RutlandH2O
Well-Known Member
Brilliant, so easy to understand and will save me bugging faracat with silly questions![]()
This^^^^!! Thanks for this thread, PMP!!
Brilliant, so easy to understand and will save me bugging faracat with silly questions![]()
Thanks Faracat for the link. Unfortunately I've read all the links I can on the subject but it all merges into a mush for mehence I hoped this basic guide could help me understand. Other more normal colours I'm fine with understanding, just this one that (maybe I have a mind block) still confuses the life out of me.
Dominant White is a pattern that was for a long time thought to be part of the sabino gene complex. Like sabino, the amount of white on the coat can vary, though most dominant white horses tend to be heavily patterned or nearly all white. Interestingly, dominant white is frequently found to be the result of a mutation, so loudly marked foals can result from otherwise plain parents. Like frame overo, dominant white is believed to be lethal in its homozygous state, but it is lethal early on in utero.
The idea of a dominant white gene has fallen in and out of favor among students of equine color genetics over the years, and until very recently, it was assumed to be a variation of the sabino pattern. (Sabino appears to be polygenic, and more than one complex of (likely related) genes can produce a sabino-type pattern. Extreme sabinos, all-white horses, are believed to be homozygous.) No evidence could be found of all-white horses that produced like-colored offspring, only those that produced a mix of white, white-patterned, and even solid foals.
In 2007, a Swiss research team found and isolated the dominant white gene. The individuals that tested for the gene were all heterozygous, leading the researchers to speculate that the gene is likely lethal in its homozygous form. These horses were a mix of white and partially white-patterned horses; phenotypically, they appeared to be sabinos.
This is awesome, I've always wanted one of those black with a silver mane and tail, but I thought they were a colour combination you only see in quarter horses or mustangs, so out of interest how would you breed one????
All double dilutes should have blue eyes - so the breed standard allowing brown eyes creams is irrelevant really.The main problem with double dilutes seems to be sunburn as they have pale skin. Being a double dilute with grey is bad as they are more even prone to melanomas.
Okay, so it's just a giant marking that covers the whole body?
Scrap that. It can't be a giant marking can it. Gawd this is why I can never understand it. I always think I have it and then I think on it more and realise I don't have it at all![]()
Thanks for replying. I suppose what I'm asking is (trying not to be thick about colour genetics but to me it is very mathematical and that is not my strong point, OH is so I'll have to pin him down) - In your opinion, is there any real relevance to not allowing a blue-eyed cream in a breed standard - any breed standard? By relevance I mean health related (melanoma/sunburn aside) or direct breeding consequences? Or is it just an aesthetic thing? Like I said, when I bought my Connemara colt (grey), I knew I wasn't going to buy a blue-eyed cream because it's not recognised by cpbs - but there were quite a few out there, very nice types indeed. Just wondering as obviously they couldn't be registered and tbh people wanted rid of them as they are considered worthless for showing and breeding as per the breed standard.
Okay, so it's just a giant marking that covers the whole body?
No your are right - dominant white is just a mutation that causes a foal to be born with unpigmented skin and hair, but that can range from a small amount of unpigmented skin and hair (white markings), to being completely covered with unpigmented skin and hair (like one giant marking that covers the whole body - so completely white). It is different to the Sabino gene that causes white markings, that's all. Hope that's easier to understand
Thanks for replying. I suppose what I'm asking is (trying not to be thick about colour genetics but to me it is very mathematical and that is not my strong point, OH is so I'll have to pin him down) - In your opinion, is there any real relevance to not allowing a blue-eyed cream in a breed standard - any breed standard? By relevance I mean health related (melanoma/sunburn aside) or direct breeding consequences? Or is it just an aesthetic thing? Like I said, when I bought my Connemara colt (grey), I knew I wasn't going to buy a blue-eyed cream because it's not recognised by cpbs - but there were quite a few out there, very nice types indeed. Just wondering as obviously they couldn't be registered and tbh people wanted rid of them as they are considered worthless for showing and breeding as per the breed standard.
Interesting thread thanks for posting.
Just wanted to correct one assertion that's been made a couple of times on here - dun does exist in Welsh ponies - the first positive test result in the UK was achieved earlier this month for the chestnut dun mare Clanmill Majorette! It is right however most "duns" in the Welsh sections should correctly be referred to as buckskins.
You need the horse to be black based as Silver Dapple does not affect chestnut. If you specifically want a black silver, then you want the horse to not have other dilution or modifying genes (eg no cream or agouti).
So breeding a Black Silver dapple horse that is homozygous (has two copies) for silver, for example, with another black horse would result in a black silver dapple foal.
Silver Dapple is found in miniature horses, Gypsy cobs, Rocky mountain ponies, some european draught breeds etc...
The bottom (dam's parents etc..) half of the pedigree is missing - is she pure Welsh?
http://www.allbreedpedigree.com/clanmill+majorette
Is there a simple way of telling the difference between buckskin and dun without dna testing? There is one that i know that has 4 white stockings, would this stop it being a dun?