Did you know...that a horse can use as much energy during a 10-mile trailer ride as on a 10-mile trail ride? It's true, according to equine nutritionist Teresa Hollands PhD of DeMontfort University in Leicestershire, England. Fluid loss is a major factor, as it is in humans. One horse, tape-weighed by Hollands before leaving for an event, lost 20 kg (more than 40 pounds) during the three-hour ride to the competition. British three-day event horses in a research study also lost an average of 14.5kg (34 pounds) on cross-country day.