But he's probably just being fussy. I have one of those too. I feed our horses a mixed feed with mineral pellets and he can eat everything and leave those little pellets at the botton of his feed bin. If I try to slip in anything, like vitamins or a supplement that has a taste he turns away and puts his head in the corner of his stall and pouts. He's so spoiled. I love him to pieces though. Lol
Good luck Brit.