Ultimately, livestock are the central tool in responsible agriculture. Ruminants convert grass forage into nourishing and useful products, mimicking the grazing impacts of native ruminants with which these ecosystems evolved. Livestock can also make valuable use of grain byproducts (e.g. hulls, screenings, brewers grain, etc) unfit for human consumption while fertilizing soil and terminating crops in place of synthetic fertilizers, herbicides and fungicides that damage land.