I've read a bit about adoptive breastfeeding and it was recommended to me at the time we adopted our little boy by someone who had done it. What I've read suggests pumping to express many times a day to stimulate the milk supply, as would a suckling baby. I had horrible visions of being in Korea with mastitis and a new baby who didn't know me and that put me off the whole idea. Not only that but as soon as you are handed the baby it's off to the airport and straight home, so a long flight also with a baby who may be fretful (luckily ours wasn't). Since breastfeeding my daughter I know now what I (and he) missed, and really wish I had tried, even if I only started the whole expressing thing after returning home from Korea. That said it may not be easy with a 5 month old who has been used to the bottle since day one.