Complex sentence: Both increase the yields of food and fiber per acre as compared to traditional animal husbandry, but in a CAFO the animal feed is brought to the animals which are seldom moved, and in MIRG the animals are bunched up and constantly moved to fresh forage.
Split into simpler sentences: Both increase the yields of food and fiber per acre as compared to traditional animal husbandry. In a CAFO feed is brought to the animals, which are seldom moved, while in MIRG the animals are repeatedly moved to fresh forage.