I personally do not offer grit. I find that it is one of those unnecessary things. If you've ever seen/felt the inside of a bird's gizzard, that lining feels like sharkskin...it's amazingly tough stuff. Of course, once the chickens are out of doors, they will pick up their own grit in the form of sand and small stones. The only thing along those lines that I occasionally offer the chickens is oystershell pieces a couple of times a month or so, but that's for my layers. :0)