First of all, dump the replacer and feed plain old whole cow milk from the store. While some kids will do fine on replacer, others cannot tolerate it and that includes the expensive replacers made especially for kids. They may scour or worse, suddenly blow up and die. Trying to get mother raised kids to accept a bottle is a challenge, to put it mildly. You might try putting some milk on your finger and see if he will suck on that. Another thing I have done is while the kid is sucking on the teat, slip the nipple in its mouth.
