Greys staying dark longer: genetic or environmental?

[Marengo]

Have there been any studies done on if grey horses keeping their dark colour longer is genetic or environmental? Any breeders have any thoughts on this based on years of breeding different lines?

I ask because I’m from Ontario and I could often guess a grey horse’s age based on its coat. Weanlings appeared in their genetic base colour with a few grey hairs flecked through the coat. Two year olds generally are a steel grey, three year olds have the beginnings of dapples in their coat but they’re still mostly dark. By the time the horse is six it has that beautiful all over dapple look. Some horses keep this look longer but by and large by age 12 most grey horses are white with dark hairs remaining to some degree in the mane, tail and lower legs. If the horse is going to be flea bitten grey it has those by age 12.

I now live in New Zealand and I keep coming across grey horses that are 90% dark with a few light hairs around age 5/6. I know these exceptions exist in North America too but I have yet to see a really greyed out young horse. I’ve also seen a few beautiful dappled greys around age 12 here too.

Sure my experiences may be limited in terms of deciding that environmental factors play a role but it did get me wondering. Is there something in the pasture or the water here that’s keeping grey horses darker longer? Or have I just met too many early greying horses in Canada? Would you say my age vs darkness observations are close to what most of you have seen?

The grey horses I’ve observed in NZ have been tbs and crosses with lots of tb blood. I suppose it could be genetics, perhaps one late greying tb is an ancestor to them all but even the ponies who get their grey colour from elsewhere seem to stay dark longer.

I know colour doesn’t really matter, and I don’t own a grey (no poo stain removal for me) but enquiring minds want to know.

[JER]

My now 4 year-old homebred TB didn’t show any signs of going grey until she was 2.5 years old. With the exception of her sire’s owner, everyone assumed she was dark brown, like her mother and sisters. Her sire’s owner always insisted she would eventually surprise me by turning grey.

Her sire is an Australian-bred TB who lived most of his life in NZ. And according to his owner, his offspring tended to stay dark for years.

Just an anecdote, of course. But no one at the very large breeding/vet clinic where my mare spent the first 3 years of her life had ever seen a horse who started greying so late and without any of the usual tell-tale signs.

[Daventry]

@Marengo;5053862

I ask because I’m from Ontario and I could often guess a grey horse’s age based on its coat. Weanlings appeared in their genetic base colour with a few grey hairs flecked through the coat. Two year olds generally are a steel grey, three year olds have the beginnings of dapples in their coat but they’re still mostly dark. By the time the horse is six it has that beautiful all over dapple look. Some horses keep this look longer but by and large by age 12 most grey horses are white with dark hairs remaining to some degree in the mane, tail and lower legs. If the horse is going to be flea bitten grey it has those by age 12.

I own both a grey stallion and broodmare and that has not been my experience. The greying has been all over the map. I had one foal go completely grey at one month of age…the next foal is still dark grey at three years of age. I had one beautiful stark white gelding who did not get flea bitten marks until the age of 16!

Below is the photo of the one month old who went grey…a photo at one day old, one month old and 2 years old.

[DandyMatiz]

There is some who say that Homozygous greys, grey quicker. Not sure how accurate it is. Otherwise, no i’d say it’s all up to the gods. Matiz and his half sister (paternal) have the same greying so far. His full brother is a year older and not as grey, her full brother is 2 years younger, and greyer. all raised the same…

[Molly_Malone]

I have an 11 yr old grey who is still very dark dappled, so I’d say it was genetic.

[TheBandit]

I have an 8 year old who is still very dark. She is very striking to look at as she has a white mane and tail. She was a solid dark bay with very little greying in her face until she was 2. She is on turnout 24/7. With her, it is all genetic.

[Thomas_1]

I’ve a pair of full sibling welsh section A ponies. They’ve been together all their lives.

So same parents and same environment and guess what?

One paled out slower than the other. AND… it was the younger who was white before the older brother.

Sooooo figure that out

[Edgewood]

I think some greying is genetic. Anyone ever seen the offspring of Riverman (Hilltop). He himself greyed his face all white before he changed color in the body. His son Royal Appearance did the same thing. And other offspring seem to grey that way too.

[SmartAlex]

My 7 year old chestnut based dapple grey (photo last week)

His 10 year old black based half brother (same grey dam) (photo last month)
and as an 8 year old.

Notice even the 10 yr old’s tail has stayed darker while mine is essentially white

[Graymaresrule]

We always thought my old Hay Hook mare was a roan

She never really turned gray but always had a lot of brown in her coat. Shortly before she died at age 16 we noticed her face was turning gray, so not a roan.

We bred her to a dark bay Connemara and the foal was dark bay/brown/black. But he always had some scattered gray hairs. Now at age 16 he is becoming obviously gray.

Sophie, by the black RID Touch of the Blues is a lovely dappled gray
http://picasaweb.google.com/carolp3231/Sophie#5467744531952687042
just becaause I always like to post her pictures. She was 9 and a half in this picture

Her dam is almost white at 18

[JB]

It’s all genetic.

Yes, GG horses to tend to gray out faster, as there is double the genetics at work.

[everafterfarm]

From my personal experience I think it’s the genes.

I had 2 ponies by the same stallion(gray) one with a grey dam and one with a chestnut dam.

Pony with chest dam is now as a 6 yr old and lovely dark dapple gray. As a foal thru yearling he was liver chestnut with a few white hairs through his coat.

Pony with grey dam was “white” by the time she turned 3 with only very faint dapples on her butt. This baby was born a bay. I knew she would turn with 2 gray parents, but man, she came out a nice medium bay with a blaze and 4 perfect white stockings!! Figures.

[JB]

You couldn’t know the pony would turn gray just because of 2 gray parents If they were both heterozygous gray, there was a 25% chance each time of producing a non-gray foal.

[Goo]

To go on a slight tangent off this topic (keeping in mind that this is NOT an area of expertise for me! :)):

While I was in Spain in 2002 and touring farms with two of the senior riders from the Real Escuela Andaluza (since one of my travel companions was looking at horses to buy, and actually came pretty close to buying Distinguido. She later stayed on studying at the Real Escuela for about a year), they got to talking about melanomas and one claimed that they were breeding for melanoma-resistant lines, and that he hardly ever had issues with melanomas anymore in their gray horses. Looking back, I so wish I’d asked him more about it, but it makes me wonder whether they might have been doing this by breeding horses who were extremely slow to gray out?

[JB]

Hmm, interesting, Goo (as opposed to interesting goo :lol: sorry!)

The little bit I know about the development of melanomas is they are a result of a “gone wrong” accumulation of the melanin that is “pulled” from the hair color. So, it does make sense that the slower that process, the slower the development of melanomas. Not all grays develop them, at least not in their lifetime (maybe they ALL would if they lived 50-60 years??) so maybe there is also a genetic predisposition to it as well.

Interesting thought!

[mikali]

I seem to have a thing for greys

Capi Rossi: Grey Born Black Gg EE aa
~4 months http://www.facebook.com/photo.php?pid=10043971&l=527baa185e&id=599515013
4yo http://www.facebook.com/photo.php?pid=13434823&l=78104e3190&id=599515013

Cornetta: Grey Born Black Gg Ee aa
As a 4yo http://www.facebook.com/photo.php?pid=1671609&l=43e0526517&id=599515013
As a 7yo http://www.facebook.com/photo.php?pid=14550227&l=2c1b232efd&id=599515013

Finnan: Grey Born Chestnut Gg ee ?a
One day old http://www.facebook.com/photo.php?pid=12741095&l=300be38925&id=599515013
3 months http://www.facebook.com/photo.php?pid=14550133&l=6669363476&id=599515013

Ellamieka: Grey Born Bay Gg Ee Aa
10 days old http://www.facebook.com/photo.php?pid=6397009&l=ba85ad1b7f&id=599515013
Yearling http://www.facebook.com/photo.php?pid=13972758&l=6f23f36ff1&id=599515013

[ponygirl]

@Edgewood;5053956

I think some greying is genetic. Anyone ever seen the offspring of Riverman (Hilltop). He himself greyed his face all white before he changed color in the body. His son Royal Appearance did the same thing. And other offspring seem to grey that way too.

I call it the cow skull look. My Riverman mare did the same thing. Light gray head, very dark body.

[Foxtrot_s]

My Royal Appearance, too. Still, a very noble mare.

[sfstable]

@Marengo;5053862

I now live in New Zealand and I keep coming across grey horses that are 90% dark with a few light hairs around age 5/6. I know these exceptions exist in North America too but I have yet to see a really greyed out young horse. I’ve also seen a few beautiful dappled greys around age 12 here too.

You should see my almost 3 month old colt. :lol: He has almost shed out completely grey. His mom is homozygous black (she is dark bay) and his dad is grey (obviously).

[columbus]

Genetics

I have a likely homozygous mare who was totally white by 5 and her heterozygous chestnut born daughter who is the black dappled body black mane variety and is faded but still pretty dark at 5, I have seen a couple of her sisters on the sires side and they have the same greying pattern though he is a red chestnut, the 4 yo heterozygous brother also born chestnut by a different sire is greying faster without as much dappling and still has orange casts to his mane and tail. I think especially in the olden days that the horses in a region were similarly bred, similar genes, so you saw similar greying patterns and now you are in a small restricted region and have the same influence by a relatively small number of genes. They will share a greying pattern. In Minnesota the Arab stallion Ferzon had a huge influence and he was a grey horse with a distinctive dapple pattern that his offspring and great offspring shared.

Forgot to mention the homozygous mare has had melanomas since she was two and her heterzygous youngsters do not have any yet. PatO