Q. I have school horses that do three hours of work per day, averaging between an hour of walk, an hour of trot, and an hour of canter, as well as jumping several times a week. Also, I have a dressage horse in training doing 10 hours of work per week. When considering their feed ration, do they classify as being in “heavy work” or “very heavy work”?

—Shaya Basnett, via e-mail

A. When nutritionists classify working horses, those classifications are based on maximum heart rate achieved during exercise and length of time working. Very heavy work would be considered a Thoroughbred racehorse running the Kentucky Derby or an event horse competing at an Olympic event.

Although the type of work the school horses and dressage horse is doing would be considered moderate work (based on their heart rate during exercise), they are working for long hours and that will influence how we classify them. I would classify both the school horses and dressage horse as in moderate to heavy work.