Therefore, if the diet is deficient in protein, a supplement high in DIP should be provided before energy supplements are considered. Examples of protein sources with high DIP values include soybean meal, legume hay, cottonseed meal, corn gluten feed and wheat middlings. Starch digesters are important for grain-fed ruminants. Energy from grain is primarily in the form of starch or nonstructural carbohydrate. However, when grain is supplemented at higher levels, forage intake and digestibility decline because the population of starch digesters is increased and the fiber-digesting bacteria are reduced.
Many byproduct feeds provide energy in the form of highly digestible fiber.
Because the energy is in the same form as that in the forage, high levels can be fed without decreasing forage digestibility. Byproduct feeds that provide energy in the form of highly digestible fiber include corn gluten feed, dried distillers grains, soybean hulls and wheat middlings. Minerals Mineral profiles of byproduct feeds may be quite different from conventional feedstuffs. Byproducts may be fairly high in potassium, copper and zinc. For many herds, a lower-cost mineral supplementation program may be used because of the minerals provided by the byproduct.