In the winter, just as in any season of the year, the horse needs a combination of nutrients such as carbohydrates, fat, protein, vitamins, minerals, and water to remain healthy.
Horses use feed energy produced from nutrients in their rations.
Each cell in the horse's body needs a certain amount of energy on a daily basis in order to live and function. The most common nutrient used for energy is carbohydrates, followed by fat, then protein. Protein is not ideal as an energy source, but it is used for that purpose, especially if the horse is not consuming enough carbohydrates or fat. Eighty to 90 percent of the total nutrients needed will contribute to body energy demands. Body condition is partly a function of maintaining a layer of fat under the skin.