To supplement or not at the birth of a baby to be nursed by an adopting
mother--
In my experience, it is wise to let the baby decide.  No baby gets loads
of milk in that first feed so there is nothing wrong with offering the
breast "as is" and seeing how it goes.  Sometimes it works and sometimes
the new baby has a strong negative reaction.  (I can only think that the
adoptive mom smells wrong to this new little one.)  If the baby won't
just go to the breast "au naturale", put on the supplementer and try
again.  In my experience, I find that babies often accept the breast
more readily from an adopting mom at day 3+ than in the first hour or
two--which goes against all my intuition.

I have not worked with a situation where there is donor milk--it adds an
interesting twist in my theory that the problem may be the baby's sense
that its the "wrong" mother. However, I have worked with experienced
nursing mothers who had sizable milk supplies and yet struggled to get
the baby to accept the breast.  Of course, in every case there were
usually lots of other possible reasons for breast rejection.  Has anyone
else seen this?