One of the best pieces of advice is that when u are reading to buy, i suggest u do some research on sellers as to not buy sick chicks or ones that arent kept well. I suggest buying from a local feed store and look for problems in the cages like dead chicks or overly nasty cages no lights. Just a...
Sounds crazy but it works or did for mine. I use cayenne pepper in their feed. Research it. I have heard giving the spoiled yogurt will do the same for them. I use oregeno for a natural anti biotic for them daily.