What is the big deal about grass and cows? Why do cows eat grass and do they really like grass? The fact is that beef is special among the top meat proteins: beef, pork and chickens. Out of the three, cattle are the only ones that can convert grass into energy. Cattle are ruminants which means they have multiple stomachs. This gastric system turns fiber into energy by fermentation which means breaking down grass (starch) into a form which can be absorbed and used by the cows. If chickens or pigs eat grass, the grass would simply pass through animals without digestion. Therefore, cattle are they only ones that can utilize this rich abundant resource. And that is why cows can turn grass into energy-giving nutrition, because of the miracle of the ruminant.