These chicks are just 3 weeks old. The SB problem has gotten much worse. The black feels like nothing but bones. I think I'm going to have to cull him. The blue I don't know though. This is a link to my original post about these two. https://www.backyardchickens.com/t/1135973/what-to-do#post_17596881 I don't want to cull unless there isn't another option.