Ruminants are herbivores that have complex stomachs and split hooves . Ruminants graze and chew their cud . Cattle , sheep , deer , camels , antelope , giraffes , bison , and llamas are all ruminants . Ruminant animals are important because of the way they digest food .
A ruminant animal has a large stomach which is divided into four compartments . One of the compartments is called the rumen . Digestion in the ruminant depends on the action of billions of microorganisms that live in the stomach and break down the plant material in the ruminant fluid .
Ruminants graze ( eat plants growing on the ground ) or browse ( eat the leaves and twigs from small bushes or trees ). Ruminants do little chewing of their food while they are grazing . They chew it enough to mix it with saliva from the mouth . Saliva wets the feed material lubricating it for swallowing . Enzymes in the saliva start the digestion process . Ruminants produce large volumes of saliva . The esophagus connects the mouth to the forestomach . The forestomach is made up of three compartments : the rumen ( 1 ), the reticulum ( 2 ) and the omasum ( 3 ). The abomasum ( 4 ) is the true stomach of a ruminant animal .
Once swallowed , the food goes to the first section called the rumen . The rumen of the cow is the largest of the four compartments . It may take up almost all of the left side of the abdomen .
The reticulum is the second compartment of the stomach . It is much smaller than the rumen , but it is part of the fermentation process . In the reticulum softened food forms small masses called cuds . When the animal rests , the muscles in the reticulum send the cud back to the mouth to be chewed and mixed with more saliva . This process is called rumination .
Rumen fluid and food particles that have been broken down to a small size pass from the reticulum to the third stomach compartment called the omasum . The omasum is mostly mechanical . Larger food particles are trapped for further digestion by the micro-organisms while the rumen fluid and small particles pass into the fourth stomach compartment . The abomasum , the fourth compartment , is very similar to the stomach of humans . The abomasum is the only part of the stomach that secretes digestive juices . The rumen fluid and small particles of food are mixed with the digestive juices and pass into the small intestine for further digestion and absorption .
Because of their amazing stomach , cattle are also being used to keep material out of our landfills . When plants are grown for human consumption , not all of the plant is eaten . While part of this waste material can be made into compost , the rest would be filling up our landfills . The cow is able to use those parts of plants that people can ’ t consume , digest it , and turn it into high grade protein . An example would be the beef . Beef is grown for human consumption and the rest of the plant is chopped up and fed to cattle in feed yards .