I have found a way of adding to my hay. when I mow I collect the grass and store in a lean to type of shed on pallets. BUT DO NOT USE if grass has been treated with pestaside or outher weedkillers. I am lucky as as I have a large yard and a small field. I bought a sickle bar mower to cut the field as I devided it into sections to mow. Then I pick up the clippings with a yard broom or sweeper. I let the areas grow to abought 4-5 inch then cut. Helps on the cost of hay only cost time. You can also mow with your mower and pic up you just have a little more dust but it fulls out as you feed. If what I was told how to figure amount I had out up a total of about 12-14 round bales.My shed is 12x12 8 feet high. Just wanted to share.