I'm in the process of selling off most of my sheep. I was going to keep a ram flock (the sire, two sons from last year, and maybe one from this year), but the girls are so much easier. I'm planning on keeping two ewes born last year, one or two born this year, and possibly another that is older. Since some of these ewes werel never breed, is this going to be a problem? Is it better for their health to be bred at least once?