Digestion is the procedure our bodies usage to malfunction and absorb nutrients stored in ~ food, but the capability to digest food is not the very same for all animals. Cows, because that example, have a very different digestive mechanism than our own, and this permits them to prosper on a menu predominantly consisted of of grass.

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Let’s explore how cows space able come eat grass. The crucial to this capacity lies in the stomach. After us chew and also swallow our food, the stomach serves as a stop tank whereby digestion begins and also food starts gift separated right into individual nutrients. Next, food passes into the small intestine wherein the break down continues and where the body absorbs nutrients. This an easy digestive procedure is additionally true of cows, but there are a couple of extra procedures along the way.


Cows are unique in the they have actually fewer teeth than various other animals. In the front of the mouth, this (known as incisors) room only situated on the bottom jaw. In place of the top incisors, there is a hard leathery pad (known as the “dental pad”). In addition, cattle have a fairly immobile top lip (compared to goats and also sheep). Because of this unique oral anatomy, a cow provides its tongue to master a clump of grass and then bite it off. This in the earlier of the mouth (known as molars) are located on the top and also bottom jaws. Plant products sometimes contain hard stems, but because a cow chews food in a side-to-side motion, the molars shred the grass into tiny pieces the are more easily digested. 

The Stomach


Diagram 1. Stomach of the CowA = Esophagus; B = Reticulum; C = Rumen;D = Omasum; E = Abomasum; F = tiny Intestine Begins 


Diagram 2. Stomach of the DogA = Esophagus; E= Stomach Body; F = little Intestine Begins 


Diagram 3. The Reticulo-rumen.

All three diagrams courtesy the Sudz Publishing

On the right, a cow’s stomach is shown in Diagrams 1 and 3, and also a dog’s stomach is displayed in chart 2. Use the letter that label the stomach components in Diagrams 1 and 2 to recognize the similarities and differences between the two stomachs. Notice that the letters do an ext than identify the structures; they additionally map the route food travels on its cradle journey. The dog’s stomach is a lot like our own. See how many more structures there room in the cow’s stomach? In the cow, fairly than having actually a solitary pouch, there are four interconnected pouches, each v a distinctive function.

When a cow an initial takes a bite of grass, the is chewed very little before the is swallowed. This is a characteristic feature of the digestion in cows. Cows are recognized as “ruminants” since the largest pouch of the stomach is called the rumen. Imagine a large 55-gallon trashcan. In a maturation cow, the rumen is around the very same size! Its big size allows cows come consume huge amounts the grass. After filling up on grass, cows find a place to lie down to much more thoroughly chew your food. “But lock have already eaten,” you could be thinking. This is true, but cows space able to voluntarily “un-swallow” their food. This procedure of swallowing, “un-swallowing”, re-chewing, and re-swallowing is dubbed “rumination,” or much more commonly, “chewing the cud.” Rumination allows cows come chew grass much more completely, which boosts digestion.

The delusion is directly connected in rumination. The delusion is made of muscle, and also by contracting, it pressures food right into the cow’s esophagus which carries the food back to the mouth. The reticulum (letter B, diagram 1) is sometimes referred to as the “honeycomb” due to the fact that of its distinct honeycomb-like appearance. See number 1 because that a close-up look.

With a basic stomach, the dog, and also even man, can not digest many plant materials. A cow’s rumen is different due to the fact that it features like a big food processor. In fact, millions of tiny organisms (mainly bacteria) normally live in the rumen and aid the cow by breaking down plant components that cannot be digested otherwise. These tiny organisms then release nutrients into the rumen. Part nutrients are absorbed right away; others need to travel come the tiny intestine before being absorbed. To help the cow’s human body capture and absorb all these nutrients, the within of the rumen is covered by small finger-like frameworks (called papillae). In figure 2, an alert that the rumen wall surface resembles a shag carpet or the imitation structure on the inside of a winter coat. The papillae provide the rumen wall surface this texture. 

There is little separation between the an initial two sections of a cow’s stomach, the reticulum and also the rumen (Diagram 3), for this reason food and also water pass back and forth easily. The following pouch in the stomach is the omasum (letter D, diagram 1). This bag acts choose a huge filter to keep plant particles within the rumen while permitting water to pass freely. By keeping grass pieces and other feed inside the rumen, bacteria have more time to break them down, offering even much more nutrients because that the cow. Number 3 shows the multiple layers of the omasum. 

After the grass pieces and other feed are damaged down to a tiny enough size, they ultimately pass v the omasum and enter the abomasum (letter E, diagram 1). The prefix “Ab-,” way from, off, or away from. The abomasum, then, is situated just past the omasum. Refer earlier to Diagrams 1 and also 2 and an alert that the center of the dog’s stomach and the abomasum that the cow’s stomach are both labeled with the letter “E”. This illustrates a similarity in function. You see, the abomasum has actually the exact same basic role as the stomach of the dog, man, or other mammal, which is the manufacturing of acids, buffers, and also enzymes to break down food. ~ passing with the abomasum, partially digested food beginning the small intestine where digestion continues and also nutrients room absorbed.

Figure 1. The Reticulum.Photo courtesy the Dr. Karen Petersen, Univ. Of Washington, Dept. Of biology Figure 2. Rumen Papillae.Photo courtesy that Dr. Karen Petersen, Univ. Of Washington, Dept. Of BiologyFigure 3. The Omasum.Photo courtesy the Dr. Karen Petersen, Univ. Of Washington, Dept. Of biologic

The Benefits

The rumen properly extracts nutrients from food other pets cannot digest. For this reason, cows deserve to eat plant products (such as seed coats, shells, and stems) that stay after grains are harvested for person consumption. This remaining materials are sometimes referred to as “by-products.” Feeding byproducts helps farmers and businesses save money by not having actually to salary to dispose of this extra materials and also make money by selling the by-products as animal feed.

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When oil is extract from seed (for example, soybean oil from soybean seed and also Canola oil indigenous rapeseed), or seed are provided to brew alcohol or make fuel-ethanol, plant by-products are made. Although key nutrients (like fat, sugar, and also protein) are gotten rid of from the plant materials throughout processing, when provided properly, these by-products can be fed to cows. The complicated nature of your four-compartment stomachs and also their rumen bacteria allow cows to eat and also thrive ~ above plant byproducts that other animals cannot digest.

The far better we know the cow’s digestive system, the better we are able to build diets and manage ours herds for the optimal production of the nutritious meat and also milk we regularly enjoy. So, the following time you have actually a cool glass the milk, a cup of ice cream cream, or a juicy hamburger, you will understand that these commodities came native cows fed grass, grain, or by-products, and also you will know, How Cows Eat Grass