I have shot doe in December that still had milk in the udder. Their fawns were no longer drinking and on solid food but they had not dried up yet. Fawns will continue to drink milk in small amounts even after they are able to live on solid food which they will start to eat at two weeks of age, it is a bonding thing with the doe, although their digestive system is not yet developed to the point where they can survive without milk, it is a bonding thing with the doe. When the doe has enough of the large fawns nursing she will no longer allow them to do so and begin to dry up. I have seen while hunting large fawns attempting to drink from the doe and get a kick for their efforts.