they stay in the fields there put mostly
Blame the badgers if they get out. Neighbour rents out her few fields to a sheep farmer. Whenever they get out on our land he always blames the badgers for making holes in the fence.Taking your question literally, depends how secure your fences are.
type of sheep would be big factor, we have texel cross Lleyns and introducing belcare to keep maternal instinct for replacements and texel for good grading
+1 better off having less ewes doing better producing more lambsIve 40 acre block that i rent from my brother. Some summers it easily supports 200 ewes and lambs with taking one crop of silage off a third of it. This year i havent taken any silage, but do have 7 acres into kale and only 150 ewes and lambs and was struggling for grass for a good while.
Only you know your ground and just gradually build numbers up until it works.
5 acres of swedes and 35 acres of grass is the way to go.