Kathleen, if parasites are an issue where you are (they're a massive problem here, to the point where the commercial sheep farmers are talking about Drenchageddon) you might want to try feeding biochar. Lots of studies and anecdotal stories out there saying that biochar will reduce or eliminate intestinal nematodes and also help with general health. My sheep like small pieces, like the size of whole grains, and screened to remove dust (makes them sneeze). I mix some sea salt minerals with it for some extra enticement, and they butt one another away from the trough when I give it to them.
On the browse topic, I feed lots of tree branches whenever the pasture growth slows down. I grow a lot of coppice willow for this purpose (as well as to produce feedstock to make more biochar -- stacking functions), and make tree hay in the summer with that and fruit tree prunings.