I have never seen chopped hay or straw offered. I use hay for my tortoises, and straw to insulate their night house. I have often thought of using some for my rodents. I bet they would even get some nutrition out of something like alfalfa. I have seen alfalfa cubes for sale, but haven't bought them.
I am not sure how finely chopped or processed it is. Yours may be processed differently than what is offered in the UK, so it might be more, or less, absorbent than what is available there. If I saw it here, I would probably try it for a month or two, and then evaluate it after that.