# Chestnut/black colour genetics



## Yorketown (11 November 2010)

Can any of you bright peeps help me with chestnut/black colour genetics?  

I have been composing my stallion shortlist for next year and one of the frontrunners is a black stallion but I have just noticed when looking up his pedigree that both of his parents are chestnut.  I always thought that any chestnut was 'ee/aa' regardless of the shade so how can they produce a black foal?  

Also any advice on Liver Chestnut genetics would be greatly appreciated because the lack of info I have found has me stumped!

Thanks in advance


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## lillith (11 November 2010)

Chestnuts are 'ee' and blacks are 'Ee' or 'EE' so 2 blacks can produce a chestnut if they are both 'Ee' but 2 chestnuts cannot produce a black as you suggested. I would think that there is something else colour wise going on there - do you have a link to any pics/the pedigree?

The reason why you cannot find much information on Liver chestnut genetics is because I am afraid there is very little out there. The cause is pretty much unknown, sooty causes dark dappling on the coat but exactly what causes one chestnut to be ginger and one to be an all over mahogany is pretty much a mystery, same with dark/clear bays. I think that breeding two liver chestnuts together would give you a better chance of a liver than two bright chestnuts but other than that...no idea. Sorry. Even the inheritance of sooty is a bit of a muddled area.

Edited to add - chestnuts can be AA or Aa as well as aa it just doesn't show because there is no black pigment for it to restrict. So you could get a bay from a chestnut/black pairing if the chestnut carried an A.


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## Yorketown (11 November 2010)

Thanks for that Lillith, the page I was using to research the stallions pedigree was the following: http://www.sporthorse-data.com/d?d=wolkenderry.


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## s4sugar (11 November 2010)

His sire is certainly chestnut and the dam is registered as chestnut with a chestnut sire but I can't find any photos of her from a quick search.
Black is not possible from two chestnuts but it is not uncommon for foal colour to be mistakenly registered.

Does that society require both parent's DNA?


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## GinnieRedwings (11 November 2010)

Not possible. The dam's colour must be recorded wrongly.


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## Queenbee (11 November 2010)

sorry to hijack the thread but on the subject of genetics for chestnut and black, my mare is Dark Bay, her sire was pure friesian (so Black) and her dam was TB (and apparently chestnut)  is this possible?


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## angrovestud (11 November 2010)

You might find some interesting posts on this topic here there is an amazing photo of a black Morgan whos parents are both Chestnut so it can happen but the hore appears black the giveaway is the coronet band which looks reddish.

http://www.pedigreequery.com/forum/viewtopic.php?t=29159


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## lillith (11 November 2010)

@queenbee
Black Fresian - Likely EE (as almost are true breeding blacks) and definately aa
Chestnut TB - Has to be ee quite possibly Aa or AA as there seems to be a lot of Agouti in the TB gene pool as true blacks are (relatively) rare but bays are common. So Your bay seems to have inherited an E and an a from dad and an e and and A from mum so is heterozygous for Black and Agouti - making bay .

@Angrove stud 
There are 'black chestnuts' out there but they are ee tested and usualy have red pasterns and sometimes manes, they seem to be extreme liver chesntnuts with LOADS of sooty. The Phara farms arabs are another good example. There is a lot of sooty in Morgans as well. They are fairly rare without serious linebreeding and I would say unlikely with the sport horse breeding where colour is rarely the primary concern. Not impossible but very, very unlikely.

@ OP
Looking at the pedigree (sire) Wolkentanz is Chestnut
Letizia (dam) is listed as chestnut and her sire Londonderry is but her dam Cyrenaika does not have her colour listed and is by a grey sire so could easily be black or bay and have passed on an E to Letizia though I can't fine a picture of her anywhere to see what she looked like. Cyrenaika's Dam Rhani does not have a colour listed but her sire was bay and her dam is listed as black so there is a strong chance Cyrenaika was black or bay.


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## s4sugar (11 November 2010)

From Wolkenderry's Facebook page it appears all his 2010 foals are chestnut or bay. 

Maybe a red test is in order although anyone not wanting to use a red carrier would be put off by chestnut parents.


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## Faberge (11 November 2010)

Yep Wolkenderry is def a red gene carrier, so mum's colour must have been input wrong as she has to have passed on the black/brown gene to Wish.

Out of interest, what black/bay dressage stallions do not carry the chestnut gene? I know of Spielberg and Ampere - who else is there?


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## Smee (12 November 2010)

Yorketown said:



			Thanks for that Lillith, the page I was using to research the stallions pedigree was the following: http://www.sporthorse-data.com/d?d=wolkenderry.
		
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Hi!

I did exactly the same as you last year when I was reseaching him to use for my mare & as you have found & people have suggested the colour of his dam must be recorded incorrectly. His owner confirmed the colour of his dam for me. I can't seem to find the email now, but I'm fairly sure she was bay.

Contact his owner if you have any questions she was always very friendly and helpful and sometimes pops up in here 'JaxMath', maybe drop her a PM?

Have you seen this coat colour calculator?
http://www.animalgenetics.us/ccalculator1.asp

And good luck...


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## KarynK (12 November 2010)

Fresian&#8217;s are very interesting as breeders have long suspected the presence of a Dominant Black gene which is dominant over Bay&#8217;s and Brown&#8217;s, my sister has done some work around this and thinks it likely to exist as ED.  However a lot of &#8220;black&#8221; Fresian&#8216;s that I have seen are prime candidates for At (black and tan) .   So I would think that At could be quite prominent in this breed. Hence an apparently black Fresian could easily produce what you would describe as a dark bay or brown.

So far Ata EE has been proven on a horse that looks black and that produced &#8220;black&#8221; offspring.  This combination could well be the minimal expression of tan with black all over and the tan restricted to a few discrete hairs and AtAt Ee produced what would have been described as a dark sooty bay, so the tan extends over the body but the extremities and along the spine remains black, like a frame effect.  From the limited black and tan research done so far and in particular my own mare, I am currently thinking that sooty might not be a gene in it&#8217;s own right but linked to Black and Tan, hopefully we will know more very soon.  

&#8220;A&#8221; was thought to influence shades of chestnut coat colour in a theory put forward before genetic testing, liver chestnut in that theory was said to be aa ee but that was proven wrong at a genetic level with bright chestnuts testing aa ee.

There is some phenotype research going on into chestnut shade inheritance but no published results as yet.  My sister has long thought that there is a close correlation between black and the very very dark shades of liver which look black. She&#8217;s annoyingly usually right,  she was about Black and Tan! There do seem to be variations in shade similar between chestnut and blacks with agouti and one that I bred shows dark chocolate coloured hairs around the pastern yet is black based.  I would not be surprised if the genes responsible for coat shade have some form of crossover from e to E.  There is also the change of coat shades from winter to summer coat to consider!

It would be interesting to study the Suffolk punch for information on chestnut shade inheritance since they are all chestnut and the confusion caused by the appearance of blacks and greys would not get in the way!!


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## JaxMath (12 November 2010)

Yorketown said:



			Thanks for that Lillith, the page I was using to research the stallions pedigree was the following: http://www.sporthorse-data.com/d?d=wolkenderry.
		
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Hi  I am responding as my stallion is mentioned in this post.  

Wolkenderry is Ee - carrys the red gene, tho the black gene is predominant -  his sire was chestnut, but his dam dark bay by a chestnut sire  (the dam colour information on the link to pedigree above is incorrect - not sure where it came from as I didn't input it!).

He currently has seven foals on the ground - 1 is chestnut out of a chestnut mare, 1 born chestnut but now grey roan (out of a grey mare) 3 bays (2 out of bay mares and a bay out of a chestnut mare) and 2 black (1 out of a black mare and 1 out of a knabstrupper chestnut mare).   Next year will be interesting as he has 30+ foals due.

What colour is your mare? and her parents?

If there is anything else I can help you with, please PM me.


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## ESH_Jess (12 November 2010)

Faberge said:



			Out of interest, what black/bay dressage stallions do not carry the chestnut gene? I know of Spielberg and Ampere - who else is there?
		
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Our dressage stallion 'Santo Hit' is tested and does not carry a chestnut gene


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## Yorketown (12 November 2010)

A bay dam definitely makes more sense!  I will PM you about using you're boy.

Thanks everyone for your help - I think I will have to read up on colour genetics


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## Yorketown (12 November 2010)

Smee said:



			Have you seen this coat colour calculator?
http://www.animalgenetics.us/ccalculator1.asp

Click to expand...

Thanks Smee,

I have just had great fun with the colour calculator


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