POTENTIAL COLOUR OF FOAL?? update!

[freya]

Interesting

I am intrigued to see what baby will look like now.

We have been looking for a sec d for a couple of years who was of this mares type and breeding. We were looking for a 4 year old to bring on for next year (now put back a year).
When we phoned the breeder she informed us that she had decided to run her out with her c stallion so she may be in foal.

We bought her suspecting she may be in foal, even though we were not planning for one, as we liked the mare so much.

So....a bonus, should be a nice pony..we hope

[sarahp]

Well, I hope it's what you want whatever it is!

[karynk]

Yes environmental factors can affect the distribution of white in identical twins however factors for white have a huge influence over how much white is inherited from parents through grandparents and great grand parents. It is theorised that a horse can be + - or neutral for those factors and that the percentage of the factors it shows in its own colouring when considering the white in it's parents affects the factors it has available to pass on to it's own offspring.

This is why you can get a horse with the tobiano gene that is extremely limited in its markings or indeed what people would describe as "solid". It is also why non characteristic Appaloosas can go on to produce a crop out to the right mate, as indeed can solid coloureds.

TB Lines especially early 19th C lines linked to derby winner Hyperion’s dam Selene carry white genes and in all cases of white TB’s I have studied there is inbreeding on both sides of the pedigree to Selene herself or to her close relatives, Selene herself goes directly back to the “spotted” TB Bird Catcher, who was covered in white splotches and who I believe is the source of extreme whites in the modern TB.

I suspect that these factors lurk on the newly discovered Kit gene which has recently spawned new discoveries on white inheritance in colour patterns largely what was theorised as sabino. Sabino is proving to be a whole series of linked genes so most textbooks on colour inheritance have become out of date in the last year or so.

For instance it was theorised that liver chestnut was aa ee, the ultimate recessive, but this has been proven not to be the case. A colour described as a dark red dun has been proven to be a bay carrying the newly discovered black and tan gene and a classic bay was proven to be in fact a homozygous black and tan.

As regards to what shade of chestnut you will get from any one mating, I believe Jeanette Gower is currently working on that, I suspect the whole story of shade inheritance is quite some time away judging by the variation seen, but we now know from recent research that there is no known effect of the Agouti gene on chestnut shades.

I do remember a family of Hackneys, the sire a beautiful near black liver chestnut, much like Denman, but with a ginger flaxen mane and tail, bred to a very rich chestnut mare with a darker than body shade mane and tail. She had one leg white right over the elbow forming a large belly splash down one side, foal 1 pale chestnut colt, ginger mane and tail one tiny white spot near his navel, classic sabino markings. Foal 2 Rich liver chestnut not as dark as dad with a dark flaxen mane and tail, very few white markings.

So yes you are guaranteed a chestnut from your mating but what shade of chestnut or palomino if you get one is anyone’s guess!!!! As well as darker chestnut shades You will also have to contend with sooty factor, dapples and smut marks which will give you a darker palomino not the golden coin. Please do post photos when the baby arrived though and good luck!!!!

[freya]

Absolutely, will post a pic when he/she makes an appearance...due end of April.

[sarahp]

I try to keep it simple on a general forum! Most of the white markings genes mentioned are not found, or so rarely as to be discountable (never say never!), in the Welsh breeds, sabino of course is widespread but I thought a discussion of its complexities was out of place here although fascinating.

The relevance of the KIT gene to white markings genes of all types, in other animals as well as equines, was discussed in my College book on the subject - my copy published 2000! I'm sure that by now there is far more known as it's obviously a subject of ongoing research though. I've never heard of the black and tan gene, will now go off and ask google! Thank you for making me aware of it.

Many palomino Ds are sooty - my sooty palomino mare had a pure gold daughter with a smut on her shoulder (which daughter's bright bay daughter also had) by a dark bay stallion, and then three palomino colts all by the same chestnut stallion, dark but not exceptionally so. At least the first two are sooty, not sure about the third which was sold at weaning. I await shading research results with interest!

[sarahp]

Having been through two pages of google refs, it seems to be an allele of the agouti gene rather than a separate gene in its own right - I'd be very interested to read first hand the cases of the dark red dun and the bright bay you mention above. I didn't realise "black and tan" referred to a brown, or seal brown which I must admit I'd always thought of as a variety of bay anyway, I have a simple brain! Lots of Ds that colour.

[karynk]

It is an allele on the Agouti gene and its extent was theorised well before discovery by my sister who noted it's similarity to black and tan in dogs. It is recessive to A (bay) but may influence the extent of black remaining on a bay. Personally I think there are a few more alleles influencing this group of colours on the Agouti gene but not as many as are on the kit gene.

I suspect that most thoroughbreds described as bay are in fact black and tan. I also theorise that it is the presence of At that creates dark duns and dark buckskins as opposed to yellow and golden respectively, but I may have to eat my hat.

A solid horse that tested Ata was black in appearance, though it’s owner did profess to seeing some brown hairs in summer and had supposed the horse to be a fading black.

This mare is homozygous At At my sisters theory is that this is the result of the tan pushing the black to the extremities creating a black frame effect. This TB traces on the male line through Tyrant to Bold Ruler, both of whom are prime candidates, on the dam side are some classic English lines. (the pics are as small as I can get them)



This is her dun son, by a theorised homozygous stallion for the genes E series A series and was a homozygous dun (sadly he is deceased). This horse is Ee AAt Dd, but this colour was previously described as dark red dun by geneticists

[sarahp]

I always understood there were various alleles of A, but the my purposes when breeding Welshies I just categorise them as "bay" without worrying too much about the details! Is there a genetic test for At then? I have never heard or see of a true dun Welsh, only lots of buckskins, but I always thought a red dun was the result of dun on chestnut, seen them in Fjords and Shetlands.

You might be interested in a blue-eyed cream mare I bought who then had 6 foals by a chestnut stallion. She preceded to have 3 dilute blacks - actually chocolate in colour, I had terrible trouble describing them of course as the breed society did not accept dilute of smokey black as a legitimate colour, to say they were black would be untrue both genetically and phenotypically and what other alternative? They do now accept dilute black due to a friend of mine who fought for it but had to have hers genetically tested to prove it! The other three were buckskins, all very dark, making her a perlino not cremello and I assumed EE Aa CrCr but maybe after what you say above EE AtaCrCr. Her sire was a yellow buckskin, not dark - actually he had roan too but I'm sure mine doesn't - and dam was heterozygous grey so could be anything.

[freya]

Can we now evaluate the theorists and their priciples of how people learn so i join in an intelligent discussion...please...lol.
Its my subject.

I wish i knew and understood your discussion so could join in.

[karynk]

There is a test for At but it is still under licence to the discoverer in the USA. I am talking to them at the moment and hopefully will be getting a group discount for a survey so we can see what is what. But since single cream has less of a visual effect on black hairs, it would explain what some call sooty buckskins, i.e. it turns the tan hairs to yellow but the black hairs of the black and tan remain dark like this little lady and her double dilute NF foal. I am beginning to wonder if there is actually a sooty gene or if it is actually the effect of black and tan.



Ah dun and cream and natives!!!! I’ve not seen a dun welsh either just cream. But cream is rife in New Forest Ponies hiding behind what they still mistakenly call duns, sometimes they are thought brown. They actually believe that pale chestnuts with flaxen manes and tails are responsible for palominos appearing so have banned them as Stallions on the forest whilst still allowing “duns” some of which are obvious creams to stand. So they are getting the “undesirable” palomino. Couple that with the “dun” mares on the forest and they are “surprised” by the appearance of “blue eyed creams” from dark dams and one colt I saw at the pony sales this year was a clear double dilute, in the purebred section described as a palomino!!!! There was also a red dun foal in the sales, described as a chestnut, with a huge red dorsal stripe!

A lot of people categorise all double dilutes as cremellos and then are surprised when they don’t get any palomino foals, but of course it is almost impossible to tell a cremello from a perlino or a smokey cream. We do after all have a cremello society and not a double dilute one and they have nothing to do with single dilutes who have a palomino society and not a buckskin one!! A lot of breed societies are to be fair having trouble getting their heads round the changes, they have to come out of a simple comfort zone and face the genetic evidence which can be difficult. Mind you if Weatherby’s can embrace it anyone can!

The thing is how can you ban something that is as a result of the same gene, you allow it on a black base but you ban it if the poor thing inherits red or in your case vice versa, I suspect that if challenged the NFP will have to accept palomino at the very least and will have to introduce testing of stallions standing on the forest for a Cr gene. My sister and I did a survey of ponies on the forest this year, here is the link to her paper:
www.brushbow.co.uk/src/NewForestPonyStudy09Web.doc

When the dun in the pic was born most of the genetic books were based solely on phenotypical observations combined with basic inheritance, whilst they were very intelligent observations the geneticists were working with a large amount of the jigsaw missing, the colour of that dun was theorised as red, the theory being that if he was a “bay” surely he’d be yellow? But of course that one has now bitten the dust with his test initial test results of AA Ee plus At has been found since so he is AAt.

[sarahp]

WPCS accept any colour for registration apart form coloureds, and don't get me started on how they define those! Problem is the terminology, not the registration acceptance. I know the NFs and Connies haven't yet caught up with the genetics, but I think are having to look at them now because of the EU regs on all pure-breds having to be registerable somewhere in the stud book. I do remember a beautiful palomino NF stallion some years ago though.

Freya - so sorry to highjack your thread! I tend to stick to the party line of what has been scientifically proven, and may be slightly out of date with newer discoveries so some of karynk's stuff is new to me. Much work is done in the US where they are more into odd colours than we are over here. And as I basically use it when arranging matings (or sometimes making observations on parentage, can be useful!) I tend to not bother too much about the details. There are quite a few good articles on the net going through the basics, try googling equine colour genetics or or pm me and I will try to look some up for you.

[karynk]

I suspect that the NFP has even more of a headache in that what is acceptable in the off forest part of the breed is not in the forest bred!

Yes the USA breeds have a few more colour variations, but then they are more clued up on the difference and how they happen, when geneticists like Guertz were calling buckskins duns, the good old rancher could tel there was a difference! But I would say the Shetland is not very far behind on colours all in one breed and they have their mushroom colour too!

Most of the Kit gene work around what was thought to be sabino was undertaken by a team in Europe, (where they also isolated the gene responsible for grey), most of the variations have been found in european breeds including TB's. I do keep up a very close eye on these advancements and the theories as it helps me avoid unregisterable foals, there are now 12 identified and 14 if you count the close cousin, Tobiano, and the not quite pinpointed roan.

I would certainly not discount all the observational theories as many of them are found to hold true when the genetics come along and they have served breeders well before anyone started locating the genes responsible for horse coat colour. Certainly with regard to some colours locating the genes responsible is a long way away and observations from breeders are all that is available.

These two sites are really helpful in explaining inheritance of single genetic traits like the coat colours. There is also a lot of useful material on BBC bitesize if anyone wants to go further

www.bbc.co.uk/scotland/learning/learningzone/clips/4197/
www.biotopics.co.uk/genes/crosses/gendia.html

which is a good starting point before embarking on the equine route, like this one which is a good starter for 10

www.horsecolor.com/

If anyone is curious this is an illustration of what is available so far, though one or two on here I would contend!

gingingray.wantlesspower.com/HorseColors.html

[oakwell]

just thought i would add i had a chestnut filly last yr out of grey X grey

[karynk]

Jan 10, 2010 19:02:47 GMT oakwell said:

just thought i would add i had a chestnut filly last yr out of grey X grey

That would prove that both the Greys you used were Heterozygous for grey, i.e. they only had one copy of the gene each.

Grey is not actually a coat colour, its like a slow release paint stripper that gradually or more rapidly strips all the pigment from the hairs over time, sometimes if the hairs are very deep rooted then they fade much more slowly or some hairs remain coloured for the horses life, sometimes called flea bitten and a group of them together are called blood marks.

As the gene is separate from the coat colours and dominant over them, grey masks the original coat colour (Black or chestnut) and anything else like, bay, cream, dun etc, though with coloureds you will still see the patches of dark skin after the coat fades, these are known as "Historicals" and can still be shown in coloured classes.

In fact Lippizanners are all a colour underneath and not all of them are homozygous (two copies of the gene which means they can only have grey foals) so thats how you get the rare solid colour ones.

So both your grey parents were either chestnut or one or both were black, bay or brown and carried a chestnut gene! So you were either lucky if you didn't want grey or unlucky if you did! You only had a 25% chance of a base colour from that mating!

[oakwell]

i got a Grey the first time round thats y i didn't get it i Will add her breeding if some 1 Will tel me how to as she only has 2 chestnuts in her hole pedigree
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[sarahp]

The trouble with observational colour research done from pedigree information is the quality of the data - certainly in the Welsh breeds many in the past (and currently) are incorrectly described at registration. Rubbish in, rubbish out! But there was only observational colour research before the molecular stuff came in, like the paper regarding true roan being unviable when homozygous which I'm very happy to go with. I like this website, amongst others:-

www.horse-genetics.com/index.html

[karynk]

Jan 11, 2010 10:21:27 GMT oakwell said:

i got a Grey the first time round thats y i didn't get it i Will add her breeding if some 1 Will tel me how to as she only has 2 chestnuts in her hole pedigree

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Chestnut is a bit of a stalker, you can have several generations of black based horses then suddenly out will come a chestnut that has been hiding! Recessives are like that they can hide for a long time, ok for colours but when they are recessive diseases they can be a real problem.

It can be very fustrating tracking colours when grey is involved as a lot of registries ignore the base colour and few breeders of performance horses or native ponies take pictures or make a note of birth base colour as they are just not interested in colour! At least now with testing you can know if a horse carries chestnut, but also with testing a lot more genes to consider will be appearing!

[kaylee]

surely you arent hugely bothered about what colour it is, as long as it is healthy!!!!!!! but like i said i had a black colt out of a blue and white mare and a chesnut and white stallion! x

[hazel]

Thank you this thread is really fascinating and I am trying to keep up with all the info, luckily I can read and reread to take it all in!

[sarahp]

kaylee - I'm sure freya doesn't mind, just interested, and of course all of us want healthy foals but some people do want to bred for, or even avoid, certain colours (I'm currently trying to avoid having a totally grey Welsh A herd!) and a knowledge of colour genetics can help with the matings to do either of the above. Breeders of coloureds usually want to avoid the grey gene so that the foals don't fade as blue and whites do. It can sometimes come in handy re checking parentage up to a point too!

[karynk]

Quite agree with the above what is the point in breeding a well conformed coloured horse if it is going to turn white and you have to get it wet to see it's colour!

Breeders of breeds of colour or a v ariety of colours have a responsibility to maintain that variety in future generations.

Not only that but if a breeder can get their head round colour genetics which is a form of genetic inheritance easily seen it also helps with the understanding of how genetic diseases are inherited and how to avoid them. With greys of course come melanomas, problematic sometimes even if they do not turn malignant. Which of course they do more readily in homozygous greys.

Grey as a dominant can take over a breed look at the Lippizaner and the Camargue and to a lesser extent the PRE. One or two prominent stallions that are Homozygous for it and you soon have a breed of greys which for Welsh A's I think would be a real shame. D's have largely bred grey out and the few examples in this section usually go back to an A in the 3rd generation of their peds.

Wth an understanding of how genetics work also comes an understanding of how genetic traits are passed on and the helpful knowledge that some breeders still do not grasp that if you breed a long backed horse to one with a short back you do not necessaily get a horse with a perfect length back!

So it's a lot more than colour!!!

[freya]

adding pics later

[smokeycott]

congrats well worth the long wait !!!