The circulatory system of a rabbit. Rabbit circulatory system

Signs indicating the relatively primitive nature of the anatomical structure of rabbits are: the presence of the orbital salivary gland, the presence of a spiral fold in the caecum, absent-mindedness of the pancreas, a reduced state of the omentum, a simplified paired scrotum with wide and short inguinal passages , into which the testes can enter, a straight, backward-directed penis, a double uterus and a number of others.

Digestive system: see Rabbit digestion

Respiratory system: see Rabbit respiratory system

Nervous system: see Rabbit nervous system

Rabbit urinary system

rabbit teeth

The structure of teeth is of great importance in mammalian taxonomy. A newborn rabbit has 16 milk teeth. Among the distinguishing features, the presence of two pairs of incisors in rabbits should be highlighted. A large space separating the molars from the incisors is characteristic. The teeth of rabbits are completely covered with enamel, unlike rodents, which have no enamel on the inside of the incisors. The incisors of a rabbit have the peculiarity of continuously growing throughout the life of the animal.

Rabbit teeth formula:

• dairy - I 2 C 0 P 3 / I 1 C 0 P 2 × 2 = 16;
• constants - I 2 C 0 P 3 M 3 / I 1 C 0 P 2 M 3 × 2 = 28.

Age-related changes in the teeth of rabbits are characterized by a change in the crowns of milk teeth and their change to permanent ones. Rabbits are born with milk teeth, which are replaced by permanent ones by the 18th day after birth. The permanent teeth are long-crowned: in the upper arcade there are two powerful incisors. Behind is a pair of small incisors supporting large incisors. In the lower jaw there are two large incisive teeth. There are no fangs. Premolars 3 on the upper jaw on each side and two on the lower jaw. There are 3 upper and lower molars on each half of the oral cavity. The teeth wear out and protrude regularly from the jaws.

Heart, like in birds, it has four chambers, and the left ventricle drives blood through the systemic circulation and has (like in birds) much thicker walls than the right one, which drives blood through the small circle. However, in contrast to the heart of birds, the right atrioventricular valve is membranous and is divided into three leaflets, while the left one is divided into two.

Great circle arteries. The aorta, like in birds, departs from the left ventricle, but then turns to the left. As always, it stretches back under the spine, sending vessels from itself to the internal organs and dividing in the pelvic region into two iliac arteries, which continue into the hind limbs in the form of femoral arteries. The first vessel that departs from the aortic arch is called the innominate artery (arteria innominata). Usually, it is immediately divided into 3 trunks upon discharge: the right subclavian artery (subclavia dextra), the right carotid artery (carotis dextra) and the left carotid artery (carotis sinistra). But often the left carotid artery of the rabbit departs independently from the aorta, so that the innominate artery divides only into 2 large branches. The right subclavian artery goes to the corresponding forelimb, and the carotid arteries go to the head, where each of them divides into 2 trunks: the internal carotid and external carotid arteries. Near the base of the innominate artery, the left subclavian artery (subclaviasinistra), heading to the left forelimb. Passing through the thoracic region, the aorta gives a number of branches: intercostal arteries, intestinal, anterior mesenteric, to the genitals, to the kidneys, posterior mesenteric, at its posterior end it splits into two iliac arteries, between which the tail artery is located.

(according to Gindze). On the left, only a network of capillary vessels remained, on the right, an opened vesicle without vessels:

1 - bronchus, 2 - artery, 3 - vein

Great circle veins. Venous blood from the hind limbs is collected in paired femoral veins (v. femoralis), which in the pelvic region merge into the posterior vena cava. Thus, in a rabbit, as in all mammals, the portal system of the kidneys is atrophied. The posterior vena cava, heading towards the heart, stretches along the spine and receives a number of veins coming from the walls of the body and internal organs, and near its confluence with the right atrium, two hepatic veins flow into it. Venous blood from the internal organs (intestines, stomach, spleen) is collected in the portal vein, which, like in all vertebrates, breaks up in the liver into capillaries, forming the portal system of the liver; the capillaries of the liver reconnect to the already mentioned hepatic veins. Venous blood from the anterior part of the body is collected in paired anterior vena cava - right and left, which also flow into the right atrium. Each of them is composed of the corresponding subclavian vein, which carries blood from the forelimb, and the jugular vein, which collects blood from the head.

Small circle vessels. From the right ventricle, as in all amniotes, the common pulmonary artery departs, dividing into the right and left pulmonary arteries, going to the corresponding lungs. From each lung, blood is collected into 2 pulmonary veins, which then merge, forming one right and one left pulmonary vein, which empty into the left atrium through a common opening.

The red blood cells of mammals differ from the corresponding bodies of all other vertebrates in that they are devoid of nuclei in the formed state.

(according to Parker):

1 - right atrium, 2 - right ventricle, 3 - pulmonary artery, 4 - left atrium, 5 - left ventricle, 6 - aortic arch, 7 - innominate artery, 8 - right subclavian artery, 9 - right common carotid artery, 10 - left common carotid artery, 11 - internal carotid artery, 12 - external carotid artery, 13 - left subclavian artery, 14 - intercostal arteries, 15 - dorsal aorta, 16 - right renal artery, 17 - left renal artery, 18 - left common iliac artery, 19 - external iliac artery, 20 - femoral artery, 21 - tail artery, 22 - right femoral vein, 23 - posterior vena cava, 24 - hepatic vein, 25 - external jugular vein, 26 - internal jugular vein, 27 - subclavian vein, 28 - right anterior vena cava, 29 - left anterior vena cava, 30 - pulmonary veins

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The structure of the internal organs and the skeleton of a rabbit are similar to the anatomy of other vertebrates, but still there are some differences. Today we will take a closer look at all the components of the rabbit skeleton and the features of other vital organs - such information will be useful to all novice farmers. Let's get started.

The skeletal system of the animal performs both supporting and protective functions, and the rabbit skeleton consists of more than two hundred bones. So, in an adult rabbit, bones occupy about ten percent of the body weight, and in a rabbit, up to fifteen percent of the body weight. This whole system is interconnected by cartilage, muscle tissues and tendons.

Note! In rabbits of meat and meat-skin breeds, the bones occupy a smaller volume relative to their weight.

Peripheral

This group includes:

1. Forepaws (limbs of the sternum). They consist of the forearm, shoulder bone, belt and hands. Each hand has a certain number of bones: five metacarpals and five carpals (fingers).
2. Hind legs (pelvic, lower limbs). Consist of the pelvis, ilium, ischium, thighs, feet (four fingers and three phalanges).

The bones of the sternum and the girdle are connected with each other by the collarbone, which allows the animals to jump. The spine of these individuals is a weak point, as are the weightless bones of the limbs, so the rabbits often get injured on the back or legs.

Axial

This group includes the bones of the skull and spine:

1. Skull box. The facial bones are movable, interconnected by peculiar sutures. The bones of the brain include: the temporal bone, the bone of the occiput, the bone of the crown. The facial section includes: the bone of the upper jaw, as well as the nasal, palatine, lacrimal bones. The skull in rabbits is oblong, like most small mammals. The main part is occupied by the organs of the respiratory and digestive systems.
2. Body (chest bone, spine, ribs). The spine in an adult rabbit consists of several parts, which we will consider in more detail. Plasticity is provided to it by cartilage pads that act as shock absorbers. They connect with each other.

Note! The widest spine is found in individuals of meat breeds. The value of such characteristics allows the farmer to make the right selection of animals for breeding.

muscles

The taste of meat products and the appearance of a rabbit depend precisely on the structural features of the muscular system. Muscle contraction occurs under the influence of nerve impulses.

There are such types of muscles:

1. Muscles of the body. Represented by striated muscles. All muscles belong to this group.
2. Muscles of the viscera. They are smooth muscle. For example, capillary walls, the walls of the respiratory system or the digestive system.

The lifestyle of rabbits does not involve training, so their muscles are not sufficiently saturated with the oxygen-binding protein myoplasma. Their meat has a light pink color, but is slightly darker in the limbs.

Immediately after birth, babies have a poorly developed muscle system, which makes up 22% of the total mass. With the process of growing up, it increases to 42%.

Important point! The meat of adult animals is slightly higher in calories than the meat of young animals. About that, you can read in our special article.

Prices for cages for rabbits

Rabbit cage

Nervous system

This system consists of:

• organs of the central nervous system;
• nerves of the skeletal muscles, skin, capillaries (peripheral system).

The brain of rabbits, like that of all living beings, is divided into two hemispheres: right and left, it is located inside the skull. At the same time, the brain still has several sections (central, posterior and bulb). Each of them has a functional purpose. For example, the bulbus regulates the functioning of the respiratory and cardiovascular systems.

Inside the spinal canal is the center of the nervous system, which runs from the brain to the 7th cervical vertebra. Its weight is just over three grams. It consists of gray and white matter.

The cardiovascular system

This system includes everything that has a connection with the blood: hematopoietic organs (spleen), lymph nodes, arteries and any vessels. Each of them is responsible for a specific function. For example, the spleen, which has a mass of just over a gram, regulates blood pressure. The function of the bone marrow is to produce red blood cells.

Note! The thymus is responsible for stimulating hematopoiesis. In newborn babies, it is small, about two grams, but increases over time.

About 275 ml of blood circulates in the body of these animals. The body temperature of healthy individuals in the cold season is 38 degrees, and in the warm season - 39-40 degrees. If the temperature is too high, rabbits experience hyperthermia, which leads to death. The heart of rodents consists of 4 chambers, paired ventricles and atria, and its mass is about 7 grams. Their heart rate is up to 155 beats per minute.

Digestion

The organs of the digestive system allow you to break down any food that enters the body of rabbits. Products pass through the entire gastrointestinal tract within three days.

Newborn individuals have sixteen milk teeth, but after a while they fall out and are replaced by molars. The grown rabbits already have twenty-eight molars. They grow gradually throughout the life of animals. They have large incisors that allow rabbits to handle tough food.

After swallowing, food first enters the larynx, and from there into the esophagus and stomach. The stomach is empty inside, its volume is up to two hundred cubic centimeters, it is necessary for the production of hydrochloric acid. Experts note that the stomach enzymes in rabbits are more active compared to other mammals. Even plant food is not broken down here, it immediately enters the intestines, where the final process of digestion takes place.

Table number 1. The structure of the intestines of rabbits.

Video - Features of the digestion of rabbits

Feed prices for rabbits

Compound feed for rabbits

Respiratory system

The respiratory system of rodents includes the nose, larynx, trachea and a paired organ - the lungs. All these organs provide animals with air. After inhalation, it passes through the stage of filtration, moisturizing, heating, then enters the throat, then into the lungs through the connecting tubes.

It is important to remember that rabbits breathe more intensively than other animals. They are able to take about 280 breaths in 60 seconds. In addition, they have an active process of gas exchange.

sense organs

Rabbits have the following sense organs:

1. Sense of smell (perception of smells). Receptors are responsible for this process, which look like small hairs (located in the nasal passage). Thanks to what animals can feel any aromas. So, the rabbit will be able to distinguish her cubs from strangers.
2. Taste. Special receptors that are located on the tongue and palate help to recognize taste.
3. Touch (tactile perception). Sensitivity is observed in rabbits in the skin of the eyes, crown, mouth and back. Animals react to pain, temperature, orient themselves in space.
4. Vision. Rabbits see this world in color. Their main apples are rounded, they are connected to the head. Rabbits see a little better at close range.
5. Hearing. Rabbits have noticeable ears, thanks to which they can hear everything that happens around them. They communicate with each other with special sounds, turning their ears to the sides.

Note! Rabbit breeds with drooping ears have poor hearing. They were bred artificially, so they will not survive in their natural habitat.

Note! When moving in complete darkness, the whiskers of rabbits play an important role, which help them navigate in space.

excretory and reproductive systems

This system represents both the reproductive and urinary organs. The functions of the latter is to remove residual products from the body. The amount of urine that accumulates per day depends on age characteristics. In 24 hours, the body of each rabbit produces up to 380 ml of urine, it is saturated with uric acid and ammonia. The urinary canal is located next to the organs of the reproductive system.

These animals have two kidneys, each of which is located in the lower back. They are necessary for the breakdown of proteins, salts and other substances.

Urine is constantly formed, first from the kidneys moves through the connecting tubes, and then is brought out. Healthy rabbits have golden brown urine. Excessively yellow or too cloudy urine is a sign of diseases in the body.

reproductive organs

In heterosexual animals, organs have some differences. In rabbits, the reproductive system consists of the following:

• two testicles;
• spermatic cords;
• appendages;
• penis.

In females, the reproductive system is represented by the following organs:

• uterus;
• ovaries;
• egg duct;
• vagina.

The reproductive organ of the rabbit is divided into two parts. This feature allows you to simultaneously bear cubs from different male producers.

In order for mating to occur between animals, the female is sent to the cage to the male when signs of sexual hunting occur. In addition, a week before this process, their body is saturated with special vitamin feeds. It is useful to feed the male with boiled potatoes during this period.

Video - Rabbit mating: features

Endocrine glands

This system includes the following organs:

Hormones enter immediately into the bloodstream, since they have no other ways to withdraw. The adrenal glands are responsible for the regulation of water-fat metabolism in the body. The lack of certain glands leads to various disorders in the body.

Milk glands

All rabbits have mammary glands and nipples, only in rabbits they are in the form of rudiments and are small protrusions above the skin.

The development of the gland is present in lactating females. They look like white formations protruding above the skin, located on both sides of the belly. Each mammary gland passes into the nipple, with milk passages. Depending on the size of the rabbit and her breed, there are from 4 to 12 pairs of nipples.

How to choose a healthy rabbit?

For breeding, it is important to choose only strong, healthy representatives of a particular breed, so novice farmers need to be careful when buying pets. It should be borne in mind that unscrupulous sellers often try to sell sick or defective animals.

Choosing a rabbit: step by step instructions

Step 1. It is necessary to observe the behavior of rabbits. These animals are active, move around the cage, and healthy rabbits will definitely not sit in one place.

Bald spots on the body - a sign of improper maintenance

Note! If possible, the seller should be asked about the vaccination of the livestock. Rabbits often die from viral and infectious diseases during the epidemic, so rabbits are vaccinated in advance.

Only knowing the features of the anatomy of rodents, it is possible to recognize the presence of a pathological process in the body in time and help the animal. Therefore, information about the structure of these rodents is mandatory for all rabbit breeders. We hope you have read it carefully.

Digestion is a complex physiological process, as a result of which the feed in the rabbit's digestive tract undergoes mechanical processing. As herbivores, rabbits are biologically adapted to consume a significant amount of voluminous, coarse, fiber-rich food (root crops, grass, hay, grain). The digestive apparatus in rabbits is well developed: the length of the intestine reaches approximately 18.5% of body weight. Well-developed digestive organs allow rabbits to digest the nutrients they consume with food relatively completely.

The digestive organs include the organs of the oral cavity, pharynx, esophagus, stomach, intestines, liver, pancreas.
The first stage of digestion begins in the mouth – mechanical processing of feed.
The dental system of rodents, to which the rabbit belongs, is characterized by a number of features. In the oral cavity of a newborn rabbit there are 16 milk teeth, the change of milk teeth to permanent ones begins at 18 days of age. Full-aged rabbits have only 28 permanent teeth, which is less than other farm animals. There are four incisors in the upper jaw and two in the lower jaw. With incisors, the rabbit cuts and gnaws food. With its molars, the rabbit grinds and grinds the food. The incisors and molars grow throughout the rabbit's life. The front part of the incisors is covered with a durable layer of enamel.
In the process of mechanical processing, the feed is abundantly moistened with saliva entering the oral cavity from the salivary glands (parotid, sublingual and infraorbital). The salivary glands open into the oral cavity. Under the action of the enzyme amylase contained in saliva, the starch of the feed is partially broken down to glucose.
Feed, crushed and moistened with saliva, is sent through the pharynx and esophagus to the stomach

Pharynx- a cavity organ, which is based on the pharyngeal muscles. The digestive and respiratory tracts pass through the pharynx. The digestive part of the pharynx has special ring-shaped muscles, under the action of which the food lump moves into the esophagus.
Esophagus is a wide, long, thick-walled tube that runs through the neck and chest cavity to the stomach. The total length of the esophagus is about 15 cm, it is equipped with muscles that serve to push food from the pharynx into the stomach.
rabbit stomach - a single-chamber, horseshoe-shaped cavity organ, which has a volume of about 200 cm3. The stomach contains glands that secrete gastric juice, which includes hydrochloric acid and the enzyme pepsin, which break down food proteins into intermediate compounds. Enzymatic activity of digestive juices in rabbits is higher than in other herbivores. The total acidity of gastric juice ranges from 0.18 to 0.35%, the content of free hydrochloric acid - from 0.11 to 0.27%. Fiber is not digested by gastric juice. Under the action of smooth muscles, the contents of the stomach move into the duodenum. Subsequent digestion takes place in the intestines.
Rabbit intestine consists of thin and thick sections.
The thin section is represented by the duodenum, jejunum and ileum. In the thin section in the mucous membrane there are numerous intestinal glands that secrete intestinal juice. The secrets of the pancreas and liver are poured into the lumen of the duodenum through the ducts. With the help of the enzyme juice of the pancreas and intestinal juice, proteins, fats and carbohydrates are broken down.
In the small intestine, the main nutrients of the feed and their breakdown products (amino acids, fatty acids, etc.) are absorbed. After passing through the epithelium of the intestinal villi, nutrients enter the bloodstream and are carried throughout the body. They serve as a source of energy for the further life of the body and material for the supply of body tissues.
From the thin section, undigested particles of chyme (stomach contents) enter the large intestine. The thick section is represented by the cecum, large colon, small colon and rectum. Under the action of enzymes secreted by microbes, fermentation processes, splitting and digestion of fiber occur in the caecum and colon.
Undigested food is formed into feces (in the form of balls), which are excreted through the rectum and anus (anus) approximately 9 hours after feeding
S. N. Alexandrov, T. I. Kosova Rabbits: Breeding, rearing, feeding

For the use of feed by the animal's body, they must be processed by the digestive organs. Digestion is the first and most important link in the complex metabolic process. The rabbit's stomach is located in the anterior half of the abdominal cavity, on the left side. The largest diameter of the stomach is approximately eight centimeters. The walls of the stomach secrete gastric juice, which contains the enzyme pepsin and hydrochloric acid. Gastric juice is continuously separated.
The enzymatic capacity of digestive juices in rabbits is higher than in other herbivorous domestic animals. Feeding significantly increases sap secretion. The total acidity of rabbit gastric juice ranges from 0.18 to 0.35%, free hydrochloric acid - from 0.11 to 0.27%, total hydrochloric acid - from 0.10 to 0.30%. The acidity of rabbit gastric juice is quite high. Starch and fiber are not digested by rabbit gastric juice. Under the influence of pepsin and hydrochloric acid, feed proteins are broken down into proteins of a less complex composition (albumoses and peptones). In the small intestine, albumoses and peptones are broken down into amino acids.
Undigested parts of the feed, according to x-ray observations, begin to be excreted in the feces after about 9 hours. According to other studies (using magenta-stained oats), the appearance of grain feed in the feces begins approximately 5-8 hours after feeding and completely ends after a few days (2-3 days). The total length of the small intestine in a rabbit is 3-4 m. In the small intestine, the main nutrients of the feed are digested: carbohydrates, proteins and fats. The function of the small intestines is not limited to the digestion of food (beans, carrots, herbs), they also absorb the products of digestion.
Proteins, carbohydrates and fats cannot be used by the body in the form in which they are in the feed. Only after these substances have been processed and broken down to their constituent parts, they are absorbed through the epithelium of the intestinal villi and enter the bloodstream, from where they are carried to all cells of the tissues of the animal's body. From the thin section of the food masses enter the large intestine. The total length of the rabbit intestine is 9-10 times the length of the body. Of great importance in the process of digestion are the large intestine, especially the blind. It is 7-8 times the volume of the stomach. The juice of the caecum contains many enzymes secreted by microbes, actively digests fiber. Fiber is known to be broken down in the colon by bacterial enzymes.
Source http://www.greenrussia.ru/

Anatomy is a science that studies the forms, structure, relationships and location of parts of the body, and physiology is a science that studies the processes (functions) occurring in a living organism and their patterns. The general data of these sciences will help you understand, for example, how to distinguish a sick animal from a healthy one and how to properly provide first aid to a sick animal before the veterinarian arrives.

The body of any animal is built from the smallest living particles - cells. Certain groups of cells, changing their shape and structure, unite into isolated clusters that have adapted to perform certain functions. Such groups of cells, as a rule, have specific qualities and are called tissues. There are four types of tissues in the body - epithelial, connective, muscle and nervous.

epithelial tissue covers all border formations in the body - such as skin, mucous membranes and serous membranes, excretory ducts of glands, glands of internal and external secretion. It communicates the body with the external environment, performs integumentary, glandular (secretory) and absorption functions.

Connective tissue subdivided into supply and support. Feeding, or trophic, tissues include blood and lymph. The main purpose of the supporting tissue is to bind the constituent parts of the body into a single whole and to form the skeleton of the body (for example, this includes bone tissue, tendons, cartilage).

Muscle capable of contraction and relaxation under the influence of various stimuli. It is divided into skeletal and cardiac muscles, which has a striated striation, as well as smooth muscle tissue, capable of involuntary contractions and found in the internal organs.

nervous tissue consists of nerve cells - neurons that have the property of excitation and conduction of nervous excitation, and neuroglia cells that perform supporting, trophic and protective functions.

Separate groups of tissues are connected to each other and form organs. An organ is a part of the body that has a certain external shape, built from several naturally combined tissues and performing some highly specific function. For example, an organ is called an eye, a kidney, a tongue.

Separate organs that perform together any one specific function form systems or apparatuses in the body. So, for example, bones, muscles, ligaments, tendons and joints form the apparatus of movement, or the musculoskeletal apparatus.

The organs of such animal body systems as digestive, respiratory, urinary, sexual, that is, the insides, are located in three cavities: chest, abdominal and pelvic.

chest cavity located inside the chest abdominal in front it is limited by the diaphragm (abdominal muscle obstruction), and behind it passes into the pelvic cavity. It is located between the chest and pelvic cavities, ending at the level of the waist.

pelvic cavity form the pelvic bones, the sacrum and the first tail vertebrae.

Most of the internal organs are located in serous cavities, which create conditions for the organs to slide around each other. For example, the heart is located in the pericardial serosa.

A necessary condition for the existence of any animal organism is metabolism- a continuously ongoing process of disintegration of the constituent parts of the body, accompanied by a process of restoration with the help of an influx of food from the external environment. Metabolism and energy conversion in a living organism are inseparable from each other. The formation and release of heat depends primarily on metabolism.

So, rabbits are warm-blooded animals, that is, their body temperature is relatively constant and, under normal conditions, is maintained at a level of 38.5-39.5 ° C, depending on age and physiological state. This indicator depends on climatic conditions (for example, on the ambient temperature - at an outside temperature of 5, 10, 20, 35 and 40 ° C, the body temperature of rabbits is 37.5, 38, 38.7, 40.5 and 41.6 ° C, respectively). C) and other factors, but most of all it changes under the influence of pathogenic microbes and viruses.

When body temperature rises to 44 ° C, rabbits die.

The body temperature of animals is measured using a medical or veterinary thermometer inserted into the rectum (rectally) to a depth of 2–3 cm. The thermometer is preliminarily shaken, lubricated with petroleum jelly, and the measurement itself is performed within 5–7 minutes. You can attach a rubber tube to the thermometer so that you can easily pull it out. The tube is attached to the tail of the animal.

The body of rabbits, like other animals, is conditionally divided into four main sections (Fig. 5):

1 - auricle; 2 - ear root; 3 - crown; 4 - forehead; 5 - eye; 6 - nose; 7 - nasal openings; 8 - upper lip; 9 - lower lip; 10 - whiskers (vibrissae); 11 - cheek; 12 - back of the head; 13 - throat; 14 - neck; 15 - dewlap, diaper; 16 - back; 17 - lower back (sacrum); 18 - chest; 19 - stomach; 20 - side; 21 - elbow; 22 - forelimb; 23 - foot with fingers and claws; 24 - croup; 25 - thigh; 26 - knee; 27 - hock; 28 - tail; 29 - scruff

1. Head. It distinguishes the cerebral (skull) and facial (muzzle) parts. This includes the forehead, nose, ears, teeth.

2. Neck. Here, the neck area and the throat area are distinguished.

3. Trunk. Represented by the nape, back, lower back, thoracic region (chest), dewlap, croup, right and left iliac region, right and left groin, umbilical region, breast and prepuce region, anal region, tail.

4. Limbs. The thoracic (front) limb is represented by the shoulder, elbow, forearm, wrist and metacarpus, and the pelvic (back) limb is represented by the thigh, knee, lower leg, heel, and metatarsus.

The appearance of the animal, the physique and features of individual parts of the body, characteristic of the breed and sex, are called exterior. The general exterior includes the main features of the physique, the structure of individual parts of the body, the most characteristic deviations and vices, the particular one considers the features of the addition of individual breeds, typical and atypical features for them. The exterior of animals indicates the breed and the degree of expression of the breed. In rabbits, the degree of development of the skeleton, the width and depth of the chest, the length and shape of the back, the croup, the strength and setting of the limbs are evaluated. So, the head of rabbits is less rounded compared to males, it looks narrower, lighter and more tender. If the breeding males have too much dewlap, this is a sign of a loose constitution and a phlegmatic temperament. Narrow-chested individuals are weaker, they are easily exposed to diseases. A humpbacked or sagging back is a sign of rickets (Fig. 6), and a long and wide loin indicates high meatiness. Poor overgrowth of paws is considered a major defect, since such rabbits are prone to pododermatitis, especially when kept on a mesh floor for a long time. :

a - normal; b - hunchbacked; c - sagging

According to the exterior, the direction of the animal's productivity, its state of health and the degree of adaptability to environmental conditions are determined.

The exterior is the external reflection of the interior. Interior called the totality of internal features, physiological, biochemical and anatomical and histological properties of the body in connection with the constitution, exterior and direction of productivity. The study of the interior makes it possible to compare the development of organs and tissues with the peculiarities of the course of physiological and biochemical processes in the animal's body.

The concept of "constitution" combines all the properties of the animal's body: the features of its anatomical structure, physiological processes and, above all, the features of higher nervous activity, which determines the reaction to the external environment. In rabbit breeding, 4 types of constitution are distinguished, proposed by P. N. Kuleshov:

› rough type: rabbits have a massive strong skeleton, thick skin, coarse hair, unpretentious animals, little susceptible to diseases;

› gentle type: rabbits have a thin skeleton, thin skin, short and sparse hairline, animals are characterized by increased metabolism, easy excitability, and are prone to diseases;

› dense, or strong, type: rabbits have a strong, well-developed skeleton, dense elastic skin, long and thick hair, the animals are the most productive, have good vitality, perfectly adapt to changing conditions of keeping and feeding, resistant to diseases;

› loose, or raw, type: rabbits have light bones, thick skin, sparse hair, are well fattened and fattening, have a low metabolism and are prone to disease.

Not only such economically useful traits as precocity, meatiness, quality of hairline, vitality, but also a certain predisposition to certain diseases are closely related to the constitution.

For example, animals of a delicate constitution are predisposed to tuberculosis, and animals of a loose constitution are prone to diseases of the gastrointestinal tract.

When determining the constitution of rabbits and evaluating the exterior, the condition is established. Condition- this is the general appearance of the animal, external signs, fatness, the condition of the muscles, skin, which helps to determine whether the animal is healthy or sick. Allocate factory, exhibition, fattening and hungry condition.

The apparatus of movement is represented by the skeleton, ligaments and muscles, which, unlike other systems, form the physique of rabbits, their exterior. To imagine its significance, it is enough to know that in newborns, the movement apparatus accounts for approximately 70–78% of the total mass of the animal, and in adults - up to 60–68%. In phylogenesis, departments of various importance are formed: the skeleton as a supporting structure, ligaments that connect bones, and skeletal muscles that set bone levers in motion.

Bone- part of the skeleton, an organ, which includes various tissue elements. It consists of 6 components, one of which is the red bone marrow - the organ of hematopoiesis. The red bone marrow is preserved for the longest time in the spongy substance of the sternum and vertebral bodies. All veins (up to 50% of the veins of the whole body) exit the bones mainly where there is more spongy substance. Through these sites, intraosseous injections are made, which replace intravenous ones. The growth and development of bones in rabbits ends by the end of the first year.

Skeleton rabbits is built from 212 bones and, like in other animals, consists of two sections: axial and peripheral (Fig. 7).

The axial part of the skeleton is represented by the skull, spine and chest.

Scull, or head skeleton, is divided into the brain part (7 bones) and the facial part (9 bones). The bones of the brain skull form the vagina for the brain, and the bones of the facial region form the oral and nasal cavities and orbits of the eyes, the organs of hearing and balance are located in the temporal bone. The bones of the skull are connected by sutures, except for the movable ones - the lower jaw, temporal and hyoid bones.

Along the body of the animal there is a spine, in which a vertebral column is distinguished, formed by the bodies of the vertebrae (the supporting part that connects the work of the limbs in the form of a kinematic arc) and the spinal canal, which is formed by the vertebral arches surrounding the spinal cord. Depending on the mechanical load created by the body weight and mobility, the vertebrae have a different shape and size.

1 - premaxilla; 2 - nasal bone; 3 - lacrimal bone; 4 - supraorbital process; 5 - zygomatic process of the jawbone; 6 - parietal bone; 7 - articular process of the lower jaw; 8 - upper occipital bone; 9 - cervical vertebrae; 10 - thoracic vertebrae; 11 - lumbar vertebrae; 12 - sacral vertebrae; 13 - tail vertebrae; 14 - lower jaw; 15 - atlas; 16 - epistrophy; 17 - the first rib; 18 - handle of the sternum; 19 - scapula; 20 - spine of the scapula; 21 - acromion; 22 - sternum; 23 - xiphoid process; 24 - rib; 25 - humerus; 26 - radius; 27 - wrist; 28 - metacarpal bone; 29 - phalanx of the finger; 30 - ulna; 31 - olecranon; 32 - patella; 33 - tibia; 34 - metatarsus; 35 - tarsal bone; 36 - the main phalanx of the finger; 37 - calcaneus; 38 - fibula; 39 - thigh; 40 - pubic bone; 41 - acetabulum; 42 - obturator opening; 43 - ischium; 44 - ilium

The spine is differentiated into sections coinciding with the direction of action of the animal's gravity - cervical, thoracic, lumbar, sacral, caudal (Table 2). Each vertebra has a hole through which the spinal cord passes. The vertebrae are connected by cartilage plates, thanks to which the spinal column is flexible.

Department of the spine: Cervical– (number of calls) 7

thoracic – 12 (13)

Lumbar – 7

Sacral – 4

Tail – 16 (15)

Total – 46

The chest is formed by ribs (usually 12 pairs) and the sternum. It contains the heart and lungs. The ribs are paired arcuate bones, movably attached to the right and left to the vertebrae of the thoracic spine. They are less mobile in the anterior part of the chest, where the scapula is attached to them. In this regard, the anterior lobes of the lungs are more often affected when the organ is diseased.

peripheral skeleton, or limb skeleton, represented by two thoracic (front) and two pelvic (hind) limbs, performing the function of movement in space.

The composition of the thoracic limb includes the scapula, which is attached to the body in the region of the first ribs, the shoulder, consisting of the humerus, the forearm, represented by the radius and ulna, the hand, consisting of 9 carpal, 5 metacarpal bones and three phalanges of 4 fingers.

The pelvic limb consists of a pelvis, each half of which is an innominate bone - the ilium is located at the top, the pubic and ischium bones are located below, the thigh, represented by the femur and patella, which slides along the block of the femur, the lower leg, consisting of the tibia and fibula, foot , represented by 6 bones of the tarsus, 4 bones of the metatarsus and three phalanges of 4 fingers.

It is important to know that rabbits have thin tubular leg bones and a relatively weak spine. Therefore, they often (especially rabbits) break their legs, and with a sudden fright and awkward movements, they damage the spine and, along with it, the lumbar nerve, which leads to paralysis of the hind legs.

Bundles are bundles of collagen fibers that connect bones or cartilage to each other. They experience the same load of body mass as the bones, but by connecting them to each other, these fibers provide the necessary buffering to the skeleton, significantly increasing the resistance to the loads falling on the joints of the bones as supporting structures.

There are several types of bone connections:

› continuous. This type of connection has great elasticity, strength and very limited mobility (for example, the bones of the skull);

› discontinuous (synovial) type of connection, or joints. It provides a greater range of motion and is built more complex (for example, the bones of the limbs). The joint has an articular capsule, consisting of two layers of the outer (which fuses with the periosteum of the bone) and the inner (synovial, which secretes synovium into the joint cavity, due to which the bones do not rub against each other). Most joints, except for the capsule, are fixed by a different number of ligaments. With ruptures and severe sprains of the ligaments, the bones are separated from each other, and a dislocation of the joint occurs.

Among the diseases of the organs of the apparatus of movement, pathological processes are more common than others at the junctions of the bones, especially the joints of the limbs in animals. Pathology at the junction of the bones is dangerous with such consequences as loss of mobility, which is accompanied by a loss of the ability to move normally and significant pain symptoms.

Muscle has an important property - to contract, causing movement (dynamic work) and provides the tone of the muscles themselves, strengthening the joints at a certain angle of combination with a motionless body (static work) and allowing you to maintain a certain posture.

Only the work (training) of muscles contributes to the growth of their mass both by increasing the diameter of muscle fibers (hypertrophy) and by increasing their number (hyperplasia).

Each muscle has a supporting part - the connective tissue stroma - and a working part - the muscle parenchyma. The greater the static load performed by the muscle, the more developed the stroma in it.

Muscle tissue can be of three types depending on the type of location of muscle fibers: smooth (vascular walls), striated (skeletal muscles), cardiac striated (in the heart). According to the nature of their activity and the work performed, the muscles are divided into flexor and extensor, adductor and abductor, locking (sphincters), rotating, etc. The work of the muscular apparatus is built on the principle of antagonism. In total, the body has up to 200–250 paired muscles and several unpaired ones.

The combination of skeletal muscles with ligaments, muscle sheaths, blood vessels, nerves and bones forms rabbit meat, or rabbit meat. This is white-pink meat, since the muscles are less saturated with myoglobin and sarcoplasm due to the lack of strong loads, and the meat is darker on the limbs than on the body. As rabbits grow, the meatiness of the carcasses and the yield of edible parts increase as a result of an increase in muscle and fat content and a decrease in bone content. As meat ages, its protein and fat content increases and its calorie content increases.

The body of rabbits is covered with hairy skin and organs, or derivatives of the skin. Their appearance, texture, temperature and sensitivity reflect the state of metabolism and functions of a number of organ systems.

Leather protects the body from external influences (mechanical and biological - the introduction of pathogenic microorganisms), through a variety of nerve endings acts as a receptor link in the skin analyzer of the external environment (tactile, pain, temperature sensitivity). Through many sweat and sebaceous glands, a number of metabolic products are secreted, through the mouths of hair follicles and skin glands, the surface of the skin can absorb a small amount of solutions. The blood vessels of the skin can contain up to 10% of the blood of the animal's body, so it is a blood depot. Constriction and expansion of blood vessels are essential in the regulation of body temperature (about 82% of all heat loss of the body occurs through the skin surface).

The mass of the skin is on average 12% of the total live weight.

In the skin of a rabbit covered with hair, the following layers are distinguished (Fig. 8):

› cuticle (epidermis) – the outer layer that determines skin color. Dead cells are exfoliated from it, thereby dirt and microorganisms are removed from the surface of the skin. The epidermis makes up approximately 2–3% of the total thickness of the skin;

› the dermis (skin itself) consists of two layers - the upper (papillary), formed by loose connective tissue, where hair bags, sebaceous glands, hair lifting muscles are located, and the lower - mesh, in which there are bundles of collagen and elastin fibers that determine strength , firmness, elasticity and extensibility of the skin. In rabbits, the dermis occupies about 70% of the thickness of the skin;

› subcutaneous base (subcutaneous layer) is the link between the dermis and the body of the animal. It consists of loose connective tissue, formed by interweaving of thin bundles of collagen and elastin fibers, between which are located fat cells and blood vessels.

1 - epidermis; 2 - dermis; 3 - subcutaneous tissue; 4 - cortical layer of hair; 5 - core; 6 - hair shaft; 7 - muscle straightening hair; 8 and 9 - external and internal hair sheaths; 10 - hair papilla; 11 - bulb

Skin with hair and subcutaneous tissue removed from the body of an animal is called hide.

To derivative of the skin include sweat, sebaceous, and mammary glands, claws, crumbs and hair.

Sebaceous glands. They are located at the base of the skin over the entire surface of the body, and their ducts open into the mouths of the hair follicles. The sebaceous glands secrete a sebaceous secret, which lubricates the skin and hair and gives them softness and elasticity, protects them from brittleness, and the body from moisture.

sweat glands located in the reticular layer of the skin over the entire surface of the body. Their excretory ducts, through which a liquid secret is released - sweat, open to the surface of the epidermis.

Breast. Rabbits have a multiple mammary gland, consisting of 4 pairs of mammary glands, lying on the sides of the white line from the region of the xiphoid cartilage to the pubic region. The main function of this organ is the formation and accumulation of milk (a fluid secreted by the mammary gland of mammals 5–7 days after birth and necessary for feeding the cub) with its periodic excretion during suckling, i.e. lactation (Table 3). Milk secretion is a complex reflex process associated with successive structural and functional changes in glandular cells and various breast tissues. The duration of the lactation period (the time from the moment of birth to the cessation of milk production) and the milkiness of the female depend on the breed, feeding and keeping of animals, the timing of the onset of a new pregnancy, etc. when fed only dry food, it decreases slightly.

In rabbits, the lactation period is 25 days after birth and more, which allows them to be used as nurses for other rabbits after their own jigging. A rabbit during lactation gives from 50 to 270 ml of milk daily, more often 100–200 ml. The separation of milk begins shortly before birth. Until about the 20th day, the milk production of rabbits gradually increases, from the 21st to the 25th day the amount of milk secreted remains unchanged, and then decreases. The highest milk production is usually distinguished by rabbits in the second round. In young females, this figure is approximately 1/3 lower than in adult females up to 2–2.5 years of age. Starting from the age of 3 years, the milk production of rabbits decreases sharply, although in some individuals it can persist until the age of 4 years.

Depending on the milk production of rabbits, the intensity of growth of rabbits and their health also change. The difference in the weight of 20-day-old pups with high and low milk production is at least 30%, and 60-day-old pups - 20%.

claws. These are horny curved tips covering the last, third, phalanges of the fingers. They, under the influence of muscles, can be drawn into the groove of the roller and move out of it. The claws are involved in the function of defense and attack, and with their help the rabbit can hold food and dig the ground.

Crumb. This is the base of the limbs. In addition to the support function, it is an organ of touch. The cushion of the crumb forms the subcutaneous layer of the skin.

Hair. The body of all animals is covered with hair. Hair is a spindle-shaped filament of stratified keratinized and keratinized epithelium. The part of the hair that rises above the surface of the skin is called the shaft, the part located in the dermis is called the root, it is surrounded by blood capillaries. The root passes into the bulb (the expanded part of the hair root), inside the bulb is the papilla of the hair. Hair growth occurs due to cell division of the bulb. Each hair has its own muscles that allow it to straighten, as well as sebaceous glands.

The coat of rabbits is heterogeneous. Hair is covering: guide, guard and down. There are also vibrissae. Covering hair protects down hair from unwanted mechanical impact, and down hair itself performs the function of protecting the body from the cold. Vibrissae are sensitive hairs that perform the function of touch.

Guide hair straight, spindle-shaped, long. They rise above the entire hairline, giving it a beautiful look. The color is mostly monochromatic.

Guard hair there are significantly more guides in number, but they are shorter and thinner. Such hair is either straight or curved. Their coloration is monophonic or zonal.

downy hair the shortest and thinnest, they form the bulk of the hairline (more than 90%). This hair has a wavy-curved shape, and their color is usually solid. The ratio of guard hairs to down hairs ranges from 1:20 to 1:65.

Vibrissae- These are long tactile hairs located on the skin in the area of ​​​​the lips, nostrils, chin and eyelids.

The most important indicator of the quality of the rabbit's hairline and, accordingly, the health of the animal, is the density, that is, the number of hairs per unit area of ​​​​the skin. The most dense hairline is on the rump (closer to the tail), less dense - on the sides and back. The nature of the hairline, that is, the length, thickness, composition and position of the hair in relation to the body, is a hallmark of the breed.

The rabbits are born naked, and on the 5th-7th day they develop a hairline 5-6 mm long, consisting of guard hairs and guiding hairs. By the 20-25th day, the primary hairline reaches its full development.

In rabbits, as in other animals, there is a change in the integument of the body, or molt. In this case, the hair or coat is completely or partially replaced (except for tactile hairs). During molting, the skin thickens, becomes looser, and the stratum corneum of the epidermis is often renewed.

Distinguish between physiological and pathological molting. The physiological change of coat is divided into 3 types:

› age (primary soft hair is replaced by coarser spinous): the first age molt at the age of 1 month, the second - at 3.5–4.5 months, the third - at 7–7.5 months;

› seasonal (spring and autumn), which must be taken into account when putting on fattening and slaughtering rabbits;

› compensatory (formation of hairline at the site of damage or destruction of hair).

Pathological molting is an unmotivated change of hair as a result of illness, improper feeding conditions or the maintenance of an animal.

At the time of molting, rabbit fluff falls out easily. This is especially useful for those who raise downy rabbits. The fluff is plucked from them every 2–2.5 months.

At the time of slaughter, rabbits should have completed their age or seasonal molt.

This system carries out the morphofunctional integration of body parts, the unity of the body and the environment, and also ensures the regulation of all types of body activity: movement, respiration, digestion, reproduction, blood and lymph circulation, metabolism and energy.

The structural and functional unit of the nervous system is a nerve cell - a neurocyte - together with gliocytes. The latter dress nerve cells and provide support-trophic and barrier functions in them. Nerve cells have several processes - sensitive tree-branching dendrites that conduct to the body of the neuron the excitation that occurs at their sensitive nerve endings located in the organs, and one motor axon, along which the nerve impulse is transmitted from the neuron to the working organ or another neuron. Neurons come into contact with each other using the ends of the processes, forming reflex circuits through which nerve impulses are transmitted (propagated).

The processes of nerve cells together with neuroglial cells form nerve fibers. These fibers in the brain and spinal cord make up the bulk of the white matter. From the processes of nerve cells, bundles are formed, from groups dressed in a common sheath, nerves are formed in the form of cord-like formations.

Anatomically, the nervous system is divided into central, including the brain and spinal cord with spinal ganglia, and peripheral, consisting of cranial and spinal nerves connecting the central nervous system with receptors and effector apparatuses of various organs. This includes the nerves of skeletal muscles and skin - the somatic part of the nervous system, as well as blood vessels - the parasympathetic part. These last two parts are united by the concept of "autonomous, or autonomic, nervous system."

Central nervous system. The brain is the head part of the central part of the nervous system, it is located in the cranial cavity and is represented by two hemispheres with convolutions separated by a groove. The brain is covered with a cortical substance, or bark.

The following sections are distinguished in the brain: cerebrum, telencephalon (olfactory brain and cloak), diencephalon (optic tubercles (thalamus), epithalamus (epithalamus), hypothalamus (hypothalamus) and perituberosity (metathalamus), midbrain (cranial peduncles and quadrigemina), rhomboid brain, hindbrain (cerebellum and pons) and medulla oblongata, responsible for different functions. Almost all parts of the brain are involved in the regulation of autonomic functions (metabolism, blood circulation, respiration, digestion). Respiratory centers are located in the medulla oblongata and blood circulation, and the cerebellum coordinates movements, muscle tone and balance of the body in space.The main elementary manifestation of the activity of the brain is a reflex (the response of the body to irritation of receptors), that is, obtaining information about the result of a perfect action.

The brain is dressed in three layers: hard, arachnoid and soft. Between the hard and arachnoid membranes there is a subdural space filled with cerebrospinal fluid (its outflow is possible into the venous system and into the lymph circulation organs), and between the arachnoid and soft shells there is a subarachnoid space. The brain consists of white matter (nerve fibers) and gray matter (neurons). The gray matter in it is located on the periphery of the cerebral cortex, and the white matter is in the center.

The brain is the highest part of the nervous system that controls the activity of the whole organism, unites and coordinates the functions of all internal organs and systems. In case of pathology (trauma, tumor, inflammation) there is a violation of the functions of the entire brain, which is expressed in a violation of movement, a change in the functioning of internal organs, a violation of the behavior of the animal, a coma (lack of the animal's reaction to the environment).

The spinal cord is part of the central part of the nervous system, which is a cord of brain tissue with the remnants of the brain cavity. It is located in the spinal canal and starts from the medulla oblongata and ends in the region of the 7th lumbar vertebra. Its mass in a rabbit is 3.64 g.

The spinal cord is conditionally subdivided without visible boundaries into the cervical, thoracic and lumbosacral regions, consisting of gray and white medulla. In the gray matter there is a number of somatic nerve centers that carry out various unconditioned (innate) reflexes, for example, at the level of the lumbar segments there are centers that innervate the pelvic limbs and the abdominal wall. The gray matter is located in the center of the spinal cord and is shaped like the letter "H", while the white matter is located around the gray.

The spinal cord is covered with three protective membranes: hard, arachnoid and soft, between which there are gaps filled with cerebrospinal fluid. Veterinarians may inject into this fluid and the subdural space, depending on the indications.

Peripheral nervous system- a topographically distinguished part of a single nervous system, which is located outside the brain and spinal cord. It includes cranial and spinal nerves with their roots, plexuses, ganglia and nerve endings embedded in organs and tissues. So, 31 pairs of peripheral nerves depart from the spinal cord, and only 12 pairs from the brain.

In the peripheral nervous system, it is customary to distinguish 4 parts - somatic (connecting centers with skeletal muscles), sympathetic (associated with smooth muscles of the vessels of the body and internal organs), visceral, or parasympathetic, (associated with smooth muscles and glands of internal organs) and trophic (innervating connective tissue).

autonomic nervous system has special centers in the spinal cord and brain, as well as a number of nerve nodes located outside the spinal cord and brain. This part of the nervous system is divided into:

› sympathetic (innervation of the smooth muscles of blood vessels, internal organs and glands), the centers of which are located in the thoracolumbar region of the spinal cord;

› parasympathetic (innervation of the pupil, salivary and lacrimal glands, respiratory organs, organs located in the pelvic cavity), its centers are located in the brain.

A feature of these two parts is the antagonistic nature in providing them with internal organs, that is, where the sympathetic nervous system acts excitatory, the parasympathetic - depressing.

The central nervous system and the cerebral cortex regulate all higher nervous activity of the animal through reflexes. There are genetically fixed reactions of the central nervous system to external and internal stimuli - food, sexual, defensive, orientation, sucking reaction in newborns, the appearance of saliva at the sight of food. These reactions are called innate, or unconditioned, reflexes. They are provided by the activity of the brain, the spinal cord stem and the autonomic nervous system. Conditioned reflexes are acquired individual adaptive reactions of animals that arise on the basis of the formation of a temporary connection between the stimulus and the unconditional reflex act.

Compared to other farm animals, rabbits are more shy. They are especially afraid of sudden strong sounds. Therefore, handling them should be more careful than with other animals.

Various excitations coming from the external environment and internal organs of the animal are perceived by the sense organs and then analyzed in the cerebral cortex.

An animal has 5 sense organs: olfactory, gustatory, tactile, visual, and auditory-equilibrium analyzers. Each of these organs has departments: peripheral (perceiving) - receptor, middle (conducting) - conductor, analyzing (in the cerebral cortex) - brain center. Analyzers, in addition to general properties (excitability, reactive sensitivity, aftereffect, adaptation and contrast phenomenon), perceive a certain type of impulses - light, sound, thermal, chemical, temperature, etc.

Smell- the ability of animals to perceive a certain property (smell) of chemical compounds in the environment. Molecules of odorous substances, which are signals of certain objects or events in the external environment, together with the air reach the olfactory cells when they are inhaled through the nose (during meals - through the choanae).

The olfactory organ is located in the depths of the nasal cavity, namely in the common nasal passage, in its upper part, a small area lined with olfactory epithelium, where receptor cells are located. The cells of the olfactory epithelium are the beginning of the olfactory nerves, through which excitation is transmitted to the brain. Between them are supporting cells that produce mucus. On the surface of the receptor cells there are 10–12 hairs that react to aromatic molecules.

The sense of smell in rabbits is much more developed than vision. This is confirmed by the fact that when alien rabbits are planted with a rabbit, their color does not matter at all, since only by smell can the mother distinguish strangers and destroy them. By smell, rabbits also distinguish food. They treat new food with caution, sniffing for a long time. It takes patience to accustom animals to them. The rabbit, when moving forward, sniffs everything that comes his way, and constantly keeps his nose up, catching the slightest change in the state of the atmosphere around him. He is able to feel the faintest traces of this or that smell. This provides the animal with invaluable help not only when looking for food or a mating partner, but also when orienting in an unfamiliar area, determining the social status of fellow tribesmen and recognizing friends and enemies.

The sense of smell is disturbed during inflammatory and atrophic processes in the nasal mucosa and damage to the central parts of the olfactory system, which is manifested by increased sensitivity to odors (hypersomia), decrease (hyposomia) and loss (anosomia).

Taste- analysis of the quality of various substances entering the oral cavity. The taste sensation arises as a result of the action of chemical solutions on the chemoreceptors of the taste buds of the tongue and oral mucosa. This creates a sensation of bitter, sour, salty, sweet or mixed taste. The sense of taste in newborns awakens before all other sensations.

taste buds contain taste buds with neuro-epithelial cells and are located mostly on the upper surface of the tongue, and are also located in the oral mucosa. In shape, they are of three types - mushroom-shaped, roller-shaped and leaf-shaped. From the outside, the taste receptor is in contact with food substances, and the other end is immersed in the thickness of the tongue and is connected to nerve fibers. Taste buds do not live long, die off and are replaced by new ones. They are unevenly distributed over the surface of the tongue, in certain groups, and form taste zones that are sensitive mainly to certain substances.

Well-developed taste abilities are indispensable for survival in the wild. With their help, rabbits can successfully avoid foreign toxic impurities in food. The slightest taste or olfactory change in a piece of food is enough for these animals to consider it dangerous.

Touch- the ability of animals to perceive various external influences (touch, pressure, stretching, cold, heat). It is carried out by receptors of the skin, musculoskeletal system (muscles, tendons, joints, etc.), mucous membranes (lips, tongue, etc.). So, the most sensitive skin is in the area of ​​the eyelids, lips, as well as the back, forehead. The tactile sensation can be diverse, as it arises as a result of a complex perception of the various properties of the stimulus acting on the skin and subcutaneous tissues. Through touch, the shape, size, temperature and consistency of the stimulus, as well as the position and movement of the body in space, are determined. It is based on the stimulation of special structures - mechanoreceptors, thermoreceptors, pain receptors - and the transformation in the central nervous system of incoming signals into the appropriate type of sensitivity (tactile, temperature, pain or nociceptive).

Many pathological processes are accompanied by a pain reaction. Pain signals an emerging danger and causes a defensive response aimed at eliminating sharp stimuli. Therefore, the absence of this kind of reaction in various injuries is an alarming sign.

In rabbits, as in cats, vibrissae act as a kind of probes that record changes in the surrounding space. Sensitive whiskers help rabbits navigate in complete darkness, such as through underground passages. Long vibrissae are also located above the eyes of rabbits, thanks to which these relatively large animals know when to bend their heads or deviate to the side so as not to run into an obstacle.

Vision- the ability of the organism to perceive objects of the external world by capturing the emitted or reflected light. It allows, based on the analysis of the physical phenomena of the surrounding world, to organize expedient vision. Rabbits have color vision. The process of vision in vertebrates is based on photoreception - the perception of light by the photoreceptors of the retina - the organ of vision.

The eye consists of the eyeball, connected by the optic nerve to the brain, and auxiliary organs. The eyeball itself is spherical in shape, it is located in the bone cavity - the orbit, or orbit, formed by the bones of the skull. The anterior pole is convex, while the posterior pole is somewhat flattened.

The eyeball consists of the outer, middle and inner membranes, light-refracting media (the lens and the contents of the anterior, posterior and vitreous chambers of the eye), nerves and blood vessels.

Auxiliary organs of the eye - eyelids (cutaneous-muco-muscular folds located in front of the eyeball and protecting the eye from mechanical damage), the lacrimal apparatus (the lacrimal secret is formed and accumulates there, consisting mainly of water and containing the enzyme lysozyme, which has a bactericidal effect; when the eyelids move, tear fluid moisturizes and cleanses the conjunctiva), eye muscles (ensure the movement of the eyeball in different directions within the orbit), orbit, periorbita (location of the back of the eyeball, optic nerve, muscles, fascia, vessels and nerves) and muscle fascia . The location of the eyeball is called the orbit, and the periorbit is the place where the seven eye muscles are located.

Rabbits have large bulging eyes that are well adapted to active life at dusk, while they are able to perceive objects that are at a considerable distance from them quite sharply.

Hearing- the ability of animals to perceive and analyze the sound vibrations of the environment, which is carried out when sound is picked up by such an organ as the ear. This is a complex set of structures that provide the perception of sound, vibration and gravitational signals. It consists of the outer, middle and inner ear.

In rabbits, as in most mammals, sound vibrations, passing through the auricle and external auditory canal (outer ear), cause vibrations of the tympanic membrane, transmitted through a system of articulated bones (middle ear) into liquid media (the so-called perilymph and endolymph ) cochlea of ​​the inner ear. The resulting hydromechanical oscillations lead to oscillations of the cochlear septum with the receptor apparatus located on it, which convert the mechanical energy of oscillations into excitation of the auditory nerve and, accordingly, to auditory sensation.

Rabbits have large ears, thanks to which animals have excellent hearing. They can perceive even the weakest sound signals. For example, females of these rodents are able to perceive the extremely quiet squeak of newborn rabbits. At the same time, rabbits can differentially perceive both aggressive sounds made by adult animals during a fight and sound signals indicating their peaceful mood or calls for mating. At the same time, the animals turn their ears in all directions in order to better catch the sound. Between themselves, these animals are explained by high-frequency sounds that are outside the range of human auditory perception.

The excellent acoustic abilities of rabbits, together with an excellent sense of smell, are the most important means for them in assessing the environment.

When the auditory system is damaged in animals, the ability to distinguish between certain sound parameters, the sound sequence and the position of the sound source in space is impaired.

Equilibrium- the ability of animals to perceive changes in the position of the body in space, as well as the effects on the body of acceleration and changes in gravitational forces. It is represented by the vestibular apparatus, the receptor part of which is located in the inner ear in the form of semicircular canals. The signals coming from the balance receptors associated with the position of the body or with acceleration occur with mechanical irritation of the sensitive hairs located there. The combination of sensory signals from channels, eyes, muscle, joint and skin receptors causes statokinetic reflexes, as a result of which the animal maintains normal orientation (the ability inherent in animals to determine their position in space, among individuals of the same or other species) in relation to the direction of gravity and counteract acceleration in all planes. These reflex reactions occur with the participation of the spinal cord and lower parts of the brain.

Balance disorders in animals are observed in a number of diseases of the nervous system in the form of impaired coordination of movements and loss of orientation in space.

Endocrine glands include organs, tissues, groups of cells that secrete hormones into the blood through capillary walls - highly active biological regulators of metabolism, functions and development of the animal body. There are no excretory ducts in the endocrine glands.

In the form of organs, there are the following endocrine glands: the pituitary gland, the pineal gland (pineal gland), the thyroid gland, the parathyroid glands, the pancreas, the adrenal glands, the sex glands (in males - testes, in females - ovaries).

Pituitary lies at the base of the sphenoid bone and secretes a number of hormones: thyroid-stimulating (stimulates the development and functioning of the thyroid gland), adrenocorticotropic (enhances the growth of cells of the adrenal cortex and the secretion of hormones in them), follicle-stimulating (stimulates the maturation of follicles in the ovary and the secretion of female genital organs, spermatogenesis (formation sperm) in males), somatotropic (stimulates tissue growth processes), prolactin (takes part in lactation), oxytocin (causes contraction of the smooth muscles of the uterus), vasopressin (stimulates the absorption of water in the kidneys and an increase in blood pressure). Violation of the functioning of the pituitary gland causes gigantism (acromegaly) or dwarfism (nanism), disorder of sexual abilities, exhaustion, loss of hair, teeth.

epiphysis, or pineal gland, located in the region of the diencephalon. Hormones (melatonin, serotonin and antigonadotropin) are involved in the regulation of animal sexual activity, biological rhythms and sleep, as well as in reactions to light exposure.

Thyroid the isthmus is divided into the right and left lobes, located behind the trachea in the neck. The hormones thyroxine and triiodothyronine regulate oxidative processes in the body, affect all types of metabolism and enzymatic processes. They contain iodine. Thyrocalcitonin, counteracting parathyroid hormone, reduces the calcium content in the blood.

The thyroid gland also influences the growth, development and differentiation of tissues.

parathyroid glands located near the wall of the thyroid gland. The parathyroid hormone secreted by them regulates the content of calcium in the bones, enhances its absorption in the intestines and the release of phosphates in the kidneys.

Pancreas performs a dual function. As an endocrine gland, it produces insulin, a hormone that regulates blood sugar levels. An increase in blood sugar leads to an increase in its content in the urine, as the body tries to reduce the amount of sugar.

Adrenals- paired organs that lie in the fatty capsule of the kidneys. They synthesize the hormones aldosterone, corticosterone (hydrocortisone), and cortisone, which is the opposite of insulin.

gonads in males, they are represented by the testes, which produce male germ cells and the endocrine hormone - testosterone. This hormone stimulates the development and manifestation of sexual reflexes, takes part in the regulation of spermatogenesis, affects the differentiation of sex.

In females, the gonads are paired ovaries, where sex ova are formed and mature, and sex hormones, estradiol and metabolites, are also formed. Estradiol and its metabolites estrone and estriol stimulate the growth and development of female genital organs, are involved in the regulation of the sexual cycle, and affect metabolism. Progesterone is an ovarian corpus luteum hormone that ensures the normal development of a fertilized egg.

In the body of females, under the influence of testosterone, which is produced in small amounts in the ovaries, the formation of follicles and the regulation of the sexual cycle occur.

Hormones produced by the endocrine glands have the ability to have a dramatic effect on metabolism and on a number of important life processes in the animal body. In violation of the secretory function of this group of glands (decrease or increase), specific diseases occur in the body - metabolic disorders, deviations from normal growth, in sexual development, and a number of other deviations.

The digestive system carries out the exchange of substances between the body and the environment. Through the digestive organs, all the substances it needs - proteins, fats, carbohydrates, mineral salts, vitamins - enter the body with food, and some of the metabolic products and undigested food residues are released into the external environment. In rabbits, food passes through the entire gastrointestinal tract in about 72 hours.

The digestive tract is a hollow tube, consisting of a mucous membrane and muscle fibers. It starts in the mouth and ends at the anus.

Along the entire length of the digestive tract, there are specialized sections that are designed to move and assimilate ingested food.

The rabbit digestive tract consists of several sections: the oral cavity, pharynx, esophagus, stomach, small and large intestines, rectum and anus (anus), as well as digestive glands (salivary, pancreas and liver) (Fig. 9).

Oral cavity includes upper and lower lips, cheeks, tongue, teeth, gums, hard and soft palate, salivary glands, tonsils, pharynx. With the exception of the crowns of the teeth, its entire inner surface is covered with a mucous membrane, which may be pigmented.

Lips and cheeks designed to hold food in the oral cavity and serve as the vestibule of the oral cavity.

Language- a muscular movable organ located at the bottom of the oral cavity - performs several functions: tasting food, participating in the process of swallowing, drinking, as well as in feeling objects, stripping soft tissues from bones, caring for the body, hairline, and also for contact with other individuals. On the surface of the tongue there are a large number of horny papillae: mechanical (capturing and licking food) and gustatory (organ of taste).

1 - salivary gland; 2 - heart; 3 - esophagus; 4 - aorta; 5 - stomach; 6 - ureter; 7 - kidney; 8 - ovary; 9 - oviduct; 10 - uterine horn; 11 - bladder; 12 - vagina; 13 - anus; 14 - spleen; 15 - large intestine; 16 - pancreas; 17 - gallbladder; 18 - liver; 19 - caecum; 20 - appendix (appendix); 21 - thyroid gland; 22 - trachea; 23 - easy

Teeth- bone enamel organs for capturing and grinding food. Teeth are divided into incisors, premolars, or premolars, and molars, or molars. Like all rodents, rabbits do not have fangs.

Rabbits are born with 16 milk teeth, and replacement with permanent ones occurs on the 20-28th day of life.

The jaw of an adult animal consists of 28, rarely 26 teeth (Table 4).

Permanent: 4(2)I 0C 6P 6M (upper jaw)? 2 2I 0C 4P 6M (lower jaw)

I - incisors, C - canines, P - premolars, M - molars

Rabbits cut and gnaw food with incisors, and grind and grind it with molars. Rabbit incisors are constantly growing and self-sharpening. The front part of them is covered with a strong layer of enamel, and the back part is covered with a thin and less durable layer, because of which it is erased faster than the front one, and thus constant sharpening is carried out. Sometimes, in the absence of roughage, there is an overgrowth of the incisors, which are bent into the oral cavity. In this case, they have to be shortened with wire cutters.

Gums are folds of the mucous membrane that cover the jaws and strengthen the position of the teeth in the bone cells. The hard palate is the roof of the oral cavity and separates it from the nasal cavity, and the soft palate is a continuation of the mucous membrane of the hard palate and is located freely on the border of the oral cavity and pharynx, separating them. The gums, tongue, and palate may be unevenly pigmented pink. A change in color is a sign of a disease.

Several steam rooms open directly into the oral cavity. salivary glands, whose names correspond to their localization: parotid, submandibular, sublingual, molars and supraorbital (zygomatic). The secret of the glands, or saliva, contains enzymes that break down starch and maltose.

tonsils are organs of the lymphatic system and perform a protective function in the body.

Digestion in rabbits begins in the mouth, where food is stored for a short time. Here it is subjected to mechanical grinding and initial processing under the action of saliva enzymes, which also ensures the formation of a food coma. The formed food lump, with the help of movements of the tongue and cheeks, falls on the root of the tongue, which raises it to the hard palate and moves it to the pharynx. The entrance to the throat is called the pharynx.

Pharynx- a funnel-shaped cavity lined with a mucous membrane and having powerful muscles. It connects the mouth to the esophagus and the nasal cavity to the lungs. The oropharynx, nasopharynx, two Eustachian or auditory tubes, trachea and esophagus open into the pharynx.

Esophagus is a muscular tube through which food is transported in a circular way from the pharynx to the stomach. It is almost entirely formed by skeletal muscles.

Stomach- a direct continuation of the esophagus, is a sac-like abdominal organ. In rabbits, the stomach is shaped like a horseshoe-shaped sac. This organ is located in the anterior half of the abdominal cavity on the right side. The volume of the rabbit's stomach is 180-200 ml.

From the esophagus, mushy food enters the stomach, where it mixes with gastric juice. It is constantly secreted by the glands of the mucous membrane of the organ. Gastric juice contains hydrochloric acid and the enzyme pepsin, which is highly acidic. Under its action, feed proteins break down into amino acids. Depending on the type of food eaten, food stays in the rabbit's stomach for 3-10 hours. After several hours from the start of eating, half of the food remains in the stomach, and the other half moves to the intestines due to wave-like contractions of the stomach muscles.

Intestines rabbit is a hollow tube, located in the form of numerous twisted loops. This segment of the digestive system is subdivided, in turn, into a thin and thick section. The total length of the rabbit intestine ranges from 4 to 6 m, which is about 8-10 times the length of the body. The ratio of the length of the intestine to the length of the body is 2–3 times greater than that of carnivores. This is due to the fact that the rabbit is adapted to the consumption of a significant amount of voluminous roughage rich in fiber.

The small intestine starts from the stomach and is divided into three main parts:

› duodenum (the first and shortest part of the small intestine, 40–60 cm long, into which the bile ducts and pancreatic ducts exit);

› jejunum (the longest part of the intestine, suspended in the form of many loops on an extensive mesentery);

› ileum (is a continuation of the jejunum).

The small intestine is located in the right hypochondrium and has a length of 275–320 cm. The mucous membrane of the small intestine is more specialized for digestion and absorption of food: it is collected in folds called villi. They increase the absorptive surface of the intestine.

Pancreas also lies in the right hypochondrium and secretes several liters of pancreatic secretion into the duodenum per day, containing enzymes that break down proteins, carbohydrates and fats, as well as the hormone insulin, which regulates blood sugar levels.

Liver located in the right hypochondrium. Through it passes and filters the blood flowing through the portal vein from the stomach, spleen and intestines, complex metabolic processes (nitrogenous compounds, carbohydrates, fats) are performed, toxic metabolic products are neutralized. The liver produces bile, which converts fats for absorption into the blood vessels of the intestinal wall. Bile accumulates in the gallbladder, and from there through the bile duct enters the duodenum. During the embryonic period, the main processes of hematopoiesis take place in the liver. Its removal leads to the death of the animal.

In the small intestine, the contents of the stomach are exposed to the action of bile, intestinal and pancreatic juices, which contributes to the breakdown of nutrients into simple components and their absorption into the blood and lymph.

The large intestine is represented by the caecum, colon and rectum, ending in the anal canal with the anus. The contents of the small intestine enter the large intestine, where it stays for several hours. There are no villi on the mucous membrane of the large intestine, but there are depressions - crypts, where the general intestinal glands are located, which secrete a small amount of juices containing a lot of mucus, but few enzymes. The microbes of the intestinal contents cause fermentation of carbohydrates (fermentation processes, splitting and digestion of fiber occur in the caecum and colon), and putrefactive bacteria destroy the residual products of protein digestion, and such harmful compounds as indole, skatole, phenols are formed, which, being absorbed into the blood, can cause intoxication, which occurs, for example, with protein overfeeding, dysbacteriosis, and a lack of carbohydrates in the diet. These substances are neutralized in the liver. In the large intestine, water is intensively absorbed (up to 95%), some minerals.

Due to strong peristaltic contractions of the muscles of the large intestine, the remaining contents through the colon enter the rectum, where the formation and accumulation of feces occurs.

The excretion of feces into the environment occurs through the anal canal (anus). During the day, an adult rabbit excretes up to 0.2 kg of feces, and the day one looks like hard balls, and the night one has a soft, wet consistency. The chemical composition of feces is different.

Rabbits have a physiological feature - coprophagia, or eating their own feces (only night). By eating soft feces directly from the anus, rabbits receive an additional amount of nitrogenous substances (it contains 28.5% proteins), B vitamins and vitamin K.

The respiratory system ensures the supply of oxygen to the body and the removal of carbon dioxide, that is, the exchange of gases between atmospheric air and blood. In land animals, gas exchange occurs in the lungs, which are located in the chest. Alternate contraction of the inspiratory and expiratory muscles leads to the expansion and narrowing of the chest, and with it the lungs. This ensures that air is drawn in through the airways into the lungs (inhalation) and pushed out again (exhalation). The contractions of the respiratory muscles are controlled by the nervous system.

During passage through the airways, the inhaled air is humidified, warmed, cleaned of dust, and also examined for odors using the olfactory organ. With exhaled air, part of the water (in the form of steam), excess heat, and some gases are removed from the body. Sounds are produced in the airways (larynx).

The respiratory organs are represented by the nose and nasal cavity, larynx, trachea and lungs.

Nose Together with the mouth, they make up the anterior part of the head in animals - the muzzle. On the nose, the apex, back, lateral parts and root are distinguished, which are devoid of hair and contain numerous glands, receptors, short sensitive hairs.

The nose contains a paired nasal cavity, which is the initial section of the airways. AT nasal cavity the inhaled air is examined for odors, warmed, humidified, and cleaned of contaminants. The nasal cavity communicates with the external environment through the nostrils, with the pharynx through the choanae, with the conjunctival sacs through the lacrimal canals, and also with the paranasal sinuses.

The paranasal sinuses communicate with the nasal cavity. The paranasal sinuses are cavities filled with air and lined with mucous membrane between the outer and inner plates of some flat bones of the skull (for example, the frontal bone). Because of this message, inflammatory processes from the mucous membrane of the nasal cavity can easily spread to the sinuses, which complicates the course of the disease.

Larynx- a section of the breathing tube located between the pharynx and trachea and suspended from the hyoid bone. The peculiar structure of the larynx allows it to perform, in addition to conducting air, other functions. It isolates the airway when food is swallowed, is a support for the trachea, pharynx and the beginning of the esophagus, and serves as a vocal organ. The skeleton of the larynx is formed by five movably interconnected cartilages, on which the muscles of the larynx and pharynx are attached, and the cavity of the larynx is lined with a mucous membrane. Between the two cartilages of the larynx there is a transverse fold - the so-called vocal lip, which divides the cavity of the larynx into two parts. It contains the vocal cord and vocal muscle. The tension of the vocal lips during exhalation creates and regulates sounds.

Trachea serves to carry air into and out of the lungs. This is a tube with a constantly gaping lumen, which is ensured by the rings of hyaline cartilage that are not closed from above in its wall. The inside of the trachea is lined with a mucous membrane. It extends from the larynx to the base of the heart, where it divides into two bronchi, which form the basis of the roots of the lungs. This place is called the bifurcation of the trachea.

Lungs- the main respiratory organ, directly in which gas exchange occurs between the inhaled air and blood through a thin wall separating the lungs. To ensure gas exchange, a large area of ​​​​contact between the air and blood channels is necessary. In accordance with this, the airways of the lungs - bronchi - like a tree, branch many times to bronchioles (small bronchi) and end in numerous small pulmonary vesicles - alveoli, which form the parenchyma of the lungs (parenchyma is a specific part of the organ that performs its main function). The blood vessels branch parallel to the bronchi and encircle the alveoli with a dense capillary network, where gas exchange takes place. Thus, the main components of the lungs are the airways and blood vessels. The connective tissue unites them into a paired compact organ - the right and left lungs. The lungs are located in the chest cavity, adjacent to its walls. In a rabbit, the relative weight of the lungs is 0.3% of body weight, and in a hare it is 1–1.2%. The right lung is somewhat larger than the left, since the heart located between the lungs is displaced to the left.

Both lungs in a rabbit weigh 12-15 g, and the right one is 1.35 times larger than the left one.

Rabbits are characterized by intensive gas exchange. For 1 kg of live weight in 1 hour, 378–690 cm3 of oxygen is absorbed and 451–632 cm3 of carbon dioxide is released. Normally, the number of inhalations and exhalations (the frequency of respiratory movements of the chest per minute) in a healthy adult rabbit ranges from 50-60, and in a newborn - 80-90 at a moderate temperature, but the breadth of the range depends on a number of factors, for example, on ambient temperature , physiological state, pathogenic factors and other reasons.

The urinary system is designed to remove from the body (from the blood) to the external environment the end products of metabolism in the form of urine and to control the water-salt balance in the body, such as water and drugs. In addition, the kidneys produce hormones that regulate hematopoiesis (hematopoietin) and blood pressure (renin). Therefore, a violation of the functions of the urinary organs leads to serious diseases and often to the death of animals.

The urinary organs include the paired kidneys and ureters, the unpaired bladder and urethra. In the main organs - the kidneys - urine is constantly formed, which is excreted through the ureters into the bladder and, as it is filled, is excreted out through the urethra. In males, this canal also conducts sex products and is therefore called the urogenital canal. In females, the urethra opens into the vestibule of the vagina.

kidneys- paired long organs of a bean-shaped shape, dense consistency, red-brown in color, smooth, covered on the outside with three membranes - fibrous, fatty, serous - and lying in the lumbar region.

Near the middle of the inner layer, the vessels and nerves enter the organ and the ureters exit. This place is called the kidney gate. On the incision of each kidney, a cortical, or urinary, cerebral, or urinary, and intermediate zone, where the arteries are located, is isolated. In the cortical layer there are renal corpuscles, consisting of a glomerulus - a glomerulus (vascular glomerulus), which is formed by the capillaries of the afferent artery and a capsule, and in the brain - convoluted tubules. The renal corpuscle together with the convoluted tubule and its vessels constitute the structural and functional unit of the kidney - the nephron. In the renal corpuscle of the nephron, the primary urine is filtered from the blood of the vascular glomerulus into the cavity of its capsule. During the passage of primary urine through the convoluted tubule of the nephron, most (up to 99%) of water and some substances that cannot be removed from the body, such as sugar, are absorbed back into the blood. This explains the large number of nephrons and their length. Then urine passes from the tubules into the ureter.

Ureters- a typical tubular paired organ designed to divert urine into the bladder. It travels to the pelvic cavity, where it flows into the bladder. In the wall of the bladder, the ureters make a small loop that prevents urine from flowing back from the bladder into the ureters without interfering with the flow of urine from the kidneys to the bladder.

Bladder- a reservoir for continuously flowing urine from the kidneys, which is periodically excreted through the urethra. It is a pear-shaped membranous-muscular sac, in which there is a special sphincter that prevents the arbitrary exit of urine. The emptied bladder lies at the bottom of the pelvic cavity, and when filled, it partially hangs into the abdominal cavity.

The urethra, or urethra, serves to remove urine from the bladder and is a tube of mucous and muscular membranes. In males, the urethra is long, thin with numerous stenoses (narrowings), while in females it is relatively short and wide. The inner end of the urethra starts from the neck of the bladder, and the outer opening opens in males on the head of the penis, or penis, and in females - on the border between the vagina and its vestibule. The oud part of the long urethra of males is part of the penis, therefore, in addition to urine, it also removes genital products.

Depending on the type of feeding per day, an adult rabbit excretes 180-440 ml of urine with an alkaline reaction (pH > 7.0). Urine is a clear, straw-yellow liquid. If it is painted in intense yellow or brown, this indicates any health problems.

The system of organs of reproduction is closely connected with all systems of the body, in particular with the organs of excretion. Its main function is to continue the view.

The genital organs of the rabbit are represented by paired organs - testicles (testicles) with appendages, vas deferens and spermatic cords, accessory sex glands - and unpaired organs - the scrotum, urogenital canal, penis and prepuce (Fig. 10).

1 - left and right kidneys; 2 - adrenal glands; 3 - ureter; 4 - bladder; 5 - urogenital canal; 6 - testis; 7 - appendage of the testis; 8 - seed tube; 9 - serous fold of the testis; 10 - external genital organ; 11 - cavernous bodies; 12 - ampoules of the seed tube; 13 - prostate gland; 14 - Cooper's gland; 15 - preputial gland

Testis- the main sexual pair organ of males, in which the constant development and maturation of sperm occurs. It is also an endocrine gland - it produces male sex hormones. During mating, an adult male releases 1–1.5 cm3 of sperm, and during the first mating, the amount of sperm is the largest, during the second it decreases, and its fertilizing ability also decreases.

The rabbit testicle is an elongated, oval-shaped organ 2.5–3.5 cm long, 1.5 cm wide and weighing 2.5–3.5 g (with appendages 6–7 g). It is suspended on the spermatic cord and is located in an adult in the cavity of the saccular protrusion of the abdominal wall - the scrotum, and in young animals up to 3 months of age - in the inguinal canals. Closely associated with it is its appendage, which is part of the excretory duct.

In the epididymis, mature spermatozoa can remain immobile for quite a long time, providing nutrition during this period, and when animals mate, they are ejected into the vas deferens by peristaltic contractions of the muscles of the appendage.

Scrotum- the receptacle of the testis and its appendage, which is a protrusion of the abdominal wall. In a rabbit, it is located closer to the anus.

The temperature in the scrotum is lower than in the abdominal cavity, which favors the development of sperm. The skin of this organ is covered with fine hair, has sweat and sebaceous glands. The muscular-elastic membrane is located under the skin and forms the scrotal septum, as a result of which the organ cavity is divided into two parts. The muscular formations of the scrotum provide the pulling of the testis to the inguinal canal at low external temperatures.

vas deferens, or vas deferens, is a continuation of the duct of the appendage in the form of a narrow tube of three shells. It starts from the tail of the appendage, as part of the spermatic cord through the inguinal canal goes to the abdominal cavity, and from there to the pelvic cavity, where it forms an ampulla. Behind the neck of the bladder, the vas deferens connects with the excretory duct of the vesicle gland into a short ejaculatory canal that opens at the beginning of the urogenital canal.

spermatic cord- this is a fold of the peritoneum, which contains the vessels, nerves leading to the testis, and lymphatic vessels leaving the testis, as well as the vas deferens.

urogenital canal, or male urethra, serves to remove urine and sperm. It begins with the opening of the urethra from the neck of the bladder and ends with the external opening of the urethra at the glans penis. The initial, very short part of the urethra - from the neck to the confluence of the ejaculatory canal - conducts only urine. The wall of the male urethra is formed by the mucous membrane, the spongy layer and the muscular layer.

In addition to the glands present in the ampullae of the vas deferens, to adnexal sex glands include paired vesicular, prostate and paired bulbous glands located on the upper wall of the bladder neck. The ducts of these glands open into the urethra.

Vesicular glands produce a sticky secretion that dilutes the mass of sperm. The secret of the prostate gland activates sperm motility. The secretion of the bulbous glands promotes the release of the urogenital canal from urine residues and lubrication of the mucous membrane of the urethra before the passage of sperm.

Penis, or penis, performs the function of introducing male sperm into the female genital organs, as well as excreting urine from the body. The penis consists of the cavernous body of the penis and the penile part of the urogenital canal.

On the penis, the root, body and head are distinguished. The root and body are covered with skin from below, the latter also extends to the head, forming a fold on it - the prepuce, or foreskin.

Prepuce is a skin fold. In a non-erective state of the penis, the prepuce completely covers its head, protecting it from damage.

The genital organs of the female rabbit include paired organs - the ovaries, fallopian tubes, - unpaired - the uterus, vagina, vestibule - and the external genitalia (Fig. 11).

1 - ovaries; 2 - uterine horns; 3 - the junction of the two horns of the uterus; 4 - funnel and opening of the fallopian tube; 5 - vaginal cavity; 6 - bladder; 7 - clitoris; 8 - genital gap

Ovary- a bean-shaped organ located in a rabbit in the abdominal cavity in the lumbar region. In the ovary, female sex cells - eggs - develop, and female sex hormones are also formed. Most of the ovary is covered with rudimentary epithelium, under which there is a follicular zone, where the development of follicles with eggs enclosed in them takes place. The wall of the mature follicle bursts, and the follicular fluid, together with the egg, flows out. This moment is called ovulation. In place of the bursting follicle, a corpus luteum is formed, which secretes a hormone that inhibits the development of new follicles. In the absence of pregnancy, as well as after childbirth, the corpus luteum resolves after 15-20 days. Sometimes eggs after mating are released from the ovaries, but fertilization does not occur. The so-called false pregnancy occurs, passing by the 17-18th day from the moment of mating.

Oviduct, or oviduct, is a narrow, highly convoluted tube connected to the uterine horn. It serves as a site for the fertilization of the egg, conducts the fertilized egg to the uterus, which is carried out both by the contraction of the muscular membrane of the fallopian tube and by the movement of the cilia of the ciliated epithelium lining the oviduct.

Uterus is a hollow membranous organ in which the fetus develops. During childbirth, the latter is pushed out by the uterus through the birth canal.

In the uterus, horns, body and neck are distinguished. Two horns from above start from the fallopian tubes, and below they fuse into the body, and they open into the uterine cavity with independent holes, so sometimes embryos from the first mating develop in one horn, and from the second - in the other. In connection with the multiplicity of rabbits, they are twisted like intestinal loops. The body of the uterus is small.

The uterine cavity passes into a narrow cervical canal that opens into the vagina. The uterus lies completely in the abdominal cavity.

Vagina- a tubular organ that serves as an organ of copulation and is located between the cervix and the urogenital opening.

Vaginal vestibule- the common area of ​​​​the urinary and genital tract, the continuation of the vagina behind the external opening of the urethra. It ends with the external genitalia.

external genitalia females are represented by the female genital area - the vulva, the genital lips located between the genital slit, and the clitoris.

Vulva located below the anus and separated from it by a short perineum. The opening of the urethra opens on the lower wall of the vestibule of the vulva.

shameful lips surround the entrance to the vestibule of the vagina. These are skin folds that pass into the mucous membrane of the vestibule.

Clitoris- this is an analogue of the penis of males, it is built from cavernous bodies, but less developed.

Reproduction (reproduction) - the ability of all living organisms to reproduce their own kind (offspring), ensuring the continuity of the life of the species and the continuity of generations when two germ cells merge - the sperm and the egg. The formation of germ cells is possible at the onset of puberty. In rabbits, puberty usually occurs at 3-4 months - this age depends on the breed and the physical condition of the animal, but such young individuals are usually not allowed to mate, since its onset does not indicate the readiness of the body to reproduce offspring. A month after the onset of puberty, female rabbits are considered physiologically mature and ready for reproduction. Sexual maturity in males occurs at about the same time as in rabbits, but they are allowed to mate at the age of 6–7 months. When mating, the rabbit is placed in a cage with the rabbit. 2 weeks before mating, more concentrated vitamin and mineral feeds should be introduced into her diet, and males should be fed with boiled potatoes with steamed oats or other grains.

Rabbits are ovulatory animals, meaning that estrus is determined by the mating process as well as the season. Sexual hunting in unfertilized rabbits occurs every 5–6 days in summer and 8–9 days in winter and lasts 3–5 days. During the hunt, the rabbit is excited, does not eat well, the external genitalia become bright pink in color, and swell. The release of mature eggs from the ovaries of a rabbit occurs during mating. Each ovary releases 3 to 9 eggs. The eggs enter the oviduct only 10-12 hours after intercourse. Fertilization occurs in the upper part of the oviduct, where the sperm enter 2–2.5 hours after mating. The fertilizing ability of spermatozoa in the body of a rabbit lasts about 1 day. During fertilization, not one, but several spermatozoa most often enter the rabbit's egg. 10-12 hours after the penetration of the spermatozoa into the egg, the latter begins to split up and pregnancy occurs, or pregnancy, lasting an average of 31 days. Since the uterus in rabbits is bicornuate, this can lead to double fertilization - during the first coating, the eggs are fertilized from one ovary, and during the control mating, from the other. In the case of double fertilization, birth occurs twice, or childbirth (after the same period of time after which fertilization occurred). Second litter rabbits are usually stillborn.

The development of the embryos is very fast. Already on the 5-7th day, germ layers are formed, from which various organs of the embryos are subsequently formed. On the 8th day, the embryos are attached to the wall of the uterus. On the 13th day, they reach a length of 6–7 mm. At this time, they can already be felt through the abdominal wall. The development of the embryos ends on the 29-34th day of birth, or childbirth. The dependence of the duration of intrauterine development of rabbits on their number in the litter was noticed. With multiple litters, intrauterine development is shorter, and with multiple litters, it is longer.

Pregnancy can be detected using the so-called control mating, carried out on the 5-7th day after the previous mating. If the female covered herself in the previous mating, she beats off the male - she runs away from him, making characteristic sounds similar to a groan. But this is not a completely reliable way.

It is possible to determine pregnancy by gently palpating the abdominal wall on the 16th day after coating, otherwise an abortion can be induced. To do this, the rabbit breeder puts the rabbit on a flat surface with his head towards him. With one hand, he holds her by the sacrum or back, and with the other he carefully probes the embryos. In the female rabbit, the uterus is greatly enlarged, in the pelvic region, elastic, oblong-shaped soft embryos the size of a hazelnut are palpable, located in a chain. Sometimes, when feeling, the rabbit tenses the abdominal muscles. In this case, it is necessary to make a light massage of this area.

To learn how to determine pregnancy, you must first select uncoated females and feel them well. In the female, the back of the abdomen appears denser, as the uterine horns are enlarged and filled with placental fluid.

From time to time there is a so-called false pregnancy, when fertilization did not occur during the coating. Such pregnancy is also found in the group maintenance of young females after sexual arousal. At the same time, the female behaves like a female - she is restless, makes a nest, her mammary glands swell, milk is released from the nipples when pressed. On the 18th day, the signs of pregnancy disappear.

It is not recommended for female rabbits to drastically change the type of feeding and the composition of the granules, which leads to indigestion, and transplant from place to place, but if necessary, then no later than 1 week before birth, gently holding the scruff of the neck with one hand and supporting the body from below with the other . Pregnant individuals need peace, because with a strong fright, animals make sharp jumps, which is often accompanied by bruises and leads to abortion (premature termination of pregnancy with the expulsion of a dead or immature fetus from the uterus).

Pregnancy ends with birth, or childbirth, a physiological process in which a mature fetus, its membranes (afterbirth) and the fetal waters contained in them are expelled from the uterine cavity. Childbirth is accompanied by contractions of the muscles of the uterus (contractions) and abdominal muscles (pulls). The cervical canal opens due to the introduction of the membranes of the fetus into it in the form of amniotic fluid. Passing through the vagina, the germinal bladder often bursts, and the front or rear limbs of the fetus appear. Then the afterbirth (placenta) is immediately released. Most often, okrol happens at night or early in the morning and lasts from 5-10 minutes to 1 hour.

A rabbit usually gives birth to 6–9 blind and naked rabbits weighing 40–60 g with 16 milk teeth. There are cases of birth up to 18 rabbits. They get to the mother's nipples in sharp jumps due to the contraction of the muscles of the entire body. Shortly before birth, the female begins lactation (the process of formation and secretion of milk from the mammary glands), lasting up to 60 days or more. The feeding conditions, the quality of the feed, the age of the animal, the number of births, the season of the year, the breed, etc., have an effect on the milk yield. In the summer, the milk yield increases, which is explained by the predominance of green and succulent feed in the diet.

You can determine the milkiness of a rabbit by the state of newborn rabbits. In a high-milk female, the rabbits lie calmly in the nest. Their bodies are rounded, the skin is smooth, shiny, without wrinkles and folds. They are growing fast. You can determine the milkiness in another way - turn the chicked female over on her back and press the mammary gland with two fingers. In a high-milk rabbit, milk will come out in a large drop or even a trickle.

Maximum milk production occurs after 3-4 births. The reason for low milk production in rabbits is often their obesity and inactivity. Obese female rabbits lose the ability to reproduce rabbits. This can be avoided by reducing the percentage of high-protein feeds (grain, compound feed) in the diet and introducing more green and succulent feeds, as well as providing the animal with greater freedom of movement.

After okrol, the rabbit drinks heavily and a lot, and if there is no water in the cage, with improper feeding during pregnancy and with roughening of the nipples from cracks and bites, she eats her offspring. When the nipples are coarsened, it is necessary to massage the swollen mammary glands, milk the milk and, holding the rabbit, put the rabbits to the nipples and forcibly force her to feed. With cracks and bites, they check if there is milk. In the presence of milk, the nipples are disinfected and lubricated with fresh fat, preferably vegetable. If the rabbit does not have milk, you can put the rabbits to another rabbit, having previously removed her from the cage. The rabbits, having cleared of fluff, straw and shavings left over from the previous nest, are placed in the middle of someone else's droppings, rubbed and covered with fluff. If there is no rabbit, then they resort to artificial feeding. For this, a special nipple is made from a vial with a cork. A hole is burned in the cork, through which a tube or a chicken feather rod is passed. A nipple gum is put on the part of the rod protruding from the cork. Cow's milk or 3 parts of cow's milk and 1 part of condensed milk is poured into the vial. The tip of the nipple gum is inserted into the rabbit's mouth. In the first days, each rabbit is given approximately 4-5 ml of milk at a time, feeding it 4-6 times a day. At the age of 20 days, milk is drunk from an ordinary nipple, and at the age of one month, milk is poured into a saucer.

On the 6th day after birth, the mass of newborn rabbits doubles, and at the age of one month it increases 10 times. Such a high energy of growth and development of rabbits is associated with a high concentration of nutrients in rabbit milk: on average, it contains 10–20% fat, 13–15% protein, 1.8–2.1% milk sugar, 0.64% calcium and 0.44% phosphorus, vitamins and other substances. At the age of 3–5 months, a rabbit grown under good feeding conditions has a mass of 2.2–3.5 kg. The highest intensity of growth is noted up to 3-4 months of age.

On the 5th–7th day, the rabbits develop a hairline 5–6 mm long, consisting of guard hairs and guiding hairs. By the 20-25th day, the primary hairline reaches its full development. On the 10th-14th day, the rabbits begin to see clearly, and on the 15th-20th day they begin to leave the nest and eat their mother's food on their own, but continue to feed on her milk until jigging. The change of milk teeth begins from the 18-20th day of life and ends by the age of one month.

It is best to wean rabbits from their mother at 45 days of age. The rabbits deposited before this period develop worse and are more often exposed to various diseases.

The sex of rabbits is distinguished by hand pressure on the abdomen near the genitals. The rabbit is taken with the left hand by the skin in the region of the sacrum, grabbing the tail, turned upside down and the fingers of the right hand push the skin on the abdomen forward. In the female, an elongated slit is visible, directed towards the tail, in males - the penis in the form of a tube (Fig. 12). Sex can also be determined by secondary sexual characteristics, although in this species of animals it is less pronounced. The male is slightly smaller, with a short square head and a coarser constitution. In females, the head is narrower, the lines of the body are more delicate, the croup is wider (Fig. 13).

a - male; b - female

a - female; b - male

The restoration of the female reproductive apparatus after birth occurs so quickly that the rabbit can be inseminated the next day. In rabbit breeding, there is the concept of “compacted birth” - this is the covering of the rabbit on the 2nd-3rd day after birth, when she continues to feed the rabbits born without prejudice to intrauterine development of the subsequent birth, that is, her pregnancy proceeds with lactation. From such a rabbit, rabbits are taken away at 28 days of age. With semi-compacted rounds, the rabbit is allowed to mate on the 10-15th day after the round, and the rabbits are taken away at 35-40 days of age. After jigging the rabbits, the cage must be thoroughly cleaned, disinfected and fresh bedding should be laid, from which the rabbit will make a new nest.

It is impossible to carry out compacted rounds all year round, as they exhaust the rabbit and can even cause her death. Usually they are used in the most favorable summer time, when there is an abundance of juicy and cheap food.

On average, 4 rounds can be obtained from one rabbit per year, and when fertility is combined with lactation, up to 6–8 rounds.

To improve the quality of meat, speed up fattening and reduce aggressiveness, castration of males is carried out. Castration is the surgical removal of the sex glands. Males intended for slaughter are best castrated at 3 months of age.

The best way to castration is open. It is so simple that every rabbit breeder can master it. Prepare iodine, a cotton swab, a sharp scalpel, or a safety razor blade. Sit on a chair or low bench and hold the rabbit in your arms. Calm him down and, turning on his back, hold him on his knees with your left hand so that his hind legs are in front of you, and his head is behind your back.

Massaging the testis towards the anus with the fingers of the hand holding the rabbit, hold the testis at the base, and with your free hand, treat the place of the future incision with a swab with iodine. Then, with a disinfected scalpel or a safety razor blade, cut the scrotum and, pulling the testis, cut the spermatic cord, and treat the wound again with tincture of iodine. Then repeat the same manipulation with the second testis.

Just make sure that the rabbit does not catch on the sleeve of your clothes with its claws, because in this case, straining, it can tear the thin membrane of the peritoneum, and then the rabbit will have to be slaughtered.

When pulling the testis, do not take it to the side, otherwise, with a stretched spermatic cord, you will cut the peritoneum like a string and kill the rabbit.

After castration, place the rabbit in a carefully cleaned cage. If you use bedding, try to keep it clean and soft. Dirty and spinous bedding can get into the wound and cause it to fester.

How easily rabbits tolerate such an operation is evidenced by the fact that immediately after castration, males do not lose interest in females and food. After the operation, provide them with food and drink in the best possible way.

Castrated rabbits at the time of slaughter are much fatter than their uncastrated peers, and their hairline becomes smooth and shiny.

The cardiovascular system in the animal body provides metabolism through constant circulation of blood and lymph through its vessels, which play the role of liquid transport. This process is called "blood circulation". With its help, there is an uninterrupted supply of cells and tissues of the body with oxygen, nutrients, water, absorbed into the blood or lymph through the walls of the respiratory and digestive apparatus, and the release of carbon dioxide and other metabolic end products harmful to the body.

Hormones, antibodies and other physiologically active substances are carried with blood, as a result of which the activity of the immune system and the hormonal regulation of the processes occurring in the body are carried out with the leading role of the nervous system. Blood circulation is the most important factor in the body's adaptation to changing conditions of the external and internal environment and plays a leading role in maintaining its homeostasis (the constancy of the composition and properties of the body). Violation of blood circulation leads primarily to disorders of metabolism and functional functions of organs throughout the body.

The cardiovascular system is represented by a closed network of blood vessels with a central organ - the heart. According to the nature of the circulating fluid, it is divided into circulatory and lymphatic.

The circulatory system includes the heart - the central organ that promotes the movement of blood through the vessels - and blood vessels - arteries (distribute blood from the heart to organs), veins (return blood to the heart) and capillaries (carry out the exchange of substances between blood and tissues). The vessels of all three types along the course communicate with each other through anastomoses that exist between vessels of the same type and between different types of vessels. There are arterial, venous or arteriovenous anastomoses. At their expense, networks are formed (especially between capillaries), collectors, collaterals - lateral vessels that accompany the course of the main vessel.

Heart- the central organ of the cardiovascular system, which, like a motor, moves blood through the vessels. This is a powerful hollow muscular organ located obliquely in the mediastinum of the chest cavity, in the region from the 3rd to the 6th rib, in front of the diaphragm, in its own serous cavity.

The heart in mammals is four-chambered, from the inside it is completely divided by the interatrial and interventricular septa into two halves - the right and the left, each of which consists of two chambers - the atrium and the ventricle. The right half of the heart, by the nature of the circulating blood, is venous, poor in oxygen, and the left half is arterial, rich in oxygen. The atria and ventricles communicate with each other through the atrioventricular openings. The embryo (fetus) has an opening through which the atria communicate, and there is also an arterial (botall) duct through which blood from the pulmonary trunk and aorta mixes. By the time of birth, these holes are overgrown. If this does not happen in a timely manner, the blood mixes, which leads to serious disturbances in the activity of the cardiovascular system.

The main function of the heart is to ensure a continuous flow of blood in the vessels. At the same time, blood in the heart moves in only one direction - from the atria to the ventricles, and from them to the large arterial vessels. This is provided by special valves and rhythmic contractions of the heart muscles - first the atria, and then the ventricles, and then there is a pause and everything repeats from the beginning.

The wall of the heart consists of three membranes (layers): endocardium, myocardium and epicardium. The endocardium is the inner shell of the heart, the myocardium is the heart muscle (it differs from skeletal muscle tissue by the presence of insertion bars between the individual fibers), the epicardium is the outer serous membrane of the heart. The heart is enclosed in a pericardial sac (pericardium), which isolates it from the pleural cavities, fixes the organ in a certain position and creates optimal conditions for its functioning. The walls of the left ventricle are 2-3 times thicker than the right one.

The heart rate largely depends on both the condition of the animal and its age, physiological state and ambient temperature. Under the influence of heart contractions (due to blood flow), there is a consistent contraction of blood vessels and their relaxation. This process is called the pulsation of the blood, or the pulse. The pulse is determined along the femoral artery or brachial artery for 0.5–1 min (four fingers are placed on the inner surface in the region of the femoral canal or shoulder, and the thumb is placed on the outer surface of the thigh or shoulder). In newborn rabbits, the pulse rate is 280-300 beats / min, in an adult - 125-175 beats / min.

According to their functions and structure blood vessels divided into conductive and energizing. Conductive vessels are arteries (they conduct blood from the heart, the blood in them is scarlet, bright, as it is saturated with oxygen, they are located deeper in the body of the animal, under the veins); veins (bring blood to the heart, the blood in them is dark, because it is saturated with metabolic products from the organs, they are located closer to the surface of the body); feeding, or trophic, - capillaries (microscopic vessels located in the tissues of organs). The main function of the vascular bed is twofold - conducting blood (through arteries and veins), as well as ensuring the metabolism between blood and tissues (links of the microcirculatory bed) and redistributing blood. Entering the organ, arteries repeatedly branch into arterioles, precapillaries, passing into capillaries, then into postcapillaries and venules. Venules, which are the last link in the microcirculatory bed, merge with each other and become larger, forming veins that carry blood out of the organ. Blood circulation occurs in a closed system, consisting of large and small circles.

Blood - it is a liquid tissue that circulates in the circulatory system. This is a type of connective tissue that, together with lymph and tissue fluid, makes up the internal environment of the body. It carries out the transfer of oxygen from the lung alveoli to tissues (due to the respiratory pigment hemoglobin contained in red blood cells) and carbon dioxide from tissues to the respiratory organs (this is done by salts dissolved in plasma), as well as nutrients (glucose, amino acids, fatty acids, salts, etc.) to tissues, and the end products of metabolism (urea, uric acid, ammonia, creatine) from tissues to excretory organs, and also transports biologically active substances (hormones, mediators, electrolytes, metabolic products - metabolites). The blood does not come into contact with the cells of the body, nutrients pass from it to the cells through the tissue fluid that fills the intercellular space. This liquid tissue is involved in the regulation of water-salt metabolism and acid-base balance in the body, in maintaining a constant body temperature, and also protects the body from the effects of bacteria, viruses, toxins and foreign proteins. The volume of circulating blood in the body of a rabbit is 5–6.7% of the total live weight and depends on the age, type and breed of the animal.

Blood consists of two important components - formed elements and plasma. The share of formed elements accounts for approximately 30-40% of the volume of all blood, plasma - 70%. The formed elements include erythrocytes, leukocytes and platelets (Table 5).

Hematocrit - 34-44%

Erythrocytes - 5-7 million / mm 3

Hemoglobin - 10-15 g / 100 ml

Leukocytes - 6-13 thousand / mm 3

Lymphocytes - 60%

Platelets - 125-250 thousand / μl

The amount of blood - 55–63 ml / kg of live weight

Erythrocytes, or red blood cells, carry oxygen from the lungs to organs and tissues; the immunological characteristics of the blood depend on them, due to the combination of erythrocyte antigens, that is, the blood type. Leukocytes, or white blood cells, are divided into granular (eosinophils, basophils and neutrophils) and non-granular (monocytes and lymphocytes). The percentage of individual forms of leukocytes is the leukocyte form of blood. All types of leukocytes are involved in the protective reactions of the body. Platelets, or platelets, are involved in the process of blood clotting.

Blood plasma is its liquid part, consisting of water (91–92%) and organic and mineral substances dissolved in it. The ratio of the volume of formed elements and blood plasma as a percentage is called the hematocrit number.

The lymphatic system is a specialized part of the cardiovascular system. It consists of lymph, lymphatic vessels and lymph nodes. It performs two main functions: drainage and protective.

Lymph It is a clear yellowish liquid. It is formed as a result of the release of part of the blood plasma from the bloodstream through the capillary walls into the surrounding tissues. From the tissues, it enters the lymphatic vessels (lymphatic capillaries, postcapillaries, intraorganic and extraorganic lymphatic vessels, ducts). Together with the lymph flowing from the tissues, metabolic products, the remains of dying cells, and microorganisms are removed.

In the lymph nodes, lymphocytes from the blood enter the lymph. It flows, like venous blood, centripetally, towards the heart, pouring out into large veins.

The lymph nodes- These are compact bean-shaped organs, consisting of reticular tissue (a type of connective tissue). Numerous lymph nodes, located on the path of lymph flow, are the most important barrier-filtration organs in which microorganisms, foreign particles, and degrading cells are retained and subjected to phagocytosis (digestion). This role is carried out by lymphocytes. In connection with the performance of the protective function, the lymph nodes can undergo significant changes.

Formed elements of blood and lymph are short-lived. They are formed in special hematopoietic organs. These include:

› red bone marrow (erythrocytes, granular leukocytes and platelets are formed in it), located in tubular bones;

› spleen (lymphocytes, granular leukocytes are formed in it and dying blood cells, mainly erythrocytes, are destroyed). This is an unpaired organ located in the left hypochondrium;

› lymph nodes (lymphocytes are formed in them);

› thymus, or thymus gland (lymphocytes are formed in it). It has a paired cervical part, located on the sides of the trachea to the larynx, and an unpaired thoracic, located in the chest cavity in front of the heart.

Summing up, it should be noted once again that the state of health of an animal is judged in a complex way: it is not only body temperature, respiratory rate, pulse, but also the exterior of the animal and behavior. A healthy rabbit, taken by the scruff, creates a feeling of an elastic spring. The rabbit is weak, on the contrary, languidly hanging in your hands. Pay attention to the structure of the external genitalia. Deformation, rash and other deviations from the norm are unacceptable. Clumped hair on the inside of the front paws is a sign of a contagious cold. The eyes should be clear, lively, the eyelids should not be swollen, the hairline should be smooth and shiny.

The rabbit is a very gluttonous animal, capable of eating day and night, due to its precocity. Therefore, lack of appetite (anorexia) or poor food intake is a sign of a possible disease of the animal.

The rabbit is a very shy animal with a fragile nervous system. Unusual noise, the sudden appearance of even a familiar object can lead to serious consequences - abortion, eating rabbits or injuring them by a frightened rabbit. Rabbits are especially shy and irritable on the eve and after birth. Therefore, all care operations must be performed calmly, measuredly, if possible limiting the presence of strangers. Lethargy and lack of response to the environment are warning signs.