It's possible to raise cattle in this way, but that doesn't mean that if you buy beef, any of it will be raised in that way. If you buy cattle that's grazing at all, you're paying extra for it. It's not possible to satisfy more than a fraction of current demand with ecologically friendly grazing. It's not grazing I'm referring to which is resulting in desertification, but monoculture agriculture which is used to support the livestock.