OTOH, hay is hard to make and expensive to store, because you absolutely cannot let it get wet. If it even becomes damp it can give cows the heaves (and will g

OTOH, hay is hard to make and expensive to store, because you absolutely cannot let it get wet. If it even becomes damp it can give cows the heaves (and will give horses), and it can give farmers farmer's lung. Plus an untimely rain after you cut it can ruin a growing season's entire yield. If you get it wet, you'll burn your barn down because it composts.