W20 is a very very old W mutation, and likely the cause of many of the old “sabino” markings.
Right, all black-based requires is E?aa whether that’s EE or Ee. Black x black always = black, but it can be EE or Ee depending on the parents.
Probably a Splash White, testable or not. Many foals are born with blue eyes, the distinguishing factor is whether they are the darker blue of a typical “foal blue”, or a lighter/brighter blue due to Splash or potentially another white mutation
Some horses seem very prepotent at producing similar, recognizable markings. A great many Sempatico offspring, for example, have very similar face markings, as does Tico himself, and a lot of his offspring are more minimally marked Tobianos.
Donor mares provide MtDNA. That’s why the more serious cloning breeders seek out mares from the same motherline as the original mare.
But the mare’s uterus - surrogate or otherwise - does play some role, if nothing else, the sizes of white markings. This was proven in the cloning arena, as clones of originals with white markings do have white in the same places, but in different sizes. This is perhaps more apparent in the Smart Little Lena clones, all their face markings are different
TB breeders definitely accept that genetics & random chance are at play in every mating. Random chance can be both good, and bad… but generally a breeder who is pouring loads of $$$$$ into a foal wants something predictably good.
My comment about Birdstone is that he became predictably “less than desirable.” Meaning breeders had a fairly good idea of what they would get-- and that wasn’t going to be a commercial success.
Compare/contrast that to California Chrome. Lots of fans were EXTREMELY upset and did not understand why he was so undervalued and “overlooked” as a stallion in Kentucky. Contrary to their uneducated opinions, it had nothing to do with his “blue collar California history vs the jealous Kentucky Bluebloods” (LOL). It had everything to do with the unpredictability of his foals and weak pedigree. Chrome was a hell of a racehorse…but based on the physical type of his first two crops, breeders were doubtful he would reproduce himself. Of the ones I have seen, plus others’ opinions I trust, Chrome’s offspring were all over the place. And not just “letting the mare shine through.” Many of them looked unproportional, a mix of spare parts, lacking balance and consistency. That scares breeders-- not knowing what you will get after spending $$$$ on vet bills, mare care, etc, and spending a year of your mare’s breeding career. Some of the Chromes are running decently, he has a few stakes performers, but more of them are in the claiming ranks.
As a breeder, I acquire the best mares I can afford. I am limited in the quality of pedigree/female families I can get with my budget, but I want a mare that earned 100k and/or has black type herself or at minimum her mother/siblings. I want a mare with a great physical type, and a pedigree that encourages me she will reproduce that type. Then I match her with stallions that complement her female family, and meet my requirements for physical type. I choose stallions that are predictable (at least in pedigree, and offspring I’ve seen); even if they are first-year sires, I study what their sires/siblings produce and how heritable their genetics are.
Is there some luck involved? Yes, but moreso on the buying end; as breeder, you try to create the BEST foal you can, in hopes that it will go on to a successful racing career with the right connections to give him the best chance to succeed. As a breeder, once you sell them you are at the mercy of luck…the right owner, the right trainer, the right decisions made in training, the right races selected for him to enter and win, the right racing luck to make it to the wire first… you can breed a horse with the physical traits you want, but once it is out of your hands it still takes the stars aligning for the horse to make it.
Financially, your mare’s future foals’ value is hanging on her previous offspring doing well. So every year you are trying to make a commercial race horse-- one that will both sell well, AND race well, to keep improving her page and subsequent value. We have a mare that consistently produces OUTSTANDING physical foals-- she is a big, pretty mare herself, but she certainly lets the stallion come through. However none of them had raced terribly well until this spring, when her 3yo colt picked up black type. Suddenly, her current 2021 yearling and 2022 foal are worth a whole lot more (though they were, and still are, exceptionally good looking). It also allowed us to take a HUGE opportunity to breed up, to a stallion at a level we could only dream of…on foal share, because we don’t have the $$$$ to fork over, but still. That is the “luck” breeders hope for…not that you can produce the right type of horse, but that the horse ends up in the right situation to best realize the talent they have.
These are not lines known to produce color such as Sempatico or other colored WBs which is why I’m curious. Neither parent is EE but the prevalence is still there which I also find interesting. Part of the eyes remained blue - not your typical baby blues. I’m just assuming w20 or a dominant white gene based on progeny. Won’t know what’s going exactly going on until I pull a panel, assuming it is testable.
Did I say that? I can’t find where I did - if I did, I didn’t mean to! I know I said “Donor mares provide MtDNA.”, and then also talked about the recip mare playing a role in the shape and size of white markings
Sempatico is Tobiano, so I’m not referring to that kind of white. But his face white isn’t from Tobi, it’s from some other white pattern, and it’s just interesting how his offspring often have very unique and identifiable face white. Most horses who produce or contribute to things like that don’t reliably produce such identifiable placement or shape
In your scenario, “all with 4 whites” says there is white there. Some of the W patterns are only boosters - W20 is one. So, they can boost the white from another pattern, W or otherwise.
2 Ee horses have a 25% chance each time producing an EE foal. While over enough offspring, that would be more or less the stat of the total, but any given run can produce more, or less than that 25%.
There are lots of suspected Splash genes that aren’t testable. New W mutations pop up frequently, and only a handful are commercially testable even among the 35 or so known Ws.
