A cow that is milking eats about 100 pounds each day of feed, which is a combination of hay, grain, silage and proteins (such as soybean meal), plus vitamins and minerals. Farmers employ professional animal nutritionists to develop scientifically formulated, balanced and nutritious diets for their cows. Cows also need fresh, clean water.
USDA statistics show that US dairy farmers are producing almost three times more milk with about half the number of cows compared to 1960, thereby reducing the total amount of feed, water and space needed, and resulting in less manure.   _{Your Comment}