QUOTE (LoveToLaugh @ Feb 7 2008, 11:19 AM)

Let's say a mother exclusively BFs baby for first six week. When she goes back to work and is BFG her baby while she is at home, does it matter if she leaves the baby-sitter with a couple of bottle of her own milk as opposed to bottles of formula?
Yes, what's in the bottle is also important.
Breastmilk is her best defense against catchable diseases, pumping is the best way for mommy to keep up her supply, any and all breastmilk the baby gets just adds to the benefit. Many babies who are breastfed don't like the taste of formula.
Switching to formula is not as easy as it sounds, and i know quite a few babies who had negative reactions to cows-milk based, soy based, and had to get expensive hypoallergenic. Pumped milk won't have this problem, is less likely to spoil, free, a way to connect with the baby even if you're not there, the right balance of everything she needs.
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Also I've heard from some mothers that if you don't get the baby used to taking a bottle and/or taking other milk besides for breast-milk when they are young, they will have a much harder time adjusting to it when they are - let's say a year old. Is this universally true?
Switching to cow's milk: I have NEVER seen that to be true of a child who doesn't have a sensitivity or allergy to cow's milk. Since breastmilk is constantly changing in taste, babies who are used to bottles, from what I've seen, don't necessarily take too badly to a change in types of milk. Some mothers have introduced it gradually (by mixing in their milk), but never have I seen a baby refuse it because he was breastfed if he didn't have a medical reason not to drink it. (Babies are instinctive that way, BTW).
As far as getting used to a bottle, that might be true on baby's temperament, but at a few month's old you might be able to introduce a cup.