Their major function is a source of energy. Barley, oats, and wheat can contribute significantly to the protein content of the ration, but palatability problems may occur when the grain mixture exceeds 40 percent wheat. The main consideration in selecting grains for dairy rations is price. High moisture grains are equal to dry grains on a dry matter basis. When formulating rations containing high moisture grain, adjustments should be made to account for their lower dry matter content.
Protein supplement is required in most grain mixtures for dairy cows.
Because the dairy cow is a ruminant, there are a variety of protein supplements which can be fed with good results. Commercial protein supplements are used extensively in dairy rations. They are usually made from soybean meal and other by-product feeds. Most commercial supplements will be supplemented with vitamins and minerals, which can be convenient for on-the farm mixing. Some commercial supplements contain urea and therefore will have less energy.