Won't she turn around some day and attack the chickens? This is the first question that people ask when I suggest Bess working on the farm as livestock guardian.
In theory this will not happen. If trained right, Bess a Pyrenean Mountain dog will protect the poultry flock at all cost. But as with any dog, training is the key.
So to save you a lot of googling, the sites below give background information on livestock guardian dogs.