To create the perfect diet for you horse, or horse to be lol, you need to take lots of things into consideration. Like how much excercise he receives, his size, age, and what is availible for you in your area etc. Some horses need supplements along with their diet to ensure they get what they need, or they may be prescribed by a vet or farrier. So, you can't really determine the perfect diet, until you know what horse you are preparing the diet for. You can also always ask a vet or experienced horseman etc for help when you do know what horse you are dealing with.