It is actually quite simple. Unless you artificially restrict the ability for a herd to migrate, herds will migrate from a spot where they have eaten the greene

It is actually quite simple. Unless you artificially restrict the ability for a herd to migrate, herds will migrate from a spot where they have eaten the greenery to an area where there is more greenery. This rotation allows the soil to regain its fertility without the grasslands becoming completely denuded. That is to say: Rotational grazing is very beneficial. Grazing only becomes problematic when rotation is severely restricted.