I've been using straw for bedding. My feed stores seem to only have straw or pine shavings available. I've read that pine shavings aren't great for birds so I've been sticking with the straw. But it's getting expensive a $15 bag lasts me 1 and a half cleanings and I clean out the coop about once per week depending on how dirty it is or if it got wet. I was going to buy a round bale of hay and use that but I've been reading that it wouldn't be a good idea. As of right now I'm literally paying more money for bedding than I am for feed. I'm not trying to run a profit with my chickens or anything like that but I need a more sustainable solution.