Feeding them a high forage diet will cause a stunting of growth.
People are so afraid of having bone problems, they create a whole new set by starving their horses.
Your extension agent or feed dealer can help you pick a feeding program that will meet both your horses' and your needs. If all else fails, read the directions on the bags J , and pick a food that is designed for your horses lifestyle. That molasses will cause him to get a sugar high. Overloading on starch will make your horse just like a kid and a candy bar. Feed a low starch food to reduce the risk of high glucose levels.