Whats up with these Slewpy mares?

[TomFool]

It seems rather odd to me that mares by sprinter sire Slewpy bred to Northern Dancer line stallions have produced champion route horses in Falbrav & Arch winner Helissio both by Fairy King & now maybe budding superstar High Fly by the lowly sire Atticus. There has to be more to this as these are not just common stakes horses. I am a ND man and never really thought about Seattle Slew line mares much at all as on another post I posted my thoughts on Slews sire line. Dont get me wrong SS was a very good sire but I just dont see his line staying that strong in the upcoming years with top level horses. With that said I would love to hear everyones views on Slewpys big success with Fairy King & Atticus as they are bred similiar? You have to look at Prince John & that French bred bottom I believe but still you have speed source Mr Music a full to Spy Song sitting there. Its just very interesting to me & would love to hear others thoughts on this topic. Thanks

[aurora]

I can't comment on the pedigree aspects but Slewpy was leading sire of turf horses in CA.

[Pan Zareta]

Just a semi-educated thought or two - High Fly combines a broodmare sire who has a singularly unusual (imho, given his pedigree) ability to throw speed with a sire whose heart score(160) is backseat only to Key to the Mint & Secretariat. Obviously HF couldn't have received a copy of the X-linked large heart gene from Atticus. He may well have from Versable though, and from Atticus he could and did receive 50% of a complement of recombinant DNA that's apparently optimized for expression of that sex-linked trait. It would have been interesting to see how this worked in reverse (Slewpy x mare by Atticus), but I don't think it ever happened. It's possible (in theory) that the same thing could be going on with Helissio & Falbrav.

[Pan Zareta]

Another thing - Atticus's sire Nureyev & Fairy King were from same dam line (female family 5h) through Special (by Forli) & her dau. Fairy Bridge, which complements ND's Hyperion through Lady Angela w/ his son Aristophanes. I don't think Slewpy had any Hyperion (but looking at his extended pedigree does help explain why he threw good speed - hello, Domino).

[llbean]

I have no idea what Pan Zareta just said; is she saying that Slewpy's damsire Prince John is a speed influence? Cause he's not.

Tom Fool has pointed out something of great importance that I had actually noticed before but didn't post because I didn't want someone stealing it. Namely: "From a tiny sample Slewpy and Fairy King have combined 2x1 in two tremendous Arc Winners who were great Champions, and now Fairy King's 3/4 brother Nureyev is the grandsire of a very promising Kentucky Derby prospect named High Fly, who is from a Slewpy mare."

I fail to see how the "X factor" theory can help explain this in any way; but if Pan Zareta wants to clarify what it was she just intended to say, I'd be happy to read it with a open mind.

BTW, what evidence do you have that Versable had the large-heart trait to pass on to High Fly? Was she measured?

But the thing that really confused me to the point where I gave up on thinking the author had a point was where Pan Zareta said "Maybe the same thing is going on with Falbeav and Hellisio", without it being in any way clear to me what the "Thing going on" is.

Let us say that High Fly got 1/2 his genes from Atticus; let us say that Atticus had a large-heart; let us say that Versable had a big heart; let us say that she passed it on to High Fly; let us say that certain genes go better with the large-heart trait; let us say that Atticus had these genes. That is six "let us says" right there; and the only one that is self-evident is that High Fly got 1/2 his genes from Atticus.

It's not scientific to make assumption on top of assumption on top of assumption without providing evidence of at least some kind.

-llbean

[llbean]

I tend to see some circular reasoning getting involved when people discuss the X-Factor theory, here's some examples of circular reasoning:

"The Mexicans must have invented the Automobile as Mexicans have invented all the great inventions; for instance the Burrito, Mexican Festive Dancing, and the Automobile."

"High Fly must have the X-Factor as all the top horses have it; for instance Secretariat, Key To The Mint, and High Fly."

Why is the assumption made that High Fly has the X-Factor when he has not been measured?

-llbean

[Pan Zareta]

I have no idea what Pan Zareta just said; is she saying that Slewpy's damsire Prince John is a speed influence? Cause he's not.

I fail to see how the "X factor" theory can help explain this in any way; but if Pan Zareta wants to clarify what it was she just intended to say, I'd be happy to read it with a open mind.

BTW, what evidence do you have that Versable had the large-heart trait to pass on to High Fly? Was she measured?

-llbean

First, no I'm not trying to rewrite history to make Prince John into a speed influence - as I said, I think all that Domino blood explains Slewpy's, at least in large part. But I apparently didn't make myself understood very well.

In re. the large heart gene - I don't know whether High Fly, Verbasle, or most of the other individuals in the relevant pedigrees have been measured, tho' pedigree-wise the potential certainly exists. Atticus has been measured, and has a very high score indicating a very large heart.

Most genes are not self-contained little islands, even the X-linked traits. They are mitigated, or variably expressed, by factors within the individual such as metabolism, intrauterine environment, et al. Many, maybe most, of those other factors are also genetically controlled and most of the genes which control them are on recombinant DNA (that which is not on the sex chromosomes or in the mitochondrion), which a sire passes along equally to sons as well as daughters. Not all large hearts are created equal, and this is probably a big reason why.

What I'm getting at is that perhaps within his complement of recombinant DNA Atticus carries traits that allow the large-heart gene to be expressed to its fullest - traits which can be passed on to a son, like High Fly. And that is the "thing" I meant *might* also be going on w/ Helissio & Falbrav.

[Michael D.]

high fly's dam, verbasle, has princequillo represented in her pedigree FOUR times.

[Pan Zareta]

high fly's dam, verbasle, has princequillo represented in her pedigree FOUR times.

....but only once(through Quill) in a position where she could actually have inherited his 'X'. She *could* also be a double copy mare.

[llbean]

Thanks for the explanation; if Slewpy or his daughter Verbasle has a sex-linked large heart trait that he and/or she passed on to High Fly, then Atticus having a large-heart AND a great deal of racing ability could be having a effect on the sucess of High Fly because of the reasons you set forth.

Though of course the problem in saying this also has something to do with the success of Helissio and Falbrav is that whereas Atticus evidently does have the large-heart trait, I've never heard of Fairy King being measured.

-llbean

[Pan Zareta]

Though of course the problem in saying this also has something to do with the success of Helissio and Falbrav is that whereas Atticus evidently does have the large-heart trait, I've never heard of Fairy King being measured.

-llbean

I haven't either (heard of Fairy King being measured). It doesn't matter. He could still be passing on traits that optimize expression of the trait when present. That would have been the case w/ Secretariat. Bold Ruler had a normal size heart, but his son was obviously expressing the trait optimally, and I think it would be naive to assume that only one parent had something to do w/ that optimization.

[llbean]

But what evidence is there of Fairy King optimizing the large-heart trait? Does he do better with large-heart broodmare sires? Cause that's the only form of viable evidence I can think of.

With Bold Ruler, why don't you try looking at his best offspring and checking what perecentage of Champions (or whatever) had mares with Large-Heart broodmare sires in the "X-Trail" as compared to the percentage of mares bred to Bold Ruler in general with that those stallions in those parts of their pedigrees?

One horse, even Secretariat, doesn't prove anything of itself.

-llbean

[Pan Zareta]

One horse, even Secretariat, doesn't prove anything of itself.

-llbean

No, one horse doesn't prove anything in & of itself. But Secretariat's just the preeminent representative of the highly successful Nasrullah sire line/Princequillo mare cross, which imho does prove something, and that "something" probably has a lot (but not everything) to do w/ how the large heart is expressed in individuals w/ this cross that possess the trait.

To turn your logic around on you, how do we know Princequillo had the large heart gene? He was of course never tested, & I don't believe a necropsy was done. His daus. that had the trait could have gotten it from their dams. For that matter, how do we know that the a gene or set of genes for the trait exists on the equine X chromosome at all? It hasn't been mapped to a specific part of the X, has it?

We "know" these things because they're inferred from compelling circumstantial evidence, which is the same type of evidence that leads me to think that Fairy King and his bro. Sadler's Wells were/are able to optimize expression of the large heart trait, and most likely had/have it themselves.

To get back to the original thread - I don't necessarily believe the large heart trait & how its expressed is all that's going on w/ the success of Slewpy's grandsons that are by ND line stallions. But I also doubt it's in any part coincidental random luck of the genetic shuffle. What's your take on the original issue?

[llbean]

My take on the original issue is that there are so many Northern Dancer line stallions in the World that them siring two Champions from one broodmare sire means nothing.

What does mean something is that one specific stallion, Fairy King, has sired two Champions from Slewpy mares; this is not a Northern Dancer/Slewpy nick, it is a Fairy King/Slewpy nick or at most a Fairy King or his 3/4 brother Nureyev/Slewpy nick.

Perhaps there is a Northern Dancer/Slewpy nick; but not one shred of evidence for one has been set forth in this thread and if you have some, Pan Zareta, I'd appreciate you sharing it.

-llbean

[llbean]

Before I get into possible reasons for the Fairy King or Nureyev/Slewpy nick; I just want to clarify my opinion that compelling circumstantial evidence has not been presented.

Nothing in your "Bold Ruler liked large heart mares" theory explains why Bold Ruler did better with the supposedly X-Factor stallion Princequillo than he did with all the other large-heart damsires out there at the time.

Therefore it has not successfully predicted what happened and cannot honestly be termed a theory backed up by compelling circumstanial evidence at this point in time.

I agree with you 100% though that something is going on between Slewpy and Fairy King for them to have combined in two great Champions like Helisio and Falbrav from so few examples; and perhaps the clue that will help us unpack the heart of this mystery is High Fly himself.

What elements in their pedigrees or phenotypes, I ask you, do Fairy King and Atticus share? This will lead to the answer, or at least it will push you in the right direction.

-llbean