About a week ago one of my calves lost interest in feed, gave him probios and b-12, and all the hay he could eat. 2 days later still not much interset in feed. So I washed his feed pan, and started mixing white cake mix in with his feed, still not much interset in feed. So I started mixing in a different brand of feed, gave him some appetite express and champions choice, and still not interseted in feed. His stool is good not runny or bloddy and he eats hay, just not interseted in feed. All my other calves eat like theres no tommorow. I have done everything I know to do. Any more suggestions?