Hello, it seems I've always had one or two chicks that get pasty butt. People say that it is caused when a chick is a bit too chilly. I think that might be true, because I currently have two five day old chicks in one brooder, and then six three week old chicks in another brooder in the same room. Since there are two heat lamps, the room gets super warm. The chicks don't seem to mind at all and not a single chick has gotten pasty butt......
So I'm thinking it's true about chicks being a bit chilly and getting the pasty butt. I dont' cut off their tushy fluff unless it's a really bad case of pasty butt. The thing is, their little bottoms get red when you clean them off, and this red naked tush is attractive to other chicks and they will peck it! OUCH! So I soak their little butts in some warm soapy water and then I dry their tushies off too.
Keep those chickies nice and warm and all will be well.
Sharon