[member=163873]Lswswake[/member] amongst all the other variables mentioned, for me breed is important. If yours are Primitives, then they will need less feeding than a large downland type, say. So, what breed/cross are your sheep?
As I keep Primitives I am able to give feed in response to how the sheep perform and how hungry they are - ie if they eat all I put down within about 10 mins, then they needed that much, as they are not greedy and will not put on fat, as other breeds. If they nibble then walk off, they don't need so much. Expected condition score is lower in Primitives - what is normal for, say, a Hebridean, would be skinny for another breed; just right for another breed is decidedly hefty for a Heb.