Why?
Moderators: Roguelet, hpkingjr, WaveMaster
Why?
My mares granddam produced a filly named Ecstacizm. She didn't do much, but produced Tasso, a Grade 1-2 winner of over a mil., by What A Pleasure. They bred this mare 5 X to What A Pleasure and never duplicated Tasso. What happened?
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Intrinsic Worth
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Actually, Ecstacism produced 6 foals, four of which were by Fappiano. The first of her Fappiano foals was champion 2yo Tasso. The other three were non-winners, although Desse Zeeny was placed and had some decent speed figures. Neither of Tasso's full sisters cut any figure as broodmares.
Mares produce so few foals in a lifetime compared to stallions that I'd have to say that any mare that manages to produce a G1 winner has done something pretty special, even if she never puts out anything else worth mentioning.
Mares produce so few foals in a lifetime compared to stallions that I'd have to say that any mare that manages to produce a G1 winner has done something pretty special, even if she never puts out anything else worth mentioning.
"A man who was merely a man and said the sort of things Jesus said would not be a great moral teacher...You must make your choice. Either this man was, and is, the Son of God: or else a madman or something worse." C. S. Lewis
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chiggins6
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I like what Mahubah says, and, I always have to remind myself that so much can happen in a horse's carreer to - I was going to say sabotage - but to throw him/her off the winning track, that is really hard to say "duplicate" very well, its so much more than the breeding that makes a winner, isn't it? The trainer, the personaliities, the handlers, the injuries or lack of them, the pace of the training, etc. More than the breeding needs to be duplicated.
Who is to say that any of the full siblings truly "duplicated", the horse which had success?
Who is to say that any of the full siblings truly "duplicated", the horse which had success?
Where am I going and why am I in this handbasket!
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louis finochio
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You can breed Somethingroyal, by Princequillo many times to Bold Ruler, and mother nature will only give you one Secretariat. You may get other foals from this mating that will be quality TB but you will only get one Secretariat. This is the way it is in the breeding shed. Why does this happen, is something I'll ask god when I leave this earth and go to heaven.
Those without sin cast the first stone.
Louis Finochio
Louis Finochio
I don't know why this surprises people so much... I mean think about how many families you know with children (who are not twins) How many brothers and sisters do you know who are replicas of eachother? I mean, there might be similarities, but you really don't see the same kid over and over again. There are just so many genes and so many ways that they can split and combine... to me it would be much more amazing if a horse WAS duplicated!
In many ways, the answer is quite simple, and I will try to explain.......
Horses have 32 pairs of chromosomes - including the XX or XY sex determination pair. The non-sex chromosomes (31 pairs in horses, 22 pairs in humans) are termed autosomes.
During sperm or egg development, meiotic (as opposed to mitotic) cell division results in the generation of sex cells that contain only 1 of each pair of the chromosomes in the genome of that individual. For example, a single Sadlers Wells sperm will contain 32 chromosomes (not 32 pairs). Some of those chromosomes will have come from Northern Dancer, the others from Fairy Bridge. Which chromosomes came from which parent in any given sperm occurs randomly during cell division. For example, if the sperm is a "male" that means the sex chromosome came from Northern Dancer (in this case a Y chromosome), and the sperm obviously has no X chromosome. Whether a sperm is male or female is random. This means that most sperm are genetically different. For example, all of the chromosomes in one individual sperm might have come from Northern Dancer, while the next one might have chromosomes 11 and 12 from Fairy Bridge....... Therefore, there are potentially 2 to the power of 32 [(2x2x2x2x2x2.....and so on...32 times) which equals 4,294,967,296] different combinations of parental chromosomes in the sperm of a horse. And this estimate of genetic diversity doesn't even begin to address genetic variations that arise as a result of the myriad recombination or mutation events that can occur.
So, the sperm involved in the fusion is almost certainly not genetically the same, in each breeding of the same 2 horses. And all of the above is true in the female egg also!
As Roguelet asked, how similar are human siblings? In some cases, not very much at all. Siblings have different combinations of chromosomes from each of their parents.
Another thing that contributes to failure to reproduce an equine athlete by breeding the same stallion to the same dam, is that the characteristics we are trying to select for, ie. speed, soundness, stamina etc., are multi-gene traits. [Not to mention - these traits are also heavily heavily influenced by environment]. They're not like some well characterised horrific genetic abnormalities like cystic fibrosis which is a mutation in a single gene, or Downs' syndrome which is triplication of a single specific chromosome. Presumably, racing ability is a function of many many enzymes and other proteins working in concert to facilitate oxygen exchange and transport, strength and metabolism etc. Presumably, also, the many genes which encode for these vital proteins are scattered throughout the genome on several different chromosomes. This then means that heritability of these traits is extremely complicated and far less likely to occur linearly through generations than it would be were all of the necessary gene(s) on a single chromosome. It is (presumably) the combination of the different genes, and how these genes impact each other (epistasis) that is important and what creates the freakishly talented individual once in a blue moon (Secretariat). Because of all of the variabilities that can arise in sex cell development as explained above, the chances of 2 full sibs being genetically identical are negligible. Furthermore, the chances of them being similar enough to have a similar genetic predilection for racing ability are also somewhat slim. This variability in genetic makeup between indivduals can be part of the reason why one full sib fails to break his maiden, while another wins G1s.
Geneticists (which I am not) have strived to estimate the "heritability" of speed in racehorses. As far as I am aware, the best estimate is about 0.25 to 0.3. Meaning that speed is about 25-30% heritable. The rest of the racehorse's ability comes from conformation, durability, training, luck etc. I am a little hazy on that last stat and I must check that my interpretation is correct, but suffice it to say that speed is estimated to be a lot less heritable than other traits, such as milk production in cattle, or bone density.
I hope this sheds some light on the question of repeat breeding with little success. The permutations and combinations of genetics are staggering, and the chances of exact replication proportionally tiny.
I don't want to appear as though breeding is all "luck" either. There is a science to it, and many people have had great success. But you absolutely cannot take the genetic component for granted.
Horses have 32 pairs of chromosomes - including the XX or XY sex determination pair. The non-sex chromosomes (31 pairs in horses, 22 pairs in humans) are termed autosomes.
During sperm or egg development, meiotic (as opposed to mitotic) cell division results in the generation of sex cells that contain only 1 of each pair of the chromosomes in the genome of that individual. For example, a single Sadlers Wells sperm will contain 32 chromosomes (not 32 pairs). Some of those chromosomes will have come from Northern Dancer, the others from Fairy Bridge. Which chromosomes came from which parent in any given sperm occurs randomly during cell division. For example, if the sperm is a "male" that means the sex chromosome came from Northern Dancer (in this case a Y chromosome), and the sperm obviously has no X chromosome. Whether a sperm is male or female is random. This means that most sperm are genetically different. For example, all of the chromosomes in one individual sperm might have come from Northern Dancer, while the next one might have chromosomes 11 and 12 from Fairy Bridge....... Therefore, there are potentially 2 to the power of 32 [(2x2x2x2x2x2.....and so on...32 times) which equals 4,294,967,296] different combinations of parental chromosomes in the sperm of a horse. And this estimate of genetic diversity doesn't even begin to address genetic variations that arise as a result of the myriad recombination or mutation events that can occur.
So, the sperm involved in the fusion is almost certainly not genetically the same, in each breeding of the same 2 horses. And all of the above is true in the female egg also!
As Roguelet asked, how similar are human siblings? In some cases, not very much at all. Siblings have different combinations of chromosomes from each of their parents.
Another thing that contributes to failure to reproduce an equine athlete by breeding the same stallion to the same dam, is that the characteristics we are trying to select for, ie. speed, soundness, stamina etc., are multi-gene traits. [Not to mention - these traits are also heavily heavily influenced by environment]. They're not like some well characterised horrific genetic abnormalities like cystic fibrosis which is a mutation in a single gene, or Downs' syndrome which is triplication of a single specific chromosome. Presumably, racing ability is a function of many many enzymes and other proteins working in concert to facilitate oxygen exchange and transport, strength and metabolism etc. Presumably, also, the many genes which encode for these vital proteins are scattered throughout the genome on several different chromosomes. This then means that heritability of these traits is extremely complicated and far less likely to occur linearly through generations than it would be were all of the necessary gene(s) on a single chromosome. It is (presumably) the combination of the different genes, and how these genes impact each other (epistasis) that is important and what creates the freakishly talented individual once in a blue moon (Secretariat). Because of all of the variabilities that can arise in sex cell development as explained above, the chances of 2 full sibs being genetically identical are negligible. Furthermore, the chances of them being similar enough to have a similar genetic predilection for racing ability are also somewhat slim. This variability in genetic makeup between indivduals can be part of the reason why one full sib fails to break his maiden, while another wins G1s.
Geneticists (which I am not) have strived to estimate the "heritability" of speed in racehorses. As far as I am aware, the best estimate is about 0.25 to 0.3. Meaning that speed is about 25-30% heritable. The rest of the racehorse's ability comes from conformation, durability, training, luck etc. I am a little hazy on that last stat and I must check that my interpretation is correct, but suffice it to say that speed is estimated to be a lot less heritable than other traits, such as milk production in cattle, or bone density.
I hope this sheds some light on the question of repeat breeding with little success. The permutations and combinations of genetics are staggering, and the chances of exact replication proportionally tiny.
I don't want to appear as though breeding is all "luck" either. There is a science to it, and many people have had great success. But you absolutely cannot take the genetic component for granted.
Johar,
I enjoyed reading your post.
On the same theme here, I recall being at an auction with a friend with a good eye for a horse. I saw that a full brother to a good stakes winner was in the ring and bringing less than what he would appear to be able to bring based on his catalog page. My friend gave me a humorous reply. He said that he would not want to box with Mike Tyson. But maybe my friend would be able to whip Tyson's brother in the ring.
Many times there sure is a big difference between full brothers.
Reviewer
I enjoyed reading your post.
On the same theme here, I recall being at an auction with a friend with a good eye for a horse. I saw that a full brother to a good stakes winner was in the ring and bringing less than what he would appear to be able to bring based on his catalog page. My friend gave me a humorous reply. He said that he would not want to box with Mike Tyson. But maybe my friend would be able to whip Tyson's brother in the ring.
Many times there sure is a big difference between full brothers.
Reviewer
Since approximately 1 % of all runners are graded SWs, it is notable when a mare produces one, much less multiples.
For a different perspective, I look to my other passion which is growing roses. There are alot of similarities between the great rose hybridizers and the great TB breeders and the product is more alike than you would think.
One of the great smashing commercial and aesthetic successes of all time is the Kordes floribunda "Iceberg" released in the 50s. Even if you have zero interest in roses, you've seen it and chances are good you grow one. Home Depot sells it, it's in every municipal garden, Hollywood Park has a lovely stand of them near the Gold Cup wall.
Iceberg, a white rose, was bred from two very obscure parents, Red Robin (red) and Virgo (white blend). It took thousands of crosses (seedlings) before Kordes bred Iceberg and afterwards other breeders tried their own hand using these two relatively new influences but no one had any further success. Even Kordes didn't but his creation Iceberg went onto be a very successful parent in a lot of different breeding programs.
A major hybridizer, Weeks Roses, breeds and raises 100,000 seedlings a year to come up with the 3-5 new introductions you see at your local nursery. Many, many of those crosses are full "siblings" and the overwhelming majority are tossed in the dustbin.
Sometimes I get the feeling that there are people who think breeding a horse is like baking a cake: a little Mr Prospector, a dash of Turn to, a smidgen of Bull Lea and voila: stakes horse! If it were only that easy....
Anyway, being an amateur rose breeder is alot like being a small TB breeder competing with the Sheiks, even though you are outgunned in every way, there are successes out there. One of the successful amateurs, a guy named David Clemons, is clearly a Thoroughbred fan and probably a frustrated horse breeder as well:
http://users.nehp.net/rosetech/
For a different perspective, I look to my other passion which is growing roses. There are alot of similarities between the great rose hybridizers and the great TB breeders and the product is more alike than you would think.
One of the great smashing commercial and aesthetic successes of all time is the Kordes floribunda "Iceberg" released in the 50s. Even if you have zero interest in roses, you've seen it and chances are good you grow one. Home Depot sells it, it's in every municipal garden, Hollywood Park has a lovely stand of them near the Gold Cup wall.
Iceberg, a white rose, was bred from two very obscure parents, Red Robin (red) and Virgo (white blend). It took thousands of crosses (seedlings) before Kordes bred Iceberg and afterwards other breeders tried their own hand using these two relatively new influences but no one had any further success. Even Kordes didn't but his creation Iceberg went onto be a very successful parent in a lot of different breeding programs.
A major hybridizer, Weeks Roses, breeds and raises 100,000 seedlings a year to come up with the 3-5 new introductions you see at your local nursery. Many, many of those crosses are full "siblings" and the overwhelming majority are tossed in the dustbin.
Sometimes I get the feeling that there are people who think breeding a horse is like baking a cake: a little Mr Prospector, a dash of Turn to, a smidgen of Bull Lea and voila: stakes horse! If it were only that easy....
Anyway, being an amateur rose breeder is alot like being a small TB breeder competing with the Sheiks, even though you are outgunned in every way, there are successes out there. One of the successful amateurs, a guy named David Clemons, is clearly a Thoroughbred fan and probably a frustrated horse breeder as well:
http://users.nehp.net/rosetech/
Excellent post Johar,
I thought I was maybe the only one to get that even though you get 1/2 from the male sire and 1/2 from the dam; you don't neccessarily get 1/4 from the grandsire or 1/8 from the great-granddam. The implications of this are pretty important to my way of thinking and you've helped to refine my understanding of the mechanism involved.
Is there a mathmatical formula to calculate the graph of disturbution? It tried doing four chromosone pairs on a piece of paper and I got:
All Sire: 1
All Dam: 1
Three Sire: 4
Three Dam: 4
Two Sire and Two Dam: 6
The chances of 100/0 is 12.5%
The chances of 75/25 is 50%
And the chances of 50/50 is 37.5%.
-llbean
I thought I was maybe the only one to get that even though you get 1/2 from the male sire and 1/2 from the dam; you don't neccessarily get 1/4 from the grandsire or 1/8 from the great-granddam. The implications of this are pretty important to my way of thinking and you've helped to refine my understanding of the mechanism involved.
Is there a mathmatical formula to calculate the graph of disturbution? It tried doing four chromosone pairs on a piece of paper and I got:
All Sire: 1
All Dam: 1
Three Sire: 4
Three Dam: 4
Two Sire and Two Dam: 6
The chances of 100/0 is 12.5%
The chances of 75/25 is 50%
And the chances of 50/50 is 37.5%.
-llbean
I finally got it!
If they are 32 Chromosomes then:
32 Sire: 1 possiblity
31 Sire: 31
30 Sire: 992
29 Sire: 29,760
28 Sire: 863,040
27 Sire: 24,165,120
And so on and so forth.
The trick is to take the Chromosome Number (A), and minus from it the number of Chromsomes the foal would inherit from the grandsire or granddam (B), and then you left with (C), the number of empty holes.
Now to fill the first empty hole you have A possibilties; but then to fill the empty hole the second time you have A-1 possiblities. And then A-2, A-3, A-4, and so on and so forth.
-llbean
-llbean
If they are 32 Chromosomes then:
32 Sire: 1 possiblity
31 Sire: 31
30 Sire: 992
29 Sire: 29,760
28 Sire: 863,040
27 Sire: 24,165,120
And so on and so forth.
The trick is to take the Chromosome Number (A), and minus from it the number of Chromsomes the foal would inherit from the grandsire or granddam (B), and then you left with (C), the number of empty holes.
Now to fill the first empty hole you have A possibilties; but then to fill the empty hole the second time you have A-1 possiblities. And then A-2, A-3, A-4, and so on and so forth.
-llbean
-llbean