We have had Great Pyrenees for years, since our oldest children were little ones. Our first Great Pyrenees came from a goat farm in Washington back when we lived in Idaho & had Babydoll Sheep.
Now, living in Mchigan, we don't currently have sheep or any other common livestock other than rabbits. So, our Pyrs are used to "little livestock", the rabbits. We primarily have Great Pyrenees for our family's / property guardianship sake. Our children all love their majestic white dogs, the GREAT Pyrenees!
Great Pyrs watch over human children just as much as they watch over livestock.... keeping their eyes, ears & noses always on the lookout for any would-be predator. They bark most of the night when outside. The night barking is is to ward off potential predators like wolves, coyotes, mountain lions, etc or anything they sense doesn't belong on "their land".
When your have multiple Great Pyrenees working as a team, and a foe does advance, the Pyrenees will attack.
Great Pyrenees will respect a fence as long as they have a job at home. Some people who keep Pyrs are on large farms/ranches where they do not have everything fenced, and the Pyrenees will stay with the livestock for the most part, but, in general, fencing is a must-have for this breed. Great Pyrenees have a general scope of about a 15 mile radius that they'll consider their territory to guard. So if not fenced, us people will perceive that the Pyrs are wandering off, when really (most of the time), the Pyr just has a very broad scope of his work.
In the winter months here in northern Michigan, our Great Pyrenees have a nice pole barn that they come & go from as needed per the elements. During the winter they grow the biggest most luxurious fur coats, which insulate their inner temperature and enables them to thrive in the snow and keep on' a working!
Inf act, this breed is much more comfortable in the cold winter than they are during the hot summers. In the Summer time, Great Pyrenees shed much of their coats.
Our few adult Great Pyrenees have 1 or 2 litters a year. The puppies are raised in our workshop which is joined to our house as well. So, the pups are in a heated or cooled (depending on the time of year), clean and integrated setting. Our whole family enjoys checking on our puppies all the time as newborns, and as they grow up, we gradually update the Pyrenees puppies' setting towards the outdoors.
The puppies are also introduced to our rabbitry, so their natural instinct to be comfortable with livestock is instilled. Their instinct to watch over & protect is developed.