Well, perhaps night time isn't the best time to try, but the foals are separated; technically, the mares are separated from the foals and other mares, as I put up a mesh panels so the babies couldn't reach through the panels, and put up two other panels to block the alley, so while they can see each other, they shouldn't be able to reach through and try to nurse.
I put out hay in the new paddock, the mares went right in and went to eating, the foals ran back and forth for 5 minutes and then joined the other mares around the hay feeder and went to eating. Now, all I need to do is figure out how much feed to give each baby, they've just been sharing with their dams so far, so I really don't know just how much they've been getting. [But, Spotty is taking enough away from Tana both by nursing and directly from the pan, that Tana is thinner than she's ever been, even when she nursed Monte, 4 years ago.]