Hi No problem to mix in the lucerne pellets I only give my ewes half brebis half lucerne anyway as the brebis is too much for them; as for moveable shetletrs if you are able to get hold of a plastic veal calf shelter ( niche à veau) they work great you can move them around put a gate on the front and they are instant shelters. You may get a farmer neighbour to lend you one or you can pick them up second hand on le boncoin