Cows have one large stomach that is divided into four compartments to go through the different stages of digestion.
Depending on what a bovine eats, it may take one to three days for the food to pass through the digestive tract. Cattle have ruminant stomachs, stomach with four separate compartments. The compartments are called the rumen, the reticulum, the omasum and the abomasum. Each compartment has its own specialized duty in the digestive process.
The rumen is the largest part of the cow's stomach, holding up to 50 gallons of partially digested food at any given time. It contains enzymes that start the digestion process, breaking down the hard food and cellulose.
The reticulum traps anything that the cow should not have eaten, such as pieces of fencing, rocks and pieces of wire. The reticulum also softens the grass that has been eaten and forms small wads of cud.
The omasum has many folds to filter the food, squeeze out the water and further break down the cud.
The abomasum completes the digestion process.