A rumen.
T-rex did not have two stomachs. Today, ruminants (grass eating animals such as cattle) have two stomachs in order to better digest the grass they eat, which is very difficult to digest.
A cow has a four part stomach. A cows stomach helps it to digest grass easier and to get more nutrients from the grass.
Cattle that are laying (or sitting) in the grass, or cattle laying down in the pasture.
Wherever grass grows, whether it be on lawns or in fields, anywhere that grass grows often cattle will find them and eat the grass in those areas.
shrubs and cattle grass
No. If grass-fed cattle got any grain, they wouldn't be grass-fed then. Grass-fed beef comes from cattle that are finished on grass only, with absolutely NO grain.
Man.
Grass.
Well, it depends on what species you are referring to (since you have the question posed for not just cattle, but also for goats, sheep and horses), and the quality of the grass or hay. Poor quality grass will take longer to digest than good quality hay, and poor quality hay will take longer to digest than high-quality grass. In ruminants such as sheep, goats and cattle, a low quality forage can starve an animal to death because all it's doing is sitting in the stomach and not doing anything for the animal. It's different for horses, though, as they are able to digest poor quality forage than ruminants because they have a different digestive tract. Horses can digest forage that is high in fibre because it can move through quicker and won't get piled up in the stomach like that will happen with most ruminants.
Where cattle defecate there will sometimes be a hillock of grass.
Watusi's eat grass, just like other breeds of cattle do.
Most cattle graze on green grass in the summer; some of the cattle that are used for dairy are put outside occaisonally to get some exercise and maybe eat a little grass.