had another internet search today, found different pages to my first search.
wish i'd thought of this years ago!
bamboo apparently very good for goats, supplies nutritional needs for adult goat, helps keep down internal parasites, (goats not grazing short grass picking eggs/larva up).
I'm thinking of some clumps I could have divided and had a lot more by now, as well as autumn windbreaks
Miscanthus does have some sort of sugar in stem, but nutritional value in leaves varies through summer.
Apart from Dry matter most of it is above my head, but if its safe, they like it and it's in anyway good for them, - well i now just have to find best time for dividing, which I bet, frustratingly, will be spring,
SO LONG to wait to start putting my plan into action!