Over 100 years ago, a French Cavalry officer by the name of Jean-Joseph Vuillier while researching pedigrees discovered that a very limited number of horses could be found in the pedigrees of the most successful racehorses. He termed these horses “chefs-de-race” which is quite literally French for the “leaders of the thoroughbred.”
Basically though, Vuillier was concerned principally how often these “chefs” appeared in a pedigree, thereby conducting fundamentally a quantitative study. His results were exceptional, and he used these original dosage theories in the employ of the Aga Khan to establish one of the most successful thoroughbred breeding programs in the world.
During the 1950’s, an Italian lawyer called Dr Franco Varola continued Vuillier’s study. His seminal work, “The Typology of the Racehorse” though was not published until 1974. He expanded the list of “chefs” to update the more modern influences. Critically, Varola looked not only at the number of times that these horses appeared, but at the influence that they had on their progeny. Because most were prolific stallions in their era, we have a large number of horses to assess and therefore a good vantage from which to observe the characteristics that they most commonly pass on to their progeny.
It is critical at this stage to emphasize that we are looking at traits that stallions pass on to their progeny. While these may reflect their own racing performance, this is not always the case. This distinction also is one of the greatest misconceptions about genetic inheritance. Many pedigree students assume that it is the best or strongest genes
