Gotta love em. Lots of ranchers around here use those huge white dogs ...and we've seen many a dead coyote hanging on the fence rows, due to their effectiveness.
The coyotes are so numerous and brazen... they come right into the yard during the day. I'm not complaining though...it gives me target practice. :)
Near to my house here in Texas one of the ranchers has a flock of sheep. He has a couple of Great Pyrenees that guard them. I stopped one day to admire the dogs from a distance. They ran up to me about 20 feet away and just sat down and looked at me. They were between myself and the sheep. They were not aggressive nor threatening. However, it was very plain what they meant. "Do Not Get Near the Sheep."
Those are good dogs.