Is Silverbulletday Skipping a Generation?

re: Is Silverbulletday Skipping a Generation?

sceptre — Tue, 02 Apr 2013 16:34:11 GMT

I never did offer a reasonable genetic hypothesis for how a Mumtaz Mahal or, perhaps, a Silverbulletday-given their race records, produce records, and the produce records of their daughters-could have occurred. My second reply to Alan was a poor one. I got lost, merely touching upon how elite racehorses can sometimes make poor breeding animals. (I did attempt to rectify this in a later follow-up, but there was a site malfunction). I won't try to recreate it now, but instead say that our present understanding of genetics (sans the genome "map") does offer clues on how such a circumstance could be possible, and that such analysis could prove beneficial for breeders and buyers alike.

Cassandra.Says:

You have once again spoken in circles, and misconceptions. Also, veterinarians will tell you that foal birth size shows no correlation to size of (mating) stallion.

re: Is Silverbulletday Skipping a Generation?

big john t — Tue, 02 Apr 2013 03:28:49 GMT

Pedigree Anne,

You are absolutely correct. There are other variables too numerous to mention when breeding, raising, training and racing a thoroughbred which make all of these "theories" impossible (although very interesting) to prove.

re: Is Silverbulletday Skipping a Generation?

Cassandra.Says — Sun, 31 Mar 2013 16:06:21 GMT

I agree with the recommendation for browsing produce records especially because if teaches how little genetics has to do with it.

Over and over and over in the best of families and the rest of families, produce records show mares producing top quality foals for their first five and unraced or unraced foals for their last five.

This phenomenon has ended in this century; old mares are producing stakes horses in unprecedented numbers. I haven't been in to many barns or breeding sheds lately (does it have a ramp?) but I'm wondering if the sudden proliferation of ridglings has anything to do with modern hormonal manipulation of mares.

re: Is Silverbulletday Skipping a Generation?

Cassandra.Says — Sun, 31 Mar 2013 15:51:58 GMT

Apart from misstating the odds ("should" have a certain percentage of genes) does this discussion not overlook the obvious. Silverbulletday is tiny. Dystocia is the first thing I'd look into if her progeny fail to make racing. (I've always wondered if Secretariat's daughters might not have an edge over his sons because they have broad, roomy Andalusian pelvises: the proverbial behind of a cook.)

There has also been a marked tardiness in naming the foals in this family. Perhaps mating them to a giant stallion is iffy.

re: Is Silverbulletday Skipping a Generation?

sceptre — Sat, 30 Mar 2013 02:53:20 GMT

Hi Byron,

That's a good point, your mention of Devil's Bag/Saint Ballado. Perhaps similar to Rhythm/Not For Love, and one of Alan's favorite examples, Viceregal/Vice Regent. Your Devil's Bag/Saint Ballado is, though, probably the best example to illustrate your point/query, as both full siblings displayed a relatively high order of phenotypic prowess-Devil's Bag being far the superior. Yet, despite far less opportunity early on, Saint Ballado proved clearly the better sire. How can this occur, and does it lend evidence to refute some of our hypothetical genetic mechanisms? I don't think so. Yes, part of the answer (reason) could be that Saint Ballado fortuitously possessed a far greater nummber of + hymozygous performance alleles. As we attempt this exercise it must be kept in mind that we're comparing full siblings who BOTH demonstrated great phenotypic ability. So, to avoid any misunderstanding or tangential arguments, let's instead substitute the Devil's Bag/Saint Ballado for a hypothetical male sibling pair that evidenced identical elite racing prowess, but where one became a superior sire, while the other proved to be a flop. I'd maintain that this result could occur, and that the abovementioned homozygosity disparity could contribute to its cause. But, I think there are likely many other potential genetic causes for such a circumstance, the clusters/loci notion one among them. I think it's important to consider that great racehorses can be great due to differing genetic "configurations" and/or "makeups". While they may cause the same level of phenotypic excellence, those genetic differences can lead to disparate siring, etc. results. Using the cluster/loci notion as a start, one full-sibling might owe a reasonable degree of his racing prowess to a few fortuitous groups of gene clusters (that may code for a group of particularly desirable rarer proteins that very harmoniously function together which contribute greatly to phenotypic racing excellence), whereas the other full-sibling may not possess this, but instead possesses (even full siblings possess in their genomes many differing alleles) an exceedingly large number of relatively more common and somewhat + allelic sub-types (perhaps held more heterozygositly ?), essentially "unclustered", that by chance produce an assortment of proteins (throughout his genome) that just happen to harmoniously cause a phenotypic masterpiece. In these extreme examples I've attempted to allude to several mechanisms, and one might deduce from this how the former example might well tend to lead to greater siring ability than the latter. Notice, for one, that in the latter example it required almost this "perfect genetic storm"-the whole- for this horse to be a great. He is incapable to transmit it to the next generation in its entirety. One can see that in the former example it would be far more possible to transmit to the next generation much of the (genetic) cause for his greatness. As said, these are exaggerated examples, and there are many other mechanisms, but it may illuminate the point. Allow me to close by mentioning another likely phenonmenon: I think it's quite possible that a relatively few extremely positive (perhaps very rare) allelic variants can, all else equal, play a major role in high quality racing ability. I see evidence for this in influences such as Foggy Note. Should this be correct, it is yet a different angle then the ones I mentioned, and one, perhaps, more ammenable to "control".

re: Is Silverbulletday Skipping a Generation?

Byron Rogers — Fri, 29 Mar 2013 19:16:32 GMT

Sceptre,

Fundamentally I agree with your hypothesis re: homozygosity of positive alleles. I also appreciate your concept of clusters/loci of positive selection. That is sort of getting towards the Devil's Bag/Saint Ballado question...talent aside (and there is evidence to suggest Saint Ballado was talented, just had issues) why was one such a more superior sire? Is it because Saint Ballado had a higher percentage of homozygous performance alleles?

On the project we are looking at now that I had referred to, we are looking at both half and full relations. The stunningly obvious first notable comment is how few times a mating to a champion is repeated!

re: Is Silverbulletday Skipping a Generation?

sceptre — Fri, 29 Mar 2013 15:27:52 GMT

John T:

Either you have failed to properly comprehend what you quoted (my statement), my statement was written unclearly, or you chose to be sarcastic. So, to clarify for others, John T's Mumtaz Mahal examples are examples which squarely counter my point. As John T. lists, Mumtaz Mahal's daughter's were not successful runners, but became highly influential producers, as did many of their descendants. Trust me, though, I was well aware of the Mumtaz Mahal history, and that of many others, when I offered my remarks. But, it's all about perspective-how versed one is about the TOTAL/COMPLETE picture-the amount of representative examples accumulated in their personal memory "data base" through time and then integrated properly. Too many of us tend to focus on the successes and/or haven't had the time, the years, or desire to become acquainted with enough of the vast history of the sport. They jump to false conclusions based upon insufficient data. Nothing new here, it happens throughout all disciplines. That's why I suggested some time spent perusing The American Produce Records. Brisnet recently offered it on-line free for a month+. Perhaps next year they'll repeat the courtesy.

re: Is Silverbulletday Skipping a Generation?

sceptre — Fri, 29 Mar 2013 04:02:58 GMT

Hi Byron,

Just noticed your post. As you well know, full siblings and offsping (of the full sibling in question) share, ON AVERAGE, the same NUMBER of identical genes (of the full sibling in question). So for openers, I wouldn't bother investigating the half-siblings. I suppose you could attempt to resolve this through mere historical research/statistical computation of the data, but I doubt you'll get your answer. The answer likely lies in the recognition of the true, fundamental genetic mechanisms and applying them analytically. So, do we yet know, let alone universally accept, enough of these mechanisms to feel it would be reasonably fruitful to take the next step? Well, if you take a look at my last post to Alan, you'll notice that even he and I, perhaps, differ on aspects of cause/effect. You could also try several widely accepted, yet differing "mechanisms" and may perhaps find that all yield the same answer to your question. Off the top of my head, I'd say that if the "clusters" play a large part, all else equal, the daughter would be preferable to the full-sibling. A somewhat separate question, which might lead to a different result, would be a comparative of full siblings vs offspring (of the full sibling in question) to a "blue-hen" producing mare (rather than a GI winning mare).

re: Is Silverbulletday Skipping a Generation?

John T — Fri, 29 Mar 2013 04:01:59 GMT

Sceptre

You make the statement ''My message was that their daughters as a whole are far less reliable as producers than many might expect''

In a sense you are right take for example the case of the brillance of Mumtaz Mahal. Her offspring paticulary her fillies were very disappointing,but when her daughters retired to stud it was a very different story. Mah Mahal bred the 1936 Epsom Derby winner Mahmoud who after a brief period at stud in England was sold to America were he did extremly well. A daughter of Mah Mahal, Rose O'Lynn was the dam of Buisson Ardent who won the Middle Park Stakes , St James Palace Stakes and the Sussex Stakes. One of Mah Mahal's daughters Mah Iran was the dam of the Arc winner Migoli who went on to sire the Belmont winner Gallant Man. Mah Iran's daughter Star Of Iran bred Petite Etoile who won the 1000 Guineas , Epsom Oaks, Sussex Stakes, Champion Stakes, and Coronation Cup twice. Mumtaz Begum bred eight winners but by far the most important was Nasrullah. His English Classic winners were Never Say Die, Epsom Derby and St. Leger, Musidora, 1000 Guineas and Epsom Oaks, Nearula, 2000 Guineas, Belle Of All, 1000 Guineas and a very fast sprinter called Grey Sovereign. Exported to America Nasrullah went on to sire Nashua and Bold Ruler who both went on to sire the who's who of North American racing. So although the daughters of Mumtaz Mahal let the family down immensely on the racetrack it is chiefly through them that Mumtaz Mahal has exercised great influnce on bloodstock breeding throughout the world. So without a doubt it is very much a case of ''Skipping A Generation'' Even if most people do not see it that way.

re: Is Silverbulletday Skipping a Generation?

sceptre — Fri, 29 Mar 2013 03:11:33 GMT

Hi Alan,

Thank you, very much, for the clear, well thought out, and extremely well written reply. As a small aside, I was particularly taken with your choice of the word, "apparency", one that wouldn't have occurred to me, but rather ideal.

Your work load, no doubt, leaves far less time than this retiree's, so don't feel obliged to again respond. Readers here should be aware of this, and not assume that Alan concurs with this follow-up (which I doubt he does) should he remain silent.

Alan, it appears we may differ on how we hypothesize some fundamental genetic "mechanisms" (perhaps not the best choice of word). Alternatively, we may be in agreement, and I have simply misinterpreted your language due to its necessary brevity. I first call attention to your phrases, "inhibition to expression" and "possession and expression of genes...". It appears (but I could be mistaken) that you are alluding to a genetic "turn-on", "turn-off" mechanism which has been mentioned in the literature. Your apparent somewhat high expectations for my hypothetical daughters of a female Vindication twin-here, we disagree-, and your full second to last paragraph, citing particularly its second into third sentences in which you list the "excuses", reinforce my suspicion that we view the mechanism differently...Allow me to offer my mechanistic hypothesis for this topic.- Using a Silverbulletday, a Silver Charm, a Skip Away-type, etc, those reasonably well-bred types who performed at a high level, but failed to succeed as breeding horses. Yes, they must have indeed possessed a relatively high number of positive genetic variants, or an extremely high number of a bit less positive variants, or a high, but somewhat less high number of extremely positive variants, or other combinations of the above; and/or perhaps, also, a relatively low number of negative genetic variants and/or any combination of the above. But, as you note, their offspring inherit only 50% of this genetic makeup. I suggest that the variation in positive gene "clusters"/linkages, and the variation in degree of positive homozyosity from one high class individual to another is far more causative of the variation in later "breeding" success. The homozygosity component becomes a non-issue re-the "breeding" potentialities of the next generation. The + gene clusters, etc. can, however, continue to come into play, as can the variation in the specific "mix" of +, somewhat less +, less -s, etc. possessed by their parents, and inherited in part by their sons and daughters, and the variations in type of mix may very well have significance... Some inherit, in their 50%, a higher degree of the better, some otherwise, but what isn't inherited, isn't inherited, and thus can't be transmitted to the next generation. There's more to this "mechanism" and, more importantly, the probability analysis, but I'll leave it here. I'm not suggesting that there aren't other more discrete mechanisms at play, perhaps even some "turn-on"/"turn-off" varieties, but it's quite possible that the mechanism I discused here is the major player. Should this be the case, it's far less likely that a genetic twin female of a Vindication would produce daughters capable of highly successful production, or that we would harbor high hopes for daughters as producers who were produced from high class performers whose produce was of little merit.

re: Is Silverbulletday Skipping a Generation?

Byron Rogers — Thu, 28 Mar 2013 22:20:15 GMT

Sceptre,

You have alluded to an interesting question which we are currently researching the answer to.....

Is it better to own the unraced daughter of a G1 winning mare, or an unraced half or full sister to a G1 winner?

Is there a market misallocation where the unraced daughters of G1 winners are more highly prized than the unraced half/full sisters?

re: Is Silverbulletday Skipping a Generation?

Alan Porter — Thu, 28 Mar 2013 18:09:04 GMT

Hi Sceptre,

The term "generation skip" is probably a bit of a misnomer in terms of what's really happening, although it describes the apparency pretty well.

Obviously, Silverbulletday's daughters should (assuming, for simplicity's sake, a straightforward Mendelian inheritance) inherit somewhere around 50% of the positive genetic variants possessed by Silverbulletday). Similarly, they will also inherit around 50% of the genetic make-up of their sires (in this case Storm Cat and Vindication).

Historical experience tells us that possession and expression of genes are two very different things. We only have to look at the number of very good racehorses (clearly possessed of a good set of positive genetic variants for athletic ability), who become very bad sires (apparently unable to consistently transmit those variants in a form that is expressed in their offspring). If we just assume for the moment that Silverbulletday is the female equivalent of such a stallion, then perhaps her daughters are receiving some of her genetic "goodies" (as well as some from their sires), but without the same inhibition to expression in their own offspring.

On that basis, I would have similar expectations of the daughters of a hypothetical "genetic twin" sister to Vindication who was a Champion Two-Year-Old Filly, but a disappointing broodmare.

Of course, the limited opportunities that a mare has, compared to a sire, makes it harder to know whether she is the female equivalent of the "great runner/bad sire" or has been incorrectly mated, or is just plain unlucky. Similarly, the ratio of stallions to mares ensures that lots of modestly-performed daughters of very good racemares that disappointed as producers have their chance at stud.

Conversely, you can scour the ranks of major Kentucky farms without finding a moderately performed son of a great runner who was a bad sire. Were we to need 40 stallions for every mare, it wouldn't surprise me if, for example, an ability challenged son of Vindication and a top-class mare, turned out to be a good sire.

re: Is Silverbulletday Skipping a Generation?

sceptre — Thu, 28 Mar 2013 17:23:24 GMT

Pedigree Ann:

I'm aware of those you mentioned, as well as many more, such as Fall Aspen, Terlingua, etc., etc. There's no question that the better performers, the better bred, or both, tend to be the better producer. I'm sure you agree. My message was that their daughters, as a whole, are far less reliable as producers than many might expect. Yes, as a group they are "better", but not sufficiently better to warrant their inflated expectations, or prices. I also feel that the cause is less due to improper matings, but rather the relative disparity of genetic material mother vs daughter. My advice to buyers: the "paper" does count, but be very mindful of racing ability (not just the pps) and physical. Otherwise, you may end up with "paper", and little else.

re: Is Silverbulletday Skipping a Generation?

Pedigree Ann — Thu, 28 Mar 2013 15:27:02 GMT

Dahlia, who won 10 G1s (plus the G2 Canadian International) in 5 different countries produced 4 G1 winners, plus a G2 winner who was G1-placed, another G2 winner, and a G1-placed winner.

Champion sprinter Affectionately produced Horse of the Year (in one poll, before Eclipse awards) Personality. Her half-sister Priceless Gem beat Buckpasser to win the Futurity and foaled Allez France; a full sister to PG, Admiring, won a G1-type race and foaled Diana H winner Glowing Tribute, who herself produced 7 SWs, including Ky Derby Sea Hero. The dam of Affectionately, Priceless Gem and Admiring, Searching, won 12 stakes races in 89 starts.

Champion older mare Relaxing (third to John Henry in the Jockey Club Gold Cup) produced Easy Goer and G1 winning sprinter Cadillacing.

Champion sprinter My Juliet produced G1 winners Tis Juliet and Stella Madrid.

Champion 2yo filly and Horse of the Year (in one poll) Moccasin foaled 7 SWs, including G1 winner Appalachee.

Canadian Horse of the year and US champion 3yo filly (in one poll) Fanfreluche produced 5 SWs, including 3 Canadian champions.

Some outstanding racemares produce further excellent SWs and champions, while others don't - that is the only thing that we can conclude. It may have to do with how their mates are chosen; blindly sending 'the best to the best,' while ignoring issues of conformation, temperament, etc., may not result in a useful racing animal.

re: Is Silverbulletday Skipping a Generation?

John T — Thu, 28 Mar 2013 02:37:34 GMT

Pretty Polly was barren for her first two years and after that she slipped twins to the Epsom Derby winner Spearmint.

But from 1911 to 1920 with the exception of 1917 she had a foal regulary. Although she herself only bred four winners her stud reputation was ensured through the many successes won by later descendants. So although we can have this so called ''Missed Generation'' In the long run it can be very rewarding.

re: Is Silverbulletday Skipping a Generation?

sceptre — Thu, 28 Mar 2013 02:15:31 GMT

Yes, Ian & mz, Bayakoa may be another example of the Silverbulletday theme. But, there are far more examples to the contrary. Just off the top of my head, take a look at Gallant Bloom and Tosmah. Both were better runners than Silverbulletday, and Tosmah was clearly far better bred. Neither produced much, as did their daughters as well. The great and magnificently bred, Allez France, failed as a producer, and only one of her daughters produced much of note... For me, the real eye-opener is the failure rate (as producers) of daughters out of top producing mares, many of whom (the mares) were also top racehorses. Just leaf through the American Produce Records to get a taste of what I mean.

re: Is Silverbulletday Skipping a Generation?

carrie — Wed, 27 Mar 2013 22:23:48 GMT

my thoughts are this. Foals out of supermares for the most part are treated differently. They are raised in cotton wool... they are kept separate with one buddy and not treated as a herd animal because they are too valuable. In my mind, the next generation is not so valuable so the progeny of these horses are raised more like runners, in big groups and out to fend for themselves and learn to be tough and sound. This is my own particular observation as a breeder.

re: Is Silverbulletday Skipping a Generation?

Ian Tapp — Wed, 27 Mar 2013 21:23:44 GMT

Good one, mz...

Fort Larned is a perfect example.

re: Is Silverbulletday Skipping a Generation?

mz — Wed, 27 Mar 2013 21:07:46 GMT

Bayakoa?

re: Is Silverbulletday Skipping a Generation?

sceptre — Wed, 27 Mar 2013 20:48:22 GMT

Hi Alan,

I've never much cared for the term "generation skip", because it can mislead some to assume a genetic mechanism that probably doesn't exist. For now, I'll dispense with the tedious discussion-instead, hand it over to you-, and simply ask: What if we exchange a genetically duplicate (but for the x/y) Vindicaton female version for Silverbulletday-with the 20/20 hindsight of knowing what was the siring performance of (the male) Vindication. Now, what if this female Vindication had a similar produce record to that of Silverbulletday (just her immediate produce). Would you have similar (to Silverbulletday) expectations for her (female Vindication) descendants down the line?