PDA

View Full Version : Chev, the lo-down on blue eyes please!


Wally
4th Mar 2005, 08:16 AM
Chev would you give me the ins and outs of the blue eye gene, specially in Piebalds.

Especially where the pigment does not cover the eye area. You seem to know more about this than anyone.

When will a blue eye appear.

chev
4th Mar 2005, 09:49 AM
That's one of the things no-one has really been able to explain. As far as I know, no-one has been able to find a genetic link to blue eyes, other than that associated with the cream gene - two cream genes means a horse will always have blue eyes. Other than that it does seem to be a bit of a lottery.

It's certainly far more common in horses where a white marking on the face crosses over the eye - horses with white faces often have blue eyes (which is why they crop up in coloureds fairly regularly - a lot of coloureds have sabino, which causes the big white faces - and therefore seem to be more likely to have one or two blue eyes).

I think it's linked more to sabino than tobiano in coloured stock. Tobiano doesn't cause lots of white on the face - a tobiano with no sabino often has a dark face (and dark eyes). Blue eyes are a lot more common in the overo complex of patterns, which includes sabino.

They crop up fairly regularly in Welsh stock (no tobiano there, but lots of sabino) which would support that.

My tobiano stallion, who had no sabino markers, had brown eyes. I put him to a chestnut sabino mare with brown eyes, and lo and behold got a bay tobiano colt with sabino markers and one blue eye. He was odd - he had a blaze that extended right over one eye (which was brown) and nowhere near the other eye (which was blue). I had a sabino/tobiano mare with two blue eyes, who produced a colt with two brown eyes.

White horses often have brown eyes, which suggests that blue eyes are a random result of some gene other than just one restricting pigment.

I'd guess that they are linked in some way to the overo patterns - just like some sabinos have belly splashes and others don't.

Wally
4th Mar 2005, 07:09 PM
Thanks Chev,

I ask because in Shetland blue eyes have been frowned upon and not allowed really in stallions.

It is now, or seems to be relaxing that rule as more blue eyed stock seem to be being accepted.

Now Charlie has a blue eye (Piebald) There is a lady down the road with a piebald stallion, (brown eyes) he has been throwing quite a lot of piebalds with blue eyes.

Now I have heard some more vociferous folk shouting that blue eyes should be bred out. They are passed on by the stallion or mare.

In my experience blue eyes come with cremello or Palomino with ease, or out of the blue when you least expect it. Can it be bred out of Piebalds?

I used to not like blue eyes, but Charles Buttons Esq has changed my mind.

chev
5th Mar 2005, 08:08 AM
I'm not sure it can be bred out - blue eyes seem to be a result of more than one gene, or part of the action one or more genes have. If you think of it as similar to sabino it becomes clearer how difficult breeding it out would be.

Take Welshies for example. Sabino's very common there - but it's not usually very loudly expressed. It's usually within the confines of big white faces and legs, with roaning and maybe belly splashes - the equivalent of brown eyes, and all acceptable to the WPCS. Then every now and then a loud sabino crops up - which then becomes classed as broken coloured and is refused registration with the WPCS - that's a bit like the blue eyes showing up. Some horses seem more likely to throw loud sabinos than others, just as some seem more likely to throw blue eyes (there was a Welsh stallion called Criban Socks who threw a lot of blue eyed stock. 9 generations on they still crop up, even from two brown-eyed parents) but there's no guarantee - a loud sabino could throw no loudly marked offspring at all, just like a pony with two blue eyes might never throw a blue eyed foal.

I've seen Welsh stock with no real white markings other than one small ragged sock and a lip spot (so likely to be minimal sabino) with one or two lovely blue eyes - even where there's little white on the face. Some of them have never thrown a blue eyed foal. Then there's mares like my C - obvious sabino markings but two brown eyes - who throw blue eyes even when put to brown-eyed stallions. It would make breeding blue eyes out nigh on impossible - there's no real way of predicting when it's going to crop up.

The WPCS used to frown on blue eyes too - not so much now, although the prejudices do still exist (there's a beautiful cremello stallion standing in South Wales who's only been shown once thanks to prejudice against his colour). I was put off blue eyes early on by a horrible little pony called Lucky Gem (who was neither lucky nor a gem) who was white with blue eyes, and out of an exmoor mare with no papers. He was vile. We eventually came to an uneasy truce and tried to keep out of each other's way. Blue eyes filled me with trepidation for years afterwards. Then I met Mair, a beautiful black and white mare with tobiano and sabino - and two blue eyes. I'm sure she also carried splash white. She has huge white eyelashes and was the kindest mare imaginable.

Wally
5th Mar 2005, 08:37 AM
I know that feeling, I had a blue dun who was a nutter, Frances had a blood bay who was a nutter.

We then got Rossi (Blood bay) and Kvikur (blue dun) You still get flash backs when riding "that" colour, then you realise it's not the nutter you are on and you are, in fact, quite safe.

My blue dun phobia is now almost gone thanks to Kvikur.....think Frances still gets the jitters on a bright bay though.........memories of steri-strips! :D