We went down the several smaller paddock route when we kept a number of different breeds, and more than one tup per breed. So the reason for all the smaller paddocks was mostly just for tupping time. Across the road we have two separate bits and the males of all ages, stock tups and younger males, all live over there from 4 months, except when tupping.
On the main patch, we had 7 subdivided bits, some quite small, some larger. This gave us room to have all the non-breeding ewes of all ages in one large area, then 6 small paddocks for tupping groups. It was never enough
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When we had larger sheep numbers, we rotated the ewes round all those paddocks, moving them on when they all stood at the gate and shouted. This equated to when the grass was well eaten down so was good enough for me. In the winter all the gates would be left open and the sheep went where they wanted to, except in areas of growing hay.
Now we have far fewer sheep and a single tup this year. We have taken down one dividing fence and set aside the hay aftermath for the tupping group. The rest can wander around the other paddocks.
I appreciate that you are dividing for worm control. By keeping our stocking rate low and running a virtually closed flock, with dosing and 4 week quarantine for any stock brought on, we have a minimal worm problem. We worm if we see a scoury animal, and once a year the whole flock gets done. Our Fecs are very low.
So in our circumstances we get good parasite control by keeping the stocking rate down, rather than rotation of paddocks. We keep a close eye on our stock and would change our system if problems arose.
For paddock size, ours vary from 2 acres to about 1/4 of an acre. The larger areas can cope with a tractor and implements, but the smaller ones are difficult to get machinery into. We need a variety of paddock sizes for our particular circumstances.
I don't think there is any standard ideal size or number of paddocks as it all depends on your stock numbers, your acreage, your ground quality, your management methods and any number of other considerations.
In other words, I agree with what the others have said