Good looking boy! He has a little weight on my boys' birth weights at abt 7-1/2 lbs. each. Of course now my 4 yr old will be 5 in May, and my 8 yr old as of January are only 10 lbs apart and both wear the same size pants. 8 yr old is a head taller because of longer legs.
Congratulations on your son, good ending. Now don't you go copying that goat and not hold still for him to nurse.
On a serious note...hold that doe and make her let him nurse. They usually feed for a few seconds at a time, literally. But if mom is truly being a brat hold her/tie her/ whatever and let him get a good long drink. You may have to do this for a few days and hopefully she will catch on. Pen them in a small stall together too.