Mine are still out at overwinter grazing, they are gathered to be scanned in mid Jan bu they will be left at grazing with no supplements until maybe mid feb
they are then brought home and put into small paddocks with hay, then the twins are given lifeline buckets 3 weeks pre lambing plus hay,
singles get hay and yellow rockies, nothing else, all lambing outside, ewes and lambs are taken to new grazing in batches once the lambs are 24-48 hours old
Lambs and ewes dont get any concentrates or creep, I had lambs away in june after being born in April and had some go off in July weighing 56kilo (woops)
Ewes do loose some condition over winter but they should be lean during lambing to prevent problems, they have the whole summer to put it on again and right now are in condition score 2-3 with the charmoise's being higher due to amount of muscle
So I would say nope, they dont need anything else other than grass, if you dont have grass offer some hay