http://www.kalmbachfeeds.com/shopping/mobile/poultry/T770BLK.aspx I went to a chicken whisperer seminar sponsored by Kalmbach products. I use Kalmbach chicken feed anyways because my very good friends family owns a feed/grain store that carries it. At the seminar the rep said the block is considered a healthy treat for the flock. I bought one for myself and one for my grandma. I only have 7 birds so I've been breaking it apart and giving it to them once a week or so. My grandma has 48 birds, she split hers in half as to not create too much havoc. My birds love it. It's advertised to have probiotics a prebiotics in it so that's good too.