Squad ruminants. Ungulates: classification and structural features

Tall legs, in most cases (slender animals). The number of fingers is two or four, but functionally the limb is always two-fingered, since the lateral fingers, if any, are underdeveloped and, under normal conditions, usually do not touch the soil when walking. Metapodia of the lateral rays of the foot and hand are reduced to one degree or another and do not articulate with the bones of the tarsus and wrist; from lateral metapodia, usually only proximal or distal vestiges are preserved; often, especially on the hind limbs, they disappear altogether. Metapodia of the middle (III and IV) rays, as a rule, are fused and form an unpaired bone. The ulna in the distal and middle parts is significantly reduced, often fused with the radius. The tibia is subjected to even greater reduction; from it, as a small independent bone, only the distal end is preserved, the so-called ankle bone, articulating with the tibia, calcaneus (calcaneus) and talus (astragalus) and functionally part of the tarsus. An exception is members of the deer family (Tragulidae), in which the tibia is more fully preserved and merges with the tibia in the lower half. In the wrist, a small polygonal bone (trapezoideum) merges with the capitate (capitaturn s. Magnum) or is rudimentary; a large polygonal bone (trapezium) disappears or merges with previous bones. In tarsus, fusion of the cuboid bone (cuboideum) with the scaphoid (naviculare) is characteristic of all ruminant groups. The second and third sphenoid bones (cuneHorme II and III) also merge into one. On the distal articular block of the middle metapodia there is a pronounced median crest to one degree or another. The bases of the transverse processes of the cervical vertebrae are perforated by a channel for the passage of the vertebral arteries.

Unlike the callosus, the final phalanges of the ruminant fingers are dressed with real hooves. Instead of the coracoid process, the lower arch of the atlas carries only a slightly protruding tubercle on the ventral surface. The tooth-like process of the second cervical vertebra (epistrophy) has the shape of a hollow half-cylinder. The thoracic vertebrae are thirteen, rarely fourteen.

The mastoid (mastoid) part behind the scaly bone extends to the outer surface of the skull. The eye socket is always closed. The frontal bones usually carry some form of outgrowths, horns. The sagittal sagittal crest on the skull is not developed, even though the parietal scallops on both sides are in contact with each other. The articular fossa for articulation with the lower jaw and the articular condyle of the latter have a transversely elongated shape. The front and orbital part of the lacrimal bone are developed evenly. On its front surface there is often a preorbital fossa for the preorbital cutaneous glands. Between the lacrimal, nasal, frontal and maxillary bones, many forms have so-called ethmoid fissures.

Incisors in the upper jaw are absent. In the lower they have a scapular or chisel shape. The upper fangs can also disappear, but in hornless forms they, on the contrary, get a strong development and protrude from the mouth down (deer, musk deer). The fangs of the lower jaw are adjacent to the incisors and take the form of the latter. Posterior teeth are cinque (selenodont). Some groups develop hypsodontia. Anterior (premolar) form a continuous row with posterior. The first premolar does not develop. The second premolar does not have the shape of a canine, like that of camels. There is a significant toothless gap between the fangs and molars.

The skin has a normal hairline, consisting of thinner than pigs, awn and thin, delicate fluff (undercoat). The formation of a thick subcutaneous layer of adipose tissue does not take place. In addition to the mammary, sebaceous and sweat glands that are characteristic of all mammals, and the skin of most ruminants, a number of special skin glands, characteristic only of them, are formed. The main ones are:

1. Inter-hoofed, or interdigital in the form of a bag-like or bottle-shaped invagination of the skin, opening either between the bases of the hooves, or slightly higher than them on the front side of the limbs;

2. The preorbital glands of various sizes and shapes, located in the corresponding recesses on the surface of the lacrimal bones of the skull;

3. Carpal glands, externally protruding in the form of a pillow or a bundle of hair on the anterior (dorsal) side of the limbs, lower than the wrist joint (available only in some canids.

4. Tarsal (tarsal) and metatarsal (metatarsal) glands, also having the form of pillows or tufts of protruding hair; the former are located on the inner (medial) side of the hock (ankle) joint, and the latter are lower, on the inside of the metatarsus;

5. Inguinal glands - bag-shaped invaginations of the skin in the back of the abdomen on the sides of the mammary gland (only available in some canids.

The skin glands secrete a different secretion and odor of secretion, which probably serves for recognition and tracing of animals by each other. The function of some glands is associated with sexual activity. The presence or absence of individual glands in some cases is a systematic sign of a particular group.

The stomach is complex, divided into clearly delimited four (rarely three) departments: a scar, a net, a book and an abomasum. Actually the stomach, its digestive part, represents only the last of these sections. In the process of digestion, belching of food swallowed in the first part of the stomach and its secondary chewing (chewing gum) takes place. The placenta is plural cotyledon, with the exception of deer. The mammary gland is two- or four-lobed, located in the posterior part of the abdominal wall.

The evolution and classification of ruminants

Ruminants appeared on the geological scene in the Eocene in the form of small forms, which, compared to non-ruminants, occupied an insignificant place in the fauna of that era. Currently, they represent the most progressive and numerous group of ungulates that have not yet survived their heyday. The evolution of ruminants went in the direction of adapting to eating exclusively plant foods and running fast as a means of salvation from enemies and a way to use vast, but scarce and devoid of watering fodder areas. Associated with this: the shape of the molar molars adapted to chewing hard plant foods, lengthening of the middle and reduction of the lateral rays of the four-fingered limb, which functionally turns into a two-fingered limb, strengthening of the central rays (III and IV) and fusion of their metapodia into one unpaired bone, which increases limb fortress. The complication of the stomach is also associated with the adaptation to food of indigestible, rich in fiber, plant foods and with protection from possible enemies. The voluminous first section of the stomach, the scar, allows the animal to quickly swallow a large amount of weakly or completely undigested food and process it in a shelter, in a calm environment. Under the influence of saliva and microorganisms that break down cellulose (ciliates), food in the rumen macerates and burps up in small portions for secondary chewing in the oral cavity. Re-chewed, it is supplied for further processing by digestive juices and bacteria in the following sections of the stomach and intestines. This direction of evolution made it possible for initially small ruminants to become victors in the struggle of life and to supplant most of the remaining groups of ungulates less adapted to changing environmental conditions.

Like other groups of pair-fingered, ruminants originate from primitive Lower- or Middle Eocene Paleodonts (Palaeodonta). Their earliest representatives appeared in the second half of the Eocene.

Morphologically close and, most likely, a direct ancestor of modern higher ruminants (Resoga) was the genus Gelocus Aymard from the lower Oligocene of Europe. Gelocus's upper incisors were lost; the anterior premolars did not have the shape and position of the canine. On the hind limbs, the middle metapodia already merged into one bone, but on the forelimbs they were still separate. It is close to modern deer (Tragulidae) and is sometimes included with them in the same family. Gelocus itself can be considered as one of the immediate ancestors of the bovids (Bwidae). The divergence that started early in the Gelocidae group led to the appearance of forms (the genera Lophiomeryx, Prodremotherium and some others) that served as the source for other families of the Resoga.

Of the other extinct groups of ancient ruminants, protoceratids (Protoceratidae), the probable descendants of hypertragulides that existed from the Lower Oligocene to the Lower Pliocene in North America, should be mentioned. Representatives of this group for the first time in the history of pair-fingered appeared horns. The latter represented two or three pairs of bone outgrowths on the maxillary, nasal and frontal bones, probably covered with skin with hair, as in modern giraffes. In the modern fauna, protoceratids left no descendants.

Modern ruminants comprise five or six families.

1. Deer  (Tragulidae), the most primitive group that has retained a large number of archaic features common to the common ancestors of the suborder. There are no horns. The ulnar, tibia, as well as the bones of the lateral rays of the wrist are fully preserved, although to a weaker degree. The metapodia of the central rays completely merged only on the hind limbs; on the front, they remain either completely independent, or only partially merge. Only three sections are developed in the stomach, the book remains in its infancy. The placenta is diffuse. It includes only two modern genera: Tragulus Brisson from Southeast Asia and Hyemoschus Gray from Equatorial Africa.

All the rest, the so-called higher ruminants, have a fully developed tarsus on all extremities, a four-separated stomach, a plurality of cotyledon placenta, and are usually combined into a superfamily (or infraorder) of the Resoga, including the other five families.

Class - Mammals

Infraclass - placental

Suborder - ruminants

Literature:

1. I.I. Sokolov "Fauna of the USSR, Ungulates" Publishing House of the Academy of Sciences, Moscow, 1959.

Owners of personal farmsteads with ruminant animals in order to receive the greatest amount of products from them and for the animals to be healthy need to know the digestion features of this group of animals.

In ruminants, of all farm animals, the stomach is the most complex — multi-chamber, divided into four sections: a scar, a net, a book, the first three sections are called pre-stomachs, the last - the abomasum is a true stomach.

Scar- the largest section of the ruminant stomach, its capacity in cattle, depending on age, is from 100 to 300 liters, in sheep and goats from 13 to 23 liters. In ruminants, it occupies the entire left half of the abdominal cavity. Its inner shell, as such, does not have glands, it is keratinized from the surface and is represented by many papillae that roughen its surface.

Grid- is a small rounded bag. The inner surface also has no glands. The mucous membrane is represented by protruding in the form of lamellar folds up to 12 mm high, forms cells that look like a honeycomb in appearance. With a scar, a book and an esophagus, the mesh communicates with the esophagus groove in the form of a semi-closed tube. The net in ruminants works on the principle of a sorting organ, letting only sufficiently chopped and liquefied feed into the book.

Book- lies in the right hypochondrium, has a rounded shape, on the one hand it is a continuation of the mesh, on the other it passes into the stomach. The mucous membrane of the book is represented by folds (leaflets), at the ends of which short coarse papillae are located. The book is an additional filter and grinder of roughage. In the book there is abundant absorption of water.

Abomasum- It is a true stomach, has an elongated shape in the form of a curved pear, at the base - a thickened narrow end of which passes into the duodenum. The mucous membrane of the abomasum has glands.

Food swallowed by animals will first enter the vestibule of the scar, and then into the scar, from which, after some time, it returns to the oral cavity for re-chewing and thoroughly wetting with saliva. This process in animals is called chewing gum. Belching of the food mass from the rumen into the oral cavity is carried out according to the type of vomiting, in which the mesh and diaphragm are successively reduced, while the larynx in the animal closes and the cardiac sphincter of the esophagus opens.

Gum  in animals usually starts 30-70 minutes after eating  and proceeds in a rhythm strictly defined for each type of animal. The duration of the mechanical processing of a food coma in the form of chewing gum in the mouth is about one minute. The next portion of food feed enters the mouth. after 3-10 seconds.

The ruminant period in animals continues in average 45-50 minutes, then the animals have a dormant period, which lasts for different animals at different times, then again there is a period of chewing gum. For a day, the cow thus chews about 60 kg  nutritional content of the scar.

The chewed food is then re-swallowed and enters the scar, where it is mixed with the entire mass of scar contents. Due to the strong contractions of the muscles of the pancreas, the food mixes and moves from the vestibule of the scar to the abomasum.

A multi-chamber stomach in ruminants performs a unique, complex digestive function. In the rumen, the animal's body uses 70-85%  digestible dry matter diet  but only 15-30%   is used the rest of the gastrointestinal tract  animal.

The biological feature of ruminants is that they consume a lot of plant foods, including roughage, which contain a large amount of hard-to-digest fiber. Due to the presence of numerous microflora in the contents of the rumen (bacteria, ciliates and fungi), plant feeds undergo a very complex enzymatic and other treatment. The number and species composition of microorganisms in the rumen of animals depends on a number of factors, of which feeding conditions play a paramount role. At each the change in diet in the rumen also changes the microfloraTherefore, for ruminants, the gradual transition from one type of diet to another is of particular importance. The role of ciliates in the rumen is reduced to the mechanical processing of feed and the synthesis of their own proteins. They loosen and break the fiber so that the fiber later becomes more accessible to the action of enzymes and bacteria. Under the action of cellulolytic bacteria in the stomach, up to 70% of digestible fiber is split, out of 75% of the dry matter of the feed being digested. In the rumen under the influence of microbial fermentation, a large amount of volatile fatty acids - acetic, propionic and butyric, as well as gases - carbonic, methane, etc. For a day in the rumen of a cow is formed up to 4 l of volatile fatty acids, and their ratio directly depends on the composition of the diet. Volatile fatty acids are almost completely absorbed in the pancreas and are a source for the animal energy, and also used for the synthesis of fat and glucose. When entering the abomasum, microorganisms die under the influence of hydrochloric acid. In the intestine, under the influence of amylolytic enzymes, they are digested to glucose. 40-80%   received with feed protein (protein) in the rumen is exposed hydrolysis  and other transformations, is broken down by microbes to peptides, amino acids and ammonia, amino acids and ammonia are also formed from non-protein nitrogen entering the rumen. Along with the processes of cleavage of vegetable protein in the rumen, synthesis occurs bacterial protein and protozoa protein. For this purpose, non-protein nitrogen (carbomide, etc.) is also used in practical activities. In a rumen per day, it can be synthesized from 100 to 450 grams  microbial protein. In the future, bacteria and ciliates with the contents of the rumen enter the abomasum and intestines, where they are digested to amino acids, here the digestion of fats and conversion of carotene to vitamin A. Due to the protein of microorganisms, ruminants are able to satisfy up to 20-30% of the body's protein needs. In the rumen of animals, microorganisms present there synthesize amino acids, including and irreplaceable.
  Along with the cleavage and synthesis of protein in the rumen occurs ammonia absorptionthat turns in the liver urea. In cases when a large amount of ammonia is formed in the rumen, the liver is not able to turn it all into urea, its concentration in the blood increases, which leads to the appearance of clinical signs in the animal toxicosis.

Lipolytic enzymes  microorganisms in the rumen hydrolyze fats feed to glycerin and fatty acids, and then synthesized again in the wall of the scar.

The microflora in the rumen synthesizes vitamins: thiamine, riboflavin, pantothenic acid, pyridoxine, nicotinic acid, biotin, folic acid, cobalamin, vitamin K in quantities that practically satisfy the basic needs of adult animals.

The activity of the scar is closely interconnected with other organs and systems and is controlled by the central nervous system. The mechano- and baroreceptors present in the rumen are irritated by stretching and contraction of the muscle layer, chemoreceptors by the environment of the rumen contents and all together affect the tone of the rumen muscle layer. The movement of each of the departments of the pancreas affects the other parts of the digestive tract. So overflowing abomasum slows the motor activity of the book, overfilling of the book weakens or stops the reduction of the grid and scar. Irritation of the mechanoreceptors of the duodenum causes inhibition of contractions of the pancreas.

Pancreatic diseases are most often observed in cattle, less often in small cattle, leading to a sharp decline in productivityand sometimes i will.

Most frequent causes of disease  pre-stomachs are: untimely feeding, poor-quality feed, contamination of feed with metal objects, a quick transition from succulent feed to dry and vice versa.

One-sided abundant feeding with concentrates, beer pellet and bard or coarse malnutrition entails a violation of the function of the pancreas and metabolism.

A leading factor in the occurrence of diseases of the pancreas is a violation of the motor and microbial functions of the pancreas. Under the influence of severe irritation of mechano-, thermo-, and chemoreceptors, inhibition of scar contractions occurs, chewing gum is disturbed, digestion in the rumen is disturbed, the pH of the rumen contents changes to the acid side, the contents undergo microbial decay with the formation of toxins.

Gaur is a rare artiodactyl animal, not known to wide circles of nature lovers. This ingloriousness seems unfair, because the gaur, along with the bison, shares the title of the largest wild bull on the planet. But if the bison claims to first place only because of its weight, then the gaur deserves the palm due to its size. From the point of view of taxonomy, the closest relative of this ungulate is the banteng, and the farthest are the bison, bison and buffalo.

Gaur (Bos frontalis).

At first glance at the gaura, its colossal dimensions are striking: old males can reach a record 330 cm in length and 220 cm at the withers! The tail length of them reaches 1 m, the length of the horns is up to 115 cm, the weight can reach 1 ton, and according to some reports, more. Females are about a quarter smaller. Most surprisingly, with such a size, the gaur does not at all make the impression of an overweight and clumsy animal. His heavy, broad-faced head is compensated by a well-developed neck, high withers and sloping shoulders - with strong and slender legs. In short, the gaur looks like a real athlete.

Gaura's short coat emphasizes its sculptured musculature.

The color of these bulls is brown, turning into almost black in the area of \u200b\u200bthe head, neck and upper legs. The lower part of the legs is white, the nasal mirror is bright. The horns diverge to the sides, and then bend up and a little back, while their lower part is dirty white, and the ends are black. Sexual dimorphism is reduced only to the indicated difference in size and thinner horns in females. By the way, this makes it possible to accurately distinguish gauras from bantens, in which males seem to be colored, and females, on the contrary, are bright red.

Old male on vacation.

Once the range of the Gauras encompassed the vast expanses of South and Southeast Asia: from the Hindustan Peninsula to the Indochina Peninsula, Malaysia, China, Nepal and Bhutan. Today, haurs are still found in these territories, but their populations are very few and scattered, and in Sri Lanka this species is completely destroyed. These bulls inhabit humid evergreen forests, and they prefer hilly areas with sparse forest stand and avoid impenetrable thickets. In the mountains, Gauras rise to a height of 2000-2800 m, but regularly visit the valleys.

Female with young.

In search of such food, they can visit pastures, but they never produce seed crops in the fields.

The diet of gaurs includes all kinds of herbs, bamboo shoots and branches of shrubs.

Like domestic cattle, these animals need a lot of minerals and water.

They satisfy the need for minerals by licking dirt, but, unlike Indian buffaloes, they do not like to wallow in puddles for days.

The character of the gaurs matches their appearance. As follows the strong men, aware of their power, these animals radiate indestructible calm, equanimity and ... caution. The latter quality is, of course, explained not by cowardice, but simply by unwillingness to enter into conflicts that are not worth their attention.

In case of danger, the gaura simply move away with a quick step, and they move extremely quietly in the thick of the forest.

The same friendliness is shown by these animals in relation to each other. Their herds consist of 8-11 females with calves, males stand alone. The herd is controlled by an old female matriarch; males join the herd only during mating. Individual herds adhere to a specific site, but can sometimes be combined into groups of up to 50 individuals. It is noteworthy that in the pastures these bulls can create mixed herds even with zambars (Indian deer).

Gauras breed all year round, but most often mating occurs between November and April. Males during the rut loudly roar, but fights between them are rare. As a rule, applicants limit themselves to demonstrating serious intentions, lowering their heads low and directing one horn towards the opponent. Pregnancy lasts 270-280 days, usually one calf is born, twins very rarely occur. At the time of birth, the female is removed into the thick of shrubs and returns to the herd already with the baby. She feeds the calf with milk for up to 7-12 months (on average, up to 9). Young people become sexually mature in 2-3 years, and the maximum life expectancy of the Gauras reaches 30 years.

Bull Gaura in a characteristic pose of threat.

These giants have few enemies. The worst of them is man. People, firstly, displace the Gauras from their habitats, developing land, cutting down forests, and occupying the best watering places. Secondly, livestock infects Gauras with dangerous infections, and if pets can get the help of a veterinarian, then wild bulls die. Crocodiles, leopards and tigers sometimes attack young Gauras. By the way, the tiger is the only predator that can kill an adult bull. Avoid the dangers of gaurams with caution, sensitivity and strength. In case of danger, they snort loudly, and if the enemy is within sight, adults attack him with a special lateral movement. In this case, the predator has every chance to be pinned to the horn and thrown to a considerable distance, which is often equivalent to death.

Even tigers prefer to bypass the mighty giants, and attack only when it is not possible to catch smaller prey.

Despite such impressive self-defense, the gaura have long been tamed. Their domesticated form - guayal - is not too common compared to buffaloes. Gayals are characterized by smaller growth, more massive physique, short horns. They inherited calm from their wild ancestors and are greatly appreciated for this complaisance. They are used as draft power and a source of meat. But the fate of the wild Gauras is not yet encouraging. Widespread undermining of the food supply and the destruction of suitable habitats lead to an inexorable reduction in numbers throughout the range. That is why the gaurs are listed in the International Red Book, and you can see these beauties only in some reserves and the largest zoos.

12.07.2016

Artiodactyl and equinoid representatives of the fauna have a number of differences and dissimilar features not only in external data and structure, but also in behavior and life activity in nature. For most students, distinguishing between these two classes of mammals is quite problematic.

Speaking of horses, this family has one hoof, so you can not even visually attribute it to the class of artiodactyls. Therefore, in addition to theory, in textbooks and books on zoology, according to external signs, both horses and various rhinos and tapir representatives are referred to as artiodactyls. In total, there are about 17 species of such animals. Combined all the apparently different animals into one class of equine zoologist Richard Owen, having carried out a number of studies in the 19th century.

Signs of Artiodactyls

In order to understand what the distinctive features of the two classes of cloven-hoofed mammals and artiodactyl mammals are among themselves, one should initially determine which families are part of them.

Artiodactyl animals include such representatives of the fauna:

• ruminants - bulls, sheep, giraffes, deer, bison, Pronghorn, as well as antelopes;
• non-ruminant - pigs, hippos, bakers;
• callosities, namely camels.

As a rule, the limbs of such animals end with a special case in the form of hooves. A distinctive feature of artiodactyls is the reduced first finger on the limbs, as well as the underdeveloped second and fifth fingers. Typically, individuals of this type have large or medium body sizes, as well as an elongated muzzle, if they are ruminants, additional horns.

All continents of the world are inhabited by artiodactyls, only Antarctica became an exception. Previously, these creatures were not located on the territory of the island of Australia, but thanks to the efforts of man, this "defect" was corrected. Most often, animals of the artiodactyl class inhabit the steppe and lowlands, tundra, deserts, savannahs. They are much less common in forests and thickets.

The main differences between artiodactyls and artiodactyls are the following points:

1. Artiodactyl representatives of the fauna have a hoof with a pair of fingers, in turn, artiodactyls have a limb with an odd number of fingers covered with a hoof.
2. In the wild, representatives of the artiodactyl class are more common throughout the world, the weeks of their "opponents."
3. In addition, cloven-hoofed animals have a complicated form of digestion, suggesting a multi-chamber stomach.

Why is a horse artiodactyl?

In addition to the horse (donkeys and zebras), the following animals belong to the order of artiodactyls: the families of tapir and rhinoceros. Initially, such representatives of the fauna were widely distributed everywhere except Australia and Antarctica. As it has already become known, the horse belongs to the equine class, as it has a single whole hoof, which is marked and focused on the third finger of the limb. The remaining fingers, namely the second and fourth fingers, are so underdeveloped by nature that they do not reach the ground.

The next sign that a horse belongs to this class of animals is its digestive system. In such creatures, the digestion of food does not occur in the stomach, as was assumed by many, but in the colon. Due to this, there is no need for such creatures to have a multi-chamber stomach; scientists discovered a single-chamber organ in their structure. In general, both horses and other animals of the class of equidae belong to this category of animals because of the odd number of active “walking” fingers.

In addition to this, there are a number of typical distinguishing features of artiodactyls:

• between the talus and scaphoid, a special additional joint is supposed, due to which the mobility of the limbs decreases;
• oblong head shape and long upper jaw;
• wide contact is located between the lacrimal and nasal bone;
• horns are made up of keratin;
• enlarged lower jaw and deepened jaw joint.

For all the above signs and characteristics, the equine family is an explicit representative of the class of artiodactyls.

Characteristic features of a horse as an equine animal

In addition to the above obvious differences between equids and other species of artiodactyls, there are a number of secondary characteristics of these noble animals. Such animals lead a more active lifestyle during twilight and night. They feed exclusively on vegetation, namely leaves and herbs, as well as other parts of plants.

In addition, equids, namely horses, produce small offspring and suggest a long gestation period. Usually, during the birth, individuals give one cub each. In captivity, animals can live up to 50 years.

Ruminant animals. Artiodactyl mammals chewing gum. These include Johnston’s okapi, deer, deer, giraffes, antelopes, cattle, sheep and goats. All ruminants, except for deer, have a four-chamber STOMACH. They got their name ... Scientific and technical encyclopedic dictionary

  - (animals). The Old Testament Law classified animals, for whom the hooves and J. were bifurcated, to pure animals; their meat could be eaten (Leo 11: 3 et seq. Deuteronomy 14: 6). An exception among chewing gum was a camel, jerboa and a hare, because they are … Brockhaus Bible Encyclopedia

  - (Ruminantia), artiodactyl suborder. Known from the Upper Eocene; come from primitive deer. Mostly slender, tall animals, with four, less often two fingers with hooves. Top, no incisors; instead, a dense corpus callosum ... Biological Encyclopedic Dictionary

Ruminants  - GUM, Ruminantia, a group of artiodactyl mammals (Artiodactyla) belonging to the order of ungulates (Ungu lata). The legs of artiodactyls carry an even number of fingers due to the reduction of the first finger; the second and fifth fingers are usually developed ... ... Big Medical Encyclopedia

Ruminants ... Wikipedia

  - (Ruminantia) suborder of mammals of the artiodactyl order. The stomach in most of J. consists of 4 departments: scar, mesh, books and abomasum; some of them have no 3rd department (book). In the process of digestion plays an important role ... ... Great Soviet Encyclopedia

  - (Cotylophora) is a group of mammals containing typical ruminants. This name is based on the structure of the fetal organs during fetal development. In mammals, it is on the outer germinal membrane (serous) of the embryo ... ...

Mammals in which the placenta (placenta, see) is equipped with villi, more or less evenly distributed over the entire surface of the serous membrane (chorion), and is called vague, or spilled (placenta diffusa). These include: ... ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

  - (Bovidae) ** * * The family of bovids, or bovines, is the most extensive and diverse group of artiodactyls, includes 45 50 modern genera and about 130 species. Gentle animals make up a natural, clearly defined group. No matter how ... ... The life of animals

Domestic artiodactyl ruminants of the family of bovids of the genus of real bulls. Came from a wild bull tour. It is bred mainly because of milk and meat. The average annual milk yield of dairy cows is 4 5 thousand kg, the maximum is about 20 thousand kg; ... ... encyclopedic Dictionary