Digestion is the process our bodies use to break down and also absorb nutrients stored within food, however the ability to digest food is not the exact same for all pets. Cows, for example, have a really different digestive system than our very own, and this enables them to prosper on a menu primarily made up of grass.

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Let’s discover how cows are able to eat grass. The key to this capability lies in the stomach. After we chew and also swpermit our food, the stomach serves as a holding tank wright here digestion starts and food starts being separated into individual nutrients. Next, food passes into the little intestine wbelow the breakdown continues and also wright here the body absorbs nutrients. This basic digestive process is likewise true of cows, yet there are a few additional steps along the way.


Cows are distinct in that they have fewer teeth than other pets. In the front of the mouth, teeth (recognized as incisors) are only located on the bottom jaw. In location of the top incisors, tright here is a hard leathery pad (known as the “dental pad”). In enhancement, livestock have actually a relatively immobile upper lip (compared to goats and sheep). Thus distinct oral anatomy, a cow offers its tongue to understand a clump of grass and then bite it off. Teeth in the ago of the mouth (recognized as molars) are located on the top and bottom jaws. Plant products occasionally contain hard stems, but because a cow chews food in a side-to-side movement, the molars shred the grass into small pieces that are even more easily digested. 

The Stomach


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


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


Diagram 3. The Reticulo-rumen.

All 3 diagrams courtesy of Sudz Publishing

On the right, a cow’s stomach is displayed in Diagrams 1 and also 3, and also a dog’s stomach is displayed in Diagram 2. Use the letters that label the stomach components in Diagrams 1 and also 2 to recognize the similarities and differences in between the two stomachs. Notice that the letters carry out more than recognize the structures; they likewise map the course food travels on its digestive journey. The dog’s stomach is a lot like our own. See how many more frameworks there are in the cow’s stomach? In the cow, rather than having actually a single pouch, tright here are four interassociated pouches, each with a distinctive feature.

When a cow initially takes a bite of grass, it is chewed very little prior to it is swpermitted. This is a characteristic feature of the digestion in cows. Cows are known as “ruminants” bereason the biggest pouch of the stomach is dubbed the rumales. Imagine a huge 55-gallon trashhave the right to. In a mature cow, the rumales is about the very same size! Its big dimension permits cows to consume huge quantities of grass. After filling up on grass, cows find a area to lie dvery own to even more thoapproximately chew their food. “But they have actually already eaten,” you could be reasoning. This is true, however cows are able to voluntarily “un-swallow” their food. This procedure of swallowing, “un-swallowing”, re-chewing, and also re-swallowing is called “rumination,” or more typically, “chewing the cud.” Rumicountry enables cows to chew grass even more entirely, which enhances digestion.

The reticulum is directly affiliated in rumination. The reticulum is made of muscle, and by contracting, it forces food into the cow’s esophagus which carries the food ago to the mouth. The reticulum (letter B, Diagram 1) is periodically referred to as the “honeycomb” because of its distinct honeycomb-prefer appearance. See Figure 1 for a close-up look.

With a simple stomach, the dog, and also male, cannot digest many type of plant products. A cow’s rumen is various bereason it functions prefer a large food processor. In reality, countless tiny organisms (largely bacteria) normally live in the rumen and also help the cow by breaking dvery own plant parts that cannot be digested otherwise. These tiny organisms then release nutrients right into the rumen. Some nutrients are soaked up appropriate away; others need to take a trip to the little intestine prior to being took in. To assist the cow’s body capture and absorb all these nutrients, the inside of the rumales is extended by tiny finger-favor frameworks (dubbed papillae). In Figure 2, alert that the ruguys wall resembles a shag carpet or the imitation wool on the inside of a winter coat. The papillae provide the rumales wall this texture. 

Tbelow is little bit separation between the first 2 sections of a cow’s stomach, the reticulum and the rumen (Diagram 3), so food and also water pass earlier and forth quickly. The next pouch in the stomach is the omaamount (letter D, Diagram 1). This pouch acts choose a large filter to keep plant pshort articles inside the rumen while allowing water to pass freely. By keeping grass pieces and other feed inside the ruguys, bacteria have actually more time to break them down, providing even more nutrients for the cow. Figure 3 mirrors the multiple layers of the omasum. 

After the grass pieces and various other feed are damaged down to a little enough dimension, they ultimately pass via the omaamount and also enter the abomaamount (letter E, Diagram 1). The preresolve “Ab-,” means from, off, or ameans from. The abomaamount, then, is located simply past the omaamount. Refer ago to Diagrams 1 and also 2 and notice that the center of the dog’s stomach and the abomasum of the cow’s stomach are both labeled through the letter “E”. This illustrates a similarity in function. You see, the abomaamount has actually the exact same fundamental attribute as the stomach of the dog, guy, or various other mammal, which is the manufacturing of acids, buffers, and enzymes to break down food. After passing via the abomaamount, partly digested food enters the tiny intestine where digestion proceeds and also nutrients are soaked up.

Figure 1. The Reticulum.Photograph courtesy of Dr. Karen Petersen, Univ. of Washington, Dept. of Biology Figure 2. Rumales Papillae.Photograph courtesy of Dr. Karen Petersen, Univ. of Washington, Dept. of BiologyFigure 3. The Omaamount.Photograph courtesy of Dr. Karen Petersen, Univ. of Washington, Dept. of Biology

The Benefits

The rumen effectively extracts nutrients from food other animals cannot digest. For this reason, cows have the right to eat plant materials (such as seed coats, shells, and also stems) that remain after grains are harvested for humale intake. These continuing to be products are occasionally referred to as “spin-offs.” Feeding spin-offs helps farmers and businesses conserve money by not having to pay to dispose of these extra materials and make money by selling the by-products as pet feed.

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When oil is extracted from grains (for example, soybean oil from soybean seed and Canola oil from rapeseed), or grains are provided to brew alcohol or make fuel-ethanol, plant byproducts are made. Although essential nutrients (prefer fat, sugar, and also protein) are rerelocated from the plant materials throughout processing, once supplied effectively, these byproducts deserve to be fed to cows. The complex nature of their four-compartment stomachs and also their rumen bacteria enable cows to eat and also thrive on plant byproducts that other pets cannot digest.

The much better we understand also the cow’s digestive device, the better we are able to formulate diets and manage our herds for the optimal production of the nutritious meat and also milk we on a regular basis enjoy. So, the next time you have actually a cool glass of milk, a cup of ice cream, or a juicy hamburger, you will certainly know that these commodities came from cows fed grass, grain, or by-products, and you will recognize, How Cows Eat Grass