the cream gene is present, it WILL express itself, making the horse's body coat color some form of cream or yellow.  There are many different shades of these cream or yellow colors....from darker like almost chocolate, to lighter where you are barely able to see the cream at all because it almost looks white.  This would be how you get your palominos and buckskins.  A palomino horse is a red based horse that received ONE cream gene from one of it's parents.  A palomino will have a white mane and tail.  A buckskin horse is a black based horse that also has the agouti allele (so the horse is bay) and they received ONE cream gene from one of their parents.  A buckskin will have a black mane and tail.  There is another color where the horse receives just ONE cream gene from one of it's parents.  In this case, the horse is black and with the cream gene present, it makes the color a smoky black.  It's not a true, deep black color, but the black always looks faded.  The smoky black horse's mane and tail will be the same faded black color as it's body.  This smoky black horse IS capable of passing on the cream gene to it's offspring, so it could produce a buckskin or palomino foal as easily as a palomino or buckskin horse could!  You have a 50% chance that any of these will pass the cream gene on to their offspring.  All of these single cream gene horses will have dark eyes.

I'm sure most of you have heard of the "double dilute" colors.  This simply means that the horse has received TWO cream genes (one from each parent).  A double dilute will ALWAYS pass on a cream gene to it's offspring, so will always produce a buckskin, palomino or smokey black foal, regardless of the color of the other parent.  If the horse is red based and receives 2 copies of the cream gene, then the resulting horse will be a cremello.  If the horse is black based and also carries the agouti allele (so it's a bay horse), and it receives 2 copies of the cream gene, the result will be a perlino.  If the horse is a black horse (no agouti) and receives 2 copies of the cream gene, the result will be a smoky cream colored horse.  All of these horses will have light colored eyes (usually blue but can be a greenish blue as well).

MSMF Vanilla Dreams, a Morgan cremello filly (the smaller one shown) owned by Kara Criner. Photo courtesy of Sue White, taken from the MorganColors.com website.  Notice her mane and tail are both white.

A perlino pinto yearling saddlebred filly, named DW Carolina Golden Fire.  Look closely for the perlino colored spots on her head, shoulder/neck and flank areas.  You can see the little bit of her mane that is flipped over on this side of her neck.  See how it has an orange tint to it?  This is very common for a perlino's mane and tail color.

Azariahs Mister Maestro, a smoky black pinto stallion owned by Azariah Miniatures in PA.

Then you have other coat enhancers, such as grey.  What you ask?  Isn't grey a color all by itself??  No, it's not!  The horse started out one of the basic coat colors of either red or black.  The grey gene will gradually "strip" the color away, making the horse grey or eventually white.  Again, there are different shades of grey.  Some are almost black, some are snow white.  Usually the grey horse will start out darker and lighten each year as they shed out their old winter coat.  If a grey gene is present, it WILL express itself eventually!  It may take a few years to notice the greying out process begin or it may happen as early as when they lose their foal coat, but it WILL happen.  There are also modifiers to the grey gene.  You can get a "flea bitten" color, where the horse turns white but looks like they have little freckles or specs all over them.  This is called flea bitten grey.  They can have dapples present.  They can simply go a snowy white color eventually.  Some will keep a black mane and tail for several years, before their manes and tails go white.  Grey has a lot of variations, but just know that if that grey gene is present it will ALWAYS present itself and it works on ANY coat color (red, black, palomino, perlino, etc, etc.).

Then you have the pinto pattern of colors.  This is another coat enhancer that gives the horse large white spots, or blocks of white color, over their bodies.  They can  have a lot of white, where you see only a small amount of their original coat color (usually seen on the head or neck region in horses like this) or they can be mostly their original coat color with a very small white patch located somewhere on the body or they can be anywhere in between these extremes.  If the pinto gene is present, it will always present itself as well.  In a horse that carries only ONE pinto gene, it has a 50% chance of passing the pinto coloration on to it's offspring.  If the horse has TWO pinto genes, it is said to be homozygous for that pinto color and will ALWAYS produce a pinto foal, no matter what color the other parent is.

A pinto that has minimal white.  See the white spot on his croup/butt?  The white spots extends to his tail as well, making his tail both white and black.  He is a buckskin that is about 90% base coat color and 10% white.  This is Back in a Flash, a homozygous tobiano pinto, saddlebred gelding.

A pinto that has mostly a white body with the base color (which is buckskin) restricted to his head and underneath his neck.  This is a miniature colt named DVM Grand Bazinga.  He does have one blue eye, which goes into a discussion for a different day!  This blue eye is NOT caused by being a double dilute.  His other eye is dark.

A pinto that shows about 65-70% base coat color (black) and 30-35% white.  This is a National Show Horse named DW Keyper of the Legacy.

This blog discussion has just touched the tip of the iceberg on color genetics for horses!  There are many, many other coat enhancers that I haven't even begun to mention!  I think the main message I want to impart, is to ALWAYS take the time to color test your horse if you have a "horse of a different color".  Until next time..... (remember, blog updates are every 2 weeks for the summer).