Leaving my dogs to protect the yard is fairly easy now that the female doesnt kill them.
Since moving in this house I have trained the female dog to protect (even though she still looking for eggs). She knows the noises of the chickens and if she hears them freak out she runs down there and barks her head off.. running back and forth where the predators usually come from.
I think this deterrent is the reason I havent had any losses lately. The predators know they dont have the time to make successful kill, even if they can get to the chickens with some effort.