The American Mint And Culling Coins

I have just posted this on the Canadian site and now on here to you guys just in case you people might know what happens.

Not sure if I have asked this topic before and my bank don't know what the answer is, so here goes my learned friends. Does the Mint take out all the American coins from the coins that it is culling, ie. Pennies, Nickels, Dimes and Quarters. I ask this because I read that the Americans keep check on what they cull so they know whats left in circulation. I am assuming that if they do this is the same reciprocated by the Americans for Canadian coins and the big question if they both do, does the mint get back American dollars in the exchange rate? As our banks do not give you American rate for coins.
Someone must know what happens.
Pennypincher

Already being discussed in another thread-echizento