The home of thoroughbred dosages in Australia

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A brief history of dosages is the Australian home for the study of dosages in the thoroughbred.


In the early part of the 20th century, the distinguished French student Lt Col JJ Vuillier extensively researched the pedigrees of numerous thoroughbreds.  Among many of his findings were some factors that continue to be effective today.  One of his major findings was that a limited number of stallions were present in the majority of pedigrees.  He called these stallions that were to shape the breed, “chefs-de-race.”  Translated into English “chefs-de-race” would be heads or leaders of the thoroughbred, and in today’s terms these are the likes of Star Kingdom, Danehill and Northern Dancer to name a few.  He also found that new chefs appeared with regular frequency throughout the history of the thoroughbred, and his studies represent an evolutionary model of the thoroughbred. 

The Italian, Franco Varola incorporated the dosage principles of Vuillier’s work resulting in his most famous work, “Typology of the Racehorse.”  While utilizing these principles, Varola’s work took the studies of dosage to a new level.  His work centered on moving the emphasis on the frequency that these horses appeared in pedigrees, to the quality of attributes contributed to their offspring. It is important to understand that these factors need not reflect the stallion’s own racetrack performance but rather they represent the aptitude of the progeny.  As the title of his work suggested, Varola was very much focused on the “type’ of racehorse being bred which he believed resulted from the pattern of aptitudinal traits inherited from key ancestors.

Dr Steven Roman, a US academic, further expanded the notion of dosages in his ground breaking work during the 1980’s.  His work largely combined both the qualitative and quantitative approaches of both Vuillier and Varola.  Dr Roman established a statistical method for evaluating dosage analysis.  He termed this the Dosage Index that is determined through a mathematical formula and central to our modern interpretation of the study.

The fundamentals

The principles of Dosage analysis however are founded on the basis that each of these chefs contributed a predictable characteristic to each of his progeny. 

These characteristics have been classified into 5 major categories (Brilliant, Intermediate, Classic, Solid and Professional) that cover the range from speed to stamina.  There is however some overlap in their practical application, as certain stallions may contribute in two aptitudinal groups.  The assignments are made to most accurately reflect the traits a stallion most consistently and predictably transmit to his progeny.  A key feature of these principles is that a champion thoroughbred will have a balance of these characteristics within their pedigree. 

Australia and NZ

Dosages have remained a well utilized tool in both Europe and the US, but it seems that they have not been embraced by Australian breeders and owners.  One of the greatest difficulties was that the list of chefs-de-race, the basis for the current dosage model, failed to include many of the influences that have formed our unique colonial breed.  Mr John Hutchinson has been central to bringing this tool to the Southern Hemisphere through the development of an Australian and NZ chefs list that accounts for these influences.

Dosages can be used in a variety of ways, but most of the research to date has been focused on racing in the Northern Hemisphere.  However, there is now some research becoming available for racing in Australia.  Many of the results reflect similar trends to those in the Northern Hemisphere as is to be expected.

Vuillier utilized these principles to assist the Aga Khan in establishing his thoroughbred empire and resulted in breeding such immortal names as Mahmoud and Nasrullah among others.  These principles can also help small breeders to gain an insight into the thoroughbred and their evolution in ways that may not normally be accessible without extensive research.

Dosages are a good guide to the aptitude of a racehorse.  We can use this method to view historical results to see if certain distances or races are more suitable to a particular type of horse.