The essence of breastfeeding is a good latch.  The better the latch,
the better the baby gets milk.  But, also, if the baby is well latched
on, the baby also should have no trouble with the nursing supplementer
tubes.  I don't think it necessary to "habituate" the baby with little
tubes.  Work on the latch, the supplementing will come easy if it's
necessary.

Jack Newman, MD, FRCPC