My goats are a pain when it comes to feeding. Everyone on here and in 'real life' says they are no more difficult/much easier than other animals.
I got some bags of hay from a couple of bales that my neighbour had cut. The goats loved it, even eating strands off the floor (unheard of!). So I got a bale of this hay; same field, same storage: they hated it. Tried feeding them Some from the bags of hay which they'd previosly loved and they wouldn't touch it either.
At first they stood about in the fields for weeks (basically the whole of last summer) refusing to eat, till they lost all condition and then decided that actually, hawthorn, willow, docks, etc, were quite tasty and started tucking in.
Any food/hay still in their rack after half hour used to be ignored, but they've toughened up a bit now and will munch through it. (Everything they get is dry, good quality, and well up off the floor.) Similarly they are now good at browsing the hedges and scrub and grazing (they take the tops of the grass and herbs and weeds, but I'm not looking for a lawn, just a bit of effort)!
The only way I got them eating greenery/hay was to cut hard feed and veg so that they had no choice. Otherwise theyd eat nothing but mix and veg which isn't good for their tummies (obviously).