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Wordplay1832
May. 8, 2012, 01:58 PM
Okay so I'm sure there are threads about this but I've never ventured to this part of the forum before.

I am thinking about breeding my grey thoroughbred mare. I don't have a ton of experience in color genetics (and I know it can vary with which coat color she started out with, and I'm not 100% positive on that actually). But, as much as I love that my horse is grey, what are the odds of being able to breed for a baby that won't grey out.

I'm sure there are certain stallion colors to breed to that are more dominant and may help over ride the grey, or be more predisposed, as well as their history and what colors their parents are etc.

Any input? Color is not the most important and if I end up with a gray offspring, that's okay, but I would like to know my odds of avoiding it, in case I find a few stallions I really like and one may be better for that than another.

JB
May. 8, 2012, 02:03 PM
You need to know her parents' colors. If one of them was not gray, then you have a 50/50 shot at any foal she produces turning gray (assuming you aren't breeding to a gray stallion).

If both parents were gray, she could be homozygous gray, meaning ALL foals will be gray.

Gray is the dominating cover-up of all colors. There is nothing that will hide gray.

You don't have less than a 50% chance of producing a gray foal. It's either 50% or 100% from her genetics, or 75% or 100% when breeding to a gray stallion based on his genetics.

quicksilverponies
May. 8, 2012, 02:03 PM
You will have at least a 50% chance of a grey foal regardless of the stallion you breed to. There are no stallions that will override the grey. If your mare is homozygous for grey, you will have a grey foal for sure - you can get her color tested. Obviously if you breed to a grey stallion, your chances of a grey foal get higher. But, again, it does not matter what color the sire is, your mare has a 50/50 chance of passing the grey gene to her foal, unless she is homozygous and then she will pass the gene 100% of the time. The color of the sire or his bloodlines do not matter. Sorry.

Wordplay1832
May. 8, 2012, 02:18 PM
She's not homozygous-her dad is grey but mom is bay.

I am assuming if I breed to a grey (both of who's parents were) the 100% holds true.

Thanks!

A grey foal is definitely okay with me if it happens.

Daventry
May. 8, 2012, 03:27 PM
I am assuming if I breed to a grey (both of who's parents were) the 100% holds true.


Nope...not unless the stallion was homozygous for grey. Your mare is heterozygous grey, and if she is is bred to a heterozygous grey, there is a 75% chance of the foal turning grey and 25% chance that it will not inherit the grey gene (of that 75% chance of turning grey...25% is a chance of being homozygous grey). We have a grey mare that we bred to our grey stallion and ended up with a chestnut. ;) (they are both heterozygous grey, so only have a 50% chance of passing the gene on to their offspring)

Simkie
May. 8, 2012, 03:38 PM
Here's how it breaks down:

Bred to a non-grey stud: 50% chance grey foal

Bred to a grey stud with one copy of the grey allele: 75% chance grey foal

Bred to a grey stud with two copies of the grey allele: 100% chance grey foal

If color is important to you, and you find a stallion that is grey that COULD be homozygous for grey (has two grey parents and no colored foals) you can request to test the stallion. The grey allele test is $25 and only requires a hair sample.

Grey is finite and nothing else about color will "influence" these odds.

rmh_rider
May. 8, 2012, 03:54 PM
What is your mares base color?

Black, bay, chestnut?

I have had arabs for years and seen alot of the people NOT want grey. When they do NOT want grey they usually breed to a stallion who has a very solid BAY background. And one who produces alot of BAY. Bay seems to be very strong on its coloring. It is a toss up on black, and chestnut. They seem to throw the color up in the air, iow any color can come out. But bay is very strong. Nothing wrong with bay - btw. Also I would choose a bay with very little color pattern ie white on legs and face.

Pretty much it is a 50-50 chance.

My current arab gelding had a grey dam and her background very much so varied. I do not know what her base was but I think it was chestnut. The sire is chestnut. Yes, every horse was chestnut on the sire side. Yes, true. Oddly enough. All chestnut.

My gelding is chestnut. The minute he was born, I knew he was to be always chestnut. Just something you learn after seeing many young arabs over time. I can spot grey easy, pretty much from birth. ;-) My arab is typical to his sire's color combo. Chestnut with a blaze, and 4 tall tall stockings. He is an Aulrab / Aurab bred on the sire side. This is Crabbet breeding.

Also your mare being a TB is even better in the odds you will not get a grey. Grey is not very dominant in the TB breed. But still, go with a stallion who is known to cookie cutter the bay color no matter what he breeds.

Good luck. Hope to see YOUR foal here on COTH next year.

JB
May. 8, 2012, 03:58 PM
Being a TB has exactly zero to do with this. Gray is gray, regardless of breed. If the horse is gray, he's either heterozygous for it or homozygous for it.

The OP's mare's parents are gray and not gray, therefore the mare is heterozygous gray.

The odds of producing a gray foal are no different less because she's a TB and not, say, an Arab.

It doesn't matter if the stallion is EEAA and always produces bays when bred to black, bay, or chestnut - the gray mare still brings a 50% chance the foal will be gray.

Gray trumps all, no matter what.

rmh_rider
May. 8, 2012, 04:11 PM
Grey is very prominent in the arabian breed. And lots of folks do not want grey these days. OR gray.

TB not so prominent.

Yes, it comes to genetics.

My horse is not grey. His dam was grey.

My friends peruvian mare is grey (chestnut based), she bred to a bay peruvian stallion, and her foal was liver, and still is.

Grey is as grey does but I don't think it trumps it all.

Here is my gelding's pedigree.

http://www.allbreedpedigree.com/diamonds+in+xs

So how does grey trump all? It didn't in this case. He is chestnut with a blaze and 4 white stocks. Go back on the allbreedpedigree and check out his ancestors pictures on the sire side. The chestnut with stockings, white legs and white face goes way way back.

http://i1122.photobucket.com/albums/l531/purpleorchid102/RSide.jpg

http://i1122.photobucket.com/albums/l531/purpleorchid102/LSide.jpg

If the OP chooses a stallion with a strong color pattern, she just may very well get a foal NOT grey.

JB
May. 8, 2012, 04:17 PM
It doesn't matter if gray is more prevalent in Arabs than in TBs.

If a horse is gray, the genetics are the same, the odds of passing it on are the same - it's not breed dependent.

Gray DOES trump all, but is has to be present. If it's not present, the horse isn't gray, can't become gray, can't be responsible for producing gray.

If it's present, the horse IS gray (or will be soon) and has at least a 50% chance of passing it on.

Your gelding had a chestnut parent and a gray parent. There was a 50% chance he would have come out gray. No more, no less, (the gray's parents were gray and bay, therefore he was heterozygous gray), and certainly no more or less because he was or wasn't a certain breed. He ended up not getting his dam's gray gene, therefore he isn't gray.

Your friend is in the same boat - bred a gray to a bay, obviously the gray mare was only heterozygous gray, therefore a 50/50 shot of passing the gray on, and she didn't; therefore, the foal was not gray.

rmh_rider
May. 8, 2012, 04:37 PM
I know the odds. 50-50.

However, grey does not trump *all*. Still 50-50 chance. And not all grey horses turn "white". If there is a grey parent, not *all* foals will be grey.

We are all in the same boat when breeding any color.

The color on my arab gelding was very strong on the sire side.

If I had another grey mare, I would breed to a horse who had zero or very little grey in the pedigree, or when bred to grey, didn't produce it. Still, regardless, it is up to genetics to determine the color. I dislike grey, I have had many many, so I will not be buying or breeding to any grey ever again.

Greys in the egyptian lines are very strong. Not so in say the polish, bays are. In the spanish there are greys and bays usually. Russian, chestnut is very dominant. Crabbet, chestnut.

Yeah, all a chance. But like I said above, if I had one to breed I would choose a color and stallion who had a VERY strong color dominance, that is if you wanted the best chance to not have grey.

I do think it does have to do with the breed. Grey is not a common color in TBs. Arabs, it is. More chance for an arab to be grey, than a TB.

My friend with the grey peruvian mare, the year before bred to a blue roan twh. Foal was chestnut grey (she was actually pink) when born, and she is now a very very light grey. As I said before, same grey peruvian mare bred to a bay peruvian, she got a liver, and filly is still liver. She also bred a chestnut roan twh mare, to a bay peruvian (different sire) and she got a blue roan filly. The same chestnut roan twh mare was bred to a black and white pinto twh stallion and she got a 95% white, and 5% bay filly.

JB
May. 8, 2012, 04:52 PM
However, grey does not trump *all*. Still 50-50 chance.
No - re-read what I wrote. If gray is there, that horse WILL be gray.

The 50/50 is based on what that horse can pass to its offspring. If the horse is heterozygous gray, Gg, then *each breeding* there is a 50/50 chance the foal will be gray (again assuming a non-gray other parent). Every gene is 2 copies. Every breeding gives a 50/50 chance one or the other of those 2 copies will be passed on.


And not all grey horses turn "white".
If they live long enough they certainly do


If there is a grey parent, not *all* foals will be grey.
Never said that - please go back and re-read ;)

However, if the gray parent is homozygous gray GG, then yes, ALL foals will be gray, regardless of the gray/non-gray status of the other parent. That's because the only copy of that gene to pass on is G, the "on" for gray, and when G is present, the foal WILL be gray.


The color on my arab gelding was very strong on the sire side.
What does that mean? His sire was chestnut - absolutely no chance of gray coming from that side. His dam was gray. HER sire was not gray, the dam was. That makes her Gg, heterozygous gray. That means every breeding gives her a 50/50 shot of passing on the G (which would produce a gray foal) or the g (which means a non-gray foal). Your guy got her g, therefore he is not gray.

His sire's chestnut "strong color" did not overcome the gray. There WAS no gray given to the foal. The stallion had absolutely nothing to do with the odds of the gray dam passing her G or her g.


If I had another grey mare, I would breed to a horse who had zero or very little grey in the pedigree, or when bred to grey, didn't produce it.
It doesn't MATTER what's in the pedigree if the horse isn't gray.

If the horse IS gray, then you keep looking back. You can have a line FULL of grays and them ALL be heterozygous gray Gg and bam out pops a non-gray foal.


Still, regardless, it is up to genetics to determine the color. I dislike grey, I have had many many, so I will not be buying or breeding to any grey ever again.

Yes, it IS up to the genetics, and I and simkie and Daventry and quicksilver have explained several times how it works.


Greys in the egyptian lines are very strong. Not so in say the polish, bays are. In the spanish there are greys and bays usually. Russian, chestnut is very dominant. Crabbet, chestnut.
ALL that means is there are more homozgyous grays in those lines/that breed. Look at Welsh ponies - HUGELY gray population, but there are some non-grays. MUCH more likely to find GG grays in Arabs and Welshes. But that doesn't matter. All that matters is the horses that are bred together. If 2 arabs are not gray, then it doesn't matter if their 10 gen pedigree is gray, they *will not* produce a gray foal when bred together.


But like I said above, if I had one to breed I would choose a color and stallion who had a VERY strong color dominance, that is if you wanted the best chance to not have grey.
If you don't want gray, don't breed a gray horse, don't breed TO a gray horse. Nothing else matters, not the horse being bay or black or chestnut, not even if the horse comes from 10 generations of black or 10 generations of chestnut. If one parent is gray, there IS at least a 50% chance of gray, regardless.


I do think it does have to do with the breed. Grey is not a common color in TBs. Arabs, it is. More chance for an arab to be grey, than a TB.

it DOESN'T have to do with breed.

Gray is gray. Black is black. Bay is bay. Horse color genetics are the SAME. Gray in a TB is not any different from gray in a Welsh or Arab or Morgan or Shire or any other breed or mix. It's just not. It doesn't matter what you think - the genetics are what the genetics are.

tucktaway
May. 8, 2012, 04:57 PM
Genetics or not, if it's anything like my grays it will be some form of dirty bay, muddy brown, pinto or green at least 75% of the time!!!! :lol:

Simkie
May. 8, 2012, 05:10 PM
Gray is gray. Black is black. Bay is bay. Horse color genetics are the SAME. Gray in a TB is not any different from gray in a Welsh or Arab or Morgan or Shire or any other breed or mix. It's just not. It doesn't matter what you think - the genetics are what the genetics are.

Well said and worth repeating :)


Genetics or not, if it's anything like my grays it will be some form of dirty bay, muddy brown, pinto or green at least 75% of the time!!!! :lol:

This too :lol:

My grey filly (http://pets.webshots.com/album/582505855rjhYQq) has only just started the process, she she's still far more dark than light. I am really relishing this color while I've got it! ;)

ElementFarm
May. 8, 2012, 05:39 PM
Interesting thread. I fully understand the math behind whether a foal is likely to be gray or not.

Here's a question I don't know the answer to: what determines how fast a horse grays out? I know ponies who are snow white at age 3 and some 10+ year olds who are practically still steel gray? Is there a variance in the Gg that determines rate of fade? How about whether they go flea-bitten vs just "white"? Thanks

Simkie
May. 8, 2012, 05:44 PM
Here's a question I don't know the answer to: what determines how fast a horse grays out? I know ponies who are snow white at age 3 and some 10+ year olds who are practically still steel gray? Is there a variance in the Gg that determines rate of fade? How about whether they go flea-bitten vs just "white"? Thanks

I believe THAT is very much an unknown. There is some belief that homozygous greys grey out faster than heterozygous greys, and some believe that grey on chestnut based horses may grey out more quickly than grey on bay or black based horses. I am unsure if either of those things has been proven in any way.

There must be some genes that modify grey that influence how quickly the horse loses it's color, but they are unknown.

JB
May. 8, 2012, 06:03 PM
I think the graying faster if GG is fairly established, though certainly not all individuals do that. I've never heard gray on chestnut vs other colors making a difference though.

Because GG horses tend to gray faster, they are also more prone to melanomas, as that is a result of that melanin transference, which happens faster in those guys.

Daventry
May. 8, 2012, 08:27 PM
I do think it does have to do with the breed. Grey is not a common color in TBs. Arabs, it is. More chance for an arab to be grey, than a TB.


JB, she doesn't get it...so I would save your breath ;)


rmh_rider, you are so misinformed on this. Yes, maybe grey is seen less in the TB world than the Arab world...so what? There is absolutely NO CHANCE of an Arab getting the grey gene more or less than a TB because of that. :rolleyes: The grey gene works the same in all breeds. You breed to a grey, you have at least a 50% chance of getting a grey. The odds don't increase just because it's an Arabian. Breed a grey Arab (heterozygous), 50% chance of getting a grey foal. Breed to a grey TB (heterozygous), 50% chance of getting a grey foal!

You need to do some Google searching and read a ton of articles...and then come back and discuss color genetics with us. ;)

I'd hate for a newbie to read any of that and think they have a better chance of getting a grey foal if they breed to a stallion just because it is Arabian. :lol: Color genetics does not care what breed a horse is. :no:


More chance for an arab to be grey, than a TB.


Whether you breed to a grey Arabian or a grey Thoroughbred...you still would have the EXACT same chance of getting a grey foal (if both horses were heterozygous grey). Just because the Arabian breed may have more greys in their breed does NOT mean there would be a greater chance of getting a grey foal. This is not rocket science! :no:

Bayhawk
May. 8, 2012, 08:50 PM
Gray is gray no matter the breed. Comohn folks ! Lets stay intelligent here.

themarchcat
May. 9, 2012, 12:22 AM
Where'd she go? I was seriously enjoying this hilarious conversation =D

PS. My purebred Arabian mare is chestnut and she had two GREY parents! :eek: shocker! lol Oye, sorry, I'm just being mean, but I did think that'd be a funny little two bits. :winkgrin:

alto
May. 9, 2012, 03:45 AM
But now imagine that there are grey modifiers - separate genes, linked genes or if you really wanna get crazy, a mix of both - & those Egyptian Arabs have more of those modifiers (especially the linked ones) so that a parent that is G/g does not actually produce 50% G foals & 50% g foals, but instead almost every foal is grey such that 85% of progeny are now grey ...
would you not then describe this as a "stronger grey" :lol:

(ie non-mendelian inheritance cause it's pretty much a given that Mendel "helped" his data)

Coincidentally FP's dam is heterozygous grey, bred to same buckskin stallion: foals are 2 grey-palomino colts, 2 grey-buckskin fillies, 1 grey-chestnut colt, 1 bay colt; bred to bay stallion: 1 grey-bay colt ... easy to see why someone might consider this mare to be a "strong grey".
So while the academic chance of her next foal being grey is 50% (assume she's again bred to a non-grey stallion), my empirical data suggests that foal will be grey :sigh:

SaturdayNightLive
May. 9, 2012, 07:27 AM
Coincidentally FP's dam is heterozygous grey, bred to same buckskin stallion: foals are 2 grey-palomino colts, 2 grey-buckskin fillies, 1 grey-chestnut colt, 1 bay colt; bred to bay stallion: 1 grey-bay colt ... easy to see why someone might consider this mare to be a "strong grey".
So while the academic chance of her next foal being grey is 50% (assume she's again bred to a non-grey stallion), my empirical data suggests that foal will be grey :sigh:

That's not right either. You're confusing a 50/50 chance of grey with the idea that 50% of the foals will be grey. You have a 50/50 chance of the heterozygous mare producing a grey foal each time. The color of the previous foal has no bearing on whether or not the grey allele will be inherited. Each foal has the same 50/50 chance. If you flip a coin 100 times, chances are that you aren't going to get heads exactly 50% of the time, but that doesn't change the fact that with each coin flip you have a 50/50 chance of getting heads.

JB
May. 9, 2012, 09:06 AM
I don't think we should make fun of rmh_rider, as she's obviously got a history of having been told incorrect information, or has made up her mind based on visuals which can be a very bad thing to do when it comes to color genetics.

rmh, if you look at the UC Davis genetics site - among the leading equine genetics researchers - you will see this

Gray results are reported as:

N/N No copies of the gray gene. Horse will not turn gray.
N/G One copy of the gray gene. Horse will turn gray and approximately 50% of offspring will be gray.
G/G Two copies of the gray gene. Horse will turn gray and all offspring will be gray.


It really is as simple as that.

SNL is right about percentages over a population. 2, 3, even 10, 20 foals may seem like it tells the whole story, but it's not statistically significant. Remember, roughly 50% of a population will be boys vs girls, but Equine Repro at one point had 49 colts in a row ;) STILL not statistically significant enough.

People like to say a stallion must be EE homozygous black because he had 30 foals out of chestnut mares and none were chestnut. Well, the odds are increasing that he's EE, but 30 isn't enough to definitively state that.

alto, there ARE some genes that are linked, which skews the 50/50 ratio. Extension and Tobiano are linked, and usually the T is linked to the e. Over time, in a given population, that means there are roughly a 50/50 mix of Tobianos with a fairly equal distribution between the red-based and black-based colors (assuming 1 horse is Tt and the other is tt).

BUT, in certainly lines, the Samber line being a well-known one, the link with T is with E. So, that same Tt bred to tt where the T and E are together, still produces roughly 50% Tobis, but NONE of them will be red-based, all of them will be black-based.

I think gray has been around long enough that any such linkage would have been discovered, so it's pretty safe to say something similar doesn't exist :)

Daventry
May. 9, 2012, 09:18 AM
The color of the previous foal has no bearing on whether or not the grey allele will be inherited. Each foal has the same 50/50 chance. If you flip a coin 100 times, chances are that you aren't going to get heads exactly 50% of the time, but that doesn't change the fact that with each coin flip you have a 50/50 chance of getting heads.

Thank you! ;)

Our 23 year old heterozygous grey Welsh Pony stallion has had approximately 75% grey foals over the years. It has nothing to do with the fact that the Welsh Pony population tends to have more greys than other breeds or that there is some strain of a stronger grey gene in there. It solely has to do with the fact that there is a 50/50 chance of each and every foal turning grey. Period. :yes:

JB
May. 9, 2012, 10:03 AM
But Daventry, how many gray mares did he cover? His Gg mixed with Gg gives a 75% chance, and any GG mares would have made it 100%.

So even with a Gg stallion, given the number of foals produced over a lifetime, especially in a breed where gray IS more common therefore the number of gray mares is likely larger, I'd fully expect more than 50% grays in his kids :)

Ibehorsepoor!
May. 9, 2012, 10:38 AM
I bred my grey mare to a grey stallion on purpose. I got a lovely bay colt...lol.. both my mares parents were grey.

the Stallion had to have a grey parent.... I was so sure I would get a grey... nope, and before anyone tells me it could happen.. he has not a grey hair around his eyes or anywhere...
:eek:

JB
May. 9, 2012, 10:41 AM
got a picture? Sometimes the tell-tale white hairs are missing. But the shade of the foal coat is a more reliable (though not foolproof) indicator.

If he's a bay like an adult, meaning black legs, they he's likely going to gray. But if he's got the tan/silver legs of a foal bay coat, it's highly unlikely he's going to gray

DLee
May. 9, 2012, 10:45 AM
Am I correct that even if both parents of a horse are grey that horse might still not be homozygous grey?

Simkie
May. 9, 2012, 10:52 AM
Am I correct that even if both parents of a horse are grey that horse might still not be homozygous grey?

Yup.

Case in point: my filly.

Pedigree: http://www.pedigreequery.com/seven+springs4

Photos: http://pets.webshots.com/album/582505855rjhYQq

Sire and dam are both grey, and both heterozygous. Filly had a 1 in four chance in coming out not-grey.

She is grey, so she had a one in three chance at being homozygous grey. Because I am a giant nerd and I like these things, I had her tested. She is heterozygous.

The only way you are GUARANTEED a homozygous grey is if both parents are homozygous for grey.

If one parent is homozygous and one is heterozygous, you have a 50/50 shot of homozygous vs heterozygous.

DLee
May. 9, 2012, 10:56 AM
Okay thanks! I am expecting a C.Quito foal any day, my mare is bay and he is grey, I *think* both of his parents are grey, but I don't think he is homozygous, kind of hoping for a grey. :yes:

And lovely filly btw!

SmartAlex
May. 9, 2012, 11:01 AM
Anecdote: Grey Foals....be careful what you wish for....

My mother wanted a grey very badly. She bred our bay ASB mare to a homozygous grey Arab stallion. The stallion owner guaranteed it. Said he didn't care if the mare was pink, we would get a grey foal....

We got twins. Two grey foals. :yes:

They both survived, but they ended up being rather small, considerably smaller than either parent. And you couldn't get two more different siblings if you tried. They were totally unalike in type and temperment. But they were both grey. :D

JB
May. 9, 2012, 11:05 AM
Okay thanks! I am expecting a C.Quito foal any day, my mare is bay and he is grey, I *think* both of his parents are grey, but I don't think he is homozygous, kind of hoping for a grey. :yes:

And lovely filly btw!

In looking at his page (oh my, he's something, LOVE his pony-like head!!) I think the 6/15/10 colt is not gray, which points to C being Gg.

Simkie
May. 9, 2012, 11:06 AM
In looking at his page (oh my, he's something, LOVE his pony-like head!!) I think the 6/15/10 colt is not gray, which points to C being Gg.

Yep, I was thinking the same thing!

DLee, looks like it's a 50/50 shot for grey for you :)

Daventry
May. 9, 2012, 11:08 AM
But Daventry, how many gray mares did he cover? His Gg mixed with Gg gives a 75% chance, and any GG mares would have made it 100%.

So even with a Gg stallion, given the number of foals produced over a lifetime, especially in a breed where gray IS more common therefore the number of gray mares is likely larger, I'd fully expect more than 50% grays in his kids :)

Oh no, I totally get that. ;) Obviously if our grey stallion was bred to grey mares, the likelihood of grey increases quite a bit. Just pointing out that his percentage of grey foals has nothing to do with JUST him being able to pass along some 75% chance of grey or some made up number just because there are a lot of greys in the breed, as rmh_rider is suggesting. ;) If she did her research and understood that breeding a grey Arab to a grey Arab could result in at least a 75% chance of grey, she would start understanding that it has nothing to do with the breed itself...and simply due to genetics. ;)

DLee
May. 9, 2012, 11:09 AM
In looking at his page (oh my, he's something, LOVE his pony-like head!!) I think the 6/15/10 colt is not gray, which points to C being Gg.


Thank you, I'm stressed/excited!

JB
May. 9, 2012, 11:16 AM
Oh no, I totally get that. ;) Obviously if our grey stallion was bred to grey mares, the likelihood of grey increases quite a bit. Just pointing out that his percentage of grey foals has nothing to do with JUST him being able to pass along some 75% chance of grey or some made up number just because there are a lot of greys in the breed, as rmh_rider is suggesting. ;) If she did her research and understood that breeding a grey Arab to a grey Arab could result in at least a 75% chance of grey, she would start understanding that it has nothing to do with the breed itself...and simply due to genetics. ;)

:yes::yes::yes:

mikali
May. 9, 2012, 02:00 PM
Well, I have my fingers firmly crossed for my 25% non-grey, and would happily take any extra wishes that you might offer up to the genetic gods for me. Sire is GgEEaa and the dam is GgEeaa - so I know I am getting black... Mare is at day 319 with her second foal, so I'll let you all know the results when the little one decides to arrive.

And as to the speed of base colour coat change to grey: My small experience has the 2010 chestnut/grey colt being the fastest to turn. The 1996 bay/grey gelding (now fleabitten), and the 2009 bay/grey, 2003 black/grey mares (fleabitten) are more of a medium speed to turn. The slowest is the 2006 black/grey gelding. All of them are heterozygous greys.

Bayhawk
May. 9, 2012, 02:12 PM
I bred my grey mare to a grey stallion on purpose. I got a lovely bay colt...lol.. both my mares parents were grey.

the Stallion had to have a grey parent.... I was so sure I would get a grey... nope, and before anyone tells me it could happen.. he has not a grey hair around his eyes or anywhere...
:eek:

I have had this happen on numerous occassions. I've bred gray to gray for 3 full siblings. 2 were bay and the one was gray.

The Holsteiner stallion full brothers Cathalido and Cormint are examples also. They are by Calido / Carthago.......both parents gray , yet Cathalido and Cormint are both dark bay.

Wordplay1832
May. 9, 2012, 02:28 PM
Thanks for all the input guys! I do have a biology/genetics background but all I could find online for it was super dependent on base color and not simply the homozygous/heterozygous etc. and whether grey was dominant or not.

Haven't decided for sure if I'm breeding the mare or not this year. She's been having some issues that may retire her and I need to figure out what they are for sure and if it was an acute injury or something that I would not want to pass on and not breed. Or-best case scenario it's something easy to fix that means she can compete a few more years before breeding, or give her a year off to make the baby and feel better and then start her back into work. But that's a completely different topic entirely and one that I have basically zero answers about yet. :)

JB
May. 9, 2012, 02:28 PM
And as to the speed of base colour coat change to grey: My small experience has the 2010 chestnut/grey colt being the fastest to turn. The 1996 bay/grey gelding (now fleabitten), and the 2009 bay/grey, 2003 black/grey mares (fleabitten) are more of a medium speed to turn. The slowest is the 2006 black/grey gelding. All of them are heterozygous greys.

That's interesting. I will do some asking around and see if there is any known correlation in that, or if you were just "special" :D

JB
May. 9, 2012, 02:39 PM
Thanks for all the input guys! I do have a biology/genetics background but all I could find online for it was super dependent on base color and not simply the homozygous/heterozygous etc. and whether grey was dominant or not.
Wow, do you have some of those sites?

SmartAlex
May. 9, 2012, 02:41 PM
I wouldn't be suprised to find that there are modifiers that work in conjunction with the grey gene that determine the speed and style of greying. Especially dappled and flea bitten.

My horse is a chestnut based grey, quite dappled.
His dam was grey, and I don't know for sure what her base color was, I think dark chestnut as both sire and dam were chestnut (dam greyed), but her mane was black even in old age.
She had several grey foals. Two were by a black stallion, and appear to both be black based. They were very dappled and very dark and slow to fade.
My horse was by a chestnut sire. Comparing photos of his (assumed) black based siblings at similar ages, he greyed much, faster than they did but does still retain nice dappling.

Wordplay1832
May. 9, 2012, 02:42 PM
http://www.horsetesting.com/CCalculator1.asp
This was one of them-and without the base color you couldn't do much. Granted now that I've looked more (I swear I looked a bunch but apparently just hit the right query now) there are more helpful searches.

This wasn't the most complicated one I found but I don't remember where that is.

JB
May. 9, 2012, 02:42 PM
Oh for sure there are different genetic components to whether a horse dapples or roans in the gray process. I THINK it's theorized that if a gray lives long enough, he'll eventually get flea bits, but certainly some horses do that pretty quickly after becoming white.

GG grays faster than Gg - I think that's documented.

JB
May. 9, 2012, 02:49 PM
The Animal Genetics calculator is a good one. They are a company that does genetic testing as well.

However, I can see how one might interpret a result as looking like the gray possibilities as dependent on being a certain color :) For example, I chose a chestnut Gg Aa stallion and a black Ee non-gray mare. The results are:
Offspring Color Probability

25.00% -
Gray (Chestnut)
25.00% -
Chestnut
12.50% -
Gray (Black)
12.50% -
Gray (Bay)
12.50% -
Black
12.50% -
Bay
The biggest chance is a gray chestnut. However, that doesn't mean you have a bigger chance of gray if it's a chestnut, or chestnut if it's gray, as I could see someone interpreting that to mean.

it means there is right off the bat a 50/50 shot at the base color being red, since ee x Ee gives you a 50/50 shot at a chestnut. But, there's also a 50% that red-base can be gray, which puts it at 25% of a gray chestnut and 25% non-gray chestnut.

Of the other 50% nonchestnut, it's split between black and bay, 25% each. But each of those also has a 50/50 shot at gray, so each of those is 12.5% gray on each of black and bay, and 12.5% non-gray on each of black and bay.

SmartAlex
May. 9, 2012, 02:51 PM
Does the amount of flea bites increase each year?

My horse has a few flea bites around his brow at age 9. His dam had none (never saw her in person, only photos) and was the same shade as he is now when she was 24. I've seen some who were so covered that it almost reversed the greying process.

JB
May. 9, 2012, 03:19 PM
Yes, flea bites tend to increase - they are a part of the continual graying process. Some start before the horse has even whited out LOL

Daventry
May. 9, 2012, 03:25 PM
And as to the speed of base colour coat change to grey: My small experience has the 2010 chestnut/grey colt being the fastest to turn. The 1996 bay/grey gelding (now fleabitten), and the 2009 bay/grey, 2003 black/grey mares (fleabitten) are more of a medium speed to turn. The slowest is the 2006 black/grey gelding. All of them are heterozygous greys.

This is our own personal experience. Our buckskin and palomino foals by our grey Welsh stallion took a few years to really start greying out. Our smoky blacks and black foal by the same stallion seem to stay dark for many years and just get a gradual greying of the head and tail. Ironically, three foals born bay (all out of bay mares) turned COMPLETELY light grey as weanlings when their first foal coats shed out.

Kerole
May. 9, 2012, 05:04 PM
Two observations:

It's possible that rmh_rider was really talking about the number of greys in the Arabian breed making it more difficult to choose quality breeding stock that is not grey. She was just wording it badly?

Also, I too believe that chestnut greys go whiter quicker than bay/brown greys, and that black greys change the slowest. It would be interesting to know whether this is actually the case or not!

JB
May. 9, 2012, 08:57 PM
Two observations:

It's possible that rmh_rider was really talking about the number of greys in the Arabian breed making it more difficult to choose quality breeding stock that is not grey. She was just wording it badly?
Nope, I really don't think so:


When they do NOT want grey they usually breed to a stallion who has a very solid BAY background. And one who produces alot of BAY.



Also I would choose a bay with very little color pattern ie white on legs and face.


Also your mare being a TB is even better in the odds you will not get a grey. Grey is not very dominant in the TB breed. But still, go with a stallion who is known to cookie cutter the bay color no matter what he breeds.
[/QUOTE]



If the OP chooses a stallion with a strong color pattern, she just may very well get a foal NOT grey.


And not all grey horses turn "white".


The color on my arab gelding was very strong on the sire side.


If I had another grey mare, I would breed to a horse who had zero or very little grey in the pedigree, or when bred to grey, didn't produce it.


But like I said above, if I had one to breed I would choose a color and stallion who had a VERY strong color dominance, that is if you wanted the best chance to not have grey.

rodawn
May. 9, 2012, 09:15 PM
Two observations:

It's possible that rmh_rider was really talking about the number of greys in the Arabian breed making it more difficult to choose quality breeding stock that is not grey. She was just wording it badly?

Also, I too believe that chestnut greys go whiter quicker than bay/brown greys, and that black greys change the slowest. It would be interesting to know whether this is actually the case or not!

I had a grey born black. He went from black, to charcoal, to a gorgeous black-grey with black mane and tail, with very black dapples spaced throughout his whole body, which progressively whitened each year. By the time he was 10, the dapples were mostly gone just mere shadows to what they were, and there were black specks that looked similar to the brown flea bits seen on other greys but his were black. He died when he was 11 so no idea what color he would have gone from there. I have no doubt had he lived to an older age, he would have turned pure white, but it was interesting to see what color he was going to shed out each spring.

His full brother was born a mahogany bay with white flecking. The flecking and greying out was much more noticeable when he was about 3 and he was looking almost strawberry roanish on his body by the time he was 6, but still kept his black mane and tail with white streaks starting to come in. I last saw him when he was 9 and he was more white with brown flecking and his mane/tail were streaking out white. His flecking hadn't started to turn flea-bit yet. Their mother (TB) was grey-white (no flea bits) with black skin. Sire was bay (WB).

Both boys were very handsome in all their various shades.

Kerole
May. 9, 2012, 09:15 PM
Hmmm, yes, confronted with the evidence I must concede my idea was a daft one!

JB
May. 9, 2012, 10:20 PM
Oh, not daft at all! I've got the question out to 2 friends who have color geneticist connections, so if anyone will know, they will :)