I have a 3 week old Boer buckling that has eaten 2.5 ounces of milk in the past 24 hours. We have not changed his milk brand, amount per feeding (10 oz), or the number of feedings (3-4 daily). He has been eating with gusto before and now seems to have little interest in the milk. He is nibbling on grass and a little grain. His stools are normal, and he acts just the same - a fiesty little boy. I have felt him over and don't see or feel any signs of bloat or pain. What could cause this?