by Michael Ventura, copyright August 6^th, 2005.

In the July 14th issue of the British Racing Magazine the Racing Post, a Writer named Tony Morris wrote a very interesting and provocatively titled article entitled “Toying with Names Deep in Pedigrees Is Strictly for the Birds”.  Partly on account of his quoting and paraphrasing certain members of a private internet discussion group to whom Morris and I belong, and partly on account of his efforts to impute futility to the sort of pedigree analysis favored by many members of said discussion group, a great deal of criticism was leveled at the article by the group members.

To defend his views Tony Morris then posted a response to the criticism that included the following passage:

“We don’t yet have a way of expressing relationships meaningfully, and until the geneticists can tell us – and they well might before too long – that certain sequences of DNA appear in the good horses, and not in the bad horses, by a certain stallion, the dogma some of you express can hardly be any more reliable than my best guess”

Here Tony has posited a fascinating route of possible inquiry for Scientists studying the Thoroughbred race horse (or for that matter any Animal bred for performance where the male sires a great many offspring).

Still, I see no silver bullet in Geneticists telling us which genes in Stallion A show up in his best offspring and which don't.  Think of it this way: It is completely out of human hands which sperm gets there first as long as A.I. remains illegal.

The real value I do see in this sort of research is that the results could very well be used to determine the answer to the fundamental question that follows:  "What is the primary reason for quality variation between full siblings?  Is it the Quality of the Genes got from the Sire and Dam or is it rather the compatibility of the Genes got from the Sire and Dam?" 

If it's strictly a quality issue we'd see GIWs by Sadlers Wells with the same Genetic Sequences inherited from the sire regardless of the dam or the bloodlines of the dam.  If on the other hand epitasis (essentially the effect of a gene on the expression of other genes) is of primary importance we'd see more or less the full scope of Sadlers Wells' genotype in his best offspring and where there was a unusually high rate of overlap in top class offspring they'd more often than not be top class offspring who shared dams or bloodlines with each other.

If the Quality of the genes are of paramount importance then the most important things in breeding are these two things:

1. What is The Quality of the Sire and Dam's Genetic Material? (This answer is usually best answered by how their offspring have done; though mares do produce so few foals that you will also have to give a great weight to how she's bred and the race record).

2. Whether the Gamete (also know as a Sperm or Egg) gets mostly the good chromosomes or mostly the bad chromosomes.  This is considered Pure Chance, as Tony Morris is fond of pointing out, but I still must note my theory that Sperms with certain genes might be more likely to get to the Egg ahead of their brethren.  Still, this is mostly out of human hands regardless of my theory's validity.

IF (and that's a big if), the quality of the genes are all-important, then I'll unhappily admit that all else in pedigree analysis save the above two points is the merest vanity.

However, there is a strong level of evidence form Science that the quality of Genes ARE NOT all-important in determining fitness and vitality.  In fact, if you look up the letter “I” in a comprehensive dictionary you’ll find the phrase “Inbreeding Depression”.  This phrase signifies the widely held scientific belief that too much inbreeding is bad for the vitality of a being.  This belief of Scientists is backed up strongly by the simple fact that multitudinous species try to avoid excessive inbreeding through a mechanism called “Incest Avoidance”.

Now try looking up "O", you'll find a nice little phrase called "Outbreeding Depression".  This concept is now also accepted by Scientists in spite of some initial resistance and signifies that too much outcrossing is considered bad to the vitality of a being. This belief of Scientists is strongly backed by the fact that the males and females of many species tend to prefer potential mates possessing similar as opposed to asimilar physical features (these physical features of course often being linked to particular Genetic Patterns).

So we find both that Scientists believe in the detrimental effects of both Inbreeding and Outbreeding Depression, and moreover we find a strong tendency on the part of living beings to avoid both when possible.  These two facts corroborate each other strongly in the same way that a Scientist’s belief in a certain Plant being poisonous could be corroborated by Herbivores instinctually avoiding the eating of said Plant.

Actually, most laymen have a common sense understanding of Inbreeding and Outbreeding Depression.  For instance, an extreme example of inbreeding depression would be to breed a brother to a sister and most people would not expect a very good result from doing that even if they had little or no knowledge of genetics. 

And for another instance, an extreme example of Outbreeding Depression would be to breed members from two different species, and most people would not expect a very good result from that either.  In fact by the strictest definition of a species, at best you'd still get a creature so undermined by outbreeding depression that it wouldn't even be able to reproduce.  In other words, it is not without reason that the members of a species will avoid breeding with the members of a similar (but different) species.  In fact, many “species” are only considered so by virtue of their members' avoidance of interbreeding with another, essentially similar, species where their ranges overlap.

To understand the mechanism behind Outbreeding Depression we have to understand that Genes are like Words: While they clearly possess some independent meaning, the complex processes of life require the interaction of many genes to create a truly significant mechanism.  Thus it is only up to a certain point that we may speak of “Good” and “Bad” Genes as a Gene may work beautifully with certain other Genes and wretchedly with others in the same way that the same word may appear both in beautifully expressed sentences and incomprehensible drivel (in the both cases the context is the key to the difference).

Thus while the Genes in a Champion Standardbred Stallion may be proven to work wonderfully in the context of other Standardbred Genes, those very same Genes may be extremely bad in the context of Thoroughbred Genes. Still, what often happens with less intense forms of Outbreeding is that the beneficial gene combinations found in a sub-population remain intact long enough after the outcrossing begins that Outbreeding Depression takes a little while to commence it’s negative effects.

Perhaps this may explain the “Outcross One Generation and then Inbreed the Next” doctrine of horse breeding as in this way you may reduce the negative effects of Inbreeding Depression with the initial Outcross and then shut the door to Outbreeding Depression by Inbreeding before it has time to get in. 

Also, another way to try and create balance between inbreeding and outcrossing is to effect a “Modified Hybrid”.  A very good example of such a thing is A.P. Indy, whose sire Seattle Slew is inbred 4x4 to Nasrullah and whose dam Weekend Surprise is inbred 2x4 to Somethingroyal (thus making him a hybrid as his sire and dam are inbred to two different strains); and who is himself inbred 3x4 to Bold Ruler, a son of Nasrullah.  This makes A.P. Indy a “Modified Hybrid”, who hopefully combined the best of both worlds. 

Inbreeding is that which leads to a zygote having two copies of the same gene: one through the sire and one from the dam.  As far as anyone can tell, the reason for the sire and dam sharing a gene is always that they share a common ancestor from whom they both got it (in other words, the ancestor inbred to is the common source of the doubled gene).

All too many don't seem to comprehend this basic fact and thus they incorrectly speak of a horse being inbred to an ancestor only found on one side of the pedigree.

But let me explain why inbreeding is so important…  Imagine you’re in a Company where every department has two people in charge of it.  It’s not hard to imagine that the influence of any Department Head would be modified and diluted in a big-time way by the other head of the department.

But now imagine that one of the department heads managed to swing it so that his identical twin brother became his Co-Department Head; it goes without saying that his influence on the department would be greatly increased in the same way that you’ll hear a Man’s Singing louder and clearer if the other fellow he’s singing with is singing the same song as opposed to a different one.

In the exact same way, whatever job a gene has to do it has to do with another gene (one gene coming from the father and another from the mother).  But with inbreeding, the resultant doubled genes no longer has their influence diluted and modified by the presence of a different gene on the same loci.  This can be very good, and this can be very bad…  Thus who is being inbred to must be given great weight and the source should also be given equal if not greater weight.

It is quite possible for inbreeding to Ancestor A to work when Ancestor A comes through his son Zolton and his other son Plantus but not to work when he comes through Zolton and his daughter Henton or through Plantus and his other son Latlan.  The reason??  It could very well be that Zolton and Plantus inherited the same Beneficial Genes from their sire and different negative ones.

Thus, even though Zolton and Plantus got bad genes from the same source (their father) crossing them in a pedigree would not result in the doubling of negative genes as they inherited different bad ones.  In the same way, crossing them would result in the doubling of good genes as they did inherit the same good ones.

But then when you tried crossing Zolton and another high quality source of his father it could be that that other source got different good genes than Zolton from his father that made him successful and perhaps even the same bad ones.

For this reason it is fruitful to check SPECIFIC modes of inbreeding.  Also, the stronger the sequence of ancestors leading back to the ancestor we’re inbreeding to the better it’ll be in general as then the bad genes of the ancestor will have “Filtered” through the strong ancestors (I say this as strong ancestors in all likelihood have less bad genes to worry about doubling and more good genes to hope get doubled).

I strongly suspect that Danehill only got the good genes from his ancestor Petition and thus even if he sees a dam descended of Petition who got bad genes from him, the resultant foal will have no particularly ill effects as the bad Petition genes in the dam were nowhere to be found in Danehill. 

Perhaps this can help explain the incredibly positive results that have come from breeding Danehill and even his sons to mares returning him that key strain (Petition).

But back to Tony Morris’ original article, in it he noted wrote: “Danehill certainly has Natalma twice in his third generation, but, equally certainly, he did not get the same complement of genes from her son and daughter. Natalma 3 x 3 does not mean what those who merely recognize duplication would like it to mean.”

But it does mean what I want it to mean; namely that in all likelihood certain Natalma genes are going to be doubled in Danehill.  Which ones are determined by these two factors:

1. The source of Natalma (by which I mean not merely which son or daughters she comes through but rather the entire sequence of descendants leading to Danehill).

2. Which Conjunction of Sperm from Danehill and Egg from Razyana produced Danehill.

Whether for good or ill, this doubling MATTERS.  Figuring if it's for good or ill is a question probably best answered by an analysis of:

1. All the foals inbred to Natalma and how many are GIWs, GSWs, SWs, etc.

2. All the foals inbred to Natalma through Northern Dancer and another strain.

3. All the foals inbred to Natalma through Spring Adieu and another strain.

4. All the foals inbred to Natalma through Northern Dancer and Spring Adieu.

5. All the foals inbred to Natalma through Danzig and another strain.

6. All the foals inbred to Natalma through Razyana and another strain.

7. All the foals inbred to Natalma through Danzig and Spring Adieu.

8. All the foals inbred to Natalma through Razyana and Northern Dancer.

9. All the foals inbred to Natalma through Danzig and Razyana.

All Nine of these populations are highly relevant to an analysis of Danehill's 3x3 inbreeding to Natalma.  The closer we get to 1, the bigger a sample we get.  The closer we get to 9, the more sure we can be that the Natalma genes given to (and perhaps doubled in) the non-Danehill foals include a high proportion of the same Natalma genes got by Danehill. 

Thus the success or failure of the above nine populations can help us determine through the Unassailably Scientific Discipline of Statistics whether or not the Natalma is playing a causative role in Danehill's tremendous success or not.  It should be noted though, that all serious livestock breeders outside the Thoroughbred Arena agree that a more inbred Animal will breed truer and I can't help but think that that would help a Stallion.

Of course, in Statistics you always need to adjust for variables and sometimes that's a bit more easily said than done... 

For instance, if we look up Danzig sons and daughters who returned him Natalma (Returns of Natalma of course being distinct from returns of Northern Dancer) and found a very high rate of Stakes Winners and GI Winners for the breed that would not be the relevant thing; the relevant thing is whether Danzig sons and daughters had a good percentage of SWs and GIWs relative to the other Danzig foals (thus we control for the positive variable of being by Danzig).

Another possible benefit of inbreeding is that it may (with the emphasize on May) lead to the reuniting of Chromosomes and Genes from a superior ancestor in the inbred foal.  Since said Chromosomes and/or Genes worked out good in the superior ancestor it is may be said that they were selected for the quality of most likely crossing better together than two Chromosomes chosen at random.

To what extent this works in the Real World is debatable, but the principle is yet of great import if only because it suggests a special strategy of inbreeding whence two strains are inbred to each other through successful examples of the cross. 

For instance, one could take a mare named Fairy Bridge, an English Highweight at two and excellent broodmare (please see Sadlers Wells, Fairy King, and Tate’s Gallery) who crossed the very important stallion Hail To Reason and the very important mare Thong; and cross her with a stallion named Lear Fan, a GI Winner at Two and a far above average sire who crossed Hail To Reason with Thong’s full brother Lt Stevens.  Thus you will have created a situation where the Hail To Reason genes coming through to the foal will be selected for the quality of crossing good with Thong and Lt Stevens and the Thong and Lt Stevens genes will have been selected for the quality of crossing good with Hail To Reason (talk about synergy!).

And as a matter of fact, out of only 47 examples of crossing Lear Fan and Fairy Bridge born after 2002 in the PedigreeQuery Database (and out of these fully 11 were in fact born in 2002 and thus are only halfway through their 3YO Year), we find the exceptional runner Kitten’s Joy, the winner of the Joe Hirsch Invitational (GI), Secretariat Stakes (GI), Virginia Derby (G3), Tropical Park Derby (G3), Crown Royal American Turf (G3), American Turf Stakes (G3), and Palm Beach Stakes (G3) besides finishing second in the 2004 Breeder’s Cup Turf (GI) and winning the Eclipse Award for the said year as the Champion American Turf Performer. 

Also we find the Treble G2W Policy Maker and The Kiddykid, a winner of the Duke of York (GB-G2) and the Greenslands Stakes (IRE-G3), crossing Lear Fan and Fairy Bridge .

While this percentage of Graded/Group Stakes Winners (6.38%) may be lower than Sadlers Wells’ overall figure of 8.00%; it must be noted that a mere 3 of the 48 Fairy Bridge/Lear Fan crosses in the PQ database are by Sadlers Wells and the rest are by stallions who get much lower percentages than he does. 

Given that one would’ve considered the Sadlers Wells/Lear Fan cross as unpromising given their both tending strongly towards stamina, I find this worthy of being accounted a very impressive level of success.  (Mark well that the sire of the best, El Prado, was a Champion 2YO Male in Ireland and that the sire of The Kiddykid was Danetime, who showed far greater speed in his racing career than any other sources of his damsire Lear Fan I know of.)

Please see the Johar section of my Gone West article for a more detailed discussion of this cross and what I consider to be the optimum sources.