How to feed a horse is one of the most popular questions that I get as a veterinarian. There are many things to consider, mainly being macro and micro nutrient provisions, which include proteins, fats, vitamins and minerals. Protein is essential for the body in a variety of ways, from building muscle mass to regulation of metabolic function. How much protein is needed is dependent on each horse and the demands present. Exact recommendations are hard to make, generally speaking, but in most cases, we have to look at each individual horse, demands, existing health problems and dietary sources.