Kat1e
Well-Known Member
With a black mare and chestnut stallion, what are the possible foal colours? Are they all equally as likely? Thanks.
Colour genetics?
- Thread starter Kat1e
- Start date
charliebo
Well-Known Member
I think you have an equal chance of a black, chestnut and (suprisingly) bay. Was reading up on it the other day. Will check.
Violet
Well-Known Member
Offspring Colour Probability
33.34% - Black
33.34% - Bay
33.33% - Chestnut
The more you know about the sire and dam's breeding the more accurate it will be.
Colour calculator
33.34% - Black
33.34% - Bay
33.33% - Chestnut
The more you know about the sire and dam's breeding the more accurate it will be.
Colour calculator
Kat1e
Well-Known Member
Thank you! I have just been looking at another post with a link to a 'colour calculator' and I tried it- it said the same as you! Am surprised bay is an option but I don't know much about colour genetics!
KarynK
Well-Known Member
If the mare has two genes for black then all you will get is black carrying chestnut. If the mare has a hidden chestnut gene, for certain if one of her parents were chestnut then its 50/50 Black carrying chestnut or chestnut. Chestnut can hide for many generations!
Chestnut is recessive to black so the only way a horse can be a chestnut is if it has two chestnut genes.
The problem is the A series which are hidden in the chestnut, they establish if the horse stays black or is a bay (A) or black and tan (At). Two aa (no agouti) means the horse stays black, Aa = bay Ata= almost black AA= bay AtAt = reddish coat with black along the back and black points AAt = bay.
So At is dominant over a but A is dominant over At.
Chestnut is recessive to black so the only way a horse can be a chestnut is if it has two chestnut genes.
The problem is the A series which are hidden in the chestnut, they establish if the horse stays black or is a bay (A) or black and tan (At). Two aa (no agouti) means the horse stays black, Aa = bay Ata= almost black AA= bay AtAt = reddish coat with black along the back and black points AAt = bay.
So At is dominant over a but A is dominant over At.
charliebo
Well-Known Member
From IDS magazine:
"Black is strictly a base coat colour. The coats of all horses, regardless of their colour, are built on one of two possible base pigments: black or red. A modification of black, bay is characterised by bay-coloured hair on the body and upper legs; the rest of the horse is black. Red (chestnut) is created by the recessive "e" or "red" gene. Chestnut horses do not have any black hair. Crossing two chestnut parents can only produce a chestnut foal. However, the black gene is dominant over red, so a foal only needs one black parent in order to become black. This does not mean that this black foal will only produce black offspring in the future. In fact, two black horses can produce a chestnut. The genetic modifier that changes black to bay is also dominant. If a horse has these modifiers (also called alleles) it will be bay and therefore cannot pass on the bay modifier-except in the case of a chestnut. The bay colour is expressed only on a black coat, and a chestnut does not have black hair. Therefore, a chestnut can inherit the genetic modifier for bay from its parents and carry it unseen. A chestnut crossed with a black can produce bay, chestnut or black offspring"
It took me a while to understand all this! Never very good at science.
If you have a parent that is homozygous black crossed with a chestnut the foal will be either bay or black.
In my experience you usually get an orange filly....
"Black is strictly a base coat colour. The coats of all horses, regardless of their colour, are built on one of two possible base pigments: black or red. A modification of black, bay is characterised by bay-coloured hair on the body and upper legs; the rest of the horse is black. Red (chestnut) is created by the recessive "e" or "red" gene. Chestnut horses do not have any black hair. Crossing two chestnut parents can only produce a chestnut foal. However, the black gene is dominant over red, so a foal only needs one black parent in order to become black. This does not mean that this black foal will only produce black offspring in the future. In fact, two black horses can produce a chestnut. The genetic modifier that changes black to bay is also dominant. If a horse has these modifiers (also called alleles) it will be bay and therefore cannot pass on the bay modifier-except in the case of a chestnut. The bay colour is expressed only on a black coat, and a chestnut does not have black hair. Therefore, a chestnut can inherit the genetic modifier for bay from its parents and carry it unseen. A chestnut crossed with a black can produce bay, chestnut or black offspring"
It took me a while to understand all this! Never very good at science.
If you have a parent that is homozygous black crossed with a chestnut the foal will be either bay or black.
In my experience you usually get an orange filly....
Kat1e
Well-Known Member
Colour of mare's sire/dam unknown, but she is fell type so I assume likely to be black also.
Thank you all very much for your replies- may have to read them a couple of times to get it totally clear in my head!!
Thank you all very much for your replies- may have to read them a couple of times to get it totally clear in my head!!
silverbreeze
Well-Known Member
I have a foal of a Black mare carrying a chestnut gene to a very very dark bay stallion and I have what is apparently known as a blood bay which is basically a very reddy brown body with all the normal points of a bay ( I think us lesser brits just refer to them as bright bay).
I was hoping for a dark bay but it just doesn't work like that and she is beautiful none the less
I was hoping for a dark bay but it just doesn't work like that and she is beautiful none the less
KarynK
Well-Known Member
Nope it never works out like that, at least you didn't get stuck on chestnuts, my place is full of em! There is a lot more at work with coat shades than the books would have you believe!!!
My mare in 3 foals has put forward her chestnut gene in each one and she is a lovely black and tan, she passes the black and tan on of course but because most are chestnut and the exception was a dun you never see it. Even with a 75% chance of bay/brown I get a chestnut, this year I have 50% with her daughter, I should know in the next few days if I've got another red one!
Cant have a black either as all the chestnuts are homozygous for bay/brown!! Ah well some have spots.
It's all part of the "fun" of breeding, basically I care not if they are sound, healthy and able to perform.
My mare in 3 foals has put forward her chestnut gene in each one and she is a lovely black and tan, she passes the black and tan on of course but because most are chestnut and the exception was a dun you never see it. Even with a 75% chance of bay/brown I get a chestnut, this year I have 50% with her daughter, I should know in the next few days if I've got another red one!
Cant have a black either as all the chestnuts are homozygous for bay/brown!! Ah well some have spots.
It's all part of the "fun" of breeding, basically I care not if they are sound, healthy and able to perform.