My chin pretty much ignores apple wood. He'll chew the bark off but leaves the wood (he's a fickle little diva....). He seems to like willow, though. Corkscrew willow, in particular. He DESTROYS that stuff, but weeping willow works for him, too. He seems to like Mulberry as well, but most wood he just seems to take the bark off of and not actually chew the wood.