Can anyone give an explanation of "grass fed"? Are grass fed cattle only fed grass their entire lives? What grasses for pasture and hay are best? Will grass fed work for any breed? Especially Angus, Hereford, Charolais, Galloway and Highland. Those are the breeds I am mainly interested in. Does grass fed work better with certain breeds? I live in north west Pennsylvania. I'm also interested in hearing from anyone who raises the breeds mentioned above that are in my area. Thank You in advance.