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How Many Stomachs Does A Cow Have?

We came across a question the other day where a person asked: “How many stomachs do cows have?” The cow, in general, has 4 stomachs which are the rumen, reticulum, omasum, and abomasum respectively.

It seems quite strange to us that an animal might have three or four stomachs. Cows belong to a category of animals called ruminants. Ruminants are herbivorous, hoofed animals that chew the cud. Such animals have a single stomach, but the stomach is divided into four compartments and sometimes three. These stomachs are very different than ours.

Read further to know more about ruminants like cows and why they have multi-chambered stomachs. It’s quite fascinating!

How Many Stomachs Does The Cow Have?

cow stomach, cow

Contrary to popular misconceptions, a cow has only a single stomach. However, the animal is a true ruminant and has a multi-chambered stomach. For the cow, names of its stomach chambers are the rumen, reticulum, omasum, and abomasum. 

  • Rumen – Micro-organisms present in the cow’s rumen ferment components of its diet, such as fiber, protein, starch, and sugar, and produce fatty acids and microbial protein. Tiny finger-like projections called rumen papillae help the cow absorb these volatile fatty acids. 
  • Reticulum – Thereticulum is the place of the cow’s stomach where saliva mixes with what it eats and produces cud. If you’ve seen cows sitting down and chewing on something, it’s probably the cud.Cowsare ruminants because they can take the cud back into their mouths by burping and then chew to break down their food further. The reticulum is placed in front of the rumen and has a honeycomb structure. This structure might lead to hardware pieces like screws getting lodged there and can cause problems for the cow.
  • Omasum – The second-last chamber of the cow’s stomach is the omasum. This chamber only holds 8 liters of water and has several tissue “leaves,” which help the cow absorb water from their food. The omasum also traps food particles and allows only fine particles and liquids to pass on to the abomasum.
  • Abomasum – The abomasum is the true stomach of the cow. It has a capacity of around 27 liters or 7 gallons. The abomasum performs the same functions as the stomachs of monogastric or simple stomached animals. The cow’s enzymes and acids act on its food for a further breakdown before it is absorbed in the small intestines.

What Do Cows Eat?

Cows around the world have different diets. Cows in developing countries are often grass-fed. In other places, cows may be fed different kinds of silage, including hay and corn. Silage is a dried, compacted green fodder that is used as animal food in the winter. Cows are also fed distillers grain and ground soybean cattle feed.

Feeding cows soybean meal lets them gain lean weight and is healthy.

Let us talk about the different parts of the cow’s stomach in greater detail –

Reticulo-Rumen or Rumen & Reticulum – The rumen of the cow is unique in many ways. Some characteristics of the reticulo-rumen are –

  • High Microbial Density – The microbial density of this region is one of the highest in the world. Rumen microbes in the reticulo-rumen digest food by fermentation. Every ml of the rumen has a billion to  10 billion bacteria and a million protozoa. Some fungi are also present in the rumen.  
  • Large Capacity –  Being the largest chamber of a cow’s stomach, The rumen has a massive capacity of 184 liters or 49 gallons. The reticulum has a smaller capacity of around 16 liters.
  • No Enzymes Secreted – All the digestion in the reticulo-rumencomes from the microbes. The cow does not secrete digestive enzymes and stomach acids in the rumen.
  • Major Site of Absorption –  The rumen wall of the cow helps it absorb volatile fatty acids or VFAs. Absorption is made easier by the undulating surface area and Rumen papillae. The proteins created by the bacteria, however, are not absorbed from the rumen. They are absorbed in the intestines.

Some physical characteristics of the rumen are-

  • Anaerobic– The rumen is anaerobic. Rumen microbes are intolerant to oxygen, and fermentation cannot take place in the presence of it.
  • Warm– The rumen is one degree warmer (39°C or 102.5°F) than the cow’s normal body temperature.
  • A pH of 5.7 to 7.3– The higher end of the pH is for cows that have a poor quality of diet that includes urea. Dairy cows, however, might have acidosis, a condition where their pH is below 6.0. Low pH is caused by the cow overeating quickly digestible sugars or starch. Saliva is the buffer that prevents acidosis. Easily digestible foods that lack fibers might inhibit cud-chewing and, thus, saliva production. Rumen microbes that digest fibers are acid intolerant, and so a problem might be created for the health of the cow.

Why Is Rumen Important?

Without the rumen, the cow would not be able to digest fibers such as cellulose and Hemi-cellulose in its diet. The microbes of the rumen help the cow transform fodder and industrial by-products into nutritious food.

Omasum – The omasum is a small chamber and has a capacity of 8 liters. It has a large surface area, however, due to the presence of several large leaves or folds of tissue called laminae. The omasum has several names because of its appearances, such as the fardel, bible, psalterium, and manyplies.

About 95% of the output of the reticulum is water. The omasum’s surface area allows it to play a vital role in the absorption of water, VFAs, electrolytes, and minerals. It allows only fine particles to move on to the abomasum.

Abomasum – The abomasum connects the small intestine and the omasum. Like some of the other chambers of the cow stomach, its walls have folded ridges. The abomasum is the true stomach and has HCL acid and enzymes that break down food before it passes into the small intestine. Like the stomach of other animals, the abomasum has a low pH of 2-3. Ruminant microbes cannot tolerate the low pH of the abomasum.

Final Words

We hope you found this article useful and found your answer regarding how many stomachs does a cow really have. Well, if you want then you can even share this with your friends. Feel free to share with others who you think might find it interesting.