I ran pastured layers, free range for 3 years and sold eggs. I wound up with problems with the resident EAGLES. A young eagle that was just getting his color carried off a hen nearly every day and I lost 122 that summer... a hawk I would be willing to shoot (yep illegal to do so) but they were putting chips in the eagles in the area... so I quit. I had an old camper trailer we redid inside and put nest boxes and roost poles and a vinyl (linoleum type) on the floor and they were locked in at night to discourage raccoons and foxes and possums... we pulled it around different parts of the pasture and they did a good job of scratching up the cow patties and such. They only ventured a couple hundred feet from the mobile chicken coop-trailer... so we moved it around more.
There are a few people that I have heard of keeping an LGD with their chickens and some are much more tolerant of the chickens that others and don't bother them... they will protect against predators... But no one that i know lets them totally free range due to not being able to keep the predators away.