Inexact Science - By Dan Liebman

In Ireland last week trainer Jim Bolger and scientist Dr. Emma­line Hill announced they have formed a company to promote the Equinome Speed Gene Test, which they claim will help horsemen identify the optimum distance for a particular
Thoroughbred.

Bolger was quoted as saying the test is “without a doubt the most important thing that has happened to breeding since it began over 300 years ago.”

I suggest it could be the exact opposite.

There is nothing exact about breeding horses, and the fact that it is such an inexact science is one of its greatest traits and most alluring appeals.

There are many exciting possibilities related to the sequencing of the genome for any animal or species. But in horses, determining a speed gene is not one of them.

If researchers are able, for example, to identify a gene that determines whether a Thoroughbred will bleed or possess any one of a number of diseases, then that might be “the most important thing that has happened to breeding since it began over 300 years ago.” But being able to use genetics to breed a horse that can win at six furlongs but not at eight is, well, not something breeders should be interested in.

The beauty of breeding is that there are so many different phil­osophies among the men and women who make the decisions about which broodmares are mated to which stallions.

It may be as simple as this: “I own a share in a stallion so I need to pick a mare to breed to him.”

Every mare owner has heard this: “Sorry, book full, choose another stallion.”

There are those who believe strongly that inbreeding should be sought in every mating, and those who feel quite the contrary.

Breed an unproven mare to a proven stallion. Ever heard that one?

How about breeding to first-year stallions because they are well-received at public auctions? Well, until the economy headed south, that is.

Breeding a small mare to a large stallion has always seemed a good idea. That is genetics, isn’t it?

Whether breeders know it or not, they have been using genetics in their matings forever. The aforementioned inbreeding is selecting to infuse a pedigree with the genes of one sire line over another. Inbreeding to certain female families, or seeking the descendants of, say, La Troienne, are other examples.

Breeders know which stallions are more likely to throw sprinters and which are more apt to sire distance runners. They also know this about their mares, and hence the decision-making of planning matings.

Numerous statistics aid breeders in evaluating speed versus stamina, things as simple as average winning distance and dosage, the latter merely a mathematical equation that seeks to estimate the balance of speed and stamina in a given pedigree.

Of course, being a trainer, Bolger knows what all conditioners know, that breeding is merely the genes within the animal. The expression of those genes depends on many other factors, such as feed, shoeing, veterinary care…and, oh, yes, training.

A few years ago when Dolly the sheep was cloned and Thoroughbred folks were discussing the impact cloning could have, I suggested what I thought would be an exciting experiment: Take 20 clones of the same Thoroughbred and give the animal to 20 different trainers. Wouldn’t it be interesting to see how the same horse would turn out in the hands of 20 different trainers?

Geneticists, scientists, and researchers are doing exciting work now that the equine genome has been mapped. Perhaps one day they will identify the markers that can help the industry breed a sounder horse, or their work will lead us to a cure for grass sickness or help us prevent osteochondritis dissecans (OCD).

But do we need a researcher to tell us to breed mare “A” to stallion “B” and you will be assured a horse whose best distance is at a mile?

No, we don’t.

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