A Note about Sugarbush Draft Horses

I see it over and over again, and no matter how many times it's said, it's still wrong. "Sugarbush Drafts are just an Appaloosa Draft Cross". Uh.... no. The Sugarbush Draft Horse was a breed created many years ago in Ohio. While the initial cross was made using Percherons to Appaloosas, in the many generations following, the breed has been solidified into a consistent type. Saying these horses are "just" a draft cross makes as much sense as saying that AQHA horses are "just" a Thoroughbred cross, American Cream Drafts are "just" a dilute Belgian, or that Morgans are "just" a grade.

Thursday, August 12, 2010

Splash White (Finally)

I really appologize to every one I left hanging waiting for the rest of the color patterns. Unfortunately, a little bit of "the rest of my life" or as gamers say "real life" got in the way.  But here it is, the middle of summer, and I can't do a thing outside, unless I want to kill my horses, my better half, or myself.

So, let's talk about Splash White.  I am a huge fan of this color pattern.  I find it amazing in minimal form, and many of my horses carry splash.  The colt shown there is "O Stop Looking" also known as "Streaker Daltrey".  He's a mismash of SO many color patterns, appaloosa (snowcap) sabino, and splash white. You can see the splash on his face here, and the 4 white legs.  In person he has chestnut ticking on his legs showing where the socks end and the blanket begins, which helps in identifying his patterns.His extreme white face has given him a few other splash traits, including 2 blue eyes, and his right ear doesn't seem to work at 100%.  I believe he can hear from it, but I don't believe he can hear all the ranges of sound.  Mid tones, such as my normal voice, do not elicit a turning of that ear to me, but squeaky baby voice, and low momma murmurs do.  When Daltrey was born, his right ear hung awkwardly.  This is a sign that the ear has been affected by splash.  Not always accurate, but accurate enough to cause suspicion.

What the splash gene does is restrict pigment from reaching the horse's extremities.  This is why splash white horses look like they may have been dunked in paint.  A splash white blaze will be bottom heavy because the muzzle is an extremity, just as the legs are.  Many horses are evenly marked, but others look like they were lop sided when they got "dipped".  Colnels Smoking Gun (aka Gunner) from McQuay Stables is a good example of the lopsided look.  Check out his back leg.

While Splash white has not been mapped - to my knowledge - the expression of it has been studied.  There is speculation that splash white is located in the same area as roan and tobiano.  It is not the same GENE, but just as tobiano and roan do not recombine, splash may also be playing in the same neighborhood, and too close for recombination.

Because splash white is often hard to see, it has been difficult to determine the "zygosity" of many horses.  In some horses, a small sliver of blue in the eye is the only indication of it.  In others, what was expected to be a solid, ends up with large areas of white, or like my foal above, a lot more pattern then was expected!  I have heard that horses with obvious splash markings are homozygous(SPLSPL), and heterozygous horses (SPLspl) show "normal" face and leg amounts of white.  I'm not sure how true this is (see my above colt who can not be a homozygous splash horse).  It is possible however that splash white is an incompletely dominant gene, resulting in more expression with a second copy of the dominant allele.  This would imply that other genetic factors give the range of possible expression.

Let me put that in layman's terms!  Lets say there is an "expression" gene in there somewhere (theoretical only, we have no real proof of this).  The expression gene would say, this horse's base line expression is 25% white, like Gunner above.  So, base coat color (either working as an enhancer like dominant agouti and recessive extension, or as a suppressor like dominant extension and recessive agouti) and other enhancing genes such as sabino (even normal face and leg markings) could restrict or encourage the amount of white shown on the horse.  Depending upon the genetics, a "25% white on average" horse could show between 10% white, and 40% white.

Now, using the above example, if homozygosity for white results in even MORE white, that "25% white on average" horse would express with 25% to 50% white.  We don't know for sure, but this is what many phenotype (studying genetics through appearance) experts believe.


Splash can be a pinto gene, resulting in horses with extreme white bodies, like this horse.
Or this horse:
Notice how Gamblin man (above) appears to have been crooked when he was dipped?  This is very common, and believed to be influenced by factors in utero.

This filly, Soliloquy (Annandales Grey Wolf, TIGRE x Jinx, SDHR) almost slipped past me.  Her sire carries sabino, her dam carries sabino and splash.
Her front legs are dark, but showing the baby fawning often seen in bays.  Her half sister Diva (The Polecat, ApHC x Jinx, SDHR) has similar markings:
Both shown at similar ages (Soli at 3 days, Diva at 2).  If you look closely, you can see that Diva (bottom picture) actually has more white on her legs, with a small white mark on her front left foot.  It does not go all the way around.  Although on closer inspection you will see that Soli has a wider blaze, rather wide for the amount of white she has on her legs, and a partially blue eye.  Diva has proportionate markings, and both eyes are dark.

Because of this ability to hide as normal markings, splash is passed through the gene pool of breeds that do not want "pinto" markings, such as Appaloosas.  Some breeds and breeders want to avoid the blue eyes, or potential hearing problems associated with the color pattern.  While deafness would be very detrimental in a wild horse, many owners have found that horses with hearing loss are often wonderful pets, and almost spook proof.  Of course, often means not all.

So, ready for your test?

What pattern is this horse likely showing?

7 comments:

  1. Sure looks like splash to me, but there's a hint of roaning in the flank (and belly?) that might hint at Sabino as well...
    btw, there's an all white filly by Gunner named Guns ahd White Roses, that the owner believes is maximum sabino. Does Gunner carry sabino too? Or is she mistaken (or maybe I am...it's not uncommon)? I'd give you a link, but I'm not at home.

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  2. It's actually a bit of a trick question. I'll give you a hint though, that's the Clydesdale Stallion Donnengal Dr. Pepper.

    And I know the filly you're talking about (er mare now I think). The one with the sway back? I honestly have no idea what she is, and I'd want to see images of her dam before even making a guess.

    It's always possible that a splash white horse can carry sabino. The debate is whether normal face and leg white counts as sabino (I think in most cases it does). If the splash is more extreme then the sabino, then the traces of sabino characteristics become harder and harder to see with the naked eye, just like frame can hide on a tobiano.

    I'll let every one guess a bit more before I discuss the answer (there's really not a right one... another hint!).

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  3. Ok, since no one else guessed, I'll give you the discussion about the test answer.

    Clydesdales have the appearance of splash white, but it's common wisdom that their markings are due to sabino.

    Because there isn't a genetic test for either, there's no way to currently answer the question, only speculation.

    Personally, I think Clydesdales carry splash white, and some pretty interesting white pattern inhibition genes. Of course, they definitely also carry sabino.

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  4. Ooooh! I love that mare, Guns and White Roses. She's come so far, too. Her latest video posted recently blew my mind and made me cry with happiness. From a filly noone thought could ever be ridden to a gorgeous, stunning horse being ridden during shows and performing skilled reining movements. wow...just wow.

    Anywa, you sure do know a lot about genetics and coloring. Splash white is very interesting. What would you say my Apache mare is?

    ~Lisa

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  5. Well Clydes technically aren't sabino at all since there is only a test for sabino1... whic hthey all have tested negative for. and their form of "sabino" doesn't work like regualr sabino as far as homozygous specimens go, so their "sabino" could vary well be the reasoning for their splash like markings. it'll be interesting to see what the new splash test turns up though.

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  6. Curiousity question, if you bred a filly (Soli) to a stud that was a blanket bay, what would the color combination be in all likelihood? Soli grew up to be a quite beautiful bay varnish, very interesting mare!

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