I don't even start the weaning process until 12 weeks, and I keep mine on 4 bottle until atleast 8 weeks, and 3 bottles until atleast 12 weeks. I actually base my weaning on each individual kid, I start weaning w/ the kids seem ready, and I know they are ready by the way the eat, once they start playing around w/ the nipple before sucking, and if they are in a large area once they stop meeting me at the gate. Those are the best indicators that they are ready to start weaning. And when grown (and generally by 6 months) my bottle babies won't take a bottle. I have one doe that was not raised by me that wants the bottle. Atleast that is how I handle my keeper kids.
On the other hand last I knew my bottle cow would still take a bottle! She may not now, it's been along time since she's seen one, but I know she would well after she was grown!