I am not sure about feeding them. They would probably be hard for them to eat and not have much nutritional value. You can however use them as a bedding material. We used to use them as bedding it works just like straw.
I've fed corn stalks and used them for bedding for years. They don't have alot of protein or feed value but for say geldings or horses that aren't being ridden in the winter and not bred they can help give them something to eat without getting to fat. I never use them as the main diet but as a supplement forage
I did some more research and found out that it is not at all close to being a replacement for hay because it is so low in energy and crude protien for my horses. I need to feed them hay and feed to keep weight on them. I guess it would be good for "easy keepers" though.