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A different take on dosage

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Shammy Davis View Drop Down
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    Posted: 15 May 2013 at 6:49am
Demystifying Dosage

DOSAGE FIGURES MEASURE APTITUDE, NOT COMPETENCE

By Roger Lyons

"All we're trying to do is find out what you're best at," was the standard explanation for that barrage of "aptitude tests" so familiar to little Jane and little Johnny, who attended American schools in the 1950s and 60s. The explanation given to little Heather and little Zachary i the 1970s and 80s probably didn't differ much. The names--of the children and the tests-- were changed, but that didn't protect the innocent. These tests had a hidden agenda, which can be illustrated thus.
Suppose little Johnny's percentile scores were 85 in English, 92 in Math, 78 in spatial relationships, and 83 in logical analysis. Now, it is clear from this that little Johnny was best in Math. But the same thing is clear from the following scores, which were earned by little Jane: 32 in English, 45 in Math, 39 in spatial relationships, and 28 in logical analysis. Even though little Jane and little Johnny both showed their highest aptitudes in Math, the difference in the scale of their scores suggests another criterion of assessment that was probably a more important variable in the lives of Jane and Johnny than the question of aptitude.

APTITUDE, NOT COMPETENCE
The variable we are looking for is competence. There is really no other word for it, whether the term is referred to humans or horses. Competence is about doing something well in either case.
Many breeders believe that dosage is like an aptitude test, that it measures both what a horse will be best at and, then, how well the horse will perform in that capacity relative to other horses. They believe that a dosage index of less than 4.00 and a center of distribution below 1.25 means that the sire and dam are a good match, that the productive possibilities of the mare are somehow optimized if she is bred to a stallion who puts the dosage right. Moreover, breeders who hold this belief do so without understanding how dosage accomplishes this. They believe that the dosage figures comprise a mysterious code that ordinary intelligence simply cannot fathom.
Many new entrants into the business of breeding thoroughbreds spend time trying to find out the secret to decoding the dosage figures, having been led to believe that these figures hold the key to breeding good racehorses. The simplistic nature of the figures beckon to them, enticing them to find the key, the hidden meaning. They assume that this meaning eludes them because they lack the knowledge to comprehend it. 
       

In fact, the dosage figures differ from an aptitude test in the respect that nothing about about them constitutes a measure of what can correctly be called competence in the racehorse. Dosage figures may predict that a horse will run his best race at 10 furlongs, but, even if that turns out to be the case, it doesn't mean he will ever win a race.
The dosage figures really are as simple as they seem. They do not reveal more than they seem to reveal. Their pertinence to the question of competence is elusive for the simple reason that it does not exist.

RANGE OF APTITUDES
Prior to Roman's entrance into the dosage game, it was generally understood that the superior thoroughbred is an athlete, constituting a fortunate mixture of speed, stamina, soundness, courage, and the will to win. Largely as a result of Roman's formulations, breeders have been led to believe that a superior thoroughbred is a blend of speed and stamina only. After all, the dosage formulations are exclusively regulated by these two aptitudes. Unfortunately, a balance of these two factors alone, as represented by the Kentucky Derby guidelines, is a poor balance indeed since it ignores other, equally important values. 
       

There is a parallel in the experience of little Johnny and little Jane. Because she had certain aptitudes that the tests forgot to measure, she became an entrepreneur in the fashion industry and earned $900,000 a year. Little Johnny went on to college, became even more competent within his range of aptitudes, and ended up with a career as a social services professional. After 20 years of that, he happily retired on his state pension, compliments of the tax revenues yielded by grown-up Jane's creativity, resourcefulness, and enterprising spirit.
But even if the dosage figures took into account all of the important aptitudes, which they don't do, how much better off would a breeder be to breed a horse with a dosage index of way above 4.0 and a center of distribution that is off the scale, if only the horse had the courage and the stoutness and the will--all heritable characteristics--to win the Breeders' Cup Sprint? Ironically, by the logic of the dosage figures themselves, if a horse doesn't have dosage figures something like that, then he can't possibly win that race. How can one explain why Texas and Oklahoma breeders--or California breeders, for that matter--would want a dosage index below 4.0? 
       

For any breeder, Roman's dosage is a red herring, in whatever direction it might be chased (with the exception of the betting window on Derby day). Breeders must attend to and learn about the aptitudinal capacities of the individual ancestors that influence a mare and make selections from among stallions whose ancestries complement that of the mare. Which stallions that might be is discovered by examining the ancestries of sires of superior runners produced by mares of similar ancestry to that of the mare in question. The dosage figures do not even presume to approximate that painstaking process.

 

http://www.compusire.com/98dosage.html
 
 
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Shammy Davis View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Shammy Davis Quote  Post ReplyReply Direct Link To This Post Posted: 16 May 2013 at 10:10am
Dosage, as it relates to the breeder, depends on the timely identification of stallions who are producing at superior level and throw one or two aptitudes consistently.
 
I personally think that dosage is a tool that should not be ingnored but I also think it is tool that should not be depended.
 
The major problem with dosage is that it is sireline focused.  We find this "ball park" focus in a number of useful tools that the breeder has at his/her disposal.  True Nicks is another "ball park" tool.  I'm not saying that "ball park" can't be good, but I realize that there are those who base their breeding plans on a few of these "ball park" tools without searching the entirety of a pedigree.
 
We know now that at the time of conception, give or take a few nano-seconds, that the "genetic schuffle" occurs.  When this occurs any number of thousands, possibly millions, possibilities can occur.  It is impossible for any breeder to assume or have the expectation that because a stallion has a certain aptitude and the mare has a certain aptitude (based on a quantitative evaluation of the sire's production) that a foal will be such and such aptitude.
 
JMHO, but I think the breeder must look at a pedigree in its entirety and ignore the fact that a horse or mare dosage for racing performance exists.  For lack of a better term, I think inheritance is cumlative and available at the conception of a foal.
 
Barry Irwin, primary partner in Team Valor, that owned ANIMAL KINGDOM produced this on their website.
 


Breeding With Dosage

The most popular use of dosage among breeders is in determining a good stallion match for a particular mare. After all other considerations have been made, such as location, stud fee, desired crosses, etc., dosage can be employed to narrow the possibilities further.

As an example, let us assume that you own the American champion juvenile filly Countess Diana and the time has come to breed her. For fun - let us say that stud fee is no object, so you have narrowed your target stallions down to these five Kentucky stallions: Seattle Slew, Glitterman, Unbridled, Go For Gin, and Gone West.

By calculating the dosage figures of the hypothetical offspring, one can "preview" the result. Here are the figures for each hypothetical mating:


Proposed Mating Dosage Profile DI CD
Countess Diana + Seattle Slew 10-5-15-2-0 2.37 0.72
Countess Diana + Glitterman 8-7-7-0-0 5.29 1.05
Countess Diana + Unbridled 6-10-12-0-6 1.83 0.29
Countess Diana + Go For Gin 4-5-12-2-3 1.36 0.19
Countess Diana + Gone West 10-9-13-0-0 3.92 0.91


Remember that these figures are for the resulting offspring, not for the stallions themselves. At this point, the breeder should already know what the goal of the mating is to be. Is a sprinter desired? Is a classic- distance runner desired? Perhaps a decent turf miler?

If the goal is to breed a sprinter, then Glitterman might be considered. The profile of his foal is definitely speed-biased, and the DI and CD figures are the highest of these options.

If a distance runner is the goal, then Unbridled and Go For Gin might be considered since the resulting DI and CD are both quite low. Both also possess far more Solid and/or Professional points than the average American runner, and therefore have the potential of being superior runners over a distance of ground.

Seattle Slew and Gone West result in similar profiles, both with large Brilliant and Classic scores. A large Brilliant score is very commercial. Juvenile runners tend not to be physically mature enough to tackle the long distances they have been bred for. They tend to tap into the Brilliant and Intermediate wells first, then later mature into the stamina wing of the profile. And since American two-year-olds are never asked to run a distance anyway, the large Brilliant figure may indicate those which can excel in the juvenile year.

The large Classic score of these two stallions indicate that the potential for "maturing into distance" is present. Buyers are sure to be especially attracted to well-conformed and attractive foals which have been bred for this type of versatility. You can see how dosage would be a helpful tool in planning a breeding.


 
I think of this as a "ball park" theory.  I wouldn't plan a breeding based on this alone.  The reason being that I believe the mare is substantially more important and it much easier to read the aptitude in a mare line than in a stallion line.
 
This link might be of interest to some of you.
 
 
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Shammy Davis Quote  Post ReplyReply Direct Link To This Post Posted: 16 May 2013 at 10:18am
Woops!Ermm  Can't touch anything without everything going haywire.  How do you edit on this website?
 
This link might be of interest to some of you.
 
 
In this link the author uses the term "equally" when discussing his position.  The article was written in 2007 and recent research is changing are view on inheritance.  We know from recent research that because of the "genetic schuffle" at or about the time of conception that "equal" is subjective and probably not representative to what actually happens.  Other than that, the author makes some good points.
 
 
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