Hi Egglady
We feed our ewes with concentrates (sheep coarse mix is sufficient for primitives, not pencils which are higher protein) for the six weeks before the first one is due to lamb, gradually increasing the amount. We carry on through lambing (April) at the high rate and then on into May. At the moment, late May, they are all still interested and are eating plenty of grass plus a slightly reduced amount of concentrates. I am expecting that some time in the next few weeks they will show less and less interest in the concentrates so we will reduce the amount they get. In practice we tend to continue to give them a little up until late June because we usually take sheep to the Royal Highland Show, where they need to eat concentrates, so we are continuing to maintain the correct gut flora until then. We stop after that. This year we are not taking ewes with lambs, just 2 gimmer shearlings and a tup, so we will stop feeding the ewes when they tell us to.
We judge the precise amount to give by a mixture of the general condition of the sheep - not too fat or too thin - and by how much they want to eat. If they eat it all very quickly we know they need more, but if they tend to wander off before it's finished then we know they are getting too much. For those who wean their lambs at 3 months, that would almost be feeding throughout milking, but in the later stage of ewes feeding their lambs, after 3 months, the lambs are getting a lot of nutrition from grass and the quantity of milk from the ewes decreases, so their need for concentrates also decreases.
We had deep snow at the end of March, beginning of April this year and plenty of frosts since so the grass was late to get going and we have been feeding more concentrates than usual. It varies from year to year.