black or bay?? what is the probability

Discussion in 'Colour Questions' started by KPF, Jun 10, 2011.

  1. KPF

    KPF Well-known Member

    HI All,

    I have a curiosity question.

    If you breed a Homo black mare to a stallion that is homo for black gene and the stllion himslef is black to the bone to look at, but when you drill down in his paper there is a grand parent who is brown or bay whatever, does this mean that because the stallion has this bay in his pedigree there is still a chance of the resultant foal being born a bay???

    Or is it basically on face value that a stallion that is truely black to look at (no tanning on flanks/muzzle or any noticeable discolour) and has been tested to be homo black gene that put to homo black gene mare who is physically also true black to look at will produce only true black foal??

    Sorry if I've confused then let me know..
  2. Sassy

    Sassy Gold Member

    Hey KPF, I am not sure if I am reading you correctly, but if both parents are homozygous for black then you will ONLY get a black foal from them.
    If he wasn't homozygous and had a bay horse way back in his pedigree, then it's possible he could have thrown a bay foal at some stage (tho not to a homo black mare), but probably unlikely if all other horses were true black... but being homozygous that possibility is removed altogether.

  3. samm

    samm Gold Member

    Homozygous for black means they don't carry the red gene so won't throw chestnut.
    Black is the most recessive colour followed by chestnut according to all the colour genetics books I have.
  4. Sharaway

    Sharaway Well-known Member

  5. Stockmans Farm

    Stockmans Farm Active Member

    That is a fantastic website thanks for sharing.

    My stallion is homozygous black and I like to know the ins and outs of genetics so that website will be very helpfull!! :)
  6. kiraSpark

    kiraSpark Gold Member

    Whether the horse is black or bay is affected by the Agouti gene.

    If you are trying to breed black horses, you need to be testing for Agouti as well. A lot of 'black' horses arent truely black - its not until you get that Agouti test back saying 'aa' that you know you have is a true black. (Unless you are talking Friesians which I think you might be - most of them ARE true black!!)

    But for the point of this exercise you have mentioned both horses are tested to be homozygous for Black (EE) and are physically 'black' to look at. Then their genotype would go like this: TRUE black mare (EE and aa) and you breed her to a TRUE black stallion (EE and aa) then NO you will never get a bay horse.

    E - Extension (red/black). This gene controls the base coat colour of a horse. There are only two base coat colours. RED and BLACK. Everything else is a modifier or masking factor or dilution.

    A - Agouti. All this gene does is control the distribution of black pigment. It is either uniformly distributed, or distributed to the 'points'. Agouti has no effect on chestnuts (ee) as there has to be black (Ee or EE) for it to work. So a chestnut could be AA or Aa or aa for Agouti and you would never be able to tell by looking, only a test will tell you.

    A bay horse is EE/Ee and AA/Aa
    A black horse is EE/Ee and aa
    A chestnut horse is ee and can be either AA/Aa/aa (as agouti doesnt show up on a chestnut coat but the horse will still carry it)

    So hence you could have a TRUE black horse that was heterozygous for black (Ee), but just as long as it has the aa for Agouti, thats what makes it a black.
    Being tested as homozygous for black doesnt make it a black horse. The agouti does.
    Last edited: Jun 11, 2011
  7. KPF

    KPF Well-known Member

    holey moley kiraspark, I think my brain just got turned to mush!:p

    Thank you - although I admit I don't understand a lot of it.....but...

    so if a horse (no I'm not talking only friesians, just any horse trying to get an understanding:))) ) is published as 'tested homo for black gene' if I understand you correctly then does this in itself mean it could possibly be misleading if they have not also done a test for the Agouti gene??
  8. kiraSpark

    kiraSpark Gold Member

    LOL KPF! :p

    You know, I was outside doing the fencing with OH for most of the afternoon, and all that time I was thinking of your thread, and ways to describe equine coat colour genetics in a simple way.....and I couldnt! LOL. Im afraid I dont have the gift of being clear and info tends to come out in a very long-winded manner *#)

    Maybe one day I will do a thread, and call it "A Crash Course in Simple Equine Coat Colour Genetics" :p

    Anyway - to answer your question - yes, it could be slightly misleading. Just by saying a horse is homozygous for Black, does NOT mean it will only ever have TRUE black foals. It will only ever have black-based foals, yes (like brown, bay etc), but not necesssarily 100% TRUE black foals. I would be asking for clarification for WHAT gene they tested for: Was it Extension, or was it Agouti?

    I think the confusion lies with people calling Extension the red/black factor test (which it is), whereas Agouti is also a kind of 'black' test....kind of....since it determines a true black horse from a dark brown horse. So some people might confuse the two.

    However - if a horse is published as being "Homozygous for black gene", then I would TEND to say that they are talking about Extension - ie the horse is EE and could NEVER produce a red-based foal. However, all that test is telling you is the horse in question cant produce a red foal. Unless the horse is TRUE BLACK itself, you need Agouti to be tested to determine if it can or cannot have a true black foal.

    OMG see what I mean about the novel! ;)
    Last edited: Jun 11, 2011
  9. KPF

    KPF Well-known Member

    Am I reading right on the web, that there is no national body for the Pinto horses. Just most states have created their own governing set of rules??
  10. Stockmans Farm

    Stockmans Farm Active Member

    Kiraspar you seem to very knowledgeable in this area and I'd love to learn more about genetics, colours breeding etc.

    The biggest question I get asked as a breeder with a paint is what colour foal will I get?

    Can I pick your brain?

    As far as I'm aware my boy hasn't been DNA tested, I have tested him for OLWS which he obviously has because he is overo.

    Now I've been told he is homozygous for black as he has never had a chestnut foal, he predominately throws bays and blacks. He has also had buckskins, duns and grullos.

    Also I have been told if he is fed vitamin e he throws coloured foals. Now is this coincidental?

    If people say there paints throw 100% colour is that to do with there DNA make up or is that also coincidental that they always throw colour?

    Sorry about all the questions but I'm new to the breeding world of paints and it absolutely fascinates me and id love to learn as much as I can

    Cheers :)))
  11. kiraSpark

    kiraSpark Gold Member

    Hi SF :)

    Firstly, I need more information. What colour is your stallion? If he is the horse in your avatar I cant see all of him, obviously he is Overo as you mentioned but is he Bay? Brown? Black? Smokey black? Secondly, what are the colour of his parents?

    He could very well be homozygous for black if he has never had a red foal - however this is not definitive (how many foals has he had? If you say 2 then thats not very good proof - if you say 200 then that is good proof!!) - the way of knowing 100% would be if he DOES have a red foal - then you know for certainty he is only heterozygous.

    Vitamin E to get 'coloured' foals is a load of bollocks. Genetics determines base coat colour.

    As you say "he has also had buckskins, duns and grullos" to what colour mares? In these cases if he is a non-dun or non-dilute, he hasnt - the mare has :p

    When people say their pinto/paint throws 100% colour (colour as in patterning, not as in dilute), it means the horse is homozygous - he has two copies of the dominant form of the gene. It doesnt matter which one he passes to his progeny as they are both dominant, you only need one (in this case) for the trait to be expressed. It is to do with their genetic make-up. Obviously an Overo cant be homozygous for the frame Overo gene - as he would have died as a newborn from OLWS. But a horse can be homozygous for any of the other coat patterns.

    SF, as you are a breeder of paint horses, the best thing you can do to learn more about what you breed is to read. Inform yourself. Google, browse the internet, or purchase some equine genetic colour books, and read and learn and absorb :)
    Last edited: Jun 12, 2011
  12. Stockmans Farm

    Stockmans Farm Active Member

    Thanks kiraspark!

    He is a black overo, his dad was a black overo and his dads dad was a black overo. Now his mum is kind of in the grey area, I have an article from a horse mag she was for sale in and it says she was bay and paint registered yet she is only registered in the quaterhorse studbook as chestnut. In her picture she is Definately bay with a very white face, also her sire was chestnut.

    Now cactus has had 35 foals 20 being solid 15 being coloured. The buckskins and duns have been out of buckskin paint mares and dun mares.

    I have recently obtained the studbook the previous owners kept records of all the mares he covered and what colour foals they had, but it doesn't have the colour of the mare. I have only found out colours of some mares from foals being registered with paint society and also photos of the foals with there mum. I am extremely good friends with his old owners and they are going to sit down with me and go through the mares colours.

    Can you gain a fair idea of what he throws from previous mares colours offspring etc?

    Sorry to bombard you but I'm truly interested in gaining all the info I can.

    I am a qualified vet nurse and did quite alot of equine study at studs and horse vets, but it was mainly collecting, AI and follicle testing. I've only since found interest in the genetics now that I have my own stallions who are coloured.

    I went to the link you posted for horse genetics and have booked/purchased the info for the genetic degree.

    But I'm sure I will still have questions which can't be answered :)))
  13. kcr1971

    kcr1971 Active Member

    pull about 30 mane hairs (with roots) and send them to the colour testing lab in the USA, for testing. You will know for sure what he is in 2 weeks! :)
  14. Stockmans Farm

    Stockmans Farm Active Member

    Kcr1971 do you have to send it through the aust paint society or just send it direct?

    Would love to get his results
  15. kiraSpark

    kiraSpark Gold Member

    Hi SF

    I think in your case you should definitely get him tested for both Extension and Agouti. This will tell you if 1) he is definitely homozygous for Extension and 2) if he is a true black and not just one of those dark browns/bays masquerading as a black.

    Here are two US labs who do coat colour testing. Its only $40US for both tests, or $25US for one test.

    Horse Tests

    Horse Testing - Equine Genetic Testing

    PS I didnt post a link to an online diploma site, Sharaway did - I think anything with 'online' and 'diploma' in the one sentence, might be a hundred types of dodgy!! :p
  16. Sharaway

    Sharaway Well-known Member

    I didn't post it the online diploma but for the very sound information that it has, it's one of the more easier to read and understand sites
  17. Stockmans Farm

    Stockmans Farm Active Member

    Thanks heaps for all you help guys!!

    I will be sure to do some testing and more research and enjoy th work of breeding!!

    Sorry about the post thing, fantastic website just when you click on it it takes you straight to the diploma screen!
  18. Gamblin Paint Bred

    Gamblin Paint Bred Well-known Member

    Brooke I think you will find he has been DNA'd as it is a requirement of being upgraded for breeding :).
    Most horses that throw 100% colour are generally the Tobiano pattern most Overos can't lay claim to that percentage although it can still be in the high 90's percent wise that is.
    To be honest I believe it is 50/50 on almost all occassions when breeding patchy ponies :D.
    I know I breed Paints but if I get colour well thats awesome but Temp Conf and Useability are far more important to me. Don't get me wrong I like patches lol but I also love my non patchy ones just as much as they tick all the important boxes so what if they aren't patchy they are still lovely horses **)
  19. KPF

    KPF Well-known Member

    is someone able to confirm or correct me on this?? please. thanks.:confused:
  20. Gamblin Paint Bred

    Gamblin Paint Bred Well-known Member

    Hi KPF I think you are right I can only find State Clubs no National Body and I know that if I want to register my patchies as Pintos the Pinto Society of WA holds the registrations.

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