To answer your first question, only if it's safe for tups and wethers, plus an overfed tup is usually not a good thing to have around, esp with higher protein intake.... So if you can make a creep area that only the lambs can get into, or put the tup and a few pals somewhere else, that would be preferable, I would say.
As to your second I don't know, sorry, and no time to look it up right now. Hopefully someone else will have answered before I get back!