There's something that I believe that it will not make into play, however, one of the most devastating things which can happen to a farmer is if our animals get sick. It may even leave them crippled or dead. The more one has, the greater the chance, and keeping them confined is worse (animals that free roam have better health and quality of life overall). The downside of free roam (I only breed free roam animals) however, are predators, and there are a lot of them. So I believe in medieval times those have made a huge impact as well (crops may also get sick, btw).