Mine hasn't read that bit of the cob manual. The only thing she really enjoys eating is grass and hay.
Now, are you sure she is not a fussy TB in a Cob coat?
Mine refused bananas too, well she backed away as if I was pointing a gun, rather than a banana, at her. She has very conservative tastes.I offered mine a banana once and he looked at me like I was mildly deranged. The warmbloods on the yard like them but clearly inappropriate for a cob who would like to be as wide as he is tall