Dogs are naturally going to kill chickens, unless you find one without ~any~ residual prey drive, or raise it so specifically with chickens that they are imprinted very young...
I just choose not to own chickens.
They chase the horses too, but sometimes the horses chase them. :~) Of course, huskies are pack dogs, so they get braver when they're let out together. So maybe we should try letting them out one at a time...