The amount of ear corn that you need to feed depends on how much additional energy you need in the ration. Cow weight, age, milk potential, and quality of the grass or hay will determine the amount of energy and protein needed in the ration. Ear corn is an excellent energy source. When you use ear corn in a ration for beef cows, it is also important to make sure that the protein is balanced in the diet. If cows are grazing dormant native range and they are in mid-gestation, then they will likely need protein and not energy if there is plenty of grass to eat. As they more toward late gestation, they will need both protein and energy. If you feed 2 lb of ear corn per head per day, you will need to also supplement some protein, 0.45 to 0.55 lb of protein per head per day. The protein source needs to be one that is highly degraded in the rumen. Protein supplements based on soybean meal, cottonseed meal, and wheat mids are degraded in the rumen, as is corn gluten feed. Distillers grains would work well in this situation. After calving, with an average-quality hay, you may need 2 to 3.5 lb of ear corn per head per day, and again you will need to supplement protein, maybe 0.75 to 0.85 lb of supplemental protein per head per day, depending on the quality of the hay. To fine-tune the ration, you might test the hay for quality, or work with your Cooperative Extension agent to develop a ration.