When you breed your buff silkies, what do you look for in order from most to least important? Like with call ducks you look for wide bodies, round heads with prominant cheeks, and short wide bills. What do you look for when breeding buff silkies? Also, at what age do you cull (and pick the best to use as breeders), 6 months 8 months? ETA: Also, do you trim vents, or are the roosters pretty much able to get the job done?