Bird eggs. Why birds have different eggs. Chicken egg structure

This is a product consisting of chicken protein and yolk. For their rich composition, they are also called treasure in the shell: they contain vitamins A, B, E, K, D (in terms of their content, they are second only to fish), as well as calcium, phosphorus, iron, manganese, iodine and amino acids. The product is high in calories (in an egg weighing 50 g - about 75 kcal), therefore nutritionists advise starting the day with it in order to enjoy the feeling of fullness for longer. Also, eggs must be in the diet of children and athletes, especially bodybuilders, because they are a source of protein.

Opinions differ as to how many eggs should be in the diet, but most nutritionists agree that it is undesirable to eat more than 10 eggs. in Week.

Goose

Goose eggs have appeared in the human diet since the time of the domestication of geese. This refers to the Neolithic era - about 10 thousand years BC. Goose eggs belong to dietary products, the nutritional value of which is several times higher than chicken eggs. The egg is large enough - weighing about 200 g with a white shell. Goose eggs have a fairly dense shell, so to cook hard-boiled eggs, boil them for 15 minutes in salted water under a lid over medium heat. Also, goose eggs are quite dirty and should be washed under running water before use. In terms of fat content, eggs are significantly inferior to duck eggs. Depending on the food of the bird, the taste of the eggs also changes. The more fresh herbs in their diet, the softer their taste.

Pigeon

Pigeon eggs are quite small in size, 4 cm long. In almost all species of pigeons, eggs are white without specks, with a pearlescent, shiny tint, but in some breeds, eggs are light brown or cream in color. Pigeon eggs have very fragile shells and are difficult to transport and require careful handling.

Turkey

These are the eggs that are closest to consumer properties to chicken. An average turkey egg weighs 70-75 g. The shell is quite dense, usually white with a creamy shade and small lighter specks. The size and color of the eggs directly depends on the age of the bird, the younger it is, the smaller the eggs and the lighter the shell.

Chicken

The hen lays an egg every 24-26 hours on average. White eggs are laid by white chickens, while brown eggs are laid by red or dark ones. In terms of nutritional value, white and brown eggs are no different. The size of the eggs depends on the age, weight and breed of the chickens. More mature chickens lay larger eggs. Stress factors also affect egg size: temperature rise, space restriction, poor chicken nutrition, etc.

Quail

The quail egg is considered a dietary product necessary in the diet for the normal development of the child's body, for recovery in the postoperative period and for various diseases. The egg has a fairly thin light shell with characteristic dark spots. The weight of one quail egg ranges from 10 to 12 g.
Quail eggs and their beneficial properties have been known to mankind since the time of Ancient Egypt. Research on the properties of quail eggs in modern society conducted by the Japanese, and the publication of scientific articles on the benefits of this type of eggs made quail eggs world famous.

Ostrich

Ostrich eggs are of high commercial value and are not among the main products of ostrich farming, and practically all are sent for incubation. In the diet, non-fertilized ones are used - table eggs, eggs obtained from young females, early or late eggs. Ostrich eggs are in no way inferior to chicken eggs and are prepared in a similar way. One ostrich egg holds 25-40 chicken eggs and weighs from 450 g to 1800 g, the similarity to porcelain allows the shell to be used in art products by painting and engraving it. China has the world's largest ostrich egg weighing 2.35 kg and a diameter of 18.67 cm.

Duck

Duck eggs are the most nutritious waterfowl eggs, which contain a large amount of fat and at the same time they have a specific smell and taste. The weight of an average duck egg is 90 g, which is 1.5-2 times more than a chicken egg. The shells of the eggs are dense, and their color can vary from white to bluish-green. In some countries, duck eggs are considered a very expensive delicacy. This is how canned duck eggs are prepared in Japan. In China, they are stored for a hundred days, but for this they use an aqueous solution to which green tea, potash, salt and burnt oak bark are added. In the Philippines, duck eggs are cooked when the chick is already fully formed inside (beak, plumage, skeleton). The dish is called "balut".

Fasagne

Pheasant eggs are literally a storehouse of all kinds of useful substances and various vitamins. They are small in size, about half the size of chicken eggs. Pheasant eggs can be colored sandy, dark gray, gray, light gray, greenish gray, light green, green and almost marsh colors, can be solid or speckled.

Guinea fowl

Refers to dietary products that have low cholesterol and hypoallergenic properties. Guinea fowl egg is pear-shaped, yellowish-brown in color and very dense shell. That is why they are easy to transport and there is less chance of contracting salmonellosis. Eggs retain their useful properties and freshness enough long term(up to six months) at a temperature of 0-10 ° C. The average guinea fowl egg weighs 45-48 g. In most European countries, more guinea fowls are bred than chickens.

Turtle

A very nutritious and rare product that belongs to special delicacies. This type of egg is round, white in color and has a soft leathery shell. The egg weighs 30-35 g. The yolk has a color from pale to bright yellow, and is very close to chicken in size and taste. The protein, in turn, has a gelatinous structure and is completely transparent. For European countries, turtle eggs are exotic and are considered a great delicacy. In eastern countries, however, this product is an everyday food.

Ostrich emu

Emu eggs are healthy as well as chicken eggs. They don't even differ in cooking methods. The weight of one egg is from 450 grams. up to 1800g., which is equal to about 25-40 chicken eggs. The largest egg is 18.67 cm in diameter and 2350 grams in weight. was registered in China. The shell of an emu egg is very dense and durable, despite this it is quite easy to break. It is dark green, almost black in color, and the eggs themselves have a rich yolk and translucent white.

  • Go to the section table of contents: * Breeding birds, mating behavior

Bird eggs

Birds reproduce by laying eggs. There are many variations in size, color, shell structure, etc. etc.

The bird lays an egg in about a day. This process includes time, starting from the release of the egg cell from the ovary, the formation of the egg membrane and the actual laying of a fully formed egg. Unlike oviparous reptiles, a bird usually lays only one egg at a time. However, a chicken from the American city of Mandham set a kind of record - she laid 421 eggs in 223 days.

The eggshell contains a lot of calcium salts, which the bird tries to include in excess in its diet. Therefore, for example, female penguins swallow a large number of mussel shells and other molluscs in preparation for laying eggs. This gives the penguins the extra calcium they need to build their shells and makes them stronger. These eggs have a better chance of not breaking if accidentally hitting rocks, ice and other hard surfaces.

The eggs of many birds are still in the oviduct, before laying, are covered with special dyes. One color or another of the eggs makes them less noticeable against the background of the nest and the surrounding area. That is why, in birds nesting in hollows and other closed places, eggs are usually monochromatic - white and bluish. On the other hand, in birds that build open nests, eggs often have a special characteristic pattern and color, serving as a protective coloration and performing a protective role. Therefore, in some species, the surface of the egg is speckled, sometimes forming a corolla around the blunt end, in others, the entire surface is in colored stains or blurred spots.

And the surface of the egg can be either rough or smooth, matte or shiny. And the eggs of most birds resemble chicken eggs in shape, but there are many exceptions here. So in kingfishers they are almost spherical, in hummingbirds they are elongated and blunt at both ends, and in waders they are strongly pointed at one of the ends.

And the color of eggs of various birds includes almost the entire spectrum. Even chickens have green eggs! Japanese breeders have bred a new breed of chickens that lay eggs in a soft green color. It is believed that this effect is determined by the specific properties of the spleen of these birds. It turned out that green eggs contain more B vitamins, as well as iron.

Outside, the eggshell is covered with a thin dissolving film that has bactericidal properties and protects the egg from the penetration of microbes into it. Therefore, bird eggs: chicken, quail and others, intended for storage, so as not to damage this protective film should not be washed in water.

During one breeding cycle, most birds lay quite a certain number of eggs: from 1-3 to 10-20, and sometimes even more eggs. Therefore, in birds, like the Californian condor, which lay one egg every two years, each pair adds only “half of the individual” to the population per year, and species with 2-3 large clutches of eggs per year can increase it by 20-30 or more individuals.

Incubation is the most important period in the development of eggs. In some species, both partners can participate in incubating eggs, in others only one of them, male or female. A bird that incubates eggs usually develops one or two brooding spots - areas of skin located on the lower part of the chest and devoid of plumage. The heavily blood-supplied skin of the brood spot is in direct contact with the eggs and transfers parental warmth to them. The incubation period, ending with the hatching of chicks, lasts from 11–12 days in small passerines, to approximately 82 days in a wandering albatross.

Brightly colored males, as a rule, do not sit on eggs if the nest is open. The exception is the red-breasted gnarled cardinal, which not only incubates, but also sings. Many partners, who incubate eggs alternately, have such strong brooding instinct that at times one bird pushes another from the nest to take its place. If only one partner incubates, he periodically leaves the nest for feeding and bathing.

Only the male is engaged in incubating the eggs of the ostrich (Struthio). At the same time, several females lay eggs at once, and the male rolls them into the nest, incubates and actively protects. The nest usually contains from 15-20 eggs, up to 50-60.

Oocytes (eggs) are usually the embryonic form of an animal or an ovum. They are studied by oology - a special section of zoology.

general information

Their sizes may vary. For example, in a mouse, the size of the egg is about 0.06 millimeters, but the diameter of the embryonic form of the African ostrich can reach 15-18 centimeters. The shape can also be different. But usually eggs are spherical or oval in shape. In some living creatures, they can be oblong, elongated, such as in mule fish, mixins or insects. Size and other characteristics are determined depending on the degree of distribution and the amount of nutrient inside the egg. The accumulation of the yolk (this substance) is carried out either in the form of a solid mass, or in the form of granules. Depending on this, specialists divide oocytes into different types. The fertilization process takes place in the upper part of the oviduct. In the course of the passage of the oocyte through the canal, cleavage occurs. This process proceeds as a discoidal incomplete. Due to the fact that the beginning of cleavage occurs already in the oviduct, in birds, the laid egg can stay at one of the stages of cleavage (as, for example, in a pigeon) or gastrulation (like in a chicken).

Bird egg

Females of all species of feathered fauna lay oocytes. Different species lay eggs of different shapes. This is due to the place where the masonry will be located. For example, if the nest is arranged in holes or pits, then the eggs will be round. In birds whose clutch is located on rocky ledges, oocytes will be oblong. Usually, the larger the bird, the larger and the size of the egg. But there are exceptions to this rule as well. So, for example, brood species, the offspring of which are immediately adapted to independent feeding, lay eggs, the size of which is larger (in comparison with the body of the female) than those whose chicks are born helpless. Moreover, the ratio of oocyte mass to body weight in small species is often higher than in larger species. It is believed that the largest eggs are laid. In relation to the body weight of this feathered representative, its oocyte is 1% of the body weight. But the weight of the hummingbird egg is 6% of the weight of the bird.

Some structural features of a bird's egg

In birds living in mountainous regions, oocytes have "ribs", like stiffening ribs. They are necessary to preserve the integrity of the eggs so that they do not break when the birds land in the nest, which has a small area. It should be noted, by the way, that this rib is capable of withstanding a pressure of about 40 kg / sq. cm, and the side where it is absent - no more than 2 kg / sq. see The surface of the eggs is rough or smooth, shiny or dull. The color can be absolutely anything: from pure white to green and dark purple. The surface of the eggs of some species is covered with specks, in some cases forming a corolla around the blunt edge. The color will depend on the image and nesting place. So, in many individuals and domestic birds that secretly lay eggs, the shell is white. For those who leave the clutch on the ground, the color becomes identical to the surrounding conditions: it merges with pebbles or plant rags that line the nest. The egg gets its color even in the birth canal of the female. So, for example, biliverdin (pigment) in combination with zinc gives a blue or green color to the egg surface. Due to protoporphyrin, a red or brown color is obtained, or spots of such shades. Let's take a closer look at internal structure bird eggs.

Oocyte device

The birds are fit for purpose. It contains everything necessary for the formation and development of a young organism. The embryo in the egg feeds on the compounds contained in the yolk. This mass is presented in two forms - in white and yellow. They are arranged in concentric alternating layers. The yolk is enclosed in a vitelline membrane. It is surrounded by protein. In the early stages of development of the shell, the eggs of birds perform a nutritional function. Protein also protects the new organism from contact with the shell. The content of the oocyte itself is surrounded by two sub-shell layers: outer and inner. Considering the structure of a bird's egg, it is necessary to say a few words about the shell itself. It consists mainly of calcium carbonate. On the blunt edge of the oocyte, after laying, an air chamber is gradually formed.

Yolk

Considering the structure of a bird's egg, the diagram of which is given below, it should be said that deutoplasm (yolk) is an integral component of the internal contents of the oocyte. The yolk mass contains all the necessary substances that provide nutrition and normal development of the body. Deutoplasm is found in the ovum not only of birds, but also of other animals (and in humans) and is an accumulation of plates or grains, which in some cases merge into a solid mass. The amount of yolk, as well as its distribution, can be different. With a small volume of deuteroplasm, grains or plates are evenly distributed over the cytoplasm. In this case, one speaks of "isocytal" eggs. With a large amount of yolk, the components accumulate either in the central region of the cytoplasm - near the nucleus or in the vegetative part of the oocyte. In the first case, they speak of centrolecital eggs, and in the second, telolecital eggs. In accordance with the volume and degree of distribution of the yolk mass, the type of oocyte cleavage is also established. The chemical structure of a bird's egg provides for three types of deutoplasm. The yolk can be carbohydrate, fatty, or proteinaceous. But, as a rule, in most individuals, the yolk components include, in addition to these compounds, minerals, pigments, ribonucleic acid, thus having a complex chemical structure. So, for example, in a chicken oocyte that has finished growing, the yolk contains 23% neutral fat, 16% protein, 1.5% cholesterol, 11% phospholipids and 3% mineral compounds. Different organelles are involved in the accumulation and synthesis of the yolk component: mitochondria, the Golgi complex. The synthesis of the protein component of the yolk structure in many animals occurs outside the ovary. Through pinocytosis, the protein component enters the developing egg.

Other elements of the oocyte structure

All shells prevent spreading, drying and damage to the egg. But they do not provide the necessary moisture to the growing body. It is formed In particular, they include the water (or Due to it, the cavity of the amnion is limited, which is filled with liquid, where, in fact, the body develops. Together with the water, two more layers are formed: vascular and serous (or allantois). In birds and reptiles This layer is the organ of excretion and respiration. Chalases - protein twisted dense strands - from the egg cell to the blunt and sharp edges of the egg - provide a stable position of the nucleus, preventing displacement from the middle position.

Shell

Studying the structure of the bird's egg, one should dwell in more detail on the layers surrounding the nucleus. The hardest outer layer is the shell. It is quite dense and performs the function of protection against mechanical damage and negative impact external environment... There are shells under the shell. At the blunt end, they diverge and form an air chamber. It contains oxygen, which is necessary for the breathing of a new organism.

Trophic oocytes

There is a type of eggs that in the clutch serve as food for the offspring. As a rule, they are unfertilized, and their appearance practically does not differ from ordinary ones. They are laid by females of some ants and termite queens until the colony begins to get enough food. Unfertilized oocytes of meat-egg and egg chicken breeds in some cases are mistakenly also called trophic, since they are used for food not by the birds themselves, but by humans and sometimes by domestic animals.

Bird egg

the egg itself, or the egg cell, with all the shells that cover it: yolk, albuminous, double shell and shell. Cords of thick protein (chalase) hold the yolk in a certain position so that its side, on which the embryonic disc is located, is always facing up. At one end of the egg, the shell membrane exfoliates, forming an air chamber - a pogo (see. rice. ). Dimensions P. i. range from 8 × 13 mm(in hummingbirds) up to 135 × 170 mm(in an ostrich), and the number in a clutch is from 1 (tube-nosed, many guillemots, lyrebirds, etc.) to 20 or more (chicken). The shape of the eggs varies from spherical to oblong-oval. Their color is also very different: spotted or monochromatic - from white or blue to almost black. A laid egg (except for food) usually already contains an embryo. Eggs of birds, especially domestic ones, are used by humans for food (see Edible egg). In a number of countries, a mass collection of eggs is practiced in places of colonial nesting of birds, for example, at bird colonies (See. Bird colonies) .

A.I. Ivanov.


Great Soviet Encyclopedia. - M .: Soviet encyclopedia. 1969-1978 .

See what "Bird's egg" is in other dictionaries:

    Poultry eggs, mainly domestic, used for human consumption. Consists of yolk, white, shells and shells (see. Bird's egg). Goose eggs weigh 110 180 g, turkey eggs about 110 g, chicken eggs 55 65 g, guinea fowl 45 g, quail 8 10 g ... ... Great Soviet Encyclopedia

    A; pl. eggs, eggs, eggs; Wed 1. Biol. The female reproductive cell of birds, reptiles and cloaca, from which a new organism can develop as a result of fertilization or by parthenogenesis; egg. Bird, snake me. I. a tortoise, an ostrich. ... ... encyclopedic Dictionary

    - (statistics and international trade) Ya became the subject of international commodity exchange very recently, due to the fact that this commodity belongs to the group of perishable food products that cannot withstand long-term storage, or ... ...

    Ya became the subject of international commodity exchange very recently, due to the fact that this commodity belongs to the group of perishable foodstuffs that cannot withstand either long storage or long and long distance transportation. Only after ... ... Encyclopedic Dictionary of F.A. Brockhaus and I.A. Efron

    egg- a/; pl. i / ytsa, yi / c, i / ytsam; Wed see also. testicle, egg, egg 1) biol. The female reproductive cell of birds, reptiles and cloaca, from which a new organism can develop as a result of fertilization or by parthenogenesis; egg. Bird ... Dictionary of many expressions

    - (Deut. 22: 6). Eggs are usually laid various birds, such as: chickens, ostriches, partridges, etc., and from them after incubation they hatch chicks. Some types of eggs, in one form or another, make up tasty and nutritious food for humans. V… … Bible. Old and New Testaments. Synodal translation. Biblical encyclopedia of arch. Nicephorus.

    BIRD EGG- A complex, highly differentiated living cell (blastoderm) with a large supply of nutrients (yolk and protein), enclosed in protective membranes (shells, shells). The egg is formed in the genital tract of the female. This process takes place in two ... ... Terms and definitions used in breeding, genetics and reproduction of farm animals

    DEFENDERS- or pentatoms (Pentatomidae). The bird's egg, so simple in its form, is one of the finest works of nature. A ball and an ellipsoid - these are two geometric shapes that an egg consists of, and these shapes are combined in a very diverse way. ... ... The life of insects

    - ... Wikipedia

    This term has other meanings, see Polygraph (disambiguation). This term has other meanings, see Lie detector (disambiguation). Modern computer polygon ... Wikipedia

The round or elongated shape of the egg depends on whether the bird likes to fly.

Bird eggs are difficult to confuse with something, but their appearance is still very diverse. And if with the color everything is more or less clear - the color of the shell makes the eggs invisible, in addition, without parents - then with the form there is no such clarity.

And in the form of eggs in different species can differ quite strongly, for example, in waders the eggs at one end are quite narrowed, so that they become like a pear, in owls the eggs are spherical and resemble tennis balls, and in hummingbirds they are in the shape of a bean. All eggs have the same function - to protect and nourish the chick during its embryonic development; hence, the variety of forms arose for some other reason.

Mary Stoddart ( Mary Stoddard) from Princeton University and Lakshminarayanan Mahadevan ( Lakshminarayanan Mahadevan) from Harvard, along with colleagues from other research centers, analyzed the geometric shape of almost 50,000 eggs belonging to 1,400 species of birds. Researchers even developed a special program with which it was possible to determine exactly how much a particular egg differs from an ideal ball.

Eggs, as we said, are very different, very elongated, not very elongated, with a pointed end, etc., and various geometric features are combined with each other in different ways. However, as it turned out, there are no eggs in the world that would be short and pointed - that is, not a single bird lays eggs that look like a balloon.

The shape of the egg does not really depend on the shell itself, but on the soft membrane - the shell membrane, which at first contains the entire contents of the egg; the shell appears later, when the egg has already formed. There are thicker and less thick areas in the membrane, somewhere it stretches more, somewhere weaker - all in order to be strong enough to withstand the pressure from the inside of the egg as it grows and swells in the genital tract of the bird. Calculations have shown that a variety of geometric shapes are suitable for this. However, in theory it turned out that one of such solutions could well be the form hot air balloon, meanwhile, as we said, there are no such eggs in nature.

Then the researchers tried to compare the eggs with the behavior of birds. Among the thousands of species that were selected for analysis, it was possible to identify several groups with eggs of a similar shape. However, there was no relationship between the shape and type of nest, or the choice of nesting site, or the number of eggs in a clutch (although both were often put forward as an explanation for the variety of egg geometry in the past). The coincidence was found in another: it turned out that the shape of the eggs often corresponds to the parameters of the wing, the ratio of its length and width.

The length and width of the wing determines the nature of the flight - in other words, the geometry of the eggs depended on how the bird flies. Those who fly well and spend a lot of time in the air (like albatrosses and hummingbirds) have elongated and asymmetrical eggs; if birds are reluctant to rise into the air, spend a lot of time on the ground or flying short distances from bush to bush and from tree to tree (such as African pittas and trogons), then their eggs will be more rounded. To safely lay a rounded egg, you need a wide oviduct and a wide pelvis, but if we want to fly quickly and maneuver in flight, the body must be light and elongated, and a wide pelvis is completely out of place here. (Presumably, the same applies to birds that swim and dive a lot - they also need a narrow, streamlined body shape.)

That is, the various combinations of elongation and pointedness are all the results of attempts to combine the need for a narrow oviduct with the need to supply the egg with a sufficient amount of nutrients. The combination of a spherical shape with a sharp end (like that of the notorious balloon) turns out to be meaningless - the sharpness gives an advantage only if the egg is also elongated; if the bird flies little and therefore can afford spherical eggs, then the sharp end here will be simply unprofitable, because it will reduce the volume of the egg.

 

It might be helpful to read: