Crossbreeding of animals and humans. Is it possible to cross between humans and animals? Experiments on the crossing of man and animals. Interbreeding of people and animals is already a reality Intergeneric hybrids of animals

Bold naturalist researchers have worked on both birds and pets, and even took care of the inhabitants wildlife. Their offspring are the fruit of a bizarre passion different types. What marvelous animals settled in this list?

Notable hybrid birds

Back in the late 19th century, hunters practicing the use of birds of prey thought about breeding them in captivity. Shortly before the Second World War, the master of the Order of German Falconers, Reinz Waller, received offspring from peregrine falcons, and his followers - artificially bred Saker Falcons. But what if not every creature has a pair? In the 1970s, Irish ornithologists Stevens and Morris, having crossed a peregrine falcon and a saker falcon, received the first hybrid bird. Subsequent experiments yielded even more interesting results.

perlin

A feathered creature, born from the union of a peregrine falcon and a derbnik, is famous for its hunting abilities. This falcon, very popular among English aristocrats, helps in catching small birds in open spaces. Its main prey are partridges, larks and pigeons. The name "perlin" is formed from the addition of the first two syllables of the parent breeds: peregrine (peregrine falcon) and merlin (derbnik).

Eagle hybrid

The recent experiment of the St. Petersburg falconer Sergei Shchegolkov was followed by ornithologists from all over the planet. By crossing the imperial eagle and the golden eagle, he got an elegant bird of prey. As long as a golden eagle's, the tail helps to maneuver well, and the wide span guarantees high speed. The hybrid has been tested in winter hunting and is now used for catching hares.

Bullfinch and canary mix

In 1961, an article appeared in the German magazine Deutsche Gefliigel Zeitung describing a captive-bred canary chick and a female bullfinch. The lower half of the cub's body was rusty red, and the wings and tail were brown. Foreign experience was repeated only once. As the scientist Boris Manteifel proved, crossing tropical birds and the inhabitants of the forests is not an easy task.

banduk

From Arabic, the name of a small colorful bird, which appeared from the goldfinch and the canary, is translated as "rogue". Banduks can easily become a decoration of any home. From the bright canary they inherit a greenish back and yellow breast, and from the goldfinch they inherit an orange mask around the beak. Unfortunately, it is not yet possible to obtain offspring from such hybrids.

Breeding birds is a troublesome and thankless task. It is much more interesting to create new, unusual pets.

Domestic animals obtained by crossing

By selecting two animals with similar genes, scientists try to get offspring with better qualities than their parents. Most often, crossing turns out to be fruitless, but sometimes very cute pets are born.

wolfdog

In 1998, a study by the American Veterinary Association showed that more than 300,000 wolfdogs live in the United States. The combination of two related species is very productive. This is how the Alaskan Malamutes and Siberian Huskies originated. Even German Shepherds have both wolves and dogs in their pedigree. The only disadvantage of such genetic intervention is unpredictable behavioral and physical characteristics toothy baby.

Khaynak

In appearance, livestock, born from the incest of a domestic cow and a yak, looks like a bull with a horse's tail. Its weight exceeds three centners, and the milkiest cow in the village can envy the amount of milk. Hainak is very popular in agriculture Mongolia, Tibet and Nepal. Males have good stamina and are used to transport goods, while females bring 9 more calves in a lifetime than the heifer we are used to.

Camellam

On January 14, 1998, the world learned about the new inhabitant of the Asian barnyard - the camel. Scientists have done their best by realizing artificial insemination animals that differ not only in size, but also in habitat. The cub of the inhabitants of South America and Asia has a long, like a camel, tail and short ears. Its strong legs are able to withstand the longest trip through the desert.

Savannah

In 2001, a new registered breed was added to the list of the International Cat Association. Savannah, which appeared as a result of crossing the African serval and the common murka, is very devoted and affectionate. This animal, characterized by huge ears, can be led on a leash and even trained.

But the most daring and crazy experiments were carried out on non-domesticated representatives of the fauna.

Wild animal hybrids

At the beginning of the 19th century, menagerie owners, dreaming of attracting an audience, began work on creating strange creatures. In 1837 the first famous history the feline hybrid was presented to Queen Victoria in India.

liger

The animals, born from a tiger mother and a lion father, are considered the largest cats in the world. The height of the Hercules liger living in Miami is about 3 meters. Although these animals rarely give birth, in 2004 two little ligers were born at the Novosibirsk Zoo. By the way, tigers, which are the result of crossing a lioness and a tiger, on the contrary, are distinguished by their miniature size.

Peasley

In 2006, Jim Martell, who was hunting in the Canadian Arctic, shot a wondrous beast. The identification of the corpse, carried out in the laboratory of British Columbia, confirmed: this cub of a grizzly and a polar bear was born without human intervention. Hybrid cubs have been born before - for example, in the zoo of the German Halle back in 1874.

killer bee

An experiment in crossing European bees with species from Africa is notorious for its unfortunate results. 26 families born in the laboratory of the University of Rio Clara broke free and terrorized the entire district for many years. The victims of the bites were 150 people and hundreds of animals. Not even flamethrowers could save them from the monstrous hybrids.

It is difficult to list all the creations created by an inquisitive mind and painstaking work. But both old and young know about this creature.

The most famous hybrid animal

A cross between a mare and a donkey, called the "mule", was used as far back as the Middle Ages.

Mules accompanied the conquistadors in the conquest of America and carried cannons during the Civil War. And now this pack cattle, which inherited speed from its mother and endurance from its father, is very popular in the economy. Although mules do not reproduce, they can work up to 40 years.

Many animals are surprising, and not just species obtained by crossing. .
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Some of these wondrous creatures have been bred by scientists, while others are the product of cross-species love. Some are alive and well, others have disappeared, the appearance of others is a little scary. A columnist for Modern Farmer talks about animals that are the result of crossing different agricultural species.

1. Beefalo, a hybrid of a cow and a bison

Americans associate the 70s of the twentieth century with the fashion for huge curly Afro-style hair and President Nixon with his Watergate. And this is also the time of the triumph of the bifalo. The first hybrids of a domestic cow and an American bison were discovered back in 1749 by English settlers in the South of America. Only 100 years later, people began to crossbreed cows and bison on purpose, and more than 200 years later, bifalo appeared. It has become an integral part of American culture. In the 70s, they were bred on more than six thousand ranches across America. Since then, the popularity of beefalo has declined significantly, but the meat of this animal has devoted fans. In 2013, at the All-American Steak Competition, Merril's Meat Company Bifalo Steak won a second consecutive Grand Prix in the country category.

Beefalo. Photo: Old Hickory Beefalo Farm.

Zou. Photo from Flickr.

2. "Zo", a mixture of cow and yak

To be more precise, a mixture of a cow and a Tibetan yak. Accordingly, they live in Tibet. Like mules, male zos are sterile, but female zos, called zomos, are highly fertilized, making it possible to produce hybrids in which only a quarter of the blood of domestic cows will flow. These hybrids are larger and stronger than yaks and local bulls, making them ideal pack animals for carrying equipment for mountaineers about to conquer Everest.

3. Zubron, bison + cow

Among the hybrids of livestock with wild relatives, one cannot fail to mention the bison: it is a cross between cows and bison. The bison is a critically endangered European wood bison, but got a chance to survive thanks to the efforts of biologists who launched a project to return bison to the forests. We can say that the zubron is the European answer to the bifalo.

Who exactly came up with the idea of ​​crossing a camel and a llama to create the first kama and call it Rama? Of course, the Crown Prince of Dubai.

After the First World War, many Europeans, such as the Poles, thought that bison would replace livestock due to their hardiness and disease resistance. But scientists were able to breed the first bison capable of breeding only in the 1960s, and 20 years later the Polish government curtailed the program, because farmers and state farms were not interested in bison. The only herd of bison still lives in the Bialowieza National Park in Poland.

Zubrons. Photo: Wikicommons.

Kama. Photo: Craig Wright/Flickr

4. Kama, a cross between a camel and a llama (camel +lama)

Who exactly came up with the idea of ​​crossing a camel and a llama to create the first kama and call it Rama? Of course, the Crown Prince of Dubai. A camel is 6 times heavier than a llama, so it is possible to get offspring from animals in such different weight categories only through artificial insemination. When Arab scientists took up the case in 1998, they hoped to breed a specimen with llama-like hair and the even temperament of a camel. But to their disappointment, Rama had a very capricious character. The experiment failed.

5. Yakalo, a cross between a yak and a buffalo

The only place where these incredible animals have ever roamed is the Canadian province of Alberta. In 1926, the local newspaper "Reporter" told about this hybrid, successfully populating national park Wainwright, one of the Canadian reserves created to support the American bison population. Yakalo was well endured by Canadian harsh winters, gave a lot of meat, but for some reason did not become popular. And by the beginning of World War II, Wainwright Park was turned into a military base.

Sheep goat Lisa. Photo by The Daily Mail/Flickr

Yakalo. Photo courtesy of the University of Alberta Libraries

6. Sheep goat

Millions of years of existence on different branches of evolution and a mismatched set of chromosomes did not stop one loving goat on a farm in Northern Germany. He jumped over the fence and charmed one of the inhabitants of the sheep pen. As a rule, such relationships end in a stillbirth, but the owner of the animals, Klaus Externbrink, had the good fortune to watch how a perfectly healthy sheep was born, which they named Lisa. This is the rarest case of the appearance of viable offspring in a goat and a sheep in a natural way. But scientists successfully breed such hybrids in laboratories. However, this is a different story.

7 Iron Age Pig

Scientists obtained this animal by crossing a wild boar and a Tamworth sow. The purpose of this experiment was quite pragmatic - to get a pig with delicious meat, as similar as possible to those that can be seen in old paintings. The meat of this hybrid is in demand among gourmets in many countries, but you can buy it only in specialized meat markets. In Russia, such animals were bred by farmer Pyotr Mishin, whose semi-wild boars were sold in LavkaLavka. To our great regret, for a number of reasons, it was decided to reorganize the farm.

Pig of the Iron Age. Photo: Whitelands Farms

Cheasant is a hybrid of chicken and pheasant. Photo: Blue Hill Farms

8. Game + poultry

Different types of birds, due to the peculiarities of genetics, interbreed much more easily than mammals. Hybrids of pheasants and chickens (pictured), pheasants and turkeys are known, and Canadian geese are able to give offspring from any other species of geese. But, oddly enough, no one has yet been able to successfully cross a chicken and a turkey.

9. Mules and hinnies

Donkeys and horses have given the world two of the most common and practical agricultural hybrids. This is a mule - the fruit of the love of a donkey and a horse, as well as a hinny - the son of a horse born to a donkey. In America, the forefather of crossing donkeys with horses and donkeys with horses was none other than George Washington. Since then, mules have performed the vast majority of jobs that require pack animals. They are superior to horses in strength and endurance. Although they cannot reproduce themselves, they can be cloned. In 2003, the University of Idaho saw the release of the first cloned mule mule, which was named Idaho Jim.

Mules

Chimera

10 Chimeras

Another hybrid of a sheep and a goat, but not created by nature, as in the case of the sheep goat Lisa from point 6, but by bioengineers in the laboratory. A chimera is the result of a combination of sheep and goat embryos, created from two genetically different cells. And this result is similar to the creation of Dr. Frankenstein from the world of pets. The first such hybrid was obtained in 1985, and its appearance opened up a sea of ​​\u200b\u200bopportunities for scientists, such as the study of human liver cells introduced into the body of laboratory mice. But the practical application of the results of experiments with chimeras in medical research with human tissues raises many ethical questions that are unlikely to be resolved in the near future.

There is something to think about here. If you feel the need to come to your senses after reading this seemingly light-hearted and funny list, take another look at the photo of sleeping bison - it has a calming effect.

The animal world is rich in its diversity. But a person does not get tired of experimenting, creating some types. Sometimes it makes practical sense, and sometimes people just want to get an unusual animal. Most often in the wild, human-made hybrids do not take root, but there are also reverse examples. We have created a lot of amazing new animals, the most unusual of them will be our story.

Zebroid. To create such an animal, zebras were crossed with horses or donkeys, ponies. The idea to cross related species appeared quite a long time ago, for the first time these hybrids appeared in the 19th century. Usually the father is a zebra. It is very rare for a donkey to be the father. Zebroids have distinguishing feature from zebras. A hybrid is much more comfortable to ride. The new species is noticeably distinguished by its unusual coloration. Part of it may belong to a horse, and part to a zebra. The nature of the new species is quite unpredictable, it is harder to train. Also, zebroids are born quite sickly and underdeveloped, most of these animals live only a few days. And they are often deprived of the opportunity to have offspring.

Liger and tiger. These animals were born by crossing predatory felines. A liger has a lion father and a tigress mother. A tigrolev, on the contrary, is a cross between a male tiger and a lioness. Ligers are quite large, they are generally considered the largest cats in the world. They look like big lions, but with blurry stripes. But tigers suffer from small sizes, they eventually grow smaller than their parents. The Hercules liger lives in Miami, whose height is as much as 3 meters and weight is 544 kilograms. In a hybrid, males are sterile. But their females sometimes have the opportunity to bear offspring. Ligers love to swim, just like tigers, unlike lions.

Beefalo. This breed was bred in order to get the best source of meat. To do this, scientists crossed a cow and an American bison. Similar hybrids are also known to science - bison, crossbreeds of cattle and yaks. New species are created so that they can inherit the best properties of their parents and give more meat. Bifalo has a bright red color, which is important, it contains much less cholesterol than traditional beef. True, most buyers are generally unaware of the existence of such a product. After all, you can buy it only in a few stores in Seattle. Beefalo breeders say that its meat also has a more delicate and delicate aroma and taste than beef.

Camel. This animal is a hybrid of a llama and a camel. The camel was first born in 1995. Since the size of the animals does not allow them to mate in natural conditions, scientists were forced to resort to artificial insemination. The resulting hybrid has short ears and a long camel tail. But the camel's hooves are double, the legs are very strong and rather long. But this is very important for long journeys through the deserts. The camel is a strong but small animal. In addition, it is also devoid of a hump, while its fur is fluffy, like that of a llama. Breeders have long tried to develop a new hybrid. It was obtained only by using a camel as a father and a llama as a mother.

Levopard. This animal was obtained by crossing a lioness and a male leopard. The body resembles a leopard, there is also a characteristic color. The spots are not black, but brown. But the head is more like a lion's. The size of the new hybrid exceeds the size of a leopard. Leopard loves to climb trees and swim in the water. The first documented mention of this animal is found in 1910 in India. The most successful experiments on the removal of levopard were carried out in Japan. The lioness Sonoko from the leopard Kaneo in 1959 gave birth to two cubs, and three years later three more. Male hybrids were infertile, the last of them died in 1985. But one of the females was able to give birth to offspring from a hybrid of a lion and a jaguar.

Servakot. This hybrid is often referred to as the Savannah cat. It was obtained by crossing an ordinary domestic cat and a wild African serval cat with a spotted color. And in order to get the most beautiful individuals, different breeds of cats are used. It can be Bengal, Serengeti, Egyptian Mau or Oriental Shorthair. The Serengeti breed itself was created recently by crossing the Bengal and Oriental breeds. It is named after a national park in northern Tanzania, Africa. This is where the serval lives. In 2001, the Savannah cat was officially recognized as a new breed by the International Cat Association. The servakot turned out to be a beautiful and strong animal. It is much friendlier than ordinary domestic cats. Servakats are believed to be as loyal as dogs. They are taught to walk on a leash, bring a thrown stick or even a shot game. According to the standards, the servakot should have black or brown spots, silver or black. Usually these animals have high erect ears, a long thin neck and head, and a short tail. Servakot's eyes are blue in childhood and green during adult life. These cats weigh from 6 to 14 kilograms. They are not cheap, as for pets - from $ 600 and above.

Polar grizzly. Such a hybrid was obtained by crossing a polar bear and a grizzly bear. Surprisingly, the genetic relationship does not lead to the crossing of these species in the wild. They simply avoid each other, occupying different ecological niches. Grizzly prefers to live and breed on the ground, but polar bear loved water and ice. However, in 2006, a strange bear was discovered in the Canadian part of the Arctic, on the island of Banks. The study of his DNA allowed him to be declared a polar grizzly born in natural conditions. Similar individuals met before, just then DNA analysis was impossible. The polar bear has thick, creamy white fur, similar to polar bears. It has long claws, a hunchbacked back, small features, and brown spots around the eyes and nose, which is characteristic of a grizzly.

A hybrid of sheep and goat. In 2000, a ram and a goat were accidentally crossed in Botswana. The animals were simply kept together. The new animal was named "Toast of Botswana". Sheep and goats have different numbers of chromosomes - 54 and 60. Therefore, their offspring are usually stillborn. But the surviving hybrid was able to inherit the signs of both of its parents at once. He has long wool, like a sheep, and goat's feet. The outer hair was coarse, while the inner part of the coat was soft. The animal turned out to have a heavy ram's body. At 5 years old, it weighed 93 kilograms. The animal had 57 chromosomes, which turned out to be the average between the number of its parents. The hybrid turned out to be very active, with increased libido, although sterile. That is why at 10 months he was castrated. Cases of obtaining such a hybrid were noted in New Zealand and Russia.

Fish red parrot. In Asia, they love aquarium fish, constantly creating new species. This species was bred in Taiwan in 1986. How such a mutation was obtained is still a secret. After all, this allows local breeders to continue to maintain a monopoly on these fish. Rumor has it that the midas cyclid was crossed with a red cichlid. Their fry are gray-black, but by 5 months they become bright orange or pink. We learned this fish in the 90s, they bring it here from Singapore and other countries of Southeast Asia. If a red parrot is placed in an aquarium, then the fish can grow up to 10-15 centimeters there. The color can vary greatly, in addition to orange, yellow is also possible. At some point in their lives, parrots can be crimson, purple, and bright red. However, over time, they all acquire an orange color. Experts advise feeding this fish with special food with carotene, this will help enhance the bright red color of their body. The resulting hybrid also has some pronounced anatomical deformities. For example, the mouth looks like a narrow vertical slit. Because of this, these fish are very difficult to feed, which is why many of them die prematurely.

hybrid pheasant. This bird was obtained by crossing a golden pheasant with a diamond one. As a result new bird received a unique coloring of its plumage.

Orca dolphin. Quite rarely, but still it is possible to cross aquatic animals. This is the fruit of a dolphin from the family of bottlenose dolphins and a small black killer whale. There are only two such individuals in captivity. Both of them live in Hawaii, in a marine park. The sizes of the hybrids are somewhere between the original species. The name of the first orca dolphin is known - Kekaimalu. The mixture is well defined by the teeth. If the bottlenose dolphin has 88 of them, and the killer whale has 44, then the hybrid has 66 of them.

Pig from the Iron Age. To obtain such a breed, domestic pigs of the Temvor breed are crossed with wild boars. So it turns out a pig from the Iron Age. This hybrid is much more tame than the wild boar. However, it is not as malleable as ordinary domestic pigs. The resulting animals are raised for their meat, which is used in some specialty sausages and other products.

Dogwolf. These animals interbreed quite often and freely in nature. The wolf is a rather cautious animal, its behavior is unique, the hunter's instinct is very developed. The jaws of the dog are not as strongly developed as those of its wild predatory relative. When crossed, wolves are more shy than dogs. It is impossible to predict how the hybrid will behave in the future. To tame a dog wolf, a long training is required. After all, a hybrid can unwittingly choose the line of behavior of any of its parents. A dog wolf can become a very dangerous creature. After all, he will be cunning and predatory, like a wolf and fearless in relation to a person, like a dog. Recently in the Czech Republic, cynologists decided to cross the Carpathian lone wolves with German shepherds. Specialists wanted to get the perfect police dog. But it turned out that the resulting dog wolf was in no way suitable for such work. The animals were either nervous and cowardly, or unnecessarily angry and aggressive. The resulting breed, however, was recognized and named the Czech top. In Holland, they tried to cross all the same German Shepherds and Canadian pack wolves. The results were also not what they expected. But another breed appeared - the Saarloos Wolfhond. And in Moscow they crossed the Siberian husky and the jackal. The goal was to get a new breed that would be as obedient as a dog and would have the sharp scent of a wild animal. However, the results will be clear only after the third generation of the new breed.

Hybrids are a mixture of two different animals with similar genes. Basically, such animals live in captivity, and their appearance is the result of human intervention. Below is a list of ten rather interesting hybrid animals.

The species was created in Taiwan in 1986 by crossing a Midas cichlid with a red cichlid or red devil. Parrot cichlids are usually bright orange, and their color can vary, including red and yellow. The females of these animals tend to be fertile, while the males, on the contrary, are sterile, but isolated cases of successful reproduction have been recorded. Considered one of the most beautiful fish in the world.

Zebroid is common name for any zebra hybrid. This species is obtained when a male zebra is crossed with a female from the equine family. These hybrids are never found in nature, as they are almost always sterile. There are many different animals that make up the Zebroid group, including the Zorse (zebra and horse), Zonkey (zebra and donkey), and Zoni (zebra and pony).

Zou or yakow is created by crossing a Yak with a simple cow. As a result, the animal is much larger than a cow or yak and is considered more productive in milk and meat production. All females born from this cross are fertile, while males, on the contrary, are always barren. These animals were originally bred in Tibet and Mongolia as working animals, as they are very strong and hardy.

Kama was created in a laboratory in Dubai, and is descended from male camels crossed with a llama. This animal was created with the intention of doing something with the size and strength of the camel, and the gentle temperament of the llama. Interestingly, Kama is one of the few hybrids that is always fertile because their parents have the same amount of chromosomes. Since llamas are six times smaller and lighter than a camel, the only way to get Kama is through artificial insemination.

Grizzly polar bear or Grolar bear was seen both in captivity and in nature, back in 1964. Polar bears and grizzlies usually distance themselves from each other. Grizzly loves woodlands, while polar bears live closer to water and ice. This fact led scientists to come up with the theory that polar bears were forced to migrate south as the polar ice began to melt, thus forcing polar bears into grizzly territory. The grizzly-polar bear is a fertile hybrid.

coywalk

Another amazing hybrid. A coywolf is a creature mixed with coyote and hybrid wolves that are regularly found in nature.

This cat is a hybrid of a domestic cat and a wild African serval. It is considered the most expensive cat breed. It began to be bred in the USA in the early 1980s. Breeders sought to create a domestic cat that would have big sizes with a characteristic spotted color and a wild look. For the first time, Judy Frank managed to do this. Savannah is a large cat, its weight reaches up to 15 kg.

A cross between a female dolphin from the bottlenose dolphin family and a male little black killer whale. A very rare hybrid. The first representative of this species was a killer whale named Kekaimalu. It was a female, which, as it turned out, was able to have offspring. She gave birth to a baby in a very young age. However, the baby died a few days after birth. Later, in 1991, Kekaimalu gave birth again, her daughter was given the nickname Pokaikealoha. For 2 years, she cared for her cub until she died at the age of 9 years. There are currently only two members of this hybrid in captivity, both in a marine park in Hawaii.

A hybrid of the African bee Apis mellifera scutellata with different types of bees common in Europe. Killer bees were bred in Brazil in 1950. These dangerous insects differ from other bees in size and incredible aggressiveness. According to statistics, since 1969 in Brazil, more than 200 people have died from the stings of African bees, and several thousand more have been seriously bitten.

liger

A liger is obtained by crossing a male lion and a female tigress. Liger is the largest of all big cats. They have characteristics from both parents, such as a love of swimming from tigers and a high social behavior from lions. Currently Liger can only live in captivity. At the Jungle Island Interactive Theme Park, located on Watson Island in downtown Miami, Florida, USA, you can see Hercules. Hercules is a huge Liger, weighing over 410 kg. In 2006, he was registered in the Guinness Book of Records as the largest feline living on Earth.

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Absorption (transformative) crossing consists in the fact that unproductive queens of one breed are crossed in a number of generations with producers of another highly productive breed. Thus, the properties of the improved rock are absorbed or displaced by the properties of the improving rock. The absorption process is stopped if the hybrids do not differ in productivity, conformation and constitution from the animals of the improving breed. In the future, such crossbreeds are bred "in themselves."

With each new generation of crossbreeding, the “bloodliness” of the original (maternal) breed is reduced by half compared to the previous generation.

Transformative crossbreeding- one of the most common; its effectiveness largely depends on the technique of crossing, the choice of an improving breed and the conditions of feeding and keeping animals.

The purpose of absorption crossbreeding is to radically improve animals of an unproductive breed. Crossbreeds obtained as a result of crossing during several generations of mating with purebred producers of the improving breed are brought to a high degree of similarity with the animals of the improving breed.

The offspring obtained by breeding "in itself" crossbreeds of the second generation (3/4 blood), depending on the severity of the desired type, are classified as crossbreeds of the fourth or third generations according to the breed being improved. The offspring obtained as a result of breeding "in itself" crossbreeds of the third and fourth generations, depending on the severity of the desired type, are classified as crossbreeds of the fourth or third generations according to the breed being improved. The offspring obtained as a result of breeding "in itself" crossbreeds of the third and fourth generations, and the fourth generation, depending on the severity of the desired type, are classified as crossbreeds of the fourth generation or purebred animals. In the absence of documents on the origin of animals, but a good expression of the type of improving breed, they are referred to as crossbreeds of the first or second generations (1/2 - 3/4 blood) of this breed.

Absorption crossbreeding- an important method for the transformation of unproductive animals, and it is often desirable to obtain those that, along with the improvement of economically useful qualities, would not lose some of the properties of local improved livestock.

When choosing an improving breed, it is important that the representatives of the latter significantly outperform the animals of the improved breed in terms of economically useful traits and, in addition, adapt well to local conditions.

As a result of the widespread use of transformative crossbreeding, the number of purebred animals in our country is increasing every year. The use of purebred producers of improving domestic and imported breeds has made it possible over the past 35-40 years to dramatically transform the main array of the country's animal porridge.

Before embarking on absorptive crossing, one should find out the characteristics of the improving breed, its adaptability to local conditions. So, in a number of regions of the country, little suitable for natural conditions for the breeding of fine-fleeced rams, the absorption crossing of local coarse-wooled sheep with fine-fleeced rams gives poor results.

The success of absorptive crossing also depends on the quality of the producers of the improving breed, as well as on the conditions of feeding and keeping the crossbred offspring. Only by creating favorable conditions for feeding and keeping hybrids can high rates be achieved.

The successful application of this method is facilitated by the strict selection of crossbreeds, the speed of generational change and the hereditary stability of the traits of the improving breed.

The value of absorption crossbreeding for the rapid mass improvement of the breed composition of animals. Absorption of blood bred many breeds of animals abroad and in our country. P. N. Kuleshov in his work “Methods of Pedigree Breeding of Domestic Animals” (1932) clearly illustrated the importance of absorptive crossbreeding, noting that when breeding the famous thoroughbred riding breed of horses in the first stages of work, they resorted to absorbing the blood of a local English horse with the blood of horses of several eastern breeds. In the same way, Merino sheep were obtained in many states, and in the south of Russia, astrakhan sheep (from karakul), the American trotter (from race horses), breeds of some American and German pigs (from English breeds), many breeds of cattle in Europe and America (from the Dutch, Simmental, Swiss, Jersey, Ayrshire and Shorthorn breeds).

On the importance of absorption crossbreeding for the transformation of animal husbandry in our country IT. D. Potemkin wrote back in 1926 in his work “Massive improvement of Russian cattle breeding (excluding Siberia and the Caucasus)”. Many tens of millions of heads of unproductive outbred cattle, sheep, pigs and other animals were transformed in our country into pedigree animals of various bloodlines in a relatively short period.

A well-organized system of breeding work in our country serves as a solid basis for the mass improvement of the breed composition of animals.

In those farms where the pedigree of animals is still low, it is necessary to achieve their transformation into purebreds by absorption crossing.

Introductory crossing (blood flow). They resort to it if the existing breed meets the basic requirements in terms of its qualities, but needs to improve individual features.

The breed of animals in such a crossing is determined by the breed being improved as follows: the first generation includes the offspring obtained by crossing the original animals with the producers of the breed chosen as the improving one; to the second - offspring obtained by crossing crossbreeds of the first generation with purebred animals of the improved breed (backcrossing); for purebred animals - offspring obtained as a result of crossing crossbreeds of the second generation with producers of an improving breed, subject to the severity of the desired type.

Tasks and technique of crossing. During introductory crossing, the producers of the improving breed are used once on the queens of the improved breed to obtain crossbreeds of the first generation, which are mated with the best animals of the improved breed. Thus, the basic qualities of the animals of the original breed are preserved.

The main stages of introductory crossing. The first stage of blood infusion consists in crossing the queens of a non-trading breed with sires of another breed, the qualities of which the breeder must “infuse” into the animals of the improved breed. In this case, the correct choice of the breed is of decisive importance, the features of which are transmitted to the queens through the manufacturer. It is also important that the improving rein goes well with the one being improved.

In order to improve, for example, in terms of milk productivity, milk fat content, precocity, exterior and constitutional indicators, it is introductory crossed with animals related to red , red swedish and some . To increase milk production, he is given the blood of animals of a related Montbeliard (from France) breed; to increase fat content - animal blood.

At the second stage, crossbreeds of the first generation are crossed with purebred animals of the original (improved) breed. The main task during this period is to select for further breeding animals of the most desirable type with well-defined selectable traits.

The third stage is the transition to breeding hybrids "in itself". According to the main constitutional features, crossbred animals are very close to animals of the main (improved) breed.

Conditions for successful introductory crossing. Along with the correct choice of an improving breed and the general direction in breeding, when the qualities of animals of related breeds are used to improve the initial breeds, it is important to take into account those qualities that favor the use in animal husbandry. modern technology. In such cases, it is more expedient to resort to "blood rush" and unrelated breeds. So, in order to increase the milk production of animals of some domestic breeds, improve the shape of the udder and increase the rate of milk flow, they resort to introductory crossing with the producers of the Ayrshire breed. The results thus obtained testify to the expediency of such an approach.

The success of introductory crossing also depends on the provision of farms with feed, as well as on the conditions of keeping animals and the organization of zootechnical accounting.

The experience of our country and foreign countries confirms the high efficiency of introductory crossing. It is used to increase the milk fat content of cows, improve the meat qualities of animals. various kinds and in other cases.

In the farm "Askania-Nova" in the Kherson region, for example, long-term work is underway to increase productivity and give the animals of this breed a milk-meat type, for which they are "blooded" with a milk-meat type. As a result of many years of work in Askania-Nova, a herd of animals of a new milk and meat type has been created.

Crossbreeds with milk yield and fat content of milk approach cows, and surpass the latter in live weight; they differ in precocity to a higher slaughter yield with better meat quality and lower feed consumption per unit of production. Bulls of a new type are used for breeding purposes.

Positive results have also been obtained with the improvement of black-and-white cattle with jerseys. So, in the USA, as a result of crossing Holstein-Friesian cattle with Jersey bulls, crossbreeds of the second generation of the Jersey breed were obtained, the milk fat content of which is 4.12-4.4% .

Currently, introductory crossing is quite widely used in breeding work.

Reproductive (factory) crossing. With this breeding method, animals of two (simple) or more(complex) breeds to obtain offspring that combines their positive features. When creating new breeds of hybrids that meet the requirements for them, they are bred "in themselves", that is, hybrid queens are covered by hybrid producers. Reproductive crossbreeding has created many breeds of farm animals that are distinguished by rather high productive qualities and are well adapted to their living conditions.

Yes, sheep Altai breed, slightly inferior in productivity Ascanian, surpass them in greater compliance with their constitution to the natural conditions of the Altai Territory.

Reproductive crossing requires the involvement of a large number of animals; the eye is much more difficult than other breeding methods. In this case, not only a combination of the qualities of the original breeds in crossbreeds is achieved, but also the development of new desirable features in animals. Most often, an aboriginal breed is used as a mother, the animals of which are well adapted to local conditions; other breeds (one or more) are selected taking into account the individual and breed characteristics of animals so that they can make up for the missing qualities of the local (aboriginal) breed. The more differences in the crossed breeds, the more diverse the crossbreeds; among them it is easier to identify individuals with completely new qualities. However, it is much more difficult in such cases to fix the desired qualities in the offspring. On the contrary, the greater the similarity between the crossed breeds, the relatively easier it is to consolidate similar qualities in the offspring.

Every breed has different variants intrabreed types, therefore, the choice for crossing the appropriate breeds also provides for a careful selection of individual individuals according to the desired characteristics. In such cases, individual selection, selection, evaluation of producers in terms of the quality of the offspring are required.

At the final stage of work on the breeding of a new breed by reproductive crossing, hybrid queens that meet the desired requirements and combine the valuable qualities of the original breeds are mated with hybrid producers of the same quality and origin, i.e. they resort to breeding them “in themselves”. If necessary, the blood of animals of other or original breeds can be "fused" to the crossbreeds, which is called corrective crossbreeding.

Methods of breeding new breeds.

A. I. Ovsyannikov, summing up the methods of breeding new breeds by reproductive crossing, gives the following sequence of work:

• development of a new breed model (excellence standard). Determine the type of physique and the main economically useful features of animals of the future breed, taking into account its adaptation to climatic, economic conditions, as well as the ability to satisfy national economic needs;
• selection of source material. The initial breeds are selected (the animals of at least one of the crossed breeds must differ in the qualities that the hybrids are planned to have), the animals are evaluated and selected for crossing, and, finally, the farm is selected;
• genetic enrichment of crossbreeds according to the desired
  qualities, breeding crosses "in itself", for which it is important to create favorable conditions for feeding and keeping. If the animals obtained during the first crossing do not satisfy the breeder, one or two backcrosses are carried out on the improving breed or representatives of the new factory breed are used for this;
• when crossing, they necessarily resort to strict rejection of hybrids that do not meet the desired requirements, as well as to related mating of the best producers and queens.

To consolidate the desired qualities in the crossbred offspring, an individual selection of animals is used with a thorough justification of its purpose. Reliable results in such cases are given by inbreeding, which is combined with unrelated mating, for which animals are selected that are similar in type to inbred ones. To avoid too close inbreeding and to consolidate the necessary economically useful qualities in the offspring, several lines and uterine families are laid. With a strong deviation of the crosses in the undesirable direction, they are mated with animals of the desired type, and sometimes with producers of one or more original breeds. Crossbreeds "in themselves" are bred only when they meet the desired requirements.

Simple and complex reproductive crossing. Reproductive crossing can be simple or complex. In the first case, animals of two breeds participate in crossing, in the complex case - three or more breeds. Most breeds of cattle are created as a result of simple reproductive crossing using local cattle and animals of any factory breed.

FROM M. F. Ivanov used reproductive crossing to breed new breeds of farm animals with great efficiency. AT short time he created by this method the domestic Ukrainian steppe white breed pigs, a highly productive Askanian breed of fine-fleeced sheep, and began work on the creation of a mountain merino. The main stages in the breeding of new breeds of sheep by reproductive crossing are obtaining hybrids (hybrids) of a certain bloodline, their enhanced rejection, the use of inbreeding and constant selection work with animals. As a starting material, M.F. Ivanov selected, as far as possible, homogeneous animals of strong constitution, which he crossed with highly productive producers of factory breeds of also strong constitution. When obtaining crossbreeds of a certain bloodline, in order to consolidate desirable qualities in the offspring, he resorted to inbreeding, and in this case he used only outstanding producers. In addition, M.F. Ivanov used a very strict culling of animals that did not meet the desired requirements, as well as weak, sick, pampered, backward in development, with deformities and other defects. He paid great attention to the formation of several unrelated lines, so that after obtaining more or less homogeneous genotypes, it would be possible to start unrelated mating and create favorable conditions for feeding and keeping hybrid animals, especially young animals.

Similar methods were used in the breeding of the Ukrainian steppe white breed of pigs.

As a result of complex reproductive crossing, the Kostroma breed of cattle was also created. At the same time, purebred and crossbred bulls of the Algauz and Swiss breeds, Yaroslavl, Miskovsky and local outbred cattle were used.

When breeding Soviet merino sheep by complex reproductive crossing, local coarse-wooled sheep from various regions of the country, Merino rams and dams of the Mazaev and Novokavkaz breeds, American rambouillet rams and new domestic fine-fleeced breeds - Askanian, Caucasian, Altai, Stavropol, Grozny, etc.

Crossbreeding of local Kuban pigs with animals of large white, Berkshire and white short-eared breeds on collective farms and state farms of the Rostov region and Krasnodar Territory the North Caucasian breed of pigs was created.

In horse breeding, by complex reproductive crossing using mares of the Don and Black Sea breeds and thoroughbred riding stallions, the Budennovskaya breed of horses was created, combining the best qualities of the Don and thoroughbred riding breeds.

The value of reproductive crossing lies in the fact that it allows you to create completely new breeds with predetermined parameters of economically useful and biological qualities. The involvement of several breeds in this type of crossbreeding, the selection for a combination of desirable traits, makes it possible to sharply increase the economic value of new breeds and adapt them to the technology of industrial animal husbandry.

All countries of the world with intensive animal husbandry are working to create new breeds by the method of reproductive crossing.

Industrial crossing. It is used in all branches of animal husbandry to put into practice the effect of heterosis. It is widely used in modern non-breeding farms of an industrial type. When using animals of two breeds, crossing will be simple, and three or more breeds will be difficult. The main purpose of industrial crossbreeding is to create highly productive user herds.

In many livestock farms, especially in European countries and America, dairy and dairy-beef cows of less value in breeding terms, the young of which are grown for meat, are inseminated with the sperm of bulls of early maturing beef breeds. At the same time, the production direction of the economy does not change, since cows are used to produce milk, and non-breeding crossbred young animals serve as material for the production of high-quality meat. Industrial crossbreeding is also widely used in pig breeding to produce first-generation crossbreeds.

An important conditional application of this breeding method in all branches of animal husbandry is the presence of not only producers, but also purebred queens of a certain breed. The use of hybrids of unknown origin in such crossing does not always provide the expected effect. In a number of branches of animal husbandry, in particular in sheep breeding, the effect of heterosis during industrial crossing is also achieved with a more complex combination of breeds.

In some countries, complex industrial crossbreeding is carried out on farms that are not the same in terms of the intensity of animal husbandry and natural and climatic conditions.

For example, in the sheep farms of England, located in the mountainous regions of extensive sheep breeding, local queens are crossed with rams of the long-haired meat-and-wool Border Leicester breed. Crossbreeds of the first generation of rams are then castrated and, after fattening, sent for slaughter, and crossbred ewes are sold to farmers in lowland areas, where forage conditions are better than in the mountains. Here, these ewes are crossed with rams of more early maturing short-haired breeds (Oxfordshire, Southdown, etc.). The offspring resulting from such crossing is completely slaughtered.

In poultry farming, industrial crossbreeding is widely used to obtain the so-called hybrid bird, which is superior in productivity to the bird of the original breeds (lines). In many countries, this breeding method is also used in horse breeding in order to obtain half-breed horses, mainly for sports purposes.

The economic efficiency of industrial crossbreeding is obvious, since, compared with peers of the parent breed used in this case, crossbreeds are distinguished by better development and higher productivity.

The use of industrial crossbreeding in beef cattle breeding ensures a rapid increase in the production of high-quality beef. Good results are obtained when using bulls of the breed Charolais and Kian.

A great economic effect in pig and poultry production is provided by the method of interline hybridization, which is a high form of industrial crossing and is widely used during the transition to the production of livestock products on an industrial basis. Interline hybridization may include forms when animals of two matching lines of one or more breeds are crossed. Other forms of interline hybridization are also known.

The efficiency of the production of interline hybrids can be judged from the following data. On international markets, hybrid fastback pigs, saike, cotswold (Great Britain), spurs (Holland), animals bred by Farmer Hybrid (USA), etc. are widely used. Hybrid pigs cotswold are very prolific: under average conditions, they bring 21 piglet. Young growth at 8 weeks of age weighs 20 kg, at 160 days old - 90 kg; feed costs per 1 kg of live weight gain - 2.62 kg.

In the Canadian poultry industry, the Shaver 288 crosses were recognized as the best egg hybrid crosses in 1973 (average egg production 249.5 eggs, feed costs per 1 kg of egg mass 2.47 kg). "Babcock 305" (respectively 277.4 eggs and 2.51 kg), "Babcock 300" (240.6 eggs and 2.48 kg). Hybrids are widely used in the production of broilers.

Interline hybridization is also used in sheep breeding.

In the UK, for example, on the basis of the Dorsethorn and Finnish Landrace breeds, hybrid sheep improver Kadzova have been created. From every 100 queens - crossbreeds of Scottish black-faced sheep with these hybrids - 222 lambs are obtained per year, and from 100 hybrids of nmproper X Dorset Horn - 233 lambs.

Heterosis effect- a complex biological phenomenon, depending on the genetic capabilities of the original breeds or lines, the heterozygous structure of the genotype, the maternal effect and the living conditions of both the offspring and parents.

The higher the productivity of animals of the original breeds, the higher the productivity of hybrids obtained as a result of industrial crossing. Therefore, the choice of breeds for crossing is crucial. Many experiments have been carried out to determine the best combinations of different breeds. In beef cattle breeding, more than 50 variants of various combinations of dairy breeds and double productivity with meat, as well as beef breeds among themselves, have been studied. Similar studies have been carried out in other branches of animal husbandry. The most promising combinations of breeds for industrial crossing have been developed, which are being introduced into production. In beef cattle breeding, it is recommended, for example, to use: producers of the Hereford breed and cows of the Red Steppe, Simmental and Black-and-White; breeders of Aberdeen Angus (large type), Santa Gertrude, Charolais and Red Steppe cows; bulls of gray Ukrainian, Simmental breeds and black-and-white cows; shorthorn producers (large meat and milk-meat type) and red steppe cows.

Crossbred young animals of the farm are sold for meat at the age of 15-18 months after intensive rearing and fattening.

A distinction is made between simple industrial crossing, in which animals of two breeds are used (Fig. 16), and complex, when individuals of three breeds are mated sequentially. The complex industrial crossing shown in the second scheme is used, in particular, in the GDR in order to improve the milk and milk fat content of Black-and-White breed animals. With this combination of breeds, hybrids are obtained that are distinguished by the best indicators of udder development, fertility and productivity.

The uterine composition for industrial crossing is used, as a rule, of the breed that is well adapted to local conditions. Manufacturers are selected taking into account previously identified compatibility, and they are subject to higher requirements than queens. It is desirable that both queens and sires be purebred. In simple industrial crossbreeding, crossbreeds of the first generation are used to obtain products, while in complex crossbreeding, they are crossed with animals of one or more breeds. Only after that, complex crossbreeds are obtained that meet the goals of user animal husbandry.

Industrial crossing on farms is organized on separate farms, in herds, isolated from breeding material. At the same time, they create good conditions for feeding and keeping and keep a thorough zootechnical record. Crossbreeds obtained as a result of industrial crossing for breeding purposes are usually not used.

A type of industrial crossing is variable (rotational) crossing , in which the queens of the original (then crossbred) group are mated alternately with producers of two or more breeds. As a result of rotational crossing, the effect of heterosis is continuously maintained, which ensures the effective use of hybrids for the production of milk, meat, eggs and other livestock products. Variable crossing is especially effective in pig breeding, beef cattle breeding and poultry farming.

It is more difficult to organize rotational crossing than industrial crossing, but its economic effect is higher.

Sometimes the use of variable crossbreeding ends with the breeding of a new breed.

In particular, in France, crossbreeds of English riding and Norman draft horses were crossed alternately with English and Norman stallions. On the certain stage switched to breeding hybrids "in itself". As a result, the work ended with the breeding of the Anglo-Norman breed of horses.

When choosing breeds for crossing and determining the degree of use of each of them, they proceed from the goals set. The selection of breeds and the sequence of their crossing must be previously studied in the experiment. When animals of two breeds are used for mating, variable crossing is called simple, and three and more breeds - complex. Crossbreeds of the first generation, obtained as a result of two-breed crossing, are mated with producers of one of the original breeds, crossbreeds of the second generation - with producers of another original breed; in the next generation, backcrossing is carried out, etc.

In a three-breed alternating crossing, hybrid queens obtained as a result of mating animals of two breeds (AxB) are covered by producers of a third breed (C). Their offspring are bred to breed A sires, the next generation offspring to breed B sires, and their offspring to breed C sires, and so on. In the case of using four breeds, the crossbred breeding stock is mated alternately with sires of each of the four breeds.

The use of several breeds in rotational crossing makes it possible to obtain a combinative combination of traits in crossbred animals.

Hybridization

Hybridization is the crossing of animals belonging to different species. The resulting offspring are called hybrids. Hybridization as a breeding method also includes the crossing of hybrids with hybrids of different and identical origin. The main task of this very difficult crossing method is to involve in material culture human of new valuable wild and semi-wild forms of animals. Depending on the ability or inability of hybrids to produce offspring, hybridization is distinguished, which is widespread and produces useful animals (for example, mules in the past), and hybridization used to create new breeds and types of animals. In this regard, four types of animal hybridization are distinguished: industrial, absorption, introductory and reproductive. The most widespread industrial (user) hybridization and reproductive, or breed-forming.

It should be noted that the wild fauna (huge natural wealth) is unreasonably, and sometimes predatory, exterminated. In the last 50 years alone, more than 40 animal species have been destroyed. Species such as zebra quagas in Africa, American bison, tour, tarpan, arctic penguins, gigantic flightless geese, dodos - fat big island birds, moa ostriches, whose weight was 300 kg, height 4 m, died out or exterminated. To prevent the extinction of wild animals, special measures are now being taken to protect nature. In 1948, the International Union for Conservation of Nature was created. In the USSR in 1978 a special Law of the USSR on Nature Protection was issued. More than 350 species of animals and 650 species of birds live on the territory of our country. Among the many nature reserves of the country there are such large scientific centers as Askania-Nova, Astrakhan, Belovezhskaya Pushcha, Laplandsky, Caucasian, Issyk-Kulsky, etc. They do a lot of work on hybridization of animals and the conservation of valuable species of wild fauna.

When hybridizing animals, they face great difficulties. The main ones are the following:

1) non-crossing of species among themselves;

2) partial or complete sterility of hybrids.

The main reasons for the non-crossing of distant species and the infertility of hybrids are genetic factors: a different set and structure of chromosomes in gametes, their inability to form a viable zygote, sperm due to its morphological and biochemical features unable to lyse the shell of a foreign egg, to penetrate into it. If a hybrid zygote is formed, then due to embryonic pathology, either the resorption of the fetus occurs in the early stages of formation, or its death. This is explained by the fact that the body's immune protective bodies fight the penetrating foreign protein, destroying it. Due to the genetic differences of the parents in hybrids, the formation of male and female germ cells is disrupted and they become infertile. The sterility of the hybrids is caused by abnormalities in the development of the gonads and mitosis.

Rapid development Nowadays, cytogenetics has made it possible to study in more detail the cytogenetic causes of infertility in hybrids. They can be divided into three groups:

a) discrepancy in the number of chromosomes in the karyotype;

b) morphological structural differences in the structure of chromosomes;

c) a change in the gene composition that does not affect the behavior of chromosomes, their morphology.

Currently, scientists have developed a number of methods to overcome the non-crossing of individual species. These include: blood transfusion of animals of one species to another, mixing of sperm of individuals of different species, the use of reciprocal (back) crossing, hormonal preparations, the use of special sperm diluents, transplantation of gonads, and the creation of the necessary conditions for obtaining and raising offspring. Experiments have shown that young females more often give hybrid offspring: a greater ability to hybridize and give birth to fertile offspring is observed in those individuals that themselves are obtained as a result of crossing.

It has been established that in cases where there are gender differences in the manifestation of sterility or viability of hybrids, they appear more often in the heterogametic sex of hybrid males (y) than in the homogametic female (xx) sex. Obviously, this phenomenon is affected by cytoplasmic heredity and the maternal effect in the inheritance of traits, which can be used in the selection of pairs for crossing, taking into account the sex of the parents (reciprocal selection). We have indicated only the main methods and means of overcoming the non-crossing of distant species and the infertility of hybrids. The rapid development of genetics, molecular biology, biotechnology, genetic and cell engineering in our days, apparently, will allow in the near future to completely solve the problem of infertility in the distant hybridization of animals.

The most promising methods for solving this problem can be considered genetic and cellular engineering, hybridization of somatic cells (ultrahybridization), experimental polyploidy, etc. By hybridization of somatic cells in tissue culture, it was possible to transplant embryonic somatic cells of cattle and northern mink. Hybridization of cells is practically done like this: unrelated cells of two organisms, the useful qualities of which it is desirable to combine when crossing, are cultivated on an artificial nutrient medium, then the culture is mixed. Under certain conditions, some of the cells merge. So far, the process of formation of hybrid systems from cells is chaotic. However, with the improvement of this method, it should be expected that somatic hybridization of cells in tissue culture will be used as an experimental model of interspecific hybridization of animals.

Promising new methods for overcoming infertility during hybridization of animals include damage to chromosomes by physical and chemical mutagens, as well as the use of microdoses of biologically active compounds of supermutagens. Of particular importance are the methods of biotechnology, the production of transgenic animals, chimeras, and the cloning of the genotype of valuable animals.

The most ancient form of hybridization is crossing horses With donkey and getting mule. Also in Ancient Rome mule breeding was widely developed. The mule is an excellent pack animal, unrivaled in endurance, longevity and efficiency. It is obtained by crossing a donkey and a horse; when a donkey is mated with a stallion, a hinny will be born. The mule is larger and more valuable than the horse, but is generally sterile. Breeding these animals "in itself" is impossible.

In our country, in Askania-Nova, great work Of some interest is the hybridization of a horse with zebras and the production of strong hardy zebroids, as well as the crossing of a domestic horse and its wild ancestor, the Przewalski horse. Males from such crossing are sterile, and females are fertile. According to E. P. Steklenev, these species show differences in the karyotype (the number of chromosomes in the domestic horse is 64, in the Przewalski's horse 66), as well as features of gametogenesis. In hybrid infertile males, despite the completeness of gametogenesis, there is a difference in the size of germ cells, their degeneration, rejection on different stages formation, as well as asymmetry in the location of the testes, their underdevelopment. In hybrid females aged from one to 10 years, generative processes, sexual cyclicity, conception and fetal development occur normally.

Hybridization is also used to create new breeds of farm animals. Many farms have studied issues such as selection and selection of pairs, biological features zebu-like cattle, its adaptability to local conditions, etc. It has been established that the hybrids are resistant to piroplasmosis, inherit high milk fat and protein content from zebu, are responsive to improved feeding and maintenance conditions, pay well for feed, and have excellent meat qualities. The meat contains an increased amount of fat and protein, the slaughter yield reaches 60%. Less frequently, there is a disease of the udder, gastrointestinal tract, and hooves. It is also important that hybrids obtained by crossing cattle with zebu are fertile.

In connection with the concentration and intensification of animal husbandry in all climatic zones of the USSR, the hybridization of factory breeds of cattle with zebu makes it possible to create dairy and beef cattle that meet the requirements of the new (industrial) technology of the industry. Of great interest are the works carried out in the scientific and experimental farm "Snigiri". Here the zebu was crossed with black-and-white cattle, which made it possible to obtain highly productive hybrids with a milk yield of 3997 kg and a milk fat content of 4.27%. In the Central Asian republics, there are breed groups bred on the basis of crossing zebu with Swiss and East Frisian cattle. The milk yield of such hybrids is 10-15%, and the fat content of milk is 20-25% higher than that of purebred animals.

Of great interest are the works on hybridization of cattle with banteng, carried out in Askania-Nova. Hybrids from crossing banteng with red steppe cattle are characterized by excellent meat qualities, pronounced heterosis. Milk yield of hybrid cows was 1500-2200 kg, milk fat content was 6.1%. Rich material has been accumulated in the works of A. E. Mokeev and P. N. Buina on three-breed crossing (Santa Gertrude x Webu x Red Steppe breed; Shorthorn Zebu x Red Steppe breed). Availability
zebu blood in both variants of crossing gave excellent results. A new type of beef cattle has been created.

The hybridization of the yak with Simmental cattle in the conditions of the high mountain regions of Altai and the Kirghiz SSR is of great national economic importance. Yak hybrids with Simmental cattle are distinguished by good milk production, high fat content of milk (5.5-7), adaptability to breeding in high-mountain alpine pastures. Thanks to these hybrid forms, cattle breeding is becoming widespread in the mountainous regions of the country.

For hybridization, bison are also used, of which there are only a few hundred worldwide. Now the number of bison is being restored. Of considerable economic interest are hybrids of cattle and bison. As a result of 15 years of work, cattle breeder D. Bissolo from California managed to cross Charolais and Hereford cows with wild American bison. The new breed group was named bifalo. The hybrid offspring, which has 3/8 of the blood of a wild bison, 3/8 of the Charolais and 3/4 of the blood of the Herefords, is characterized by high precocity (weighs 400 kg at 10 months of age), well-developed meat forms. Data from laboratory studies have shown that the meat of such hybrids contains 18-20 protein and only 7 fat. The main type of food for bifalo hybrid animals, according to D. Bissolo, is pasture grass. They are hardy, have a high resistance to many diseases common in hot climates.

Hybrids have also been obtained from crossing cattle with gayals and African Watusi cattle. A very promising species for distant hybridization is African antelope eland. This is a very large species of antelope: males weigh 700 kg, females - 540-500 kg. Females give milk well, milk yield per lactation does not exceed 700 kg, but the fat content of milk reaches 10-14. The milk of eland antelopes has healing and bactericidal properties. Yogurt from this milk does not spoil for many years under normal conditions. Now methods have been developed for obtaining sperm from eland males on the vagina and is being carried out artificial insemination cows in order to obtain hybrid forms.

A lot of work is being done in Askania-Nova and in a number of other reserves of the country to create new breeds of deer. As a result of long-term complex intraspecific hybridization, the Ascanian deer breed was bred. European maral deer, Crimean and Caucasian deer and wapiti (the largest steppe deer) participated in its creation. Much has already been done to domesticate antler deer and elk.

M. F. Ivanov developed and was the first to apply the method of distant hybridization in the creation of fine-fleeced breeds of sheep. crossed wild sheep mouflon with a fine-fleeced sheep, he received a new breed of fine-fleeced sheep - mountain merino. Animals of this breed inherited from the wild mouflon the ability to move quickly, overcoming long distances, to live in high mountains, to use alpine pastures, and from the rambouillet - the valuable productive qualities of a fine-fleeced sheep. By the method of remote hybridization in the mountains of Kazakhstan, Soviet scientists have bred the fine-wooled breed of Archaromerinos.

Of great scientific and practical interest are the works of N. Gigineishvili on breeding gray karakul sheep by hybridization with wild and mountain sheep, on hybridization of sheep and goats, rabbits and hares, llamas and camels.

Remote hybridization in poultry farming gained wide scope, 96 species of birds belonging to 13 orders produced fertile offspring. Of greatest interest are hybrids of an ordinary pheasant with a wild Caucasian (Askanian pheasant), hybrids of a domestic duck with musky ducks (mulards), chicken and peacock, guinea fowl and pheasant, turkey and guinea fowl, and many others that have excellent fattening qualities. Work on remote hybridization of poultry is being successfully carried out both in the Astrakhan Reserve and in other scientific institutions of the country.

An important direction in increasing the genetic potential of pigs when transferring the industry to industrial technology is distant hybridization, the use of the gene pool of wild forms. At present, only the use of hybrids can provide an accelerated growth in the productivity of industrial pig breeding. Taking into account this situation, 19 hybrid pig breeding centers are being created in the country. Hybridization ensures the manifestation of the heterosis effect.

In the context of the intensification of pig breeding, a new direction in hybridization has appeared. The scientific substantiation of hybridization in pig breeding is based on the relatively independent inheritance of reproductive, fattening and meat qualities in pigs. This allows you to create specialized paternal and maternal forms that are successfully used in parent and grandparent herds for crossing.

In most countries of the world, in order to intensify pig breeding, create new highly productive types and breeds, long-term programs for hybridization in pig breeding have been developed and are being implemented.

Heterosis and its importance in animal husbandry

Heterosis (from Greek heteroiosis - change, transformation). Heterosis is understood as the superiority of the offspring of the first generation over the parental forms in terms of viability, endurance, growth energy, fertility, constitutional strength, resistance to diseases that occurs when crossing different races, breeds of animals, zonal types.

The term "heterosis" was introduced by G. Schell (1914), who explained the presence of "hybrid strength" by the state of heterozygosity in the genotype of an organism, which is formed as a result of crossing. The hypothesis of heterosis, formulated by G. Schell, E. East, H. Hayes, explains the phenomenon of heterosis by the presence of heterozygosity of various loci and the overdomaining that manifests itself, that is, when the effect of the Aa heterozygote on the manifestation of the phenotype is stronger than that of the homozygous dominant AA genotype (that is, the effect of the action of Aa is greater than the action of AA).

Another explanation of heterosis, formulated by Kiibl and Pellew (1910), is based on the fact that when organisms carrying different homozygous genes in the genotype, such as AAbb and aaBB, are crossed, the recessive alleles in the crossbred offspring pass into the heterozygous form of the AaBv genotype, in which the harmful effect is eliminated. recessive genes. The influence of dominant genes on the manifestation of heterosis can be explained by a simple cumulative action a large number dominant genes, that is, there is an additive effect.

A. Shell and O. East proposed a hypothesis of overdominance, which is close to the hypothesis of obligate heterozygosity put forward by D. A. Kislovskiy. Its essence lies in the fact that high heterozygosity is better than homozygosity provides diversity and amplification physiological functions organism. H.F. Kushner, based on a large number of experiments, identified five forms of manifestation of heterosis used in animal husbandry:

• hybrids (or crossbreeds of the 1st generation surpass their parents in live weight and viability;
• crossbreeds of the first generation surpass their parents in constitutional strength, longevity, physical performance with complete or partial loss of fertility;
• crossbreeds of the 1st generation in terms of live weight occupy an intermediate position, noticeably surpass their parents in terms of multiple pregnancies and viability;
• each individual feature behaves according to an intermediate type
  inheritance, and in relation to the final product there is an increased
  heterosis;
• crossbreeds, or hybrids, do not exceed the best parental form in terms of productivity, but have a higher level of productivity compared to the arithmetic mean of both parents.

The classic example of heterosis is the mule, a hybrid between a donkey and a horse. These are strong, hardy animals that can be used in much more difficult conditions than parental forms.

Modern ideas about the causes of heterosis are based on the fact that heterosis is the result of the interaction of many genes. Their multiple action leads to the heterosis effect. This explanation is called balance heterosis. Subsequently, Lerner and Turbin continued to develop this provision.

According to them, heterosis is caused by the action of many genes mutually balanced in the genome in the process of evolution, which determines the optimal development and adaptability of the organism to environmental conditions.

If during crossing the optimal genomes of both parents combine, then the descendants of the first generation have the most favorable situation in the combination of genomes, which leads to the appearance of heterosis. Consequently, heterozygosity accompanying crossing undergoes the pressure of various factors and thus creates a balanced interaction of genes in the genome.

In the practice of animal husbandry, the so-called negative heterosis is sometimes observed, when the level of the trait in the offspring is lower than the average indicator of the parents, but slightly higher than the level of the trait of the parent in which it is less developed. The higher the differences in the trait level of the parental forms, the more the average trait level of the descendants approaches the trait level of the worst parent. This feature in inheritance was described by Ya.L. The wool shearing of the first generation crossbreeds was somewhat greater than that of the Angora goats, in which it was 4-5 times greater than that of the coarse-haired and local goats.

Modern animal husbandry is characterized by the use of crossbreeding, accompanied by a heterotic effect, especially for egg and broiler poultry farming. This system includes two main stages: the breeding of inbred bird lines using different types of inbreeding and crossing (crossing) lines to obtain the so-called hybrid bird, which shows heterosis. For example, in the Netherlands, Eurybrid works with two crosses of egg-oriented chickens: Highsex White (white shell based on leghorns) and Highsex Brown (with the participation of Rhode Island and Newhamshire with brown shells. These two crosses occupy a leading position in the global poultry industry.

Work on the creation of a hybrid egg and meat poultry is carried out in our country. To carry out selection for obtaining heterosis, imbred lines are bred by mating according to the “brother x sister” type for 3-4 generations or more, combining this with a strict culling of unwanted individuals. Of the larger number of laid lines, about 10-15% of the lines remain for the final, with an average inbreeding coefficient of 37.5% (mating of full siblings for three generations). Next, the remaining lines are crossed with each other to check them for compatibility, then the most successful combinations are left for production crossing and 2-, 3-, 4-line hybrids are obtained.

The use of the effect of heterosis is also used in work with other animal species, especially in beef cattle breeding, sheep breeding, camel breeding, and fish farming. Methods for obtaining the effect of heterosis are varied. Heterosis is manifested in interspecific crossing of animals: obtaining mules from crossing a donkey with a mare, breeding new heterotic breeds by obtaining hybrids from crossing cattle with zebu (Santa Gertrude, Beefmaster, Charbray, Bridford in the USA; Sao Paulo - Brazil, haupgamitin - in Jamaica). In our country, distant hybridization has been carried out between fine-fleeced sheep and argali, and a new breed has been bred - arharomerinos. In Kyrgyzstan and Altai, hybrids of yak with Simmental cattle have been obtained. Heterosis in interbreeding. In the zootechnical literature, there are most examples of the appearance of heterosis in animals of different species when interbreeding is not used.

In beef cattle breeding, when crossing some breeds, crossbreeds of the first generation surpass the original breeds in terms of fattening quality in live weight at different age periods.

In dairy cattle breeding, heterosis in terms of milk yield and fat content in milk during interbreeding is rarely observed. Data on heterosis in terms of milk yield are given by N.F. Rostovtsev from the experience of crossing Ostofrisian cows with bulls of the Red Gorbatov breed. In dairy cattle, the effect of heterosis is observed more often in terms of the total amount of milk fat per lactation, especially when crossing cows of different breeds with bulls of the Jere breed.

In pig breeding, interbreeding industrial crossbreeding is used more widely. Scientific institutions of our country have experimentally tested more than 100 variants of industrial crossbreeding of pigs. In many cases, the effect of heterosis has been established. Basically, it manifested itself in an increase in fertility, the viability of the offspring, and an improvement in its fattening qualities. In the experiments of M.A. Selekh crosses from crossing queens of large white breed with Berkshire boars spent feed per 1 kg of live weight gain per 0.5 -1 feed. units less than the original purebred animals.

According to M.A. Zhabaliev hybrids (Landrace x Large Black) consumed 4.1 feed units per 1 kg of growth, while purebred Landrace and Large Black pigs consumed 4.2 and 5.08 feed units, respectively. units In the experiments of I.E. Zhirnov, crossbreeds from crossing pigs of Large White and Estonian breeds gave, when fed, 600 g of average daily gain in live weight, and the original breeds, respectively, 548 and 560 g. According to V.O. Chetyrkin, higher gains and better payment for feed compared to the original breeds the crossbreeds differed from the crossing of the queens of the large white breed and the boars of the Moldavian black breed group. The average daily gain in live weight was 598 g, the cost of feed per 1 kg of gain was 4.0 cor.un. Moldovan - 394 and 4.3%.

In addition to egg production, with interbreeding of chickens, heterosis is expressed in increased embryonic and postembryonic viability, in growth energy, improved meat qualities and feed payment.

To obtain heterosis in interbreeding great importance has the correct selection of paternal and maternal breeds, as well as the choice of breed representatives. In poultry farming, as N.F. Rostovtsev, where there is a rapid change of generations and there is a great opportunity for selection, methods have been developed for the directed formation of the heredity of the original crossed forms, which ensure the appearance of heterosis in their crossbred offspring.

Heterosis using heterogeneous selection in intrabreed mating. The use in purebred breeding of crosses of lines, lines of producers and families, as well as the mating of animals belonging to the same breed, grown in different conditions, are also options for heterogeneous selection. Heterosis using heterogeneous selection during intrabreed mating, in which the mated animals are in the same household, do not have a clear linear affiliation or belong to the same related group and therefore are related to each other to one degree or another. Such heterogeneity is most often expressed in the difference between mated individuals only in some respects, in particular, in conformation-constitutional features.

The problem of obtaining and enhancing the effect of heterosis has not been fully resolved. The main indefinite obstacle is the loss of the heterosis effect in the second generation, that is, the heterosis obtained in the first generation is not fixed, but is lost in subsequent generations when breeding crosses “in themselves”. Some methods allow you to maintain heterosis in several generations. One of the most accessible and effective methods is variable crossing, which is used in commercial (commercial) animal husbandry. At the same time, from the crossbreeds of the first generation obtained from crossing the queens of breed A with the producers of breed B, the best part of the queens is isolated and crossed with the producer of breed C, a crossbreed of the second generation is obtained, with the manifestation of heterosis when three breeds are combined (A, B, C) Further crossbreeds of the second generation can be crossed with the producer of the breed D and get more complex crossbreeds in which the heredity of the original maternal breed A and the heredity of the paternal breeds B, c and D are presented. Other methods to preserve the effect of heterosis have not been developed in animal husbandry.

In the practice of modern animal husbandry, it has been proven that the effect of heterosis is diverse and is expressed in the improvement of valuable economic features. The main indicators of heterosis are an increase in embryonic and postembryonic viability, a decrease in feed costs per unit of production; increase in precocity, fertility, productivity; manifestation of broader opportunities for adaptation to changing conditions and new elements of technology. The wide range of the heterosis effect, manifested in the variety of reacting traits, is a reflection of the physiological and biochemical processes determined by the peculiarities of the genetic apparatus of heterotic animals.