If your horse isn’t pregnant, lactating, growing, or performing work, then his nutrient requirements are those of a horse with his body weight in a maintenance physiologic state. This would include horses on pasture moving around freely but not undergoing forced work, as well as horses that might be laid up in stalls. | Photo: Photos.com

Q. When reading about feeding horses, I always see nutritionists refer to a “maintenance diet.” What does this mean, and how do I know whether my horse falls into this category?

A. “Maintenance diet” or “maintenance requirements” are terms we nutritionists use fairly often and are perhaps guilty of using with the assumption that horse owners commonly understand what they mean.

In the Nutrient Guidelines for Horses published in 2007 by the National Research Council (NRC), “maintenance” is defined as a physiologic state that applies to “animals that are not pregnant, lactating, growing, or performing work.” The NRC also states that in the case of energy, “the amount of dietary energy needed to prevent a change in the total energy contained in the body of these animals can be considered the maintenance requirement.” Maintenance requirements exist for all nutrients with known daily requirements