Barbara:

How can colostrum be produced in a finite amount if mothers leak colostrum
(some leak alot) during their pregnancies and mothers also tandem breastfeed.
Colostrum is a (to simplify) concentrated form of milk that is mediated by
hormonal influences, and when the hormonal influences signal that its time to
change to "mature" milk, it does. (I hate that word mature. What a misnomer.)

Now this is an oversimplification, I'm sure.

 It is also my understanding that autocrine control does not rule the roost
until 3 months pp. Until that time, prolactin is very much going to play a
role in milk quantity, hence the important role of prolactin regulating
lactose uptake and subsequent fliud uptake to the breast to create milk
volume.

Alison