That's wonderful that he's doing better, I worried all night. What a cutie!!!!!! Does he have a name yet? Who know's what it was. I had a March baby 3 years ago who had to wait 3 hours for a good feed until the mares milk came in, he finally got it just before I got home with milk replacer. He was shivering badly even though he had 3 blankets on and was them wrapped in two fleece blankets while he slept. It took him a bit to finally warm up. I wonder if it could be not getting enough to eat? If your little ones IgG is borderline maybe he wasn't getting quite enough in the beginning. Just an idea but something I'll watch for. More pictures and updates are always welcome