We already know that cardiac recovery time in endurance horses is related to their ability to perform well in races. But what we didn’t know—until now—is that recovery time is a heritable trait.

French researchers have determined that we could breed selectively for recovery time in endurance horses, as this trait gets passed on through genes.

“Cardiac recovery time in endurance racing appears to be strongly influenced by genetics, so a selection based on cardiac recovery time could be a supplemental physiological characteristic to take into consideration to improve the breeding selection of endurance horses,” said Eric Barrey, PhD, of AgroParisTech, the University of Paris-Saclay, and the French National Agricultural Research Institute.

However, for such a breeding opportunity to realistic, race organizers should record horses’ cardiac recovery time during events to obtain official data, he added.

In their study, Barrey and his team, including lead researcher Mohamed Youmes, PhD, of the University of Paris-South and University of Paris-Saclay, investigated racing data on 4,421 endurance horses with various pedigrees. Data sets included four parameters:

  • Recovery heart rate—The average heart rate of the horse during the recovery period at required resting points in the race;
  • Mean cardiac recovery time—The average amount of time it takes, all rest periods of the race combined, for the horse’s heart rate to return to the requi