I don't think I would keep guineas with silkies. Reason being, many silkies have vaulted skulls and I have guineas with large fowl chickens and the guineas are wild and jump on top of the other chickens quite a bit---like when they get in a panic once in awhile (usually about nothing lol). Anyhow, I would be afraid that the silkies might get hurt. The guineas also have huge nails.