"In the strictest sense, grass-fed beef comes from cattle that consumed only mother's milk and forage, including grasses, legumes and grass hay, and live exclusively on pasture. However, this category is the most variable of them all. Grass can make up the cattle's entire diet, or a large portion of it; beware of labels that read 'pasture-raised' and 'range-raised.' When in doubt, contact the rancher or look for the third-party certification to authenticate a grass-fed claim."
Reprinted with permission from Pure Beef © 2012 by Lynne Curry, Running Press, a member of the Perseus Book Group.