Great points. I never have fed hay that wasn't tested. Not because I liked the bill of testing feed, but because I have always been too poor to waste protein. It has already been said, but if you know your cattle's requirements you can mix different forages to balance your ration. Another thing I learned years ago is that when I was feeding several types of hay, say alfalfa, cane, oat hay & grass so that the ration was balanced, the cattle would eat salt but leave the mineral alone. If I got messed up due to poor planning and had to feed one or two types of feed for a week or so the mineral would disappear. My understanding of overfeeding protein is that extra protein has to be converted to energy at a net loss. That might be why the old timers said you could starve a cow to death on straight alfalfa. I have never seen that but I think I understand the principal. To Faster Horses original point...As easy as it is to feed good alfalfa I can't understand why a cake and range guy wouldn't buy tested alfalfa and feed 10-15#/dy instead of 1.5# of cake. The protein requirement got met way cheaper than buying cake and they got half-fed extending winter range. Old habits I guess. Good reading.