Home Dental treatment Volatile fatty acids - acetic, propionic and butyric. The stomach of ruminants: the structure of the stomach and the process of digestion The digestive system of ruminant artiodactyls

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Volatile fatty acids - acetic, propionic and butyric. The stomach of ruminants: the structure of the stomach and the process of digestion The digestive system of ruminant artiodactyls

The stomach of ruminants is complex, multi-chambered. It is an example of the evolutionary adaptation of animals to the consumption and digestion of large amounts of plant foods. Such animals are called polygastric.

The stomach is made up of four large chambers - scar, mesh, booklets and abomasum . The first three chambers are called pregastric and are non-glandular parts. The fourth chamber, the abomasum, is the true stomach. The abomasum is arranged similarly to a single-chamber stomach (see above).

Some animals (camel, llama, alpaca) have a three-chambered stomach (usually there is no book).

The mucosa of the proventriculus is covered with stratified keratinized epithelium and has a characteristic structure in different chambers: in the scar - papillae 0.5-1.0 cm high; in the grid - folds resembling honeycomb cells; The book contains pages of various sizes.

The proventriculus develops gradually, with the transition to roughage and a mixed type of feeding.

DIGESTION IN THE RUM. The rumen is the largest initial chamber of the ruminant stomach. Its capacity in cattle is 100-300 liters, in sheep and goats -13-23 liters.

The scar occupies almost the entire left half, and behind - a part of the right half of the abdominal cavity. The scar is considered as a large fermentation chamber with movable walls. The eaten food is in the rumen until it reaches a certain grinding consistency, and only then does it pass to the next sections. Food is crushed as a result of periodically repeated chewing gum, in which food from the rumen is burped into the oral cavity, chewed, mixed with saliva and swallowed again.

Ruminant process consists of separate ruminant periods, the number of which in cattle is 8-16 times a day, with a total duration of 4 to 9 hours (on average 7-8 hours) each for 30-50 minutes.

Ruminant period consists of separate cycles(from 25 to 60, each for 45–70 s). Each cycle of four phases:

1 - regurgitation of a food coma weighing 90 - 120 g;

2 - receipt of a portion of gruel in the mouth;

3 - secondary chewing for 30-60 s;

4 - swallowing after 40-50 jaw movements (more with dry food).

Thus, a cow burps and chews up to 60–70 kg of rumen contents per day. In the rumen, up to 70% of the dry matter of the diet is chewed without the participation of digestive enzymes. The breakdown of fiber and other feed substances is carried out microbial enzymes, contained in the stomach.

For the normal course of biotic processes in the rumen, optimal conditions are maintained: pH - 6.5–7.4; t - 38(39) - 41 o C (regardless of food intake); constant flow of saliva; mixing and promotion of food masses; absorption of the end products of the metabolism of microorganisms into the blood and lymph.

All these conditions favor the vital activity, reproduction and growth of rumen microorganisms (bacteria, protozoa, fungi).

Protein digestion. Feed proteins in the rumen are broken down mainly by microorganisms to peptones and amino acids. Part of the amino acids is used for the synthesis of bacterial protein, part is deaminated with the formation of NH 3 .

The amine-free residue is converted into VFA and CO 2; ammonia is used in the synthesis of bacterial protein (up to 300-500 g per day).

In the process of pregastric digestion, urea is formed. It is under the action of the enzyme of microorganisms ureases splits in the rumen to NH 3 and CO 2 . Ammonia is used for the synthesis of bacterial protein or amino acids, part of it enters the liver with blood, where urea is formed again, which is partially excreted in the urine and partially enters the saliva, returning to the scar. Urea is formed in the liver and then a scar returns with saliva, the so-called rumino-hepatic urea cycle.

The reuse of urea nitrogen is the most important adaptive mechanism of ruminants in case of uneven intake of nitrogen-containing substances with feed.

This physiological feature of ruminants served as the basis for the use of artificial urea in their feeding.

In the wall of the proventriculus, VFAs are absorbed and ketone bodies are formed, from ammonia they are synthesized glutamine, valine and other amino acids, and glucose is formed from butyric and lactic acid.

Digestion of carbohydrates. The organic matter of plant feed consists of 50–80% carbohydrates, which are divided into simple((oligosaccharides: hexoses, pentoses, sucrose), fructosans, pectins, starch) and complex(polysaccharides: cellulose (fiber), hemicellulose), and in terms of digestibility - into easily soluble and sparingly soluble.

The digestion of carbohydrates in the pancreas is due to the enzymes of microorganisms. Enzymes break down all types of sugars into glucose through a series of intermediate steps. Glucose and starch in the rumen is easily fermented to form VFAs.

Thus, we can say that the main metabolite of carbohydrate metabolism in ruminants is not glucose, but VFAs.

Digestion of fats. Vegetable feed contains relatively little fat - 4 - 8% of dry matter. Crude fat is a mixture of components: triglycerides; free fatty acids; wax; sterols; phospholipids; galactosylglycerol; cholesterol esters;

Vegetable fats, unlike animals, contain a large amount - up to 70% of unsaturated acids with a chain of 18 carbons.

Under the influence of rumen bacterial lipolytic enzymes, all classes of feed lipids undergo lipolysis (i.e., hydrolytic cleavage into glycerol, fatty acids and monoglycerides, galactose). Glycerol and galactose are fermented to form VFAs, mainly propionic. Fatty acids are used in the synthesis of lipids in microbial bodies. Long chain fatty acids pass into the abomasum and then into the intestines, where they are digested.

DIGESTION IN THE NET

The grid is a rounded organ with a capacity of 5–10 liters. in cows and 1.5–2 l. in sheep and goats. The mucous membrane of the mesh has cellular folds resembling a honeycomb. The cells sort the contents and ensure the evacuation of the prepared mass from the proventriculus.

In the net, as in the rumen, the feed masses are subjected to physical, chemical and microbiological treatment. Under the action of saliva and water, roughage is moistened, softened and swollen.

On the right side of the grid from the food hole to the entrance to the book is located esophagus, which has the shape of a semi-closed tube. In young animals during the milk period, the esophageal trough ensures the flow of milk through the canal of the book into the abomasum, bypassing the mesh and the scar. The closing of the lips of the esophageal trough occurs reflexively when the receptors of the oral cavity are irritated.

The grid takes part in ensuring the act of belching.

DIGESTION IN A BOOK

The book is especially well developed. Its volume in cows is 7-18 liters, in sheep - 0.3-0.9 liters. The book has longitudinally and radially arranged leaves of different sizes, alternating in a strict order: between two large leaves there is one medium, between large and medium - two small, and between them - four very small leaves. This whole set is one niche. (Sheep have 8 to 10).

Book features:

1. The book serves as a filter; insufficiently crushed food particles that have passed through the mesh are retained between its leaves.

2. When reduced, the book ensures further grinding of the retained feed particles and evacuation of the contents into the abomasum.

3. The large surface of the mucous membrane of the book promotes intensive absorption. Up to 50% of water and minerals, 80–90% of VFAs, and the bulk of NH 3 are absorbed here.

DIGESTION IN ANOSMUM

In multi-chambered stomachs, only one chamber plays the role of a true stomach - abomasum, which produces gastric juice containing digestive enzymes.

The wall of the stomach has serous, muscular(from three layers) and mucosa shells.

A feature of the structure of the mucous membrane of the true stomach is the presence of fields and pits in it. Gastric fields (zones) are formed by areas of the mucous membrane limited from each other with groups of tubular bodies located in their thickness. The pits are depressions in the epithelium, at the bottom of which gland ducts open. The number of these channels is in the millions.

Conventionally, the stomach is divided into three zones cardiac, fundic, pyloric. Each zone has corresponding glands, consisting of secretory cells: main; lining; additional.

In the cardinal zone, mainly additional cells are located, in the fundic zone - all three types of cells, and in the pyloric zone - the main and additional ones.

The stomach of a cow, like other ruminants, has a peculiar structure. In this article, we will tell you how many stomachs a cow has and how its digestive system works. Each department performs its specific functions, which we will describe in detail below.

The digestive system of ruminants consists of the mouth, pharynx, esophagus, and stomachs. The mouth of ruminants is well adapted for plucking grass and has only lower front teeth. Another interesting fact is the amount of saliva secreted per day in animals of this species. It's hard to imagine, but this figure is from 100 to 200 liters. The esophagus, the stern of its main function, also serves to expel enzymatic gases.

So how many stomachs does a cow have - one or four? Of course, one, but it is four-chamber. The first three chambers - the scar, the mesh and the book - are called the proventriculus. The abomasum is the fourth chamber of the cow's stomach. Let us consider in detail the structure of the digestive system of a cow, namely, each dressed her.

Scar

The structure of the stomach of a cow

It is the largest of the four chambers and has several important functions related to digestion. Scar functions:

fermentation (fermentation) - with the help of special intracellular bacteria, the initial process of digestion occurs. This organ breaks down food with the help of carbon dioxide and methane produced by it. If the animal does not burp this gas, it may experience bloating, which will interfere with the work of other organs of the digestive system.
mixing - the muscles of the rumen help to mix food and "spit" it for re-chewing. The walls of the scar have small formations that look like warts, they help absorb nutrients from food.
converting - in the rumen there are more than 150 billion microbes that help convert carbohydrates in ruminant food into fatty acids. And this is more than 70 percent of the energy supply of a mammal. These organisms include bacteria and fungi. Bacteria in the rumen convert protein and ammonia keto acids.

Net

This department can be called the "controller". The main function of the grid is to separate large pieces of food from finely chewed. The mesh returns coarser particles back to the scar for re-treatment. There are no glands in this part. The mesh walls are covered with small tubercles. The main role in this part is played by cells that determine whether the food particles are well processed by the scar.

Book

The book is the third section. It has a folded structure, divided into narrow chambers. It is in these folds that food is placed. In this department, the digestive processes continue. The food is processed by saliva and ferments. In the book, parts of the food are digested, distributed between the folds of this section and dehydrated. The special structure of the walls of the book allows absorbing moisture. Based on this, it can be noted that the main function of the book is suction. The mass of this part is quite large, but it is not very spacious.

Abomasum

This is the last section of the stomach of ruminant animals. The abomasum is most similar to the stomach of ordinary mammals. The mucous membrane of the abomasum has numerous glands that secrete acidic gastric juice. The structure of the stomach of a cow (abomasum) is simpler compared to other departments. Muscular tissues of this department are formed by longitudinal rings.

The walls of the abomasum are covered with a mucous membrane, which has a prismatic epithelium, it contains pyloric and cardiac glands. The mucous membrane forms 13-14 long folds. It is in this part that the main processes of digestion, absorption of nutrients from food, etc. take place.

Now we know how many stomachs a cow actually has and what her digestive system looks like. The normal functioning of the digestive system of ruminants directly depends on their diet. Bacterial additives are often added to the cow's feed, which allow parts of the animal's digestive system to work better.

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MINISTRY OF AGRICULTURE OF THE RUSSIAN FEDERATION

Federal State Budgetary Educational Institution

Higher professional education

"CHELYABINSK STATE AGRICULTURAL ENGINEERING

ACADEMY»

on the technology of livestock production

on the topic: "Peculiarities of digestion in ruminants"

Completed:

Ivantsova Kristina

Chelyabinsk

Introduction

1.1 Lips, tongue, teeth

1.2 Salivary glands and esophagus

1.3 Role of chewing gum

Conclusion

List of used literature

Applications

Introduction

Among herbivorous mammals, ruminants are the most adaptable. They acquired a complex multi-chambered stomach, which allows them, in the absence of specific enzymes that break down the structural components of plants, to successfully use them through a symbiotic relationship with the microorganisms that inhabit the digestive tract. Obviously, in the adaptation of ruminants to environmental conditions, the most important place belongs to a complex multi-chambered stomach, which bears the main functional load in the gastrointestinal type of digestion that arose in them in the course of evolution.

Nutrition is one of the most important environmental factors that determine the reproduction and survival of animals, and their rational use. The ability to feed certain types of plant mass in ruminants is determined by many factors, the main of which are the morphological features of the structure and function of the stomach chambers. Knowledge of these features is necessary to understand the nutritional ecology of various animal species, their relationship with various types of pasture vegetation, distribution and abundance. Elucidation of various forms of morphological adaptation of the digestive apparatus and the strategy of digestion of various animal species will make it possible to understand the mechanisms and possibilities of feeding separation of cohabiting species.

Ruminants are sensitive to a sudden change in their usual feed, associated with the content of fiber, which is of great importance for the digestibility of nutrients. Therefore, its sharp fluctuations, both upward and downward, lead to indigestion and a decrease in the digestibility of nutrients, often ending in the death of animals.

Based on this, the study of the morphofunctional features of the stomach of ruminants is of particular interest. In addition, the relevance of studying ruminants is due to the economic importance of domesticated and wild representatives of this group of animals.

animal digestion livestock ruminant

1. Description of the digestive system

Digestion consists of a series of interrelated reactions that take place in the digestive tract, resulting in the breakdown of food into simple substances. Through the cells lining the walls of the digestive tract, these substances enter the bloodstream and are carried to all tissues of the body, which ensures the normal functioning, growth and formation of milk. Cows, sheep and goats are ruminants, the stomach of which consists of four sections - chambers (polygastric animals). For comparison, the stomach of a human, a pig, a rat, a horse consists of only one section (monogastric animals). Cows are ruminants that carry populations of microorganisms in their stomachs. This coexistence is called symbiosis and is beneficial for both the ruminant and the micro-organisms. The conditions created by the cow are favorable for the nutrition, growth and reproduction of microorganisms. Microbes, in turn, provide the ruminant with the ability to absorb complex carbohydrates such as cellulose (the main component of plant tissue) and non-protein nitrogen-containing substances (ammonia, urea). In animals with a single-chamber stomach, such assimilation is limited. After bacterial fermentation in the proventriculus, further digestive processes, as well as subsequent digestive organs, differ little from the processes and organs of unicameral animals. Only thanks to the microbes in the mesh stomach, ruminants have the unique ability to digest not only forage plants, but also grain residues and by-products of the food industry, producing highly nutritious products, milk and meat in return.

1.1 Lips, tongue, teeth

The tongue is the main gripping organ in a cow. With the help of the tongue, the cow grabs grass and other grassy foods, and also mixes the food bolus in the mouth and pushes it into the esophagus. There are papillae on the mucous membrane of the tongue. There are four types of papillae: filiform (tactile) and gustatory mushroom-shaped, roller-shaped and foliate. Ruminants do not have incisors or canines, instead, a hard dental plate is located on the upper jaw, which is opposite the lower incisors. This arrangement of teeth allows the animal to efficiently pluck grass. The upper jaw is wider than the lower, which allows the animal to chew on one side or the other. The molars form a chisel-like grinding surface and, due to the lateral (lateral) movement of the jaws, significantly increase the efficiency of the chewing process along the chewing gum.

1.2 Salivary glands and esophagus

There are many salivary glands in the cow's mouth. They secrete saliva of slightly different chemical composition serous, mucous and mixed. Food mixes with saliva in the mouth and enters the scar and mesh through the esophagus. The length of the esophagus in a cow is just over a meter. Then, in the process of chewing the gum, the contents of the reticulum through the esophagus regurgitate into the oral cavity for additional chewing.

1.3 Role of chewing gum

When chewing gum, food boluses (boluses) from the rumen are regurgitated into the mouth for additional chewing. When chewing, the boluses are compressed and the resulting liquid and small food particles are immediately swallowed. Large food particles are chewed for 50-60 seconds and then also swallowed. Chewing gum is a vital part of the normal digestive process and the absorption of fiber. The main functions of chewing gum are as follows:

1. When chewing gum, there is an increase in salivation;

2. Under the influence of chewing, there is a decrease in the size of food particles and an increase in their density (the time spent by food particles in the rumen depends on these characteristics);

3. Chewing gum helps separate food particles that are ready to emerge from the rumen from those that need more time to fully ferment;

4. As a result of chewing gum, the fibrous structures are crushed, which increases the surface of the action of microorganisms on them, which means their digestibility.

Gum chewing is a reflex that is triggered when long fibrous particles enter the scar. A cow can chew up to 8 hours a day. A diet of too finely divided feed can drastically reduce chewing time, which adversely affects the digestion of fibrous substances and the saturation of milk with fats. If a cow chews a lot, it is a sign of good health. When chewing, there is an abundant secretion of saliva, which in turn provides a favorable environment for microorganisms in the rumen.

There is a good way to determine if a herd has enough fiber in its diet: if at any time of the day or night 1/3 of the livestock is chewing, it means that the diet is correct.

2. The structure of the multi-chambered stomach of ruminants

Figure 1.: 1 - scar, 2 - end of the esophagus, 3 - food trough, 4 - mesh, 5 - book, 6 - abomasum

The scar is the first and largest section of the four-chambered stomach of ruminants. Its capacity in cattle is 100 - 300 liters. It occupies almost the entire left half of the abdominal cavity, its volume in adults is up to 80% of the total volume of the stomach. The inner shell of the glands does not have, it is keratinized from the surface, with many papillae, which creates a very rough surface.

The rumen serves for microbial fermentation of food. Cellulose is fermented by symbiotic protists, with the help of their symbiotic intracellular bacteria.

The mesh is the second section of the four-chambered stomach of ruminants, which is located near the diaphragm and liver. The inner surface has no glands. The walls of the mesh contain four-, five- and hexagonal cells formed by non-expanding mobile folds of the mucous membrane 8–12 mm high. A mesh is reported with a scar, a book and an esophagus, a special formation - an esophageal trough in the form of a semi-closed tube.

The book is the third section of the four-chamber stomach of ruminants. Lies in the right hypochondrium, has a rounded shape. On the one hand, it serves as a continuation of the grid, on the other, it passes into the abomasum. The mucous membrane of the book forms mobile longitudinal folds - leaflets that divide it into narrow chambers. The leaves have different heights and cover the entire inner surface, except for the bottom of the book.

The book serves to absorb water, magnesium and light fatty acids formed during fermentation in the rumen.

The abomasum is the fourth section of the complex four-chambered stomach of ruminants. The true stomach is elongated in the form of a curved pear, thickened at the base. At its junction with the book, the opposite narrow end passes into the duodenum. The mucous membrane of the abomasum has glands, the so-called glandular stomach. In the abomasum of calves fed on milk, rennin is produced - a digestive rennet that breaks down peptides. Isolated from the abomasum of young calves and lambs, this enzyme is used in the manufacture of cheese.

The abomasum corresponds to the simple single-chambered stomach of most mammals. The mucous membrane of the abomasum is covered with prismatic epithelium, contains fundic (bottom), pyloric and cardiac glands and forms 13-14 long folds that increase its surface. The muscular membrane of the abomasum is formed by the outer longitudinal and inner annular layers.

The small intestine is the next section of the ruminant digestive system. It consists of the duodenum, jejunum and ileum. The diameter of the small intestine in an adult cow is 4.5 cm, while the length reaches 46 m. The entire inner surface of the small intestine is covered with microscopic papillae, which form a huge (in relation to its mass) suction surface, so it is the main place where nutrients are absorbed. The cells of the small intestine are among the most active in the body. The "lifetime" of the protein (protein) formed by the cells of the small intestine is one day, while the "lifetime" of the protein produced by skeletal muscle cells is one month. Enzymes secreted by the pancreas and intestinal walls digest protein, fats and carbohydrates. Liver bile enters the duodenum through the bile duct. Bile promotes the absorption of fats and prepares the products of digestion for absorption.

Large Intestine - The cecum is the first section of the large intestine. This is another reservoir (like the mesh stomach) located away from the main gastrointestinal tract. After the food undergoes chemical breakdown in the abomasum and small intestine, it further undergoes microbial fermentation in the caecum. In some animal species (horse, rabbit) the importance of fermentation in the caecum is important, but in an adult cow the role of fermentation in the caecum, compared with fermentation in the reticulum, is insignificant. The colon (2nd section of the large intestine) is conditionally divided into proximal and spiral parts. The role of the colon in the process of digestion and absorption of nutrients is insignificant. Its main function is to form excrement. The inner walls of the colon do not have papillae for absorption of nutrients, but the absorption of water and mineral salts in the colon is quite successful. The large intestine ends at the anus.

3. Features of the work of the stomach in ruminants

Usually, chewing gum begins 30-70 minutes after eating and proceeds in a rhythm specific to each type of animal. The duration of stay of each serving of chewing gum in the mouth is about one minute. The next portion enters the mouth after 3-10 seconds.

The duration of the chewing gum period is 45-50 minutes, after which there is a period of rest, which lasts for different animals for different times, followed by a chewing gum period again. During the day, the cow chews in this way about 60 kg of the contents of the rumen.

Ruminants do not bother to thoroughly chew the food they have received in their mouths. The food is chewed only lightly. The main processing of the feed takes place in the rumen, where it is until it reaches a fine consistency. This is facilitated by periodically repeated chewing gum after belching food into the oral cavity. After careful re-chewing, the feed lump is swallowed again and enters the rumen. In the rumen, the food is mixed with the entire mass of the rumen contents. Mixing food and its promotion, from the vestibule of the scar to the abomasum, occurs due to powerful contractions of the muscles of the proventriculus.

In the rumen of ruminants, the feed lingers for a long time, where complex processes of its decomposition take place. First, fiber is broken down, in which the microorganisms inhabiting the proventriculus in the form of the simplest ciliates and bacteria play a huge role. The species composition of microorganisms depends on the composition of the diet, so for ruminants, a gradual transition from one type of feed to another is important. It is with the presence of these microorganisms that the ability to digest fiber and use it as an energy source is associated. In addition, fiber contributes to the normal motility of the proventriculus, which ensures the movement of feed masses through the gastrointestinal tract. Here, in the rumen of ruminants, fermentation processes of food masses take place, aimed at the breakdown and assimilation of starch and sugars. In the rumen, almost completely (by 60-80%), the protein is split and the production of microbial protein from non-protein nitrogenous compounds, of which approximately 135 g is formed from 1 kg of digestible organic matter.

For cattle, feeds with a highly digestible protein, but at the same time having a reduced solubility in the rumen, are most desirable. The more roughage is converted into bacterial protein, the higher its value for the animal.

The mesh in the composition of the proventriculus for the organism of ruminants is necessary as a sorting organ. It creates conditions for the further passage into the book of only a sufficiently crushed, liquefied mass. The book is an additional filter and chopper of retained large feed particles. It also actively absorbs water. The processes of digestion in ruminants vary depending on the amount and ratio of individual feed groups.

Starting from the fourth section of the gastrointestinal tract, the process of digestion of a cow becomes similar to the process of digestion of other animals. Due to the presence of an acidic environment in the abomasum, all bacterial activity here completely stops. From the walls of the abomasum, hydrochloric acid, the enzymes pepsin and rennin are released in significant quantities. Only after the acidity level becomes high enough (pH=2) does the pylorus open and allow the contents, now called chyme, to flow into the duodenum. Secretions from the pancreas, liver and glands located on the walls of the duodenum are mixed with chyme. These secretions contain enzymes that hydrolyze protein (protease), starch (amylase), and fat (lipase). Protein is broken down into peptides and amino acids. Unlike fermentation in the rumen, amino acids are not converted to ammonia in the small intestine. Starch and other non-fiber carbohydrates are hydrolyzed into simple sugars such as glucose, fructose, etc. Fats are also hydrolyzed. As a result of the hydrolysis of fats, glycerol is formed, which is a sugar, as well as 3 fatty acids, which are a long chain of carbon atoms, at the end of which there is an acid group.

The absorption of substances formed in the small intestine occurs mainly in its second half. Amino acids and small peptides (products of protein breakdown), sugars (products of carbohydrate breakdown) are absorbed by the walls of the small intestine, and then enter the bloodstream. The absorption of long chain fatty acids is more complex and requires the presence of bile salts.

The large intestine does not secrete digestive enzymes, but absorption processes, especially water, take place in it.

Diets that contain almost only roughage (hay, straw) are rich in fiber, but poor in easily digestible carbohydrates, which impoverishes the nutrition of microorganisms inhabiting the proventriculus. Their activity in the rumen decreases, the digestibility of fiber also decreases, the animal's body receives less nutrients - productivity decreases. Diets that, in addition to roughage, include grain concentrates rich in carbohydrates or succulent feeds with a high sugar content create good conditions for the development of microorganisms and the digestion of feed nutrients. Due to the increased development of microorganisms, the use of non-protein nitrogen in the feed increases.

It is undesirable for ruminants and the increased content in the diet of concentrated feed rich in protein, which can cause the accumulation of ketone bodies in the body and lead to metabolic disorders.

Large doses of eaten green grass of legumes, due to the intense release of gases in the proventriculus, lead to a significant decrease in the appetite of animals and the loss of feed nutrients. At the same time, feeding green and succulent feeds together with other feeds contributes to better digestion and absorption of nutrients. Feeding ruminants an increased amount of feed containing easily digestible carbohydrates (sugars) is undesirable. A large amount of sugar in the body causes metabolic disorders, so the feeding of sugar beets to animals is limited.

Feeding good-quality silage has a beneficial effect on the digestion of animals, especially when mixed with root crops. But long-term feeding of silage alone adversely affects both the health of the animal and its productivity due to a decrease in the activity of rumen microorganisms (the result of a change in the acid-base balance of the body).

Therefore, when feeding ruminants, one should, first of all, take into account the conditions for the growth, development and vital activity of the microorganisms inhabiting their stomachs.

4. Diet of cattle

In diets for cows, the dry matter content must be taken into account. In winter rations with limited feeding of succulent feed, the amount of dry matter per 100 kg of animal live weight should not exceed 3–3.5 kg. So, for example, a cow with a live weight of 500 kg. can be fed as much as possible per day when the diet is saturated with hay and straw 17.5 kg. feed in terms of dry matter. In the pasture period, as well as in winter, if there is a lot of succulent feed in the diet, the consumption of dry matter by cattle increases to 4 kg. for every 100 kg. live weight. To account for the amount of dry matter in the diet, you can use the following standards: 1 kg of roughage and grain feed contains 0.85 kg. dry matter, fodder root crops - 0.1, potatoes - 0.2, silage - 0.2 - 0.3, sugar beet - 0.22 - 0.24, cake - 0.9 kg.

In the stall period, a medium-fed cow can be included in the diet of 15-20 kg of silage and 6-12 kg of roughage. The total amount of succulent feed should not exceed 10-12 kg per 100 kg of live weight of the animal, hay should be given 1-1.5 kg per 100 kg of live weight. It is advisable to give beetroot as a milk-producing feed to a cow for the milk it receives: fodder beet in the amount of 1-1.5 kg per kilogram of milk, but not more than 40 kg per day, and sugar beet - 0.5-0.8 kg, but no more than 15 kg per head per day. When feeding beets, the diet becomes easily digestible. As a result, other feeds are absorbed better, and as a result, milk yield increases. A cow is accustomed to sugar beet for several days, and a single feeding should not exceed 5 kg. When eating a large amount of beets, the animal develops increased thirst and disrupts the work of the stomach, diarrhea appears. In the daily diet of a cow, it is imperative to introduce table salt as well.

The higher the productivity of the cow, the more types of feed must be included in the diet, while beets and good hay, carrots and protein concentrates (bran, oilcake) are required. There may be more calcium and carotene in the diet - this is not harmful. Excess minerals are excreted from the body, and carotene accumulates in the liver in the form of vitamin A. When determining the amount of mineral supplements, it is necessary to proceed from the following calculation: 10 g of chalk contains 4 g of calcium, the same amount of defluorinated phosphate contains 3.3 g of calcium and 1.4 g of phosphorus, feed monosodium phosphate (phosphorus top dressing) - 2.4 g of phosphorus.

For cows for the entire stall period, it is required to prepare 20 quintals of roughage, including 12 quintals of hay, 40 quintals of succulent (beets, pumpkins, silage) and 3 quintals of concentrates. Proper and complete feeding of the cow has a great influence on increasing the fat content in milk. Feeds that increase the fat content of milk in winter are hay of legumes, cake and sunflower meal, bran, brewer's and bread yeast and other feeds rich in protein.

After calving, the cow is transferred to a full diet gradually, on the seventh or eighth day, carefully monitoring the condition of the udder. On the first day, good hay is fed. On the second day after calving, about 5 kg of succulent feed and up to 1 kg of concentrates are added. If the udder is hard, inflamed, then there is no need to rush to increase the supply of food; it is advisable in this case to milk the cow more often and more thoroughly. Concentrated feed for fresh cows is best fed in the form of swill.

With good feeding, milk yield in cows increases in the first two months after calving, then it is kept at the same level and begins to decrease from the fifth month of lactation. Usually a cow in the first four months after calving gives about half of the milk received for the entire lactation. The milking increase period should be used to milk the cows. It begins 15-20 days after calving, while increasing the ration by 2-3 feed units (advance feed for milking).

If a cow does not increase its milk production during the milking period for three to four days, then the feed supplement to the daily ration is removed. But you need to do this gradually so as not to reduce milk yield. If the cow increases milk yield well, then after a few days the feed rate is increased again, so they act until she stops adding milk. Usually milking is carried out until the third month of lactation. During the milking period, an udder massage is necessarily carried out, the cow is released daily for a walk.

Features of feeding a cow in the summer. In summer, cows get most of their nutrients from grazing. Grazing livestock has many advantages over winter stabling. Complete green food, combined with the beneficial effects of sunlight and fresh air on the body, improves the health of the animal and contributes to the production of strong, resilient calves. However, such keeping of a cow is effective only if the pastures are plentiful in herbage and have young grass throughout the summer.

A cow with a live weight of 450-500 kg should eat the following amount of green fodder per day, depending on the daily milk yield:

Dry cows are given the same amount of feed as animals whose daily milk yield is up to 8 kg of milk. The nutritional value of the grass after flowering is sharply reduced due to a decrease in the content of protein and carotene. In addition, with aging, green plants coarsen, and therefore the palatability and digestibility of feed decrease. Therefore, they begin to graze cattle on upland pastures with a grass stand height of 10–15 cm, on natural lowlands - 15–18 cm. On ordinary upland natural pastures, a cow eats 30–35 kg of grass. This amount is clearly not enough to ensure high milk productivity. To obtain a daily milk yield of 14–16 kg, a cow should additionally be fed 25 kg of green fodder.

Before grazing, natural pastures for cattle should be checked for the presence of harmful and poisonous herbs. Wild onions, garlic and wormwood worsen the quality of milk. When a cow eats wild onions and garlic, milk acquires a characteristic smell and taste, and wormwood becomes bitter. The poisonous group includes dope, henbane, nightshade, milestones, hemlock, belladonna, ranunculus, horsetail and other plants. They cause poisoning, sometimes lead to death. In order to avoid indigestion and reduce productivity, the cow is transferred to green fodder gradually, within 5-7 days. At this time, the animal is fed a small amount (1-2 kg) of straw cuttings, flavored with concentrates or mixed with green top dressing. This prevents the appearance of diarrhea in animals and prevents the reduction of fat and milk content.

In summer, concentrated feed is completely excluded from the diet of cows or they are given half as much as in winter. Use to tear grain cereals, especially when feeding young grass. If, however, bran, legumes, cakes are given as top dressing, then protein overfeeding may occur. It is better to save these protein concentrates for the winter.

Technique of cow feeding and preparation of feed for feeding. The cows are fed three times a day. It is desirable that the time intervals between feedings are approximately the same. The cow is fed at the same time, for example, in the morning at 6 o'clock, in the afternoon at 13 o'clock and in the evening at 20 o'clock. She quickly gets used to a certain regimen. Delay and interruptions in feeding immediately lead to a decrease in milk yield. In this case, it is necessary to adhere to the following sequence of feeding feeds if they are distributed separately, and not in a mixture. First concentrates, then juicy and lastly roughage. Concentrated and succulent feeds, especially root crops, are the causative agents of the secretion of gastric juice, as a result of which, by the beginning of the distribution of roughage, the cow's digestive apparatus is already prepared for its reception and processing. The main amount of the daily norm of roughage is given to the cow in the evening. If a cow eats roughage in the morning, then her ruminating period and the number of chewing movements decrease. As a result, the digestibility of food decreases. Feed should be distributed after the previous portion has been eaten and the feeder has been cleaned of residues, as they quickly rot in the feeder and acquire an unpleasant odor. The distribution of new portions of feed always encourages cows to eat it.

In order to improve the palatability of feed, increase palatability and digestibility, they are prepared accordingly. This is especially true for such poorly eaten food as straw. In addition to grinding and mixing with other feeds, straw in individual farms is subjected to steaming and chemical treatment. In the proventriculus of the cow, the straw eaten by her softens and steams out, for which heat is spent in the animal's body. But you can soften, steam the straw outside the animal's stomach. The daily norm of chopped straw is poured with hot, slightly salted (15-20 g of salt per 1 liter of water) water, tightly closed with a lid. After 2-3 hours, the steamed straw is fed to the cow, best of all in a mixture with silage, chopped beets or concentrates. As a result of the chemical treatment of straw, indigestible substances and shells of plant cells are destroyed, while its digestibility increases. Straw cutting is processed in a wooden box with 1% milk of lime during the day. To process 10 kg of straw cutting, lime dough is made from 300 g of quicklime and dissolved in 30 liters of water, adding another 100 g of table salt to the solution. The cow is fed without washing up to 20 kg of wet straw per day. Cooking straw, thus, should be no more than two days.

Root crops are cleaned from the ground before feeding, they can be fed without cutting. Concentrated feed is given to livestock in crushed or ground form. As a result of crushing or grinding, the hard shell is destroyed and the chewing of the grain is facilitated. Grain waste and grain containing weed impurities are subjected to fine grinding before feeding. Unground weed seeds are not digested in the cow's digestive tract. Without losing their germination, they get into manure and clog crops in the garden. Compound feed should not be steamed, as this can destroy vitamins. Sunflower cake tiles are crushed before distribution. They are fed only in the soaked form.

In order for the feed to be well digested, it is necessary to properly organize the rest of the animal. During the day, the cow lies down several times and rests for 8-10 hours a day. At this time, she chews her cud. Its duration is 40-50 minutes, after which there is a break. In a healthy animal, chewing gum is repeated 6-8 times a day. In case of violation of the feeding regimen or a strong fright, this rhythm changes and chewing gum may completely stop. Therefore, in the room where the cow is kept, it is recommended to keep silence as much as possible.

Drinking cows. Of all domestic animals, a cow consumes the most water: in winter 35-40 liters, in summer 50-60 liters. Highly productive cows need much more water than low dairy cows. After all, it takes about three liters of water to form one liter of milk. In hot weather, water is also necessary to protect the body of the animal from overheating. The cow should be given plenty of water. Water the cow at least three times a day with clean water. The best is considered water from drinking sources: artesian wells, wells and spring. It is impossible to give animals water from stagnant ponds, from reservoirs where sewage is dumped.

5. Peculiarities of digestion in young ruminants

During this period, the digestive organs of young animals are not sufficiently developed, especially in the first days after birth. At this time, in newborn calves, the scar, mesh and book, taken together, are smaller in size than the abomasum.

In dairy calves, the nutrients in the feed are digested directly in the abomasum and intestines. The scar does not function during this period. But already in the first months of life, the sections of the proventriculus begin to grow intensively. Their development is influenced by the structure of the diet of young animals. As the calf grows and its diet varies, so do its proventriculus. A feature of digestion in young animals is that they do not have chewing gum. It appears from about the third week of life, i.e. with the beginning of the reception of coarse food. Microorganisms settle in the rumen and the digestive activity is rebuilt. An important role in the first days of life belongs to the esophageal trough. During sucking from the udder or from the nipple put on the tank, the half-bent tubes of the esophagus close and the milk passes directly into the abomasum in small portions. When receiving milk directly from a bucket, the calf swallows it in large sips, as a result of which, passing through a half-closed chute in the rumen, the milk flows out of the chute and enters the rumen, but since the rumen is not yet functioning, the milk in it rots and gastrointestinal diseases. Therefore, in order to prevent this, milk is drunk with a nipple. This will prevent large portions from entering the esophagus and splashing into the rumen as it passes to the abomasum.

The first 4-5 days after birth, the calf receives all the necessary nutrients from colostrum and transitional mother's milk. Colostrum is a thick, creamy, yellowish secretion secreted from a cow's udder immediately after calving. And only at the very first milking! And the secretion obtained from the second to the eighth milking (during two milkings) is called transitional milk. The cow gives it during the first week after calving, and by the end of this period, it gradually approaches the composition of whole milk. Compared to milk, colostrum contains 6 times more proteins, especially globulin fractions, which form passive immunity in calves. It should be borne in mind that the ability of antibodies to freely penetrate the intestinal wall falls within a matter of hours, and disappears completely after 24 hours. Several times more iron and vitamin B12, which contribute to the formation of hematopoiesis. Of particular biological value is milk fat, in which vitamins A, D, carotene and hormones are dissolved. Colostrum contains an increased amount of mineral salts (especially magnesium) and vitamins. The safety of calves depends on the amount of soldered colostrum and transitional milk during the first 12 hours. According to the literature, when soldering 2-4 liters, the death rate of calves is 15%, 5-8 liters - 10%, 8-10 liters - 6.5%. It has been observed that the percentage of antibody uptake by the calf is highest when it receives colostrum in the presence of the mother. It is recommended to drink from teat drinkers 4-5 to 8-10 times a day.

The need for digestible protein per 1 feed. units is: in the first 3 months. - 120-130 g; at 4-6 months - 117-105 g. Fiber content in the first 2-3 months. - 6-12% of the dry matter of the diet; at 3-6 months - 18%. Need for sugar: in the first 3 months. - 15-16.5% of the dry matter of the diet; 4-6 months - 8-9.5%. The fat content in the dry matter of the diet is reduced from 24% at the age of one month to 5.4% at the age of 6 months.

When organizing the feeding of calves, it is necessary to plan the live weight of the future cow. Based on this, the growth rate of calves is planned, and their type of feeding is determined. The live weight of cows correlates with their productivity, which can be used in determining the type of feeding of calves and, ultimately, with the planned weight of the future animal.

Thus, by planning the productivity of a future full-aged cow and setting its live weight, it is possible to determine the average daily gains of calves by months of rearing. Young, growing animals are able to give high gains with more economical use of energy and a high use of feed protein. This biological feature must be taken into account when planning the growth of animals, providing them with full-fledged feeding that promotes intensive growth (average daily gains of 700-800 g).

Feeding schemes and diets should ensure the normal growth and development of young animals in accordance with the planned growth rates. Depending on the planned intensity of growth, different feeding schemes are used to provide a certain level of average daily gain in live weight. Conventionally, three types of feeding schemes for calves up to 6 months old can be distinguished. age, calculated for low (average daily gain 550-600 g and live weight of a full-aged cow - 400-450 kg), moderate (650-700 g and 500-550 kg) and high (750-800 g and 600-650 kg) rates animal growth. Their main difference is the different consumption of dairy feed. Higher animal growth energy requires higher levels of energy and nutrients in the diet. At the same time, milk consumption for the first type of feeding can be 175-180 kg, and milk consumption - 200 kg per heifer for the first 6 months of growing. Schemes designed for moderate growth of animals require a slightly higher consumption of dairy feed: milk - about 200 kg, skim milk - 400 kg. when using the third type, milk consumption can be 250 kg, and skim milk - up to 600 kg. It should be noted that in addition to dairy feed, a higher consumption of concentrated feed is planned for more intensively growing animals.

When growing replacement heifers, it is recommended to use an intensive rearing scheme. Then the growth rate is reduced, but with such a calculation. So that by the age of insemination she has reached a live weight equal to 70% of the mass of a full-aged cow (360-380 kg, not lower). In this case, by the breeding age (18 months), the heifer arrives well-fed, but not obese, which makes it easier to cover.

During the first 15 days of life, the only food for the calf is colostrum (the first 3-4 days) and mother's milk. Their number is at the level of 5-7 kg per day. However, from 7-10 days of life, calves can begin to be accustomed to concentrated feed (100-120 g). You can feed crushed, well-sifted grain (oatmeal), starter feeds prepared according to special recipes. The norm of concentrates by 3 months. bring to 1.2-1.6 kg. Their rate may vary depending on the provision of dairy feed. Most of the recommended feeding schemes are designed for the consumption of concentrates in the amount of 170-225 kg for 6 months. According to traditional technology, calves are taught to eat hay from 10-14 days of age. At the same time, hay should be legume-grass or cereal-legume, well leafy, of high quality. The norm of hay is gradually increased and brought to 3 months. up to 1.3-1.5 kg, and by 6 months. up to 3 kg. Juicy feed (root crops, high-quality silage) is fed from the age of one month. Silage can be replaced with an equivalent amount of haylage. Juicy foods increase the biological value of the diet, improve digestion and promote better absorption of nutrients. Daily supply of silage by 3 months. age can be 1.5-2 kg, and by 6 months. - 6-7 kg. The number of root crops by 3 months. can be brought up to 1.5 kg, and then reduced to 1 kg or left at the same level. The lack of minerals and vitamins can be compensated for by premixes, introducing the required amount of them into the feed. Feed chalk, table salt, bone meal, etc. can be used as mineral supplements.

Recently, in the practice of feeding young cattle, it is recommended to use the Dutch technology for raising calves. It involves the early accustoming of calves to concentrated feed in order to more rapidly form the proventriculus and cicatricial digestion, and they should be eaten in a dry form (so that they get into the rumen). When feeding concentrated feed carbohydrates, butyric acid fermentation prevails in the rumen, which has a beneficial effect on the development of the proventriculus and, most importantly, on the formation of the rumen wall. It is believed that early feeding of hay (10-15 days), with a poorly formed suction surface of the rumen and other parts of the complex stomach, reduces the digestibility of nutrients and slows down the formation of cicatricial digestion. And this leads to a lag in growth and to a later date for reaching the conditioned body weight before insemination. With this system, hay and other roughage can only be fed when the calf's proventriculus is sufficiently developed to digest the roughage. According to the researchers, the amount of concentrated feed consumed per day can serve as a criterion for the readiness of the proventriculus to accept roughage. This is approximately 600-800 g. As concentrated feed, you can use starter feed, a mixture of crushed grain (preferably oats, as it contains the least non-starchy polysaccharides), dry corn feed, sunflower or flax meal, wheat bran.

In the first 4-5 to 10 days of life, calves can be fed under mothers, and subsequently under cows-nurses (shift-group method of growing calves under cows-nurses) for 2-3 months. (depending on economic conditions). During the lactation period, under one cow with a productivity of 2000-3000 kg, 8-12 calves can be raised.

After weaning from cows (7-10 days), calves are fed whole milk in the first 2-3 days at the rate of 3-4 kg per day, then the watering rate is reduced, replacing part of the milk with skim milk (3-4 weeks of life). The daily norm of milk can be fed for 2 times in equal parts. It is necessary to accustom a calf to eating hay from the age of 10 days. In this case, it is better to use early mowed, well-leafed cereal-bean hay. The norm of hay for calves is gradually increased and brought to the age of 3 months up to 1.3-1.4 kg, and by the age of 6 months - up to 3 kg. From the 11th day of life, calves are given salt and chalk, and from the 15th-20th day they are fed concentrates.

As the first top dressing, they give 100-150 g per day of well-sifted oatmeal, then gradually accustom them to mixtures of concentrates consisting of ground grain (oats, corn), wheat bran, cake, grass flour and other components.

By the age of 3 months, the supply of concentrated feed is adjusted to 1.2--1.6 kg. Their norm for calves can vary significantly depending on the level of milk nutrition, the amount of grass flour in the diet, the quality of hay and silage. Most of the applied feeding schemes for heifers up to 6 months of age are designed for consumption of 170-225 kg of concentrates.

Juicy feeds (root crops, high-quality silage), which increase the biological value of the diet, improve digestion, promote better absorption of substances, are fed to calves from the age of one month. Silage can be replaced with a nutritionally equivalent amount of haylage.

Calves are given table salt, bone meal, chalk, tricalcium phosphate and other mineral supplements as sources of minerals.

For rearing heifers up to 6 months of age, various feeding schemes are recommended depending on growth plans, consumption of dairy feed and specific economic conditions.

From the age of 2 months, calves can be given the following mixture of feed (%): sunflower or flaxseed cake. - 20, wheat bran - 30, oatmeal - 20, wheat bran - 30, oatmeal - 20 and cornmeal - 30.

For calves of the dairy period, special compound feeds (starters) are produced.

In the summer grazing period, calves from the 2nd decade after birth are accustomed to eating green fodder, bringing the daily rate to 2 months of age up to 3-4 kg, to 4 months - up to 10-12 kg and to 6 months -- up to 18-- 20 kg. If there is not enough grass on the pasture or it is not eaten well, then the calves must be provided with green top dressing. Its daily rate depends on the quantity and quality of grass in the pasture.

In the schemes of the summer period, a reduced (by about 30%) consumption of concentrated feed is provided in comparison with the stall period. It is possible to reduce the consumption of end feed for calves from 3-4 months of age with a good pasture and a sufficient supply of high-quality green fodder.

With poor pasture and a small amount of green fodder, calves are given good quality hay or silage, and the rate is increased.

Conclusion

Summing up the results of the studied topic, we can conclude:

The stomach of ruminants is complex, multi-chambered. It consists of four sections: scar, mesh, book and abomasum. The first three sections are called the proventriculus, and only the last section - the abomasum - is a true ventricle. Cattle, sheep and goats have a four-chambered stomach, while camels have a three-chambered stomach (no booklet).

The digestive system consists of a series of interconnected reactions that take place in the digestive tract, as a result of which food is broken down into simple substances. Through the cells lining the walls of the digestive tract, these substances enter the bloodstream and are carried to all tissues of the body, ensuring its normal functioning, growth and the formation of milk, wool and other necessary products for the life of agriculture.

List of used literature

1. Livestock / Edited by D.V. Stepanova. - M.: Kolos, 2006.-688s. - (Textbook and teaching aids for students of higher educational institutions).

2. "Technology of livestock production" - D.N. Murusidze. - M.: Kolos 2005

3. "Fundamentals of physiology and ethology of animals" - V.F. Lysov, V.I. Maksimov

4. "Physiology of digestion", S.S. Poltyrev.

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Division of the stomach of ruminants

The cow's digestive system consists of several departments that differ in function, namely:

Of particular interest is the mouth of these animals, since its main purpose is to pluck grass, hence the presence of an exclusively front row of lower teeth. impress saliva volumes, which stands out for each day, it reaches approximately from 90 to 210 liters! Enzymatic gases accumulate in the esophagus.

How many stomachs does a cow have? One, two, three, or even four? It will be surprising, but only one, but consisting of four departments. The first and largest compartment is the scar, and the proventriculus contains the mesh and the book. No less interesting and not quite euphonious name the fourth chamber of the stomach is the abomasum. Detailed consideration requires the entire digestive system of a cow. More about each department.

Scar

The cow's rumen is the largest chamber that performs a number of very important digestive functions. A thick-walled scar is not affected by rough food. Every minute contraction of the scar walls provides mixing eaten grass, subsequently enzymes distribute them evenly. Here, too, hard stems are rubbed. What is the scar for? Let's designate its main functions:

enzymatic - intracellular bacteria start the digestive system, thereby providing the initial fermentation process. In the rumen, carbon dioxide and methane are actively produced, with the help of which all the food that enters the body is broken down. In the case of non-regurgitation of carbon dioxide, the animal's stomach swells, and as a result, a malfunction in the work of other organs;
the function of mixing food - cicatricial muscles contribute to mixing food and its further exit for re-chewing. Interestingly, the walls of the scar are not smooth, but with small formations resembling warts that contribute to the absorption of nutrients;
transformation function - more than a hundred billion microorganisms present in the rumen contribute to the conversion of carbohydrates into fatty acids, which provides energy to the animal. Microorganisms are divided into bacteria and fungi. Protein and ammonium keto acids are converted thanks to these bacteria.

The stomach of a cow can hold up to 150 kg of feed, a huge proportion of which is digested in the rumen. Up to 70 percent of the food eaten is located here. There are several sacs in the rumen:

cranial;
dorsal;
ventral.

Probably, each of us noticed that a cow, some time after eating, burps it back for re-chewing. A cow spends more than 7 hours a day on this process! re regurgitated mass is called chewing gum. This mass is carefully chewed by the cow, and then it does not fall into the scar, but into another department - into the book. The scar is located in the left half of the abdominal cavity of the ruminant.

Net

The next section in the cow's stomach is the mesh. This is the smallest compartment, with a volume not exceeding 10 liters. The mesh is like a sieve that stops large stems, since in other departments coarse food will immediately cause harm. Imagine: the cow chewed the grass for the first time, then the food got into the scar, belched, chewed again, hit the grid. If the cow chewed poorly and left large stems, then they will be stored in the net for one to two days. What is it for? The food is decomposed and again offered to the cow for chewing. And only then the food gets into another department - the book.

The grid has a special function - it separates large pieces of food from small ones. Large pieces thanks to the mesh are returned back to the scar for further processing. There are no glands in the grid. Like a scar, the mesh walls are covered with small formations. The grid consists of small cells that define food processing level the previous chamber, that is, a scar. There are no glands in the grid. How is the mesh connected with other departments - the scar and the book? Quite simply. There is an esophageal trough, resembling a semi-closed tube in shape. Simply put, the mesh sorts the food. Only enough crushed food can get into the book.

Book

Book - a small compartment containing no more than 5 percent of the consumed feed. The capacity of the book is about 20 liters. Only here the food that has been chewed many times by a cow is processed. This process is ensured by the presence of numerous bacteria and potent enzymes.

It is no coincidence that the third section of the stomach is called a book, which is associated with the appearance of the section - continuous folds, divided into narrow chambers. Food is in folds. The digestive tract of the cow does not end there - the incoming saliva processes the food, fermentation begins. How is food digested in a book? Feed distributed in folds and then dehydrated. Moisture absorption is carried out due to the peculiarities of the grid structure of the book.

The book performs an important function in all digestion - it absorbs food. By her own the book is quite big, but it holds a small amount of food. All moisture and mineral components are absorbed in the book. What is the book like? On an elongated bag with numerous folds.

The book is like a filter and grinder of large stems. In addition, water is absorbed here. This department is located in the right hypochondrium. It is connected with both the mesh and the abomasum, that is, it continues the mesh, passing into the abomasum. The shell of the third department stomach forms folds with small nipples at the ends. The abomasum is elongated in shape and resembles a pear, which is thickened at the base. Where the abomasum and book connect, one end connects to the duodenum.

Why does a cow chew food twice? It's all about the fiber found in plants. It is difficult and time consuming to process, which is why 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, constantly secreted gastric juice are 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 their epithelium, which contains pyloric and cardiac glands. The mucous membrane of the abomasum is formed from numerous elongated folds. The main digestive processes take place here.

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

Summing up

Thus, the structure of the cow's stomach is very peculiar, since the cow does not have 4 stomachs, but a four-chamber stomach, which provides the processes of the cow's digestive system. The first three chambers are an intermediate point, preparing and fermenting the incoming feed, and only in the abomasum contains pancreatic juice, completely processing food. The digestive system of a cow includes tripe, mesh, booklet and abomasum. Enzymatic filling of the rumen provides the process of splitting food. The structure of this branch resembles a similar human organ. The tripe of cattle is very capacious - 100 - 300 liters, goats and sheep have much less - only 10 - 25 liters.

Long-term retention of food in the rumen ensures its further processing and decomposition. First, fiber undergoes cleavage, this involves a huge number of microorganisms. Microorganisms change depending on the food, so there should not be a sudden transition from one type of food to another.

Fiber is very important for the body of the ruminant as a whole, as it provides good motor skills pancreatic regions. Motility, in turn, ensures the passage of food through the gastrointestinal tract. In the rumen, the process of fermentation of feed masses takes place, the mass is split, and the body of the ruminant 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 split into tiny particles, further the nutrients are completely absorbed by the body, finished mass it moves into the intestines, where the most intensive absorption of all useful trace elements occurs. Imagine: a cow has eaten a bunch of grass in a pasture, and the digestion process starts, which in the end is from 48 to 72 hours.

The digestive system of cows is very complex. These animals must continuously eat, as a break will bring great problems and affect the health of the cow very negatively. complex structure of the digestive system has negative qualities - indigestion is a common cause of cow mortality. Does a cow have 4 stomachs? No, only one, but the entire digestive system includes the oral cavity, pharynx, cow's esophagus and stomach.

Attention, only TODAY!

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.