Continuing my fascination with genetics, this post is about the coat patterns of goats.

In my previous post on coat color, I mentioned that the Agouti locus determines the color of a goat. Part of determining the color is also determining the pattern.

A goat receives two alleles on the Agouti locus – one comes from the dam, one comes from the sire. If the alleles are the same (homozygous), such as both being buckskin, then the kid would also be buckskin. However, if the alleles are different (heterozygous), different combinations of color patterns can be expressed. The Agouti alleles are co-dominant, meaning they both can be shown. In general, though, the pattern with most tan will be expressed.

Two other things to consider are pattern modifiers and white spotting. White spotting can change what we see on the goat’s coat, masking its genetic color pattern.

Agouti Allele’s

This is not a complete list, but the most common in Nigerian Dwarf Goats

SOLID

When only pheomelanin is present and no eumelanin this produces a solid pattern. This is the most dominant pattern.

Our goat, Bunny, is a solid light cream color with white spotting.

CHAMOISEE

Also known as Badgerface. Goats with this pattern are tan or brown, with a black (or dark brown) underbelly, dorsal stripe, facial stripe, and lower legs.

BUCKSKIN

Also known as San Clemente. The body on a buckskin can be cream, tan, or dark reddish brown. They are distinguished by their black (or dark brown) cape around the head, neck, and shoulders. Buckskins also express black (or dark brown) on top of their tail and chevron on the back legs. Their head is black (or dark brown) with lighter stripes.

Vern is a dark buckskin with random spotting.

COU CLAIR/COU BLANC

Also known as Peacock. These goats have a tan (cou clair) or white front (cou blanc), while their back half is black (or dark brown). They also have black (or dark brown) facial stripes.

SWISS MARKED

Also known as the Toggenburg pattern. Goats that are Swiss marked have a black (or dark brown) body. The pheomelanin (white, cream, or tan) areas include all 4 legs, facial stripes, ears, and under the tail.

WyldeStyle is Swiss marked.

SUNDGAU

The Sundgau pattern is similar to the Swiss marked pattern with a black (or dark brown) body and light legs, facial stripes, ears, and under the tail. However, the Sundgau pattern also has a light underbelly. It also has black (or dark brown) stripes on their light legs.

NO PATTERN

When there is only eumelanin and no pheomelanin present, this produces an all black goat. This is the most recessive pattern.

COMBINATION PATTERNS

Because goats can show both the pattern they inherited from their dam and the one they inherited from their sire, sometimes combination patterns occur.

Crash is a Buckskin/Swiss Marked combination.

White Spotting & Other Modifiers

Sometimes, in certain areas the eumelanin and/or pheomelanin pigments are not produced. This results in white spotting.

Genetically, the base color is still present, but it is masked by the spotting.

There are multiple genes associated with white spotting, so one goat could have multiple spotting patterns.

RANDOM

Random spots on the body

BELTED

White band around a goat’s midsection. The belt may go entirely around the goat, or not – and be referred to as a partial belt.

WyldeStyle has a partial belt with her Swiss markings.

SCHWARTZAL

The body is primarily white with dark markings on the head and sometimes the legs.

ROANING

Roaning is when white hairs are sprinkled among colored hairs. They are single hairs, not spots of white.

Georgia has roaning throughout her body.

FROSTING

When ticking occurs on the muzzle, ears, or tail it is known as frosting.

Georgia also has frosting.

WHITE POLL

A white poll refers to a white spot on top of the head.

Bunny has a white poll.

MOON SPOTS

Moon spots are random spots of color on top of a base color.

Moon has moon spots.

My goal is to take this information to learn more about and enhance our own herd.

Science is Fun & Genetics are Fascinating!

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Although it is true outward appearance is really of little importance, a fun bonus with raising Nigerian Dwarf Goats is the variety of coats and patterns. One goat can look similar or look completely different from their herd mates. I could have a herd of 15 goats and all 15 goats potentially could look different. This fascinates me.

The genetic process for goat color is complicated, but I have it narrowed down to a few basic components. This is helping me wrap my brain around the science.

For a refresher on basic genetic terms, click here.

PIGMENT

Pigment that makes up the coat color is made of the protein melanin. There are two types of melanin – eumelanin and pheomelanin. A number of different genes determine where the eumelanin and pheomelanin pigments are throughout the coat. Coat color and pattern is a result of the combination of eumelanin, pheomelanin, and white spotting.

EUMELANIN = Produces black or brown. Only one color is present, though – black or brown, not both.
PHEOMELANIN = Produces creams, tans, and reds. More than one color can be present, as can varying shades.

AGOUTI LOCUS (A)

Most of the genetics behind coat color and pattern come from the Agouti locus. This locus determines where and how much pheomelanin and eumelanin is produced. There can be a lot of pheomelanin expressed and very little eumelanin, or vice versa – and everything in between. If a goat displays only pheomelanin and no eumelanin, the goat will be a solid cream, tan or red.   If a goat does not produce any pheomelanin and only produces eumelanin the goat will be solid black or dark brown.

There are at least 21 different possible alleles for this locus – no wonder goats can come in such a wide variety of colors and patterns!

In most cases, tan is dominant in the pheomelanin areas. This can create a variety of combinations when the dam and sire have different colors and patterns because the tan areas of both patterns will generally be expressed.

BROWN LOCUS (B)

This locus is also important in determining coat color. It determines whether the eumelanic areas are black or dark brown. Dark brown is dominant over black, however dark brown is not as common.

The brown locus has four alleles, or four different possible color options. However, any one goat only has two alleles in its genetic makeup – it receives one allele from mom and one allele from dad. The two alleles could be the same (homozygous) of they could be different (heterozygous).

The four alleles in order of dominance are:
Bd: dark brown, sometimes referred to as chocolate brown
Bl: light brown
B+: black, sometimes referred to as the wild type
b: medium brown, very rare

SPOTTING (S)

To make things even more complicated, goats can also have white spotting. These white spots are a lack of pigment and can occur on any color or pattern, masking the base color. The spotting can be very little or cover an entire coat.

The majority of Nigerian Dwarf Goats have at least a little spotting.

EUMELANIN COLORS

DARK BROWN

Dark brown is dominant on the B locus. It is a modifier of black. All areas that would be black are instead dark brown.

BLACK

Black is recessive on the B locus, therefore both parents must pass on the gene for a kid to be black.

Since it is recessive, it can be hidden by another color and be passed on to the kids.

Georgia is black with roaning.

PHEOMELANIN COLORS

WHITE/CREAM

A seemingly solid white goat could actually be a a very light cream color.

Another way a goat can appear white is if their spotting is so intense that it completely masks the true base color.

Willow is cream with white spotting

TAN/BROWN

The tans and browns can range from light tan to a dark reddish brown (different from the dark brown produced by eumelanin)

Vern is buckskin in black and dark reddish brown

GOLD/RED

The golds and reds also have quite a range from a light gold to a dark reddish gold.

Wingman is a light gold color.

I consider Moon’s base color to be a medium red gold.

To determine coat color requires figuring out the base color or pattern, whether the B locus is black or has been modified to dark brown, and identifying white spotting.

Science is Fun & Genetics are Fascinating!

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I brought Vern home as a companion for Sven. He’s a good little goat who has to take a lot of crap from Sven.

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PEDIGREE

He is a wether and I don’t have registration papers for him.

BORN: about January 2014

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Vern gives me very little trouble. He doesn’t try to escape. He comes over to greet me when I’m near the fence.

He’s so well mannered that he’s another reason I decided to expand our herd.

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