Equinome's Dr. Emmeline Hill says "Test for the Best"

It’s impossible for buyers to discern the genetic potential of racing prospects by using traditional conformation and pedigree analysis, according to equine geneticist Dr. Emmeline Hill who spoke today at the Pedigree, Genetics, and Performance Conference sponsored by The Blood-Horse in Lexington, KY.

Dr. Hill cited a study demonstrating that yearling buyers paid just as much for inferior horses as they did for the ones who were most successful on the track, noting that  a thoroughbred's genetic class is a more accurate predictor of its eventual earnings than the price it commands in the auction ring.

Dr. Hill is the Chairman and co-founder of Equinome, which has developed state-of-the-art genomic tools to evaluate the genetic potential of thoroughbred racehorses.  Based in Dublin, Equinome has identified the different sets of genetic variants critical for performance in short-distance, middle-distance, and long-distance racing, and has made this data available to thoroughbred owners, breeders, and prospective purchasers through its Speed Gene Test, which measures a DNA variant--“C” or “T”—in a gene responsible for muscle mass development.

Equinome has determined that there are three possible combinations of these DNA variants:  C:C (characteristic of fast, speedy, sprint types who best compete from distances from five to eight furlongs); C:T (characteristic of fast, middle-distance types whose best distances are from seven to 12 furlongs); and T:T (characteristic of stamina types whose best distances are 10 furlongs and over).  The T:T horses are not well-suited for success as two-year-olds.  In fact, a study of 142 two-year-olds in England who were all trained by the same trainer demonstrated that the C:C and C:T types earned the most money as juveniles.

Equinome's Elite Performance Test evaluates 80 genetic variants to measure an individual's potential racing class, ranking individuals from Class I to Class IV.   In a study of 1,051 racing thoroughbreds who had been tested, Equinome found that Class I-rated horses were six times more likely to become Grade I or Grade II winners than to be non-winners, and that 46% of the Class I runners became elite (graded or listed) stakes winners.

Matthew Binns discusses the genetics of thoroughbred pedigrees

Speaking at the The Blood-Horse-sponsored conference on Thoroughbred Pedigree, Genetics and Performance in Lexington, KY today, Dr. Matthew Binns of The Genetic Edge said that a thoroughbred’s genetics contribute 35-50% toward his athletic ability. 

A founding member of The Equine Genome Project, Dr. Binns’ company performs genetic profiles of thoroughbreds to assess four traits linked to future success on the racetrack, ranking them from A to D.  About 10% of the best bred horses—such as those typically offered on the first day of the Keeneland September sale—are A-rated, with a better-than-average chance of winning in graded stakes.  Dr. Binns noted that it is impossible for even the most experienced horseman to visually identify these genetic markers, which not only tag those horses with the best chances of succeeding in elite company but also unearth their optimal distance and surface preferences and even their eventual height.

Discussing the genetic consequences of inbreeding, Dr. Binns pointed to Zenyatta’s five-cross pedigree, which shows that she is inbred to Champion and Horse of the Year Nashua, 5x5.  What this means, said Binns, is that Zenyatta may have gotten +/-four of her 64 chromosomes—or 6% of her DNA-- from Nashua, but there is also a possibility that she have gotten none of her material from him.  The chances that this inbreeding to Nashua would recreate Nashua’s genotype in Zenyatta are quite low, he said. 

The co-author of Thoroughbred Breeding:  Pedigree Theories and the Science of Genetics, with Tony Morris, Dr. Binns noted that top racemares are the best producers of stakes-class offspring, and also cited evidence that first foals tend to be less successful than subsequent ones because the “placentation” (the facility whereby nutrition is transmitted to an in-utero foal) is not as well developed in maiden mares.  Based on his research on Kentucky Derby winners during the last 40 years, Binns revealed the perhaps surprising fact that a full 50% of them had a genetic profile typical of a sprinter, rather than a router.