I am wondering how long every one tend to keep sows and boars breeding. With that, I am wondering what pushes you to stop breeding them, soundness, size, breeding ability, etc.
I always made the mistake of becoming emotionally attached to a few of mine and held on to them much longer than I should have. Ideally, my game plan was to keep them until the litters became smaller and they didn't bounce back as fast. Generally happened around 3 or 4 years old.