Doe Delivers Five Kids - one tiny struggling

My doe, Katie kidded five live babies March 28 (two days ago). First born was tiny, less than a pond, and so weak he couldn’t hold up his head. I thought we were going to lose him. Brought him in, bundled him up, syringe fed mom’s colostrum. In a couple of hours, he could raise his head and was trying to stand. Standing didn’t happen until 12 hours or so, but he is a little fighter and was progressing until this afternoon. I have been feeding colostrum replacer because I was afraid mom would not have enough for the other four. Started to slowly switch him over to cows milk today. I fear I have over fed him because he is now not wanting to eat. His little belly seems a little bloated too.

This is my first experience with bottle feeding. I need some quick advice on how I can relieve his bloat, if it is bloat, and how much he should actually be eating. Also, how often.

I read that he should be eating 10% to 12% of his body weight. Today he weighed in at 1.5 lbs, up 0.2 lbs from yesterday.