When it comes to equine nutrition, one solution doesn’t fit all cases. Heels Down Magazine talked with equine nutritionist, Dr. Joe Pagan, about how many calories an event horse needs to stay at a healthy weight.
Dr. Joe Pagan is an equine nutritionist and founder of Kentucky Equine Research. Dr. Pagan received his B.S.A. degree from the University of Arkansas in animal nutrition and received his M.S. and Ph.D. degrees from Cornell University in equine nutrition and exercise physiology. KER was formed in 1988 to be an international research, consulting and product development firm dealing in the areas of equine nutrition and sports medicine. Learn more about Kentucky Equine Research, here.
At Kentucky Equine Research, we did a study where we looked at a bunch event horses that were in training in Ocala, Fla. We recruited riders that had 26 event horses in training. They were all in training at different levels for the season and were competing. We had horses from Novice to Advanced, with the intention of better understanding how hard the horses train for the different levels.
As part of that study, we were able to calculate how many calories they need. The way we did that was by monitoring their heart rate during exercise. Heart rate during exercise is very highly correlated related to how much oxygen a horse consumes. We have an exercise physiology lab where we measure the oxygen consumption of horses on our high speed treadmill. We’ve done lots of studies looking at oxygen consumption as it relates to heart rate. From this, we were able to develop equations. By knowing a horse’s heart rate and how long they exercised for, we’re able to determine how much oxygen they consumed. With that, we’re able to determine how many calories they burned.
The best way to express how many calories a horse needs to eat is as a percentage of a horse’s maintenance requirement. It gets confusing for horse owners if you get into megacalories and digestible energy. Look at energy as this: if the horse is just standing around, how many calories does it need to not gain or lose weight? If it’s just hanging out, that’s its maintenance energy requirement. In the average older horse, that’s about 16 or 17 megacalories of digestible energy. Working eventing horses have a higher level of maintenance required. If it’s 125% of maintenance, that means they need to eat enough to meet their usual maintenance requirement of 100% plus 25% extra. We found there was a linear relationship between what level the horse was training and how much energy it needed.
The horses that were training for novice needed about 125% of maintenance, which is 25% more than if the horse were just standing around. The highest level we saw in this group was the intermediate and advanced horses; they need about 150% of maintenance. If you have a horse that is training for those levels it needs 50% more calories than it was already getting standing around. The elite eventer, like a 4* horse, is closer to twice maintenance. If you fed that many calories to your novice horse, they might end up obese.
How many hours a horse spends in training a week can also play a role in determining your horse’s needed calories. There was a positive relationship between total hours trained and number of calories a horse needed. The novice horses trained about 2 ½ hours a week. That was enough to boost their energy requirements up to 125% energy maintenance. The horses that were at the upper levels trained about 5 hours a week.
That’s the general range of caloric needs for event horses. At Kentucky Equine Research, we are trying to come up with more equations for our mobile app, KER ClockIt Sport, to help the average person remove the guesswork from their horse’s caloric needs.