For decades the Body Condition Scoring (BCS) system has been the gold standard for evaluating a horse’s nutritional status. However, it doesn't give a complete picture. This week we discuss why a horse’s topline muscling is important when evaluating your horse’s diet. Many factors do influence topline muscling in a horse and we discuss which ones we can manage, particularly diet. For example, the BCS system evaluates the energy in a horse’s diet, but misses other components such as protein, or more specifically, the amino acids in the feed. Thus, we discuss why not only protein is important, but also why feeding different types of protein is critical. We also talk about the different sources of protein and how they can influence your horse's muscling. Finally, we give suggestions on how to approach the topline of a horse with your easy and hard keepers and other important tips.