Weaning is a very complex thing. The most important thing to remember is the less stress on the animal is the most important thing.
We would put creep feeders in the paddock that only the lambs could get too just after the ewes started lambing with a small amount of pellets in them and montered usage topping up when needed. The ewes also had creep feeders right through lambing and througt to weaning. This was done to smooth out the feed transition from lamding to weaning. This prevented any stress reduced weight loss at weaning and increaced over all growth rates of lambs after weaning and in dryer years we were able to bring foward weaning as well.
Hope this is some help