Equine Colour Genetics

[kimberleigh]

Just a musing, as I have recently became involved with Connemaras; having never had any experience with the breed beforehand (more so TBs and Welshies!)

Now there are so many greys...but I've been studying pedigrees and have seen many "coloured" foals being produced from 2 grey parents - which have came from 2 grey parents themselves.

I was under the impression that if a foal is born of 2 greys (which have each came from 2 greys) then it is genetically impossible for the foal to be anything but grey...and will then in turn only be able to produce greys?!

Also "grey dun" seems to be a very common colour...now, I realise *most* of the registered duns are actually buckskins but what are these grey duns they register? Are they pale buckskins that have grey manes/tails/points, and so because they havent yet greyed out they register them as grey dun?

I have a friend who has a buckskin filly, DOB July last year, who was born rich buckskin with black points, which have now gone grey. She's just shed her winter coat (which was pale buckskin, with a grey undercoat) and is quite a nice sandy buckskin. But I am assuming she will end up grey because of her grey points - or is she one of these "grey duns"?!

 

[Snowfilly]

Okay, first of all genetics is very complex and confusing!

Grey horses can have a non grey foal. Grey is a dominant gene, meaning the foal only needs one grey gene to express it - the genes are in pairs. But a grey horse can be Grey / not grey OR Grey/ grey and both these pairs of genes will give a grey horse.

When two greys are mated, a gene is inherited from both parents. If both horses are grey / grey (known as homozygous) then the foal will Inherit grey from both parents and be grey. If only one parent is homozygous, then the foal will always be grey because it will Inherit one grey gene from the parent that has 2 of them.

However, both parents can be grey / not grey (heterozygous) and this is where you can get the non grey foal - 25% chance of both parents throwing their non grey gene resulting in a non grey foal.

You can test a horse to see what genes it carries and determine your foal chances.

Your other point, as far as I'm aware dun doesn't exist in the connemara. Their breed society is a bit stuck in the dark ages on colour. Greys are often recorded as grey / whatever they were before as this is a useful way of checking what they are carrying - especially in breeds where double dilutes (cremellos, perlinos and smokey blacks) aren't always popular.

I think your youngster will end up grey.

 

[ester]

So SF has the grey thing correct .

But I wasn't aware that connie people were also bandying the term grey dun around, I thought it more a highland thing.

In it's basic terms it is entirely possible to be base colour+ grey+ dun and sort of call that a grey dun, but not in connies.

It can be tricky when passporting as you may want to know if they carry a creme gene, although it is obvious to everyone if they have then gone grey (your friend's sounds like it is well on the way).

 

[DabDab]

And to add another (slightly more cynical) point of view, 'grey dun' in connemaras seems to be a relatively recent descriptive term, that has possibly come about because a dun (or buckskin) is much more exotic and saleable than simply 'grey'

If tracking genetics was the name of the game, then surely 'grey bay' would also be a thing

 

[ester]

ah but cream is more important, if you don't want to breed an unregisterable double dilute.

But interesting to know it is a more recent addition to the vocabularly.

 

[DabDab]

Yes, true, but I'm still cynical. There also seems to be an awful lot of young connemaras about at the moment that are 'roan', though whether that's what it says on their papers obviously I don't know.

 

[kimberleigh]

Ahh right that makes perfect sense now abput the grey/grey and grey/non grey!!

Have looked back at very early 1900s and even late 1800s in pedigrees and "grey dun" was recorded back then - but I will make a wild assumption that they were simply mislabelling colour due to limited genetic knowledge.

On the subject of roans I met an absolutely stunning 12 year old bay roan connie stallion a week ago, very striking! But I have seen many advertised as roan when they are simply greying out ��

 

[Equi]

I dont know of any "coloured" connies, as theyre not allowed in the breed. So somewhere along the line, someone has done the dirt.


edit to add, ive just realized you mean colour other than gray. Whoops

 

[ester]

I think by "coloured" the OP meant not grey, hence using coloured in """"

 

[kimberleigh]

Yes sorry coloured as opposed to grey, where colour has been "removed" 🙈

I have a couple pics of the pedigree which I added in heights/colours on both sides for past 4 gens but not sure I can add photos straight off my phone?

 

[ester]

realistically you need photos on a third party set up to post.

 

[Equi]

Yes sorry coloured as opposed to grey, where colour has been "removed" 🙈

I have a couple pics of the pedigree which I added in heights/colours on both sides for past 4 gens but not sure I can add photos straight off my phone?

You can if you use tinypic, then copy/paste the IMG link.

 

[kimberleigh]

I cant remember the sign in info for my photobucket!

Dams side of pedigree
Grey
Grey - grey dun
Grey - grey dun - dun - grey dun
Grey - grey - dun - grey - dun - grey dun - dark grey - grey

Sires side of pedigree
Grey
Grey dun - grey
Grey - grey dun - grey - black
Not recorded - grey dun - cream - grey - not recorded - dun - grey - grey

 

[Elf On A Shelf]

And to add another (slightly more cynical) point of view, 'grey dun' in connemaras seems to be a relatively recent descriptive term, that has possibly come about because a dun (or buckskin) is much more exotic and saleable than simply 'grey'

If tracking genetics was the name of the game, then surely 'grey bay' would also be a thing

Let's not joke about duns and their vairations! I saw a shetland advertised as a Silver Bay Dun the other day ... Don't know! It looked plain bay to me!

 

[Mule]

Talking of genetics does anyone know why so many Irish draughts are grey? I don't think I'm imagining it, they all seem to be grey. (I have a grey Irish draught so mabey I notice it more)

 

[Equi]

Let's not joke about duns and their vairations! I saw a shetland advertised as a Silver Bay Dun the other day ... Don't know! It looked plain bay to me!

The horse colour game has got big lately, people are not just breeding bay black and grey anymore. I know a few miniature silver bay duns.

 

[Equi]

Talking of genetics does anyone know why so many Irish draughts are grey? I don't think I'm imagining it, they all seem to be grey. (I have a grey Irish draught so mabey I notice it more)

Its a desirable colour. ID look good in grey, they look like an ID in grey.

 

[Leo Walker]

The horse colour game has got big lately, people are not just breeding bay black and grey anymore. I know a few miniature silver bay duns.

They wouldnt look plain bay though as silver affects black.

 

[Cloball]

I've never registered a foal before so I am not sure who decides the colour, is it the vet?

Grey foals are often born hyperpigmented due to the way grey effects the hair follicle and they can often be registered as their underlying color before they start to grey out. Some foals are born further into the greying process and incorrectly registered as roan (all roan TB's have turned out to be grey I think).

Two heterozygous grey horses have a 25% chance of producing a non-grey horse.

 

[ester]

vet or owner, depends which knows the most about colour .

fwiw cream dilute greys often get darker as they start the greying process too.

 

[Snowfilly]

I've never registered a foal before so I am not sure who decides the colour, is it the vet?

Grey foals are often born hyperpigmented due to the way grey effects the hair follicle and they can often be registered as their underlying color before they start to grey out. Some foals are born further into the greying process and incorrectly registered as roan (all roan TB's have turned out to be grey I think).

Two heterozygous grey horses have a 25% chance of producing a non-grey horse.

Don't let a vet near colours for a passport etc! Most of them don't know a huge amount and even what is currently being taught in this country is pretty poor - the Pony Club tests are still teaching 'cream' as a colour and preaching that thoroughbreds can't be coloured or dilute so vet school probably won't cover it in any sort of detail.

The roan TBs are a thing - there was a weird mutation in one colt, I think his name was Catch a Bird and he's thrown genetically roan foals. All the others are probably either greys caught at a bad time or one of the funky KIT gene mutations that cause white spotting. I think there's a few known in the breed but understanding them is far too complicated for me!

 

[Elf On A Shelf]

Pure bred thoroughbreds can't be coloured or black. You can however cross a coloured with a tb and cross that with a tb again and again until you get something 7/8 tb and eligible to race. Breeding specifically for colour doesn't work. But then neither does breeding for speed, stamina are specifically if you want to create the perfect specimen of a horse. You will have to accept compromise somewhere. It's amazing how many racehorses have pigeon toes or are back at the knee etc. But that's another discussion entirely!

 

[criso]

Pure bred thoroughbreds can't be coloured or black.

Why not black, it is possible to get black from two bays as long both parents are not homozygous for agouti.

 

[creamsoda]

Our cremello part bred Connie had grey parents. Lots of dun/buckskin in the pedigree as well as palomino. Her passport said white.

 

[Elf On A Shelf]

Why not black, it is possible to get black from two bays as long both parents are not homozygous for agouti.

No idea! It's not in their colour code apparently! Anything very dark is called brown or seal bay, they all have brown muzzles. But it can be black if it is a Non-TB.

 

[ester]

black does exist, it just isn't that common, as such I presume there isn't masses of recessive agouti knocking around.

http://www.whitehorseproductions.com/tbcolor1.html

 

[ester]

Our cremello part bred Connie had grey parents. Lots of dun/buckskin in the pedigree as well as palomino. Her passport said white.

with the double dilutes it is impossible to tell if they have the grey gene or not without testing.

 

[criso]

No idea! It's not in their colour code apparently! Anything very dark is called brown or seal bay, they all have brown muzzles. But it can be black if it is a Non-TB.

Seal bay/ brown is a variation of the agouti gene that causes bay but both are modifiers on a black horse. All bays are black horses with a gene that bleaches bits of them. http://www.animalgenetics.us/Equine/Coat_Color/Agouti.asp

So if there are no black tbs either every single tb is homozygous for agouti or it's not accepted as a colour like double dilutes in connies so they are not registered.

 

[stormox]

ah but cream is more important, if you don't want to breed an unregisterable double dilute.

But interesting to know it is a more recent addition to the vocabularly.

Creams (double dilute) can now be registered. They used not to be passed and be registerable but the rules have changed and they are registered now as class 4.

 

[ester]

Is that like an X registered welsh? or not quite?