Your Great Pyrenees was made to protect. Pyrenees were bred in their namesake mountains in Southern France to protect livestock of all kinds. They have been used for this purpose to this day. The Pyrenees' immense, majestic size helps to intimidate predators, while the shaggy white coat protects the dog from all weather while making it clearly visible and distinguishable from predators at night.
Pyrenees are known for being calm and laid-back, appearing almost zen-like, with a happy smile. They can move quickly, however, when it comes to protecting their livestock. They naturally patrol and protect their property and charges, and nap throughout the day and night so as to remain vigilent. With their powerful frame, excellent protection instincts, and weather tolerant capablities, the Pyrenees is a natural choice for guarding any sort of livestock, including chickens.
While your Pyrenees puppy is insanly cute and cuddly, she cannot be thought of as your pet if she is to be an efficient guardian. While your Pyrenees will love you and enjoy your company, her real family must be her livestock. Since chickens are small and fragile, your Pyrenees must learn from an early age that she must be gentle with them. Furthermore, your Pyreneese will need to learn to watch out for predators from the sky as well as from the land. A hawk can take a chicken before your Pyrenees can notice if she is not on the lookout. Finally, you will need to accustom your Pyrenees to strangers coming to your property, as well as having a vet examine her. Just because she will live with your flock doesn't mean she doens't need social skills.