Part of the stomach of ruminants. Digestion in the stomach of ruminants. Physiological phenomena in the digestion of ruminants

The stomach of a cow is arranged in a special way - it has four sections or chambers, each of which performs its own function. Violation of work at least in one of the parts of the digestive system entails various pathologies of animal health.

Features of cow digestion

Cows have an interesting digestive system - this animal swallows food whole, almost without processing it with its teeth, and then, when resting, burps it in parts and chews it thoroughly. This is why a cow can often be seen chewing. The mechanism for burping and chewing food from the stomach is called chewing gum. If this process stops in a cow, then something is wrong with her.

The digestive system of a cow has the following structure:

1. Oral cavity - lips, teeth and tongue. They serve to capture food, swallow and process.
2. Esophagus. Its total length is about half a meter, it connects the stomach to the pharynx.
3. The stomach consists of four chambers. We will consider its detailed structure below.
4. Small intestine. Consists of the duodenum, jejunum, ileum. Here, the processed food is enriched with bile and juices, as well as the absorption of useful substances into the blood.
5. Colon. From the small intestine, the food mass enters the large intestine, where additional fermentation of food and absorption of substances into the blood takes place.

The structure of the stomach of a cow and its departments

The structure of the stomach in a cow is also of interest - this organ consists of 4 chambers:

• scar;
• grids;
• books;
• abomasum.

The real stomach in the full sense of the word is the abomasum, the remaining chambers are used for pre-processing food, they are called pancreas. The scar, the book and the mesh do not have glands that produce gastric juice, only the abomasum is supplied with them. But in the proventriculus, fermentation, sorting and mechanical processing of feed takes place. Consider the sections of the cow's stomach in detail.

Scar

A scar is the first section of a cow's stomach. It has the largest volume compared to other chambers - about 200 liters! It is located in the abdominal cavity on the left side. Swallowed food enters this pancreas. The scar is filled with microorganisms that provide the primary processing of food.

Reference. The rumen contains a huge number of microorganisms, their total weight is about 3 kilograms. They contribute to the synthesis of B vitamins and protein in the animal's body.

The scar consists of a double muscle layer and is divided into 2 parts by a small groove. The mucous membrane of the proventriculus is supplied with ten-centimeter papillae. It is in the rumen that the breakdown of starchy compounds and cellulose to simple sugars occurs. Through this process, the animal receives the necessary energy.

Net

This section of the stomach is much smaller in volume than the previous one. Its capacity is not more than 10 liters. The mesh is located in the chest area, one of its sections is adjacent to the diaphragm. The main function of the net is to sort the feed. Small fractions of food from here move to the next section of the stomach, and larger ones burp and enter the cow's mouth, where they are chewed. The mesh, as it were, filters food, passing food that has already undergone primary processing further through the digestive system.

Book

Small pieces of food move into the book - the third section of the stomach. Here, the food is carefully crushed mechanically, due to the special structure of the mucous membrane. It consists of folds resembling leaflets. In the book there is a further processing of coarse fiber fibers and the absorption of water and acids.

Abomasum

The abomasum is the only part of the cow's stomach that is supplied with glands for the secretion of gastric secretions. It is located in the area between the 9th and 12th ribs on the right side. Its volume in adults reaches 15 liters.

In calves, the abomasum is actively working, while the rest of the stomach remains unused until almost three weeks of age. Their scar is in a folded position, and the milk immediately enters the abomasum through the chute, bypassing the net and the book.

Common pathologies

Cows often suffer from pathologies of the digestive system. They pose a serious danger to the life of a ruminant animal. Common digestive problems in cows:

• bloating;
• stop;
• blockage;
• injury.

Bloating

Tympania or bloating is a very dangerous condition that occurs due to a sharp change in the cow's diet, the animal eating large amounts of food that contributes to increased gas formation. Tympania can occur due to a blockage in the esophagus. Symptoms:

1. Refusal to eat.
2. Enlarged belly.
3. Lack of chewing gum.
4. Anxiety.
5. In severe cases - shortness of breath, pallor of the mucous membranes.

Attention! This condition is dangerous for the life of the cow, as the enlarged scar strongly compresses the diaphragm, preventing the animal from breathing normally. If help is not provided, the cow will die from lack of oxygen.

Treatments for bloating include:

1. Removal of a foreign body from the esophagus using a flexible probe.
2. Stimulation of the stomach to start it.
3. The use of medicines that prevent gas formation and fermentation - Tympanol, burnt magnesia, activated carbon, ichthyol.
4. In emergency cases, they resort to perforation of the scar with a trocar.

You can start the stomach with a massage. It is performed on the left side of the abdominal cavity, in the region of the hungry fossa with a fist. Dousing this area with cold water often helps. A cow needs to run for her stomach to work.

Stop

The process of digestion often stops in cows due to improper feeding, for example, if concentrates predominate in the diet or the animal ate rotten hay. Also, gastric arrest occurs when the esophagus is blocked. Symptoms of pathology: loss of chewing gum and appetite, general depression. If a cow's stomach has stopped, this can be checked. You need to lean with your fist in the area of ​​\u200b\u200bthe hungry fossa and listen to whether contractions occur.

Treatment of this pathology begins immediately. The first thing to do is to keep the animal on a starvation diet for a day. In the future, digestible feed is gradually introduced - silage, a small amount of root crops, high-quality hay.

To start the stomach, apply:

1. Hellebore tincture.
2. Gastric lavage.
3. Inside, they give to drink saline, vodka or moonshine (can be diluted with vegetable oil).
4. Scar massage.

obstruction

Sometimes the stoppage of the stomach occurs due to blockage of the book. This happens when the animal's diet is dominated by dry food, bran or grain waste. The cause of the pathology may be sand or dirt in the stern. The symptoms of blockage of the book are similar to those observed when the stomach stops. It is quite difficult to identify the true cause of the cessation of digestion. For diagnosis, a puncture of the stomach with a needle is used. If it enters hard, then we are talking about blockage.

If the diagnosis is confirmed, it makes sense to wash the stomach. To do this, use a solution of sulfate or sodium chloride at a concentration of 10%. For the procedure, you will need about a liter of such a solution. To start the digestion process, use the same means as discussed above - vegetable oil, hellebore tincture, vodka.

Injury

Since the cow swallows food in an unprocessed form, dangerous objects often get inside with food - wire, nails, chips, sharp stones. Such foreign bodies can cause serious injury to an animal - pierce the stomach or pierce its walls. Mesh injuries are often through, sharp objects can touch nearby organs - the heart, spleen, lung.

Symptoms of traumatic reticulitis:

1. Anxiety, loss of appetite.
2. Stretching the neck forward.
3. The cow takes unnatural poses - hunches over.
4. Sometimes the temperature rises by 0.5-1 degrees.
5. The animal feels pain when pressing on the sternum.

Treatment is aimed at removing the foreign object from the stomach. Metal foreign bodies are removed with a magnetic probe. If it is not possible to pull out the object, they resort to surgical intervention or the animal is slaughtered.

All sections of the stomach of ruminants perform their function. If at least one of them stops working, the entire digestive system suffers. It is important to diagnose the development of pathology in time and start treatment.

The structure of the stomach of ruminants. The digestive system of ruminants is adapted to receive and process large quantities of relatively low-nutrient, bulky feed. The ability to digest large quantities of roughage in ruminants, animals is more pronounced than in other animals, due to the complex multi-chambered stomach.

The stomach of ruminants differs significantly in structure and functional features from the stomach of carnivores, omnivores and horses. The stomach of ruminants is four-chambered. Its first three sections - the scar, the mesh and the book - are called the proventriculus. There are no proventriculus glands. The fourth section - the abomasum is a true glandular stomach, similar to the stomach of a dog. The volume of the proventriculus is over 100 liters. In the proventriculus, food masses accumulate, chemical and biological processing of the feed takes place.

The largest of the proventriculus is the scar. With several incomplete interceptions, the scar is divided into three parts: the upper and lower bags and the vestibule. The esophagus opens in front of the scar. Grid - an oval-shaped bag. The mucous membrane of the mesh with numerous folds of various sizes forms cells like honeycombs. At the top, the mesh communicates with the scar, and at the bottom, with the book.

The book has a spherical shape, somewhat flattened from the sides. The book has a large number of folds in the form of leaflets of different sizes. The leaves are covered with horny papillae, adapted for rubbing food. The book acts as the final filter, holding the rough parts of the feed with its leaves.

Some features are also present in the structure of the esophagus. The esophagus of ruminants in the lower part passes into the esophageal trough, or semi-closed tube. The esophagus passes through; scar, mesh to the book. Within the threshold of the scar, it is limited by a thickening of the mucous membrane in the form of rollers, the so-called lips. In these thickenings there are muscles and nerves.

In calves and lambs, when drinking milk and water, the muscles of the lips of the esophageal trough contract and they close, resulting in the formation of a tube that serves as a continuation of the esophagus. The closing of the lips of the esophageal trough coincides with the act of swallowing, is a continuation of the peristalsis of the esophagus and is regulated by the nervous system.

Slow feeding of milk, especially with a teat drinker, ensures normal closure of the esophageal trough. In this case, the milk is sent directly to the abomasum. When drinking quickly in large sips, the lips and esophageal trough do not close completely and the milk partially enters the rumen, where it can rot, since the rumen does not yet function in the first days of the animal's life.

By the age of 9-10 months, the closing reflex of the esophageal trough fades away, the lips of the esophageal trough lag behind the proventriculus in growth, its walls coarsen, therefore, in adult animals, not only roughage, but also liquid partially enters the scar.

Microflora of the stomach. In the proventriculus of ruminants, a significant part of the feed is digested without the participation of special digestive enzymes. Digestion of feed here is associated with the vital activity of numerous and diverse microflora that enters the rumen along with food. The constancy of the composition of the liquid medium and the optimal temperature in the rumen provide a high vital activity of the microflora. Currently, three main groups of rumen microorganisms have been identified: bacteria, ciliates and fungi. There are especially many ciliates in the rumen.

In normal feeding, 1 mm 3 of the contents of the scar contains up to 1000 ciliates. They take part in the digestion of fiber. There are more than 30 types of ciliates in the rumen. The number of bacteria is about 109-1016 in 1 ml. When feeding animals with concentrated feed, the number of bacteria increases. Despite the small size of bacteria, their total volume is equal to the volume of ciliates. Each of these groups has a large number of species. The species composition largely depends on the nature of the food. When the diet changes, the species composition of the microflora also changes. Therefore, for ruminants, a gradual transition from one diet to another is of particular importance, which makes it possible for the microflora to adapt to the nature of the feed.

In the rumen, well-crushed, swollen food undergoes fermentation and splitting under the influence of ciliates, bacterial and plant enzymes. Under the influence of the cellulose enzyme contained in feed and released by rumen bacteria, the walls of plant cells are destroyed. Bacterial fermentation of fiber occurs, resulting in the formation of many gases (carbon dioxide, methane, ammonia, hydrogen) and volatile fatty acids (acetic, propionic, butyric and lactic). Gases are removed from the proventriculus by belching. Easily fermentable and poor-quality food during fermentation gives a lot of gases, which sometimes causes swelling of the rumen.

In the rumen, microorganisms synthesize amino acids from carbohydrates, ammonia and fatty acids. At the same time, microorganisms can use urea nitrogen and; ammonia water for the synthesis of amino acids and protein. Therefore, ruminants are often given nitrogen-containing non-protein feed additives - carbamide CO (MH2) 2 or urea, ammonium salts and ammonia water. In the rumen, carbamide, under the influence of the urease enzyme secreted by rumen bacteria, reacts with water and breaks down. Ammonium salts are also resolved by rumen bacteria.

When adding nitrogen-containing non-protein feed additives to the feed, ammonia accumulates in the rumen. Rumen bacteria use ammonia to synthesize amino acids (cystine, methionine, lysine, etc.), and from them biologically complete proteins. Thus, due to the vital activity of rumen microorganisms, plant proteins are converted into complete proteins of the animal body.

Non-ruminant animals cannot use urea, ammonium salts and ammonia water as their single chamber stomach does not contain bacteria. Therefore, with a lack of biologically valuable proteins in the feed, synthetic essential amino acids - methionine, lysine, etc. - are introduced into the diet of pigs and birds.

In the rumen, not only fiber is fermented, but also starch, sugars and other substances, which leads to the formation of a large amount of low molecular weight fatty acids - acetic, propionic and butyric. These acids are absorbed by the wall of the scar, enter the bloodstream and serve as the starting material for the formation of glycogen (animal starch). It has now been established that during the stay of food masses in the rumen, about 70-85% of the digestible dry matter is absorbed. The processes of fermentation in the rumen prevail over other processes of digestion in the digestive tract.

The intensity of fermentation processes in the rumen is very high. In an adult sheep, as a result of fermentation, from 200 to 500 g of organic acids are formed per day. These acids are already absorbed into the blood in the proventriculus.

Ruminant period. Ruminants, when taking feed, make only a few chewing movements necessary for the formation of a food coma. In the rumen, the food is fermented, and then regurgitated in small portions into the oral cavity for more thorough chewing. If, when eating, the animal makes several chewing movements, then when chewing the food coma from the scar, it makes 70-80 chewing movements.

This way of processing food in ruminants was formed in connection with the use of coarse, indigestible plant foods containing a large amount of fiber, which requires careful processing. And therefore, the food is chewed twice: first hastily, if only to capture more of it, and then very carefully in a place safe from predators. This way of feeding gave the wild ancestors of modern ruminants an advantage in the struggle for existence.

The ruminant period is a biological adaptation that allows animals to quickly fill the scar with poorly chewed food, and chew it thoroughly between meals. In calves, the ruminant period begins around the third week of life, that is, when the animals begin to consume roughage. By this period, conditions are created in the rumen for processes, fermentation.

The ruminant period begins 40-50 minutes after feeding. During this time, the food in the rumen loosens, swells and fermentation processes begin. The onset of the ruminant period is slowed down by high ambient temperatures.

The ruminant period begins when the contents of the rumen are liquefied. Water intake accelerates the onset of the ruminant period. The ruminant period most easily occurs when the animals are at rest, in a supine position. As a rule, there are 6-8 ruminant periods per day, each lasting 40-50 minutes.

Suborder Ruminants - higher vertebrates, appeared in the Eocene period. They managed to take a big step in development and take a dominant place among ungulates thanks to good adaptation to a changing external environment, the ability to move quickly and get away from enemies, and most importantly, they were able to adapt to eating coarse, fibrous food.

Cow is a representative of ruminants

The complex digestive system of ruminants allows for the most efficient processing of food and extracting all the nutrients from plant-based, fiber-rich foods.

To capture leaves, grass, and other green plants, ruminants use lips, tongue, and teeth. There are no incisors on the upper jaw, but it is equipped with a hard calloused roller, molars on the surface have a hole, this structure allows you to actively absorb and grind plant foods. In the mouth, food is mixed with saliva and passed through the esophagus to the stomach.

The structure of the digestive system

The sections of the complex stomach of ruminant mammals are arranged in the following order.

Scar

Scar- This is the proventriculus, which serves as a reservoir for plant foods. Sizes range in adults from 20 liters (for example, in goats) to 300 liters in cows. It has a curved shape and occupies the entire left side of the abdominal cavity. Enzymes are not produced here, the walls of the scar are devoid of a mucous membrane, equipped with mastoid outgrowths to form a rough surface, which contributes to the processing of food.

Under the influence of microflora, food is partially processed, but most of it needs further chewing. A scar is a section of the stomach of ruminant artiodactyls, from which the contents are burped back into the oral cavity - this is how chewing gum is formed (the process of multiple transfer of food from the scar to the mouth). Already sufficiently ground food returns again to the first section and moves on.

Microorganisms play an important role in the digestion of ruminants, they break down cellulose, they themselves become a source of animal protein in the process of digestion and a number of other elements (vitamins, nicotinic acid, thiamine, etc.)

Net

Net- a folded structure, similar to a network with cavities of different sizes. The folds are in constant motion, about 10 mm high. Serves as a filter and passes pieces of food of a certain size, which are processed by saliva and rumen microflora. Larger particles are sent back to the mesh for more thorough processing.

Book

Book- a section of the stomach of ruminants (with the exception of deer they do not have it), which consists of muscle plates adjacent to each other. Food gets between the "pages" of the book and is subjected to further mechanical processing. A lot of water (about 50%) and mineral compounds are adsorbed here. A dehydrated lump of food and ground into a homogeneous mass is ready to move to the last section.

abomasum

abomasum- a true stomach, lined with a mucous membrane with digestive glands. The folds of the abomasum cavity increase the surface that produces acidic gastric juice (up to 80 liters can be secreted in cows in 24 hours). Under the action of hydrochloric acid, enzymes, food is digested and gradually passes into the intestines.

Once in the duodenum, the food bolus provokes the release of enzymes by the pancreas and bile. They break down food into molecules (proteins into amino acids, fats into monoglycerides, carbohydrates into glucose), which are absorbed into the blood through the intestinal wall. Undigested residues move into the blind, and then into the rectum and are brought out through the anus.

- the largest section of the stomach, and in newborns the second largest. At the posterior end of the scar, dorsal and ventral caudal blind sacs are isolated.

The esophagus enters the anterior end of the dorsal half-sac.

The mucous membrane of the scar is leathery, glandless, dark brown; papillae of various sizes and shapes up to 10 mm long rise on it. It has independent mobility, since they contain muscle fibers. Co-juices give the scar a rough surface. They are absent on strands, where the mucous membrane is also lighter.

The muscular coat of the scar is formed by two layers of bundles of smooth muscle fibers. In the outer layer, the beams go in a spiral shape in the form of a figure eight. In a deep layer, the beams are circular. They are also common to both scar sacs. In the region of the strands, the muscular wall of the scar is thickened.

The serous membrane of the scar in the region of the longitudinal furrows passes into the greater omentum. The ventral scar sac is located in the cavity of the omental sac.

Net

The mesh is spherical, smaller than the book and serves as a continuation of the vestibule of the scar. It lies in front of the scar, separated from it from the outside by a furrow, and inside by a strand of the scar and mesh. It communicates with the scar through a large opening, and with the book through a slit-like opening.

The mucous membrane of the mesh is leathery, glandless, covered with small keratinized papillae and is collected in non-distributing, but mobile folds that form (4) - 5 - (6) - and coal cells of the mesh.

The muscular membrane of the mesh consists of two layers: the outer transverse and the inner longitudinal, running almost parallel to the esophageal trough. The bottom of the esophageal trough is formed inside by a transverse layer of smooth muscles of the mesh, and outside by a longitudinal layer originating from the striated muscles of the esophagus. The serous membrane passes to the grid from neighboring sections of the stomach.

The stomach is a sac-like extension of the digestive tube, into which the esophagus enters on one side, and the intestines begin on the other. It serves as a container for more or less long-term storage of food masses and their partial chemical processing.

The expansion of the digestive tube can be in the form of a single chamber or a series of recumbent chambers. Accordingly, stomachs are single-chamber (dogs, horses, pigs) and multi-chamber (ruminant animals).

There are also glandular stomachs, or intestinal type, and mixed, or esophago-intestinal type. In glandular stomachs, the mucous membrane is covered with a single layer of prismatic epithelium and contains many glands that open into the stomach cavity. Glandular stomachs in dogs and cats. In the stomachs of the esophago-intestinal type, part of the mucous membrane is covered with a squamous stratified epithelium, and part is covered with a single-layer prismatic epithelium. Stomachs of the esophago-intestinal type are inherent in ruminants (cattle, sheep, goats), pigs, horses, reindeer, camels.

Single chamber stomachs

The single chamber stomach is a curved sac. It distinguishes: the entrance (cardia) - the place where the esophagus enters and the exit into the duodenum - the pylorus, or pylorus. The middle part, lying between the entrance and exit, is called the bottom, or fundus. In addition, there are large (convex) and small (concave) curvature, anterior (hepato-diaphragmatic) and posterior (intestinal, visceral) surfaces.

The wall of the stomach consists of three layers:

1) external - serous,

2) medium - muscular and

3) internal - mucosal.

In the mucous membrane of the stomach of the intestinal type, there are three types of glands: 1) cardiac, 2) fundic and 3) pyloric.

The muscular coat is formed by smooth muscle fibers that form the longitudinal, annular and oblique layers. The outer, longitudinal, layer of the muscular membrane is located mainly along the curvatures; the layer of circular fibers is located mainly in the right half of the stomach and forms the pyloric sphincter; the oblique layer is characteristic of the left side of the stomach, consists of the outer and inner layers and forms the cardiac sphincter.

The serous membrane is represented by the visceral sheet of the peritoneum.

Pig stomach- single-chamber, esophago-intestinal type, in the left dorsal part has a conical blind protrusion - a diverticulum of the stomach, directed, caudally apex. The lesser curvature is convex.

In the cardiac zone, a small part of the mucous membrane is covered with squamous stratified epithelium, in the rest - with prismatic epithelium and contains glands of all three types. The circular layer of the muscular membrane of the pylorus forms a kind of sphincter, which consists of a transverse roller on the side of the greater curvature and a button-shaped protrusion on the side of the lesser curvature. The stomach lies in the left and right hypochondrium and in the region of the xiphoid cartilage.

The horse's stomach is single-chamber, esophago-intestinal type. It is an elongated, relatively small curved sac, which has a clearly visible constriction to the left of the middle of the greater curvature, indicating the border between the glandular and non-glandular part. From the side of the mucous membrane, the glandless part is white, the glandular part is pink.

The left end of the stomach forms a round blind sac. In the cardial part, a powerful loop-shaped cardiac sphincter (compressor) is formed from the inner oblique muscle layer. This powerful sphincter, as well as the narrow lumen of the esophagus with thick muscular walls, together form a strong closing device. As a result, when the stomach is overflowing with food or gases, this device, as it were, automatically closes the opening of the esophagus, so the release of the stomach by vomiting in a horse is impossible.

The horse's stomach is located in the left hypochondrium, and only the pyloric part of it enters the right hypochondrium. The blind sac faces the vertebral ends of the left ribs, and the most ventral part of the stomach lies at half the height? abdominal cavity, on the dorsal transverse position of the large colon.

The dog's stomach is single-chamber, intestinal (glandular) type. The pyloric region is strongly narrowed and elongated like a gut. The stomach is located in the left and right hypochondria and in the region of the xiphoid cartilage.

The stomach of ruminants (Fig. 1) is of the esophago-intestinal type. It consists of four chambers: scar, mesh, book and abomasum. The first three chambers are the proventriculus, which make up the alimentary-water part of the stomach, the last chamber is the glandular stomach itself.

Rice. 1. Multichamber stomach of ruminants:

A - the stomach of a cow; B - esophageal trough; B - leaflets of the book; G - mucous membrane of the abomasum; 1 - blind protrusions (bags) of the scar and transverse grooves; 2 - half bags of the scar and the right longitudinal groove between them; h - esophagus; 4 - net; O - book 6 - abomasum; 7 - the beginning of the duodenum; 8 - entry from the esophagus 9- esophageal trough; 10 - entrance from the grid to the book; 11 - leaflets of the book; 12 - sail-like folds of the book at the entrance to the abomasum; 13 - spiral folds in the abomasum, 14 - scar vestibule; 15 - mesh combs; 16 - lips of the esophageal trough.

The reason for the appearance of such a complex stomach in ruminants is the originality of their way of eating - coarse, indigestible plant food with a huge amount of fiber that requires careful processing. The food is chewed by ruminants twice: the first time hastily, during the feeding itself, the second time more thoroughly, at rest (ruminant period). This method of feeding gave the wild ancestors of our ruminants certain advantages in the struggle for existence, as it helped to capture a large amount of food in a relatively short period of time, keep it in the stomach for a certain time, and then subject it to repeated thorough mechanical processing already in a state of rest, safe from predators. place.

Scar- the largest chamber of the stomach of ruminants. It fills the entire left half of the abdominal cavity and partly passes to the right half. The scar is flattened laterally; it distinguishes between the left, parietal, surface and the right, visceral, to which the intestines and other organs are adjacent; left, dorsal, and right, ventral, edges; thoracic end and pelvic end. Two longitudinal grooves, right and left, cranial and caudal scar grooves divide the scar into the upper half-sac and the lower half-sac. Transverse grooves at the pelvic end of the scar are delimited on each half bag along a blind ledge. At the thoracic end, the upper blind protrusion, called the vestibule of the scar, is separated from the upper half-pouch. The esophagus opens into the vestibule and continues into the esophagus.

On the inner surface of the scar, longitudinal and transverse grooves correspond to strands formed by folds of the mucous membrane and thickening of the muscular membrane.

The mucous membrane of the scar is lined with stratified squamous keratinized epithelium, does not contain glands and is covered with numerous papillae (in cattle up to 1 cm long), creating a roughness that promotes grinding and movement of food masses. In the region of the strands, the mucous membrane is smooth and lighter.

The muscular layer consists of longitudinal and transverse layers.

The grid looks like an almost rounded bag. On its inner surface, high ridges are developed, which, intersecting with each other, delimit cells that look like honeycomb cells. In the depths of these cells are smaller cells from the lower ridges. Muscle fibers are embedded in high and low ridges. This indicates that the ridges are able to contract. The mucous membrane of the mesh is covered with flat stratified keratinized epithelium and dotted with small keratinized papillae. The mesh is connected to the scar with the opening of the scar and the mesh, with the book - with the hole of the mesh and the book.

On the inner surface of the right wall of the vestibule of the scar and the mesh from the esophageal opening to the opening of the mesh and the book, the esophageal trough goes twisting in the form of a spiral. It is formed by two roll-like elevations of the mucous membrane, called lips; between them is the bottom of the gutter. At the base of the lips are bundles of longitudinal smooth muscle fibers. The musculature of the bottom of the esophageal trough consists of an inner, transverse, layer of smooth muscle fibers and an outer, longitudinal layer, which also contains striated muscle fibers. During fluid intake, the lips of the esophageal trough close almost into a tube and the fluid from the esophagus freely enters directly into the book, bypassing the scar and mesh.

The mesh is involved in the burping of the gum: with the help of its cells, a burping food lump is formed. It lies in the region of the xiphoid cartilage and in the right and left hypochondria.

Book in cattle it is spherical, somewhat flattened laterally, in small ruminants it is oval in shape. It distinguishes the right and left surfaces, large and small curvatures. The book got its name because its mucous membrane is collected in numerous folds called leaflets. In size, they are of four types: large, medium, small and the smallest (goats do not have). The leaflets have smooth muscle fibers embedded from the muscle layer of the book. The leaflets are covered with stratified epithelium that has become keratinized from the surface and are densely covered with horny papillae. There are no leaflets on the bottom wall of the book, called the bridge, or bottom, of the book. This bridge in the form of a trough is located between the holes from the mesh into the book and into the abomasum. From the sides, it is delimited by two roll-like folds of the mucous membrane. The muscular layer of the bridge forms the sphincter.

On the sides of the hole in the abomasum, two sail-like folds of the book rise, preventing the contents of the abomasum from returning to the book. The leaflets of the book are located radially in relation to the bridge. Between the free edges of the leaves and the gutter of the bridge, there remains a free space leading from the book to the abomasum - the channel of the book.

The food mass caught between the leaves is kneaded and rubbed, at the same time liquid is squeezed out of it.

The book lies in the right hypochondrium, dorsally from the mesh and abomasum, between the scar and the liver.

The abomasum is a real glandular stomach, it is an elongated pear-shaped sac. Thickened, front, its end opens into a book; narrowed, posterior, end passes into the duodenum. Dorsal, small, curvature facing the spine, ventral, large, to the abdominal wall.

The mucous membrane of the abomasum is covered with prismatic glandular epithelium and contains cardiac, fundal and pyloric glands. It forms 12-16 wide, long, permanent, non-spreading spiral folds.

The muscular coat of the abomasum consists of the outer - longitudinal and inner - annular layers.

The abomasum lies in the right half of the region of the xiphoid cartilage and in the right hypochondrium.

In cattle, the largest section of the stomach is the scar, followed by the book, then the rennet, and lastly the mesh. In sheep and goats, the first place in size is the scar, the second is the abomasum, the third is the net, and the fourth is the book.