Final answer:
A sound dry cow ration should include at least 12 pounds of alfalfa hay because it is a high-quality forage that provides essential nutrients like protein, vitamins, and minerals to the cow.
Step-by-step explanation:
A sound dry cow ration should include at least 12 pounds of alfalfa hay. This is because alfalfa hay is a high-quality forage that provides essential nutrients like protein, vitamins, and minerals to the cow. It is also rich in calcium, which is important for maintaining proper health and preventing metabolic disorders like milk fever.