mine gets all sorts of fruit - never tried oranges though! think i gave a few people at the yard a shock when she came in from the field apparently bleeding heavily from the mouth (i'd actually just given her a punnet of raspberries as a treat...)
I keep my horse on a organic farm & we get loaaaaads of free carrot tops which Honey loves, she eats it like spagetti
and my old pony ate my friends lunch which she stupidly left in his stable lol, that was oranges .. custard creams and a bag of crisps! Ponies will eat anything tbh!