I have 15 SLW and 15 blue partridge Brahmas in the incubator. We are on day 22, the SLW are doing great many zipping and one hatched, but the Brahmas are hardly doing anything. (2 small pips). Of course, the Brahmas were the ones that I paid $$ for and the SLW are from my own backyard. They all were set at the same time and looked the same at candling. Why aren't the Brahmas doing much? Is it because they are a larger breed? I really want them to hatch. It's my first time, by the way.