Structure and features of the stomach of a cow

How many stomachs does a cow have? One, two, three, or even four? This may surprise you, but only one, but consisting of four sections. The first and largest section is the rumen, and the forestomach contains the reticulum and omasum.

No less interesting and not quite euphonious is the name of the fourth chamber of the stomach – it is the abomasum. The entire digestive system of a cow requires detailed consideration. More about each section.

The stomach section of ruminants

Scheme, photo:

The digestive system of a cow consists of several sections, differing in function, namely:

• the oral cavity;
• throats;
• the esophagus;
• stomach.

The mouth of these animals is especially interesting, since its main purpose is to pluck grass, hence the presence of only the front row of lower teeth.

The volume of saliva secreted every day is impressive, it reaches approximately 90 to 210 liters! Enzymatic gases accumulate in the esophagus.

Scar

The cow’s rumen is the largest chamber, performing a number of very important digestive functions. The thick-walled rumen is not affected by coarse food.

The minute contraction of the rumen walls ensures the mixing of the grass eaten, and enzymes then distribute them evenly. Here, too, the hard stems are ground. What is the purpose of the rumen?

Let us outline its main functions:

1. Enzymatic — intracellular bacteria start the digestive system, thus ensuring the initial fermentation process. Carbon dioxide and methane are actively produced in the rumen, with the help of which all food entering the organ is broken down. If carbon dioxide is not burped, the animal’s belly swells, and as a result, the work of the other organs fails;
2. Food mixing function — scar muscles help mix food and then pass it on for re-chewing. It is interesting that the walls of the scar are not smooth, but have small formations resembling warts, which help absorb nutrients;
3. Transformation function — more than one hundred billion microorganisms present in the rumen, which help convert carbohydrates into fatty acids, which provides energy to the animal. Microorganisms are divided into bacteria and fungi. Protein and ammonia keto acids are converted thanks to these bacteria.

A cow’s stomach can hold up to 150 kg of feed, a huge portion of which is digested in the rumen. Up to 70 percent of the food eaten is found here.

There are several sacs in the rumen:

• cranial;
• dorsal;
• ventral.

Probably, each of us has noticed that a cow, after some time of eating, regurgitates it back for re-chewing. The cow spends more than 7 hours a day on this process!

The mass that is regurgitated repeatedly is called cud. This mass is thoroughly chewed by the cow, and then goes not to the rumen, but to another section – the book. The rumen is located in the left half of the abdominal cavity of the ruminant.

Сетка

The next section in the cow’s stomach is the mesh. This is the smallest section, with a volume of no more than 10 liters. The mesh is like a sieve that stops large stems, since in other sections coarse food would immediately cause harm.

Imagine: a cow chewed grass for the first time, then the food got into the rumen, regurgitated, chewed again, got into the net. If the cow did not chew thoroughly and left large stalks, they will be stored in the net for one to two days.

What does it do? The food is decomposed and offered to the cow again for chewing. And only then does the food go into another section – the book.

The mesh has a special function – it separates large pieces of food from small ones. Large pieces, thanks to the mesh, are returned back to the rumen for further processing. There are no glands in the mesh.

Like the rumen, the walls of the mesh are covered with small structures. The mesh consists of small cells that determine the level of processing of the food by the previous chamber, i.e. the rumen.

There are no glands in the grid.

How is the mesh connected with other sections – the rumen and the book? It’s very simple. There is an esophageal groove, which resembles a semi-closed tube in shape. Simply put, the grid sorts the food. Only sufficiently crushed food can get into the book.

Book

The book is a small compartment that holds no more than 5 percent of the food consumed. The capacity of the book is about 20 liters.

Only here is the food chewed by the cow many times processed. This process is ensured by the presence of numerous bacteria and powerful enzymes.

It is no coincidence that the third section of the stomach is called the book, which is due to the appearance of the section – continuous folds, divided into narrow chambers.

The food is located in the folds. The cow’s digestive tract does not end there – the incoming saliva processes the food, fermentation begins.

How is food digested in a book? The food is distributed along the folds and then dehydrated. Moisture is absorbed due to the features of the grid structure of the book.

The book performs an important function in the entire digestion – it sucks in food. The book itself is quite voluminous, but it holds a small amount of food. All moisture and mineral components are absorbed in the book.

What does the book look like? On an elongated bag with numerous folds.

The book is like a filter and a grinder of large stems. In addition, water is sucked in here. This section is located in the right hypochondrium.

It is connected to both the reticulum and the abomasum, that is, it continues the reticulum, passing into the abomasum. The membrane of the third section of the stomach forms folds with small nipples at the ends.

The abomasum is elongated and pear-shaped, thickened at the base. Where the abomasum and omasum join, one end joins the duodenum.

Why does a cow chew its food twice? It’s all about the fiber contained in plants. It’s difficult and takes a long time to process, so double chewing is necessary. Otherwise, the effect will be minimal.

Abomasum

The last section of the cow’s stomach is the abomasum, similar in structure to the stomachs of other mammals. A large number of glands and constantly secreted gastric juice are the features of the abomasum.

Longitudinal rings in the abomasum form muscle tissue. The walls of the abomasum are covered with a special mucus consisting of epithelium containing pyloric and cardiac glands.

The mucous membrane of the abomasum is formed from numerous elongated folds. The main digestive processes occur here.

Enormous functions are assigned to the abomasum. Its capacity is about 15 liters. Here, food is prepared for final digestion. The book absorbs all the moisture from the food, therefore, it enters the abomasum already dried.

Stomach diseases

A clear symptom of the presence of pathologies is the cessation of chewing in an animal.

Digestive problems are caused by:

• poor quality feed;
• violations of the eating regimen;
• unfavorable conditions for keeping the animal.

Bloating

The medical term for this phenomenon is tympania. It is a dangerous condition and is characterized by intense gas formation.

Occurs due to:

• changing the cow’s diet;
• grazing it on wet meadows;
• the presence of legumes in the feed;
• esophageal obstruction.

Symptoms of tympania are:

1. Absence of chewing reflex.
2. Refusal to eat.
3. Distended peritoneum.
4. An anxious, restless state of an animal.
5. Rapid pulse.
6. Dyspnea.
7. Pale mucous membranes.

This condition is life-threatening for cattle. The swollen rumen compresses the diaphragm, the animal cannot breathe properly and dies from lack of oxygen.

Providing assistance to cattle in this condition depends on the cause of tympania:

1. In case of obstruction of the esophagus it is necessary to push the stuck food. This action must be done with a flexible and thin probe. It is better to entrust this to a veterinarian. You can help by massaging the area of ​​the hungry pit or cooling it with cold water. Massage with a fist. Do not let the cow lie down – she must be in constant motion.
2. With increased gas production medications will help: “Timpanol”, magnesium, activated carbon.
3. If other methods did not help the animal, the veterinarian makes a puncture of the abdominal wall and perforates the scar.

Stopping digestion

An incorrectly formulated diet for a cow, a violation of the feeding regime, an abundance of concentrated feed, the animal eating rotten hay, and blockage of the esophagus most often cause digestion to stop.

Symptoms include:

• Lethargy.
• Apathy.
• Absence of chewing reflexes.
• Loss of appetite.
• Lack of contractions in the area of ​​the hunger pit.

As a therapy, cattle are left completely without food for a day.

After which, carefully introduce into the diet:

• silage;
• fresh hay;
• high-quality root vegetables.

You can start the stomach working by using:

1. Gastric lavage.
2. Saline solution as a drink.
3. Scar massage.

Injury

Due to the cow’s peculiarity of grabbing and swallowing feed without chewing it, there is a risk of the animal swallowing foreign objects.

It can be:

They damage the walls of the stomach and intestines or get stuck in them.

If a foreign object causes a through injury to the stomach wall, then the following are at risk:

The symptoms are pronounced and include:

1. Lack of appetite.
2. Animal anxiety.
3. When swallowing, the neck is stretched forward.
4. Unnatural posture of the cow, appearance of a hump.
5. Blood in the stool.
6. Increased temperature.
7. Pain when touching the sternum.

To provide assistance, a magnetic probe is used or the object is removed surgically. However, given the specifics and high cost of these methods, in most cases the animal is sent for slaughter.

Book pile-up

This digestive pathology is caused by the predominance of the following in the cow’s diet:

• dry food;
• bran;
• grain waste.

The presence of sand and dirt in the stern is also a cause of blockage.. The symptoms of the disease completely coincide with the symptoms of stomach arrest. To determine the exact cause, the stomach is punctured with a sharp needle. If it penetrates the stomach area heavily, it becomes clear that the animal has a blockage.

For treatment, all sections of the stomach are washed with a 10% sodium solution. Both sodium chloride and sodium sulfate can be used. After washing, digestion is started in the same way as when it is stopped.

Each chamber of the cow’s stomach performs its function. If even one section stops, the entire digestion of the animal suffers. The use of high-quality feed for food, a diet and favorable conditions for the cattle will help to grow a healthy livestock population.

Results

Thus, the structure of a cow’s stomach is quite unique, since a cow does not have 4 stomachs, but a four-chambered stomach, which provides the processes of the cow’s digestive system.

The first three chambers are an intermediate point, preparing and fermenting incoming food, and only the abomasum contains pancreatic juice, which completely processes food.

The cow’s digestive system includes the rumen, reticulum, omasum, and abomasum. The enzymatic filling of the rumen ensures the process of food breakdown.

The structure of this section resembles a similar organ in humans. The rumen of cattle is very capacious – 100-300 liters, while that of goats and sheep is much smaller – only 10-25 liters.

Long-term retention of food in the rumen ensures its further processing and decomposition. At first, the cellulose undergoes splitting, a huge number of microorganisms participate in this.

Microorganisms change depending on the feed, so there should be no abrupt transition from one type of food to another.

Fiber is very important for the ruminant’s body as a whole, as it ensures good motility of the forestomach sections. Motility, in turn, ensures the passage of feed through the gastrointestinal tract.

In the rumen, the process of fermentation of feed masses occurs, the mass is broken down, and the body of the ruminant animal assimilates starch and sugar. Also in this section, protein is broken down and non-protein nitrogen compounds are produced.

The acidity of the environment in the abomasum is provided by numerous glands located on the walls of the abomasum.

The food here is broken down into tiny particles, and the nutrients are then completely absorbed by the body, and the finished mass moves into the intestines, where the most intensive absorption of all useful microelements occurs.

Imagine: A cow eats a bunch of grass in a pasture and the digestion process begins, which ultimately takes 48 to 72 hours.

The digestive system of cows is very complex. These animals must continuously eat, as a break will cause big problems and will have a very negative effect on the health of the cow.

The complex structure of the digestive system has negative qualities – stomach upset is a common cause of death in cows.