My little 3.5 week old is so sleepy at his 10.30pm feed that he's not getting enough to get him through to his next feed. Have tried him on expressed milk from a bottle so I can tell exactly how much he's taking but he's getting such a shock, gagging and seems to gulp constantly taking in loads of air and very little milk. The avent teat says "1" on it and it has only the one hole. Is this the correct size for such a little baby or is there one expecially for newborns with yet a smaller hole?? He's a lazy little fella and I'm worried that if he does get the hang of it, he'll prefer that to boob - is this unfounded? Any advice?