If the ruminants are wild and forced through natural migratory routes by predators, or if ranchers put in the bare minimum effort to keep the herd moving they actively restore the land and increase the water infiltration rate and water retention leading to more grass production. Cows are beyond sustainable if you just keep them from sitting on the same small plot of land in perpetuity. There's nearly infinite low quality rocky dry land that is ripe to be converted back into grasslands through restorative grazing. It's great for biodiversity, the environment in general and the best part of americans is the byproduct is the method by which land is restored creates edible meat in massive quantities
