We have a baby that we are having to bottle feed. She is three weeks old, and she has been doing fine; but today she is not finishing her bottle. We are giving her about 12 to 14 ounces four times a day. We have hay and feed out for her, but we haven't seen her eating any feed. We have seen her nimble on her hay. What could be the problem today that is causing her not to finish her bottle? Do we need to cut back on her feedings?