FoxDog: Goat Color Predictions

In late Fall 2004 we bred two of our does, Mack and Suzy, to our two bucks, JT and Max. I got interested in whether I could predict the color and patterns of the offspring of these breedings, and did some research in order to discover if this were possible. I discovered it was, with reservations. Not a lot is known about goat color genetics, but what is known is quite interesting. Read on for an explanation of how I predicted the color possibilities in our future kids, and once they are born, I will post pictures and an evaluation of whether my predictions were correct or not.

I used four internet references to learn about goat genetics. When I get a chance, I will add library references as well. The internet references are as follows:

Sponenberg, Phil, Dr. 'Genetics of Goat Color'
Sponenberg, Phil, Dr. 'Goat Color Explained'
Waller, Chris 'Color Genetics in the Nigerian Dwarf Goat'
Sponenberg, Phil, Dr. 'Breeding for Color'

Dr. Sponenberg is an expert in animal color genetics. His articles are readable if you know something about biological terminology or are willing to learn. His article on 'Breeding for Color' is easy to understand. Chris Waller's article is quite accessible, assuming only a small familiarity with genetics.

Color Predictions

Goat Color is determined by what genes a goat has at a locus [A spot where the gene resides in the DNA]. There are several such loci (the plural of locus) which configure a goat's color. The ones that are currently understood include

the agouti locus
the eumelanic (brown) locus
moonspot locus
whitespotting loci (there are more than one of them, most likely)

The trick is to determine what two genes or alleles a goat has at each locus. And remember, a goat gets one gene each from its parents, so you need to know the parents as well, although it is possible to make guesses once you have the goat and its offspring figured out.

Method

What I did was try to determine the alleles that each of our goats might carry at the different loci using the articles and webpages I noted above. You can see the results for each goat under 'color'. I ignored the white spotting loci until the end. Then I figured out what was possible in each doe and buck pairing. Below, I've tried to summarize the results, and my predictions.

Predictions from Pairings: Suzy and Max

Suzy:

Agouti Locus: eyebar pattern (A(eb)/dominant) and no pattern (A(a)/recessive)
Eumelanic Locus: Black (B+/recessive) and black (B+/recessive)
Moonspot locus: No moonspots
White Patterning Loci: a very slight star, about 4 hairs worth

Max:

Agouti Locus: white or tan pattern (A(wt)/most dominant of all) and no pattern (A(a)/recessive)
Eumelanic Locus: black (B+/recessive) and black (B+/recessive). He doesn't have any black areas on him, because of his agouti locus patterning, but if he did, they would be black, not brown
Moonspot Locus: no moonspots
White Patterning Loci: a star, and partial belted

Predictions for Suzy and Max:

A goat with white or tan patterning at the Agouti locus (ie an all white/cream/tan goat). Possibly with a white star and/or white belted. So basically the goat would look like the buck, Max.
- Agouti: (A(wt) from Max and A(eb) or A(a) from Suzy,
- Eumelanic: B+ from Max and B+ from Suzy,
- White patterning: possibly what the parents had, I don't know what their less dominant alleles would be, as I found this hard to sort out).
There is a 50% chance from this mating that the goat will be white/cream/tan.
A goat with an eyebar agouti pattern, black eumelanic areas, and possibly a star and/or belted. This goat would look like the mother, Suzy.
- Agouti: (A(eb) from Suzy and A(a) from Max. This can't be A(wt) from Max, because A(wt) is dominant over A(eb).
- Eumelanic: B+ from Max and B+ from Suzy.
- White patterning: possibly what the parents had, I don't know what their less dominant alleles would be, as I found this hard to sort out).
There is a 25% chance of this color patterning from this mating.
3rd possibility: An all black goat possibly with a star and/or partial to full belted.
- Agouti: A(a) from Max and A(a) from Suzy.
- Eumelanic: B+ from Max and B+ from Suzy.
- White patterning: possible star and/or possible belt.
The chances of an all black goat with a possible star and/or belt is 25%.

Result for Suzy and Max:

Prediction #3: Cal

A black goat with a partial white belt. He has no star, which is somewhat surprising, except that it's possible his parents both hold recessive 'no star' alleles. He got the belt allele from his father.

Agouti: A(a) from his father and A(a) from his mother, to make him a recessive all black goat.
Eumelanic: B+ from his father and B+ from his mother.
White patterning: Belt from his father, probably no belt allele from his mother (less dominant than the belt) and no star from his father combined with no star from his mother.
Cal may have inherited blue eyes from his father. At this point its hard to tell, as his eye color seems changeable.

Predictions from Pairings: Mack and JT

Mack:

Agouti Locus: eyebar or angel pattern (A(eb)/dominant) and no pattern (A(a)/recessive).
Eumelanic Locus: black (B+/recessive) and black (B+/recessive)
Moonspot: no moonspots
White patterning Loci: star, partial belt, spotting, roaning

JT:

Agouti Locus: no pattern (A(a)/recessive) and no pattern (A(a)/recessive)
Eumelanic Locus: dark brown (B(d)/dominant) and possibly light brown (B(l)/not as dominant as B(d), or black (B+/recessive). I'm not sure about the light brown. His mother was light brown, and JT turned out to be dark brown, and his father was an all white/cream/tan pattern, so I couldn't determine what kind of eumelanic alleles his father had. I suspect the father had B(d) (dark brown) and B+(black), considering that two of his offspring are black. The father could also have plain old B+/B+ if the light brown and dark brown alleles are really one and the same.
Moonspots: None
White patterning Loci: star, partial belt

Predictions for Mack and JT:

A 'no pattern' goat (A(a)/A(a) at the agouti locus). This goat will have either true black eumelanic areas, or brown eumelanic areas, so the goat will be either black or brown. If brown it'll probably be dark brown, like JT, or perhaps light brown, like JT's mother, Choccie. It may have a star, partial belt, spotting and/or roaning. Chances of this agouti pattern are 50%, chances of black versus brown, 50%. Basically this would be a goat that looks like JT, or one that looks like Midget or Cal or Travis or Kelly (all black with white patterning).
An eyebar patterned goat (A(eb)/A(a) at the agouti locus). The eumelanic areas in this goat will be either black, or brown. If brown it'll probably be dark brown, like JT, or perhaps light brown, like JT's mother, Choccie. It may have a star, partial belt, spotting and/or roaning. Chances of this agouti pattern are 50%, chances of black versus brown, 50%. This would either be a goat that looks like Mack, or a goat with Mack's patterning but with shades of brown in the black areas.

Result for Mack and JT:

Prediction #1: Meriadoc

He's a black goat with a white star and a few random white spots. He's got speckling around the base of his ears and tip of his nose.

Prediction #1: Pippen

Pippin is a brown goat with a white partial bellyband, white star and random spots. He's got an interesting light area on one foreleg, which I'm not sure how to categorize. It's back to the genetics papers for me!