beLOVED: Goats milk is best I think because of rabbits sensative bellies... but kitten milk replacer might work. Be as gentle as possible with the bottle... try not to feed him while he's on his back so he doesn't get any fluid in his lungs.
I'd say once or twice a day. A full belly (ping pong ball belly. lol) means that they are nice and full.
Good luck!!
purplesaddle: lol yes... people just do these things to themselves.