Study Shows Longer Racing Careers when Horses Race as Two-Year-Olds

Australian researchers from the veterinary science department at the University of Sydney and the Sydney Medical School at the University of Sydney have found that Thoroughbreds that race regularly at the age of two are likely to have longer racing careers than horses that are not raced until they are three years old or older.

Using the records of 117,088 Thoroughbreds that raced in Australia, they looked at correlations between age at first race, number of two-year-old starts, number of career starts, career earnings, and distance raced. They found no evidence of adverse effects when the horses were started as two-year-olds. They also concluded that the risk of retirement from racing decreased in horses that started racing at a younger age, had a greater number of two-year-old starts, and raced at longer average distances.

Analysis of the records also showed that stallions had the shortest racing careers, mares had middle-length careers, and gelding had significantly longer careers than either mares or stallions.  As earnings for stallions increased, the chance of retirement from racing also increased, probably due to the likelihood of a profitable breeding career. The opposite was true for mares and gelding that tended to stay at the track longer as earnings increased.

Results of the study agreed with similar conclusions found in studies of Thoroughbred racehorses in other countries including the U.S.