Hobbies And Interests
Mouth and Teeth
A cow has 32 teeth, and they're configured so the cow can eat and chew a lot of high-fiber feed each day. The kinds of teeth that cut food are only present on the bottom of the cow's mouth, and the cow only has eight total---six incisors and four canines. The cow has no incisors at the top of its mouth, but instead has a dental pad. Conversely, the cow has 24 molars, the kind of teeth used to grind food.
To eat, the cow uses its mobile, strong tongue to pull grass into its mouths. It grips the grass in between its dental pad and incisors and pinches the grass off from the lower part of the stem. The cow chews by shifting the grass from one side of its mouth to the other, gripping the grass not just with its teeth but also with the rough sides of its palate and cheeks. The 20-35 gallons of saliva that a cow makes every day further breaks down the grass. The saliva has sodium carbonate in it, which helps the rumen maintain a pH that allows microbial to flourish. The food passes from the mouth down the cow's 18- to 36-inch esophagus into its stomach.
Stomach
The rumen, the first and largest compartment of the cow's stomach, contains billions of microorganisms that digest the grass fiber and give off fatty acids as a byproduct of that digestion. The fatty acids soak through the rumen's wall directly, and the cow uses them as energy -- the fatty acids supplied through the rumen give the cow 60-80 percent of the total energy the animal uses to function. The reticulum, the second compartment of the cow's stomach, has a honeycombed wall. Along with undigested feed, foreign objects accidentally eaten by the cow, such as stones or wire, also flow from the rumen into the reticulum. The foreign objects get trapped in the reticulum, but the food matter flows into the cow's stomach's third compartment, the omasum. The omasum is made up of piles of folds, like a book's pages. As the cud is sifted through the omasum, the omasum forces larger feed particles back up to reticulum and passes the smaller feed particles and fluid on into the abosasum. The fourth compartment of the cow's stomach, the abomasum, breaks down the feed further, using the enzymes and acids that it produces in the same way the human stomach does.
Small Intestine
The stomach passes fiber, microbes and some of the sugar and protein produced by the microbes, as well as other digested food matter such as protein, carbohydrates and fat, into the small intestine. Simultaneously, the pancreas floods the small intestine with enzymes, and bile flows in from the gallbladder. The small intestine also produces a small amount of enzyme. The enzymes break down the protein, starches and sugars, and the bile breaks down the fats. Once those food components are broken down into nutrients, the small intestine absorbs those nutrients, as well as any vitamins and minerals that have been passed into the intestinal tract.
Large Intestine
Anything the small intestine is unable to digest flows into the large intestine. The large intestine takes the excess water, waste products from microorganisms and any remaining feed, and forms it into fecal matter. The cow expels that fecal matter as manure. The more fibrous the cow's feed, the firmer and darker the manure.