You would want to protect from predators. Do you have a way to do so? I use an electric fence for my run, but to keep the predators from coming in. Or is that what you mean?
My run is made of cattle panel with an outer layer of welded wire. It is about 4' high. Then I have an aviary net over the top to keep hawks and such out. Plus the use of electric wire around the bottom. It is not 100% predator proof as snakes, weasels, etc could get in. While we do have weasels in this area we are not close to their habitat. As for snakes, we really wouldn't have to worry about those either as I hear muscovy will kill them.
If you have photos of your area, that would help. Also, the coop and run forum has loads of ideas to predator proof an area.