For insemination, the mare is brought into the pen or her front leg is raised so that she cannot kick with her back leg. The external genitalia of the mare are washed with a swab dipped in clean water.

Usually, during insemination, 30 ml of semen is injected into the uterus of mares, and for large mares and newly foaled mares, the dose of semen is increased to 35-40 ml. The minimum dose is 20 ml. .

Insemination of mares is carried out before ovulation at the third and fourth stages of follicle maturation (F3 and F4). Inseminated mares are checked rectally after 24-48 hours. If ovulation has not yet occurred, insemination is repeated. After ovulation, insemination is not performed.

At points where it has not yet been mastered rectal method monitoring the condition of the ovaries, insemination of mares is carried out with a good external sign of heat. Insemination is repeated every 24--48 hours until signs of heat subside.

For artificial insemination of mares, the most widely used is a soft rubber catheter, which is a thick-walled rubber tube with a narrow internal channel. The narrowed end of the catheter is inserted into the uterus, and the wide end is connected to a glass syringe with a capacity of 30 ml: The catheter is inserted into the mare’s vagina by hand, the cervix is ​​felt and its end is directed into the cervical canal to a depth of 10-12 cm. Then a syringe with semen is attached to the catheter and, pressing the piston, the seed is introduced into the mare's uterus.

To inseminate mares, you can also use an ebonite catheter designed by the Institute of Horse Breeding, model 1952. It is a thin ebonite tube 50 cm long and 0.6 cm thick. One end of it is expanded in the form of a head. The internal channel of the tube has a diameter of 1 mm. The catheter is firmly connected to the syringe using a special rubber coupling or using a piece of rubber catheter 2.5-3 cm long.

Insemination with this catheter is carried out through a speculum, which is first disinfected by burning it over a fire or wiping the entire surface of the branches of the speculum with a swab soaked in a disinfectant solution.

The mirror is wetted boiled water, inserted into the vagina, opened and held with the left hand so that the cervix is ​​clearly visible. Right hand take a syringe with semen and an ebonite catheter attached to it. The catheter is carefully inserted through the speculum into the cervical canal to a depth of 10-12 cm, the syringe plunger is pressed and the seed is injected into the uterus. Insemination using an ebonite catheter can be carried out by an artificial insemination technician without an assistant. This method is used in farms that are vulnerable to infectious diseases, since the ebonite catheter and speculum are easy to disinfect.

The ampoule method is used for inseminating mares with transported semen directly on farms. The glass ampoule serves to transport the seed and at the same time replaces the syringe. The cap is removed from the narrow end of the ampoule and attached to an ebonite or rubber catheter inserted into the mare's cervix. To connect the ampoule with an ebonite catheter, use a special rubber coupling or a piece of soft rubber catheter. The stopper is removed from the ampoule, and the seed is poured by gravity through the catheter into the uterus. If the seed does not flow out, the catheter is pulled back a little so that its end does not rest against the mucous membrane of the uterus.

Jonathan F. Pycock

The success of an artificial insemination (AI) program in the equine industry is based on the following factors: On the stallion side:

Complete examination of the stallion for suitability for reproduction.

Confirmation of acceptable semen quality.

Proper cooling and storage of semen after collection. From the mare's side:

Satisfactory results of examination for fitness for reproduction.

Stimulation of ovulatory estrus.

Accurate preliminary determination of the time of ovulation.

Correct timing of insemination in relation to ovulation.

Proper storage, thawing and handling of seed.

Compliance correct technique insemination.

After insemination: re-examination, treatment.

Accurate diagnosis of pregnancy on the 14-16th day after insemination.

The owner should be informed that AI in horse breeding requires large technical investments and is not a cheap alternative to natural mating.

Good communication between the mare owner, stallion owner and their attending veterinarians is vital.

For an artificial insemination program to be successful, preventative and hygienic measures must be strictly followed, strictly following country-specific animal disease prevention regulations and laws to reduce the risk of disease spread and transmission. Each shipment of fresh or chilled semen must have accompanying documentation containing information about the stallion (identification, health data), the name of the center that collected the semen, the date of collection and shipment and the number of sperm in the dose sent.

Before starting a breeding program using chilled or frozen semen, the mare owner should be informed of the difficulties associated with the use of AI and what may work well in artificial insemination. Many mare owners believe that once they decide to put a particular mare into reproduction, she will immediately become pregnant and produce a live foal the following year. This opinion is fundamentally wrong, and it is important that the owner is aware of the capabilities of the method. Under normal circumstances (i.e. when the mare is fertile and the quality of the semen is good), a pregnancy rate of 55 to 70% per cycle can be expected when bred with chilled semen, and 35-50% when bred with frozen semen. At the end of the breeding season, the foaling rate can be 50-90% (on average 75%). Of course, some mares lose embryos, so the yield of commercial foals is about 65%.

It is also important to be aware of the costs associated with using AI. Many mare owners expect cost savings by eliminating the need to transport mares, and do not consider the cost of obtaining and transporting semen, as well as monitoring the mare's reproductive cycle and inseminating her at the optimal time.

Time of insemination. Survivability of sperm in the reproductive tract of the mare

It is well known that in the reproductive tract of mares, sperm during natural mating can retain their viability both for a long time - up to 7 days, and for a very short time - about 24 hours. It is obvious that in most stallions the good fertilizing ability of the seed is maintained for at least two days. The survival rate of sperm is affected by the storage method. It is important to remember that there are different ways to store semen, as this factor has a significant impact on optimal time insemination in relation to the time of ovulation. Three storage methods include:

Freshly harvested, uncooled seed.

Chilled.

Frozen.

Storing freshly obtained uncooled semen

Semen intended for immediate insemination is used undiluted, but if the expected interval is more than 10 minutes, it is better to use a diluent. If such semen must be stored for 2 to 6 hours, the plasma should be removed by centrifugation (900 g at room temperature): this allows the fertilizing ability to be preserved longer, which is beneficial for the semen of some stallions. It is desirable that the seed is not subject to temperature fluctuations, so it can be stored in a thermos. The container for storage at room temperature (8-22C) must be light and airtight.

Storage and transportation of cooled seed

To prevent loss of energy by sperm in cases where the interval between collection and insemination is more than 6 hours, cooling of the resulting seed is required. The ejaculate, free from the secretion of the accessory glands, is diluted with a suitable diluent at a temperature of BTC. Sperm motility is determined under a microscope equipped with a heated stage.

The cooling mode becomes critical. About 12 years ago, Hamilton-Thorne developed a special container - an equitainer - for transporting stallion semen. It consists of a durable, snap-on outer container containing frozen bags, an insulating layer, thermal ballast bags and a temperature controller. A feature of the equitainer is that it is capable of providing a gradual, about 0.3°C per minute, temperature decrease until it stabilizes within 4-6°C. The seed can be stored at this temperature for up to three days. This cooling mode was specially developed after a series of experimental studies to determine the survival rate of sperm at different cooling rates. The cooling regime is controlled and maintained by frozen bags, a special copper plate placed between them and the seed, and a 60 ml thermal ballast that surrounds the seed. If the total volume of the seed and thermal ballast is in the range of 120-170 ml, the seed is cooled in the specified mode.

The author specifically describes the equitainer structure in such detail here so that readers understand the need to have special equipment to obtain seed of optimal quality after transportation. There are a large number of equitainer “clones” on the market. Some of them are much cheaper than the original and, although they often give quite acceptable results, sperm survival is not optimal. According to the author, until results are obtained demonstrating the effectiveness of competing products, breeders should be recommended to use the original equitainer model.

In the Netherlands, polystyrene boxes are used to transport cooled semen, in which two tubes of seed are placed, each with a volume of 15 ml. These polystyrene boxes are then packed into cardboard boxes, which are placed in a transport refrigerator (at a temperature of 5’C). This system is effective and inexpensive.

The semen of some stallions tolerates transportation well in a chilled state, while the semen of others does not have this property. Therefore, it is necessary to determine the resistance of each stallion's semen to refrigeration and storage before a dose of semen is sent to the customer. For this purpose, the ejaculate is mixed with a diluent (for example, a diluent based on heated and cooled skim milk) in a ratio of 1:2, placed in an equitainer and then the motility of the seed is determined every 12 hours. Since the dose of sperm in one package must contain at least 500 million progressive sperm, the dilution rate can be varied (from 1:1 to 1:6) depending on the density of the semen received.

Determining the estimated time of ovulation

In many cases, mares intended for artificial insemination are kept in the owner's stable, and therefore the use of a test stallion for heat detection may not be available. The same situation arises if, for the convenience of the examination, the mare is placed in the stall of a veterinary clinic. It is difficult to detect heat in a mare in the absence of a probe, so the breeding veterinarian must be prepared to induce and diagnose estrus.

During the breeding period, mares experience repeated sexual cycles, each lasting an average of 22 days: 3-7 days of estrus are followed by 15-17 days of diestrus, during which the corpus luteum develops in the ovaries, producing progesterone, and the mare breeds the stallion. Based on the above, during the initial examination during the breeding season, about a third of the total number of mares are in heat or are beginning to come into heat. Predicting the exact time of ovulation is not an easy task and requires taking into account a number of data and making an informed decision. Meanwhile, knowing the time of ovulation is extremely important, since the optimal time for artificial insemination with cooled semen is 24 hours before ovulation. When using frozen semen, it is ideal to inseminate between 12 hours before and 6 hours after ovulation (see below).

The diameter of the follicle, preovulatory softening, change in shape and thickening of its wall serve as indicators for determining the time of upcoming ovulation. However, in some mares the follicles, having increased to 30 mm (follicular phase), then remain almost unchanged, and ovulation occurs only after 5 or more days. In others, the follicle ovulates at a size of 30 mm. Individual mares that develop a preovulatory-sized follicle during diestrus enter the follicular phase with a large, apparent preovulatory follicle that may ovulate early in this phase or undergo regression. Over time, ovulation occurs due to the development of a new follicle.

Preliminary knowledge of the individual size of the preovulatory follicle in a mare makes a significant contribution to the accuracy of predicting the time of ovulation, since from cycle to cycle in the same mare the follicles ovulate when they reach approximately the same diameter.

It must be remembered that the preovulatory diameter is usually smaller if two follicles mature at the same time.

Daily rectal and vaginal palpation in combination with ultrasound data allows an experienced veterinarian to fairly accurately predict the time of ovulation.

Quite often, hormonal drugs are used to stimulate ovulation. The most common method is intravenous administration of 1500 IU of human chorionic gonadotropin (hCG), when a mare in heat has a softened follicle with a diameter of at least 35 mm with simultaneous uterine edema visible on ultrasound. Approximately 85% of mares ovulate between 24 and 48 hours after hormone administration.

Most mares in the AI ​​program are in the diestrus phase at the time of initial examination. Luteolysis, if there is a corpus luteum in the mare's ovary that is at least 5 days old, can be induced by administering prostaglandin analogues. If the corpus luteum is older than 14 days, it will undergo regression one way or another; however, a widespread problem is prolongation of the luteal phase, where mares do not come into heat at the expected time.

For this reason, preference is usually given to the use of prostaglandins to stimulate heat (versus waiting for the spontaneous onset of estrus). Ovulation usually occurs 8-10 days after the injection, but this interval can vary greatly. Although the use of prostaglandins can save time and make repeated testing of the mare unnecessary, misuse These drugs are fraught with a number of problems.

Treatment can be started too early early stage luteal phase, before the corpus luteum, formed at the site of the last ovulated follicle, reaches the age of 5 days. In these cases, regression of the corpus luteum does not occur.

The administration of a luteolytic drug in the presence of a follicle with a diameter of more than 30 mm makes it difficult to determine the time of ovulation. In some cases, such a follicle begins to grow rapidly and ovulates after 3 days, in others it stops developing and gradually undergoes regression. After this, ovulation may be delayed by 10 days, depending on how quickly one of the small follicles matures.

If at the time of prostaglandin administration the mare had a very large follicle, over 35 mm, it may ovulate before signs of heat appear.

In this regard, in the presence of large follicles, the use of prostaglandin should be abandoned.

If, after all, the drug was administered to the mare, do not try to inseminate her using this cycle.

Before using prostaglandin, it is advisable to carefully examine the ovaries - first, to ensure that the mare is in diestrus; secondly, to determine the age of the youngest corpus luteum, and thirdly, to measure the diameter of the largest follicle present.

Ideally, the owner of the stud stallion is notified 48 hours before the desired breeding time.

Any application for permission to export semen must be submitted well in advance of the desired insemination date.

Accurate timing of upcoming ovulation is of great importance due to the fact that the optimal time for insemination with cooled semen is 24 hours before ovulation. If this interval is not observed, the fertility rate is significantly lower. It is shorter than when using freshly taken seed or natural mating. This is not to say that fertilization will definitely not occur as this interval increases. However, it should be taken into account that different quality of semen from different producers, the use of different diluents and cooling systems cause significant fluctuations in the survival of sperm not only during storage, but also while in the reproductive tract of the mare.

Hormonal stimulation of ovulation during estrus

Since the most difficult stage of artificial insemination in horse breeding is determining the optimal time for insemination, hormonal drugs are often used to stimulate ovulation. The most common method is to administer 1500 international units of human chorionic gonadotropin (hCG) intravenously when the mare in heat has a softened follicle with a minimum diameter of 35 mm. Approximately 85% of mares ovulate between 24 and 48 hours after hormone administration.

A new hCG analog, desorelin, available as an implant, promises to be effective in stimulating ovulation during estrus. Desorelin differs from human chorionic gonadotropin in its low molecular weight, and therefore (and also due to its similarity to endogenous gonadotropin) reuse This drug is unlikely to induce the formation of antibodies, as occurs with hCG. Previous tests confirm this assumption. Desorelin causes the release of significant amounts of luteinizing hormone (LH) within 6 days after implantation. And although the nature of the increase in LH levels differs from its natural release, nevertheless, effective stimulation of ovulation occurs within 48 hours after insertion of the implant. As with hCG, this drug used only if there is a follicle with a diameter of over 30 mm.

Desorelin has at least two advantages over hCG: it can be reused without the risk of developing resistance, and it is more stable than hCG. The latter has to be reconstituted from dry powder, and unused remains are either thrown away or frozen. Unfortunately, desorelin is a rather expensive drug, 5 times more expensive than hCG.

Artificial insemination technique

The mare is identified by checking its passport or similar document. They check the accompanying documentation for the semen, which should indicate that the stallion has passed the entire volume necessary research. If the semen is imported from abroad, the documents must indicate that the stallion is seronegative for viral arteritis.

Documents for each batch of semen must also contain information about the date of collection, mobility, concentration, type and volume of diluent used.

The veterinarian performing the insemination must confirm that the semen has been received and, once the mare has been identified, confirm that her description matches that of the agreement. In the future, he will also have to confirm that only the sent semen was used to inseminate only this one mare, and any unused semen was disposed of.

The mare is prepared for breeding in a clean, well-lit area. Preference should be given to insemination in a pen. The tail is bandaged and moved away from the perineum. The vulva and perineum are thoroughly cleaned and dried.

Until this stage, the container containing the cooled seed must remain closed. Cooled seed should not be heated. Since some time passes between the end of washing the mare and the actual insemination, it is recommended, even before all these manipulations, to clean the mare’s rectum in order to avoid subsequent contamination.

Although many breeders send semen with the expectation of two inseminations, 12 hours apart, semen should not be stored in a container for possible future use (in case ovulation does not occur). The fact is that the oviducts (fallopian tubes) of a mare are a much better storage for sperm than any transport containers. In addition, the first insemination can cause an inflammatory reaction to varying degrees, and each subsequent insemination intensifies this inflammation. The current conventional wisdom is that all semen from an equitainer should be used immediately upon arrival - as opposed to the previous tendency to re-inseminate after 24 hours with the remaining dose in the container in case ovulation does not occur on time. The mare is a much better “incubator” for sperm than any device invented by man. Indeed, it is not uncommon for mares to become pregnant when ovulating 4, 5, 6 and even 7 days after insemination. This probability is much lower if the semen were cooled, even in an equitainer, since most sperm lose motility (and, most likely, fertilizing ability, or simply die) 60 hours after taking the semen. At temperatures just below 20°C, changes occur in sperm acrosomes, and storage at 4″C significantly reduces survival. That is why it is recommended to inseminate with cooled semen no more than 24 hours before ovulation. This is not to say that fertilization will definitely not occur as this interval increases. However, it should be taken into account that the different quality of semen from different producers, the use of different diluents and cooling systems cause significant fluctuations in the survival of sperm not only during storage, but also while in the reproductive tract of the mare.

The seed is carefully mixed and placed in a sterile plastic syringe (without a rubber plunger). A sterile insemination pipette is attached to the syringe. The operator puts on a sterile obstetric glove.

Sometimes it is necessary to apply a small amount of sterile, non-spermicidal lubricant to the fingers.

Holding the tip of the pipette behind your index finger, insert your hand into the mare's vulva. Insert into the external opening of the cervix forefinger and the catheter is carefully guided along it into cervical canal. It is very important that the catheter reaches the middle or cranial part of the uterine body and does not get stuck in the cervix. Passing a catheter through the cervical canal is sometimes not as easy as it might seem. You should also not be content with placing the catheter directly in front of the cervix. Carefully empty the syringe, injecting the seed into the uterine cavity. If the introduction of the seed encounters resistance, the catheter is moved back slightly.

There is a generally accepted opinion that if the volume of injected semen is in the range of 0.5-60 ml, this volume in itself does not matter, so you should not try to increase the volume of frozen semen packaged in small containers before insemination. Moreover, using the wrong diluent for frozen semen can lead to disastrous results.

It is important that all instruments used are warmed up to avoid temperature shock. A small amount of semen is heated and checked for mobility and the presence of pathological forms.

Examination of the mare after insemination

The mare is examined (if she was bred before ovulation) after 12 hours (if using frozen semen), after 24 hours (if using chilled semen) or after 48 hours (if inseminated with fresh semen). If your ovulation time is incorrect, you may have to order a second dose of semen.

Inflammatory reaction

It should not be assumed that insemination with a sufficient number of live sperm at the optimal time relative to ovulation will automatically ensure pregnancy. Insemination causes an acute inflammatory reaction, which should be considered as a natural and beneficial phenomenon. The cause of empty nests in many, especially old mares, is insufficient cleansing of the uterus from inflammatory exudate. The most acute inflammatory reaction is caused by the sperm themselves.

Inflammatory reaction to semen

Sperm introduced directly into the uterus, both during natural mating and during artificial insemination, causes endometritis.

It is believed that sperm eventually move from the uterus into the fallopian tubes without the participation of any contractions of the uterine wall. However, it is precisely the contractions of the myometrium that can explain the fairly rapid entry of sperm into the oviducts after insemination.

All this implies the need for special treatment of mares after insemination.

Semen is injected directly into the uterus of mares during natural mating or artificial insemination. This means that bacterial contaminants and sperm components, along with incidental impurities, contaminate the uterus, causing an inflammatory response. Previously, it was believed that this reaction is provoked only by bacteria that accidentally enter the uterus during insemination. However, it is now recognized that acute inflammation is caused by sperm, not microflora. Seminal plasma also plays a certain role in this inflammation.

The first products of inflammation to appear in the uterus are neutrophils (polymorphonuclear leukocytes), which can be detected within 30 minutes after insemination. The uterine glands produce a fluid that has chemoattractant properties towards polymorphonuclear leukocytes. It is believed that crucial complement serves as a chemoattractant for these leukocytes, although other types of complement may have these properties. It is currently believed that sperm initiate neutrophil chemotaxis by activating complement. The fact that sperm themselves have chemotaxis towards equine neutrophils suggests that short-term inflammation of the uterus in response to the introduction of sperm is a physiological inflammation that helps cleanse the uterus of excess sperm, seminal plasma and accidentally ingested contaminants. Damaged sperm are phagocytosed by polymorphonuclear leukocytes first. In healthy mares, the inflammatory response reaches its peak at 10-12 hours and decreases at 24-36 hours after insemination.

In most mares, this temporary endometritis resolves within 24-72 hours, thereby creating conditions in the uterine cavity suitable for embryo development. It is important to understand that this endometritis is a physiological, not a pathological condition and is rather a normal physiological reaction aimed at cleansing the uterus of sperm residues, seminal plasma and inflammatory products before 5.5 days after fertilization from the oviducts into the cavity the embryo will descend from the uterus.

However, if endometritis continues after the 4th or 5th day of diestrus, then in addition to creating conditions incompatible with the development of the embryo in the uterus, the premature release of prostaglandin F-2-alpha causes luteolysis, a rapid decrease in progesterone levels and an early return to estrus. These mares belong to the group of so-called susceptible, or prone to developing persistent endometritis.

Provided that the concentration of semen is not lower than 25X10 to the sixth power in ml, the volume itself does not have of great importance. You just need to avoid excessive dilution of the semen, which leads to a decrease in concentration: in these cases, a significant volume of sperm is ejected as a result of cervical reflux, which threatens to reduce fertility.

The conclusion that the intensity of the inflammatory reaction after insemination depends precisely on the properties of the seed itself, and not the diluent, was made by Parleviet and his colleagues, who determined the degree of inflammation after insemination with freshly taken semen, as well as diluted ones, using various diluents.

The inflammatory reaction of the uterus is the same to live and dead sperm,

“Ageless mare” syndrome

Old, unbred mares represent a special case that requires a special approach, since very often they are prone to developing endometritis after insemination, despite the fact that they have never been mated before. Often, sport mares begin to be used for reproduction only after the age of 10 years. Sometimes it can be very difficult to get such a mare to conceive. These mares usually have a number of similar symptoms that make up this syndrome. A biopsy reveals degenerative changes in the glandular endometrium and stromal fibrosis (endometriosis) - age-related changes develop despite the fact that these mares have never been bred. Another common symptom in these older mares is fluid accumulation in the uterus. Their cervix is ​​often tightly closed and does not relax during estrus, so the fluid does not flow out, but accumulates in the uterine cavity. In many cases, this fluid does not contain microflora and neutrophils. However, immediately after insemination the situation is aggravated due to insufficient lymphatic drainage and decreased contractility myometrium against the background of a closed cervix. The amount of intrauterine fluid can vary from a few ml to a liter or more in the most extreme cases. To increase fertility in these mares veterinarian should have a good understanding of this type of pathology of the uterus and cervix. Too often owners assume that these mares can be expected to be as foalable as young, unbred mares. And it is very important to convince the owner that an older mare may pose a problem in reproduction. These mares should be considered highly susceptible to endometritis and treated accordingly.

Fluid in the uterine cavity

At ultrasound examination 12-24 hours after insemination, an accumulation of fluid is often found in the uterus, which should be removed to obtain maximum fertility. The drug of choice here is oxytocin and in some cases Intrauteral administration of antibiotics may be indicated. It was recently found that treatment for such insufficient cleansing of the uterus is best done during insemination, rather than waiting for ovulation. These mares are given large volumes of warm saline lavage combined with oxytocin injections. In mares with large lymphatic lacunae, treatment with prostaglandin is also indicated. It is also necessary to evaluate the structure of the perineum and, if necessary, perform a Kaslik operation.

Early diagnosis of pregnancy

Determination of pregnancy should be carried out as early as possible using ultrasound diagnostics, better on the 14-15th day after insemination.

Conclusion

The success of reproduction depends on the fertility of the stallion, the fertility of the mare and the conditions of horse breeding. The resulting foal is the total product of the interaction of all these factors.

BIBLIOGRAPHY

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The main objective of selection is continuous improvement useful qualities offspring. This is achieved due to the fact that only the best representatives in terms of origin, external qualities, performance and quality of offspring are used for reproduction. At the same time, animals that do not meet these requirements are discarded.

The main parameters by which the selection is made:

• performance (manifested at the age of two to four years);
• strength of the constitution;
• size;
• sufficient broad body;
• Boniness and correctness of the exterior.

As a result of such selection, it is possible to develop the necessary qualities in animals, and to artificially direct the development of certain characteristics of the organism in the desired direction.

The main goal of selection is to select individuals with similar characteristics for mating, so that they develop in future offspring.

On large farms, selection is carried out by specially trained specialists, but at home this task falls on the shoulders of the horse breeder himself. For the convenience of accounting, creating a kind of catalog of animals and issuing relevant documents to breeding representatives, farms are assessed.

Young animals are graded at the age of two and a half years, producers - at the age of seven and a half years and older. At the same time, young horses are assessed on three grounds, and adult horses on five. Based on the results of this assessment, horses are assigned three levels of class: elite, first class and second. Elite horses are used to improve the entire livestock. Their semen is used for artificial insemination of mares. First class horses are mated to second class fillies, and second class stallions are used to produce custom steeds.

Selection of horses

Selection and selection are interconnected processes that follow each other. Their goal is to improve existing breeds and obtain new ones. At its core, selection is a mating system based on the following rules:

1. Determining the purpose of mating.
2. Search for a sire that will be superior to the queen in the main characteristics.
3. A horse with the best hereditary and other qualities is used as often as possible in various genealogical combinations.
4. Preservation and enhancement of the excellent qualities of parents in the offspring through related and unrelated mating.
5. Crossing horses from different lines and families leads to obtaining desirable traits in the offspring.

With various alternations of related and unrelated selection, high-class representatives with excellent characteristics are obtained.

Pair selection is carried out both in large horse breeding and small farms. It is important to understand that in the absence of this kind of work on improving and maintaining the necessary qualities in horses, if you simply let everything take its course, then in the end everything will good qualities animals will be lost, which will lead to complete degeneration of the breed and the production of weak and useless offspring.

Horse Breeding Methods

There are two methods of breeding horses, which include different types of mating, selection systems and selection of animals. Their goal is to obtain new breeds and propagate desirable types.

Breeding can be pure (purebred), in which individuals of the same breed are mated, and by crossing, when representatives of different breeds or crosses occur. Interestingly, when breeding purebred and Arabian riding breeds, the pure breeding is called purebred.

Purebred breeding is used to breed the most valuable breeds for their further improvement. Exists inbreeding– inbreeding and unrelated breeding – outbreeding.

Crossbreeding refers to the mating of individuals belonging to different breeds. This method of breeding is used by breeders to obtain new qualities of the breed. Very often, crossing is used to obtain custom horses of different directions. These can be working horses, sports horses and productive animals that are raised for meat, milk and used to produce productive offspring.

When crossing, new characteristics and properties often appear, as the hereditary qualities of two or more breeds are combined. These characteristics can be developed and consolidated through the selection and selection of animals, as well as with the help of the entire complex of zootechnical and breeding activities.

Purebred breeding is carried out by specialized farms and stud farms. The animals obtained as a result of this work are then used for breeding clean lines by artificial insemination, since this method makes it possible to obtain a large number of offspring from a valuable producer at the lowest cost. Everyone, even an ordinary horse breeder, gets the opportunity to buy the semen of a breeding stallion and use it to inseminate their mares and produce offspring with the most valuable qualities. At the same time, he does not need to spend a lot of money to purchase and maintain the manufacturer itself.

Before you start breeding horses, you need to study the biology of reproduction of these animals, find out what methods of insemination they generally have, and choose the most suitable one for your farm.

Biological characteristics of horses

In order to properly and effectively organize the mating of horses, you need to know some of the features of the structure of their genital organs, the physiology of these animals and the signs of heat in mares. Let's try to figure this out.

One of the features of reproduction is that during fertilization, the sperm of the racer goes straight into the uterus, and then, contracting, the uterus pushes it further into the oviduct. This is where the female egg and sperm meet to form a zygote. From it the embryo subsequently develops, and then the fruit. This type of insemination is called uterine insemination. For fertilization in this case, it is necessary to have only living, motile sperm in the stallion’s sperm that have good fertilizing ability. In addition, a lot depends on the health of the mare - a full-fledged follicle must mature in her ovary, from which an egg will then be released to meet the male reproductive cell.

During the maturation of the follicle and the release of the egg, the mares begin to develop sexual desire and she calmly allows the stallion to approach her. By what signs can even a novice horse breeder understand that his horse has come into heat and is ready to mate with a stallion?

• Firstly, this can be understood by the posture of the animal. The mare often assumes a posture as if urinating, raising her tail and straining.
• Secondly, her vulva becomes reddened, and liquid mucus or cloudy urine is released from its opening (horse breeders call it a loop). At this time, the “loop” convulsively contracts and unclenches – “blinks”.
• Thirdly, her behavior also changes: she worries, laughs often, eats poorly.

All this happens due to the fact that ovulation occurs in the body and special sex hormones are produced. The time from the beginning of one sexual heat to the beginning of the next is called the sexual cycle. When is the best time to meet animals? To do this, every horse breeder needs to know some facts and figures characterizing the duration of the filly’s reproductive cycle.

In most cases, the first heat of the year occurs eight to ten days after she foals. In some animals even earlier (after 4-6 days), and in some, on the contrary, later - after ten to twenty days. The first estrus in nursing queens is usually short-lived, but it manifests itself very clearly. It lasts from 2 to 15 days, but more often on average about a week.

Often the mare does not cover herself during the first heat, so after 10-18 days everything repeats again. It turns out that the duration of the sexual cycle is on average 20-25 days. Sometimes it can be longer and sometimes shorter. What can affect its duration, brightness of manifestation and quality of fertilization? There are several such factors and every horse breeder needs to know them.

Factors influencing the duration of the reproductive cycle in mares, intensity of heat and foaling rate:

• Individual characteristics of the body (age, fatness, breed, etc.).
• Living and feeding conditions. At good care sexual desire, as a rule, is pronounced, the duration is normal, the coverage is high.
• In working fillies in a state of fatigue, sexual estrus is weak and the foaling rate is low.
• Desire manifests itself most clearly in favorable weather, especially in the morning. Natural natural stimulant For her, the spring sun, fresh green grass in the pasture and a favorable, calm atmosphere serve her.
• Ovulation usually occurs at night, so evening and early morning mating is most effective.
• Mating is most effective at the end of the period of attraction than at its beginning.

If in the first heat after she has foaled, conception does not occur, then quite often she experiences a long period sexual rest. This occurs due to the fact that maternal instinct and milk production (lactation) inhibit sexual functions. In order to prevent this omission, it is recommended that the foaling mare be checked every day, starting from the fifth day after birth, and inseminated first. To do this, large farms resort to the work of stallions - samplers.

If the mare's heat is pronounced, then she is covered on the same day and repeated a day later. The rest, after a daily test, are mated on the second day after the first signs appear. All coated horses are tested again ten days after the end of heat, and this test is carried out every other day immediately before the foaling factor is determined. If the mare repels the horse, then testing with probes is continued every other day for another 35-40 days. After this, it is recommended that individuals that have not come into heat should be examined for foaling.

The onset of puberty in foals and fillies occurs on average at two years of age, and sometimes at one year.

It depends on the breed, early maturity, development and conditions of detention. But this does not mean that the animals are already ready for mating and fertilization - after all, puberty does not coincide with the physical development of the body. Therefore, allowing animals to mate so early is strictly prohibited. Otherwise, pregnancy in early age will slow down normal development the filly itself, can lead to miscarriage or the birth of weak young animals. When mated early, stallions also begin to lag behind in development, and it is not possible to raise them into full-fledged sires.

Therefore, regardless of the age of puberty, it would be correct if horses mate for the first time in an older state: fillies of all breeds and stallions of heavy breeds - at three and sometimes four years, and stallions of trotting and riding breeds - at four or five years of age .

Types of insemination of mares and methods of mating

In horse breeding, there are three methods of mating horses: hand-breeding, brooding and jamming. Manual mating is used for stall horse breeding, and the other two methods are used for herd keeping of horses.

Manual mating. With this method, heat is detected using a probe stallion or by rectal examination. To test the mare, the test stallion is brought to her head using long reins (lesses), which are pulled on both sides by the grooms. At this time, the animal is held by the reins of the bridle. If the filly presses her ears back, sensing the stallion, gets worried, tries to bite or hit him hind limbs, which means it’s not time yet.

If hunting has been established based on a number of the signs described above, then they begin to organize mating. The genitals of animals are washed before mating warm water, after which the mare’s tail is bandaged so that it does not interfere with the mounting of the stallion. Then a special breeding harness is put on the filly so that she cannot kick the inseminator during mating. It is carried out in a special room - an arena or on an area with a flat surface to prevent injuries to animals.

During mounting, the stallion must remain on the mare for a long time until the semen is completely ejaculated. This is indicated by the movement of his tail from top to bottom. If mating is unsuccessful, the stallion is allowed to rest and is led on the reins for 15-20 minutes, and then the mounting is repeated. After insemination, the horse is led again for some time (about thirty minutes), then its back, croup and limbs are rubbed with a straw tourniquet. After these procedures, he is placed in the machine. Thus, a horse should not cover more than two individuals per day. Otherwise, mating may become ineffective.

Varkova mating. It is used when a horse cannot be allowed into a common herd for a number of reasons. For example, if they are afraid for his health or he is valuable. With this method, the mares are driven into the yard (varok) and a stallion is launched towards them. He independently identifies mares in heat and inseminates them. A prerequisite for hand and boil mating is that the stallions in both cases are unshackled to prevent injury to the mares.

Sexy mating. From the entire livestock, with this mating method, schools of animals are formed, each of which has its own stallion. He independently, without human intervention, finds mares in heat and covers them several times a day. This greatly facilitates a person’s work and simplifies the entire process of a random campaign.

In addition to natural insemination, modern horse breeding also uses artificial insemination. It has a number of advantages over natural mating:

1. Semen from one stallion can be used to inseminate a much larger number of mares, which makes it possible to more fully utilize the semen of valuable stallions.
2. Artificial insemination prevents the spread of sexually transmitted infections that cause serious damage to horse breeding. Insemination can be carried out even in quarantined farms.
3. It becomes possible to inseminate a mare located thousands of kilometers from the stallion whose semen is being used. This makes it possible to obtain the maximum amount of offspring from outstanding breeding sires.

For the correct organization of a breeding campaign in horse breeding farms, regardless of the size of their livestock, it is important to know all the features of horse physiology, to be able to observe, love and care for your animals. Only in this case is your success guaranteed!

56. Artificial insemination mares

Preparation for insemination of a mare is always accompanied by additional measures to prevent injury. Therefore, to begin with, the mare is brought into the stall or held by the reins; in addition, during the injection of sperm, the mare’s forelimb is raised so that she cannot hit her hindlimb. First, the root of the tail is bandaged. The groom takes the mare's tail to the side and washes the external genitalia from Esmarch's mug with a solution of furacillin 1:5000. Mares are inseminated in two ways: vizocervical and manocervical. The sperm is injected directly into the uterus (to a depth of 10-20 cm) using a rubber, ebonite or polystyrene catheter.

Artificial insemination of mares can be performed two ways.

For manocervical method rubber and polystyrene catheters are used. The veterinarian inserts a prepared hand into the mare’s vagina, the end of the catheter, and moves it through the cervix into the body of the uterus; the assistant lifts the syringe or ampoule and injects the sperm.

For visocervical method For insemination, both ebonite and polystyrene catheters designed by the All-Russian Research Institute of Horse Breeding are used. The catheter is a tube 50 cm long, 0.6 cm thick, one end of which is expanded in the form of a head. The catheter is connected to a syringe or ampoule using a rubber coupling with a clamp. The catheter is used simultaneously with a vaginal speculum, which is sterilized and moistened with a 0.9% NaCl solution.

Mares are inseminated freshly obtained or stored at 2-4ºC for 3 days or thawed. When thawing sperm frozen in aluminum bags, they are quickly transferred with liquid nitrogen tweezers to a water bath at 40ºC for 1 minute. The dose of freshly obtained sperm is 25-30 ml. The dose should contain at least 150-300 million sperm with PPD. The activity of freshly obtained sperm is not lower than 6 points, thawed - 2 points.

Sperm is injected only when heated to 30-35ºС. After 8-9 days, inseminated mares are checked by a test stallion for the presence of heat. 35-40 days after insemination, mares are checked for pregnancy using the rectal method.

57. Assessment of sperm concentration and activity (motility)

Counting the number of sperm in seminal fluid - essential component basic semen analysis. Sperm concentration is the number of sperm per unit volume of seminal fluid. This figure is usually expressed in millions of sperm per milliliter (million/ml). Sperm concentration alone does not reflect the total number of sperm in the ejaculate. The number of sperm is calculated taking into account the concentration and volume of the ejaculate. Two methods have been developed for determining sperm concentration. Both involve counting a specific amount of liquefied sperm in a special reservoir. Regardless of the method chosen, it is necessary to ensure that the semen sample is well mixed. To do this, shake the container gently, but do not shake the vessel vigorously. The concentration of sperm in a sample can be determined by the Neubauer method using a hemocytometer. The Neubauer hemocytometer is one of the specially designed counting reservoirs currently in use. Using a pressure pipette, both reservoirs are filled with well-mixed diluted semen. The reservoir is left for 5 minutes for the cells to settle. Only individual spermatozoa on the grid are counted. Isolated heads, tails, and other germline cells should be marked but not counted. After counting the sperm on one side of the tank, counting is done on the second grid. Then find the average value. If individual values ​​differ from the average by more than 5%, the test should be repeated. If both values ​​are counted, the average is divided by the calculated surface area and multiplied by the dilution factor to find the sperm concentration in the original semen sample (millions/ml). The sperm count can then be calculated by multiplying the sperm concentration value by the ejaculate volume. The Broker Counting Chamber (Sefi Medical Instruments, Haifa, Israel) is a special device designed for rapid sperm analysis. Since its invention in 1980, the Makler counting chamber has become widespread and is now used in many laboratories. The main advantage of the Makler chamber over the Neubauer hemocytometer is that there is no need to dilute the sperm sample (except in cases of extremely high concentration). In addition, motility and progressive motion can be assessed during sperm concentration calculations. Although the Makler chamber makes it easier to determine concentrations in semen analysis, this method is inferior to traditional hemocytometry in accuracy and tends to produce erroneous results.

The concept of “zoospermia” refers to the presence of sperm in the ejaculate. Patients with a sperm concentration of less than 20x106/ml are classified as having oligozoospermia. Azoospermia is the complete absence of sperm in the ejaculate. The diagnosis of azoospermia is made only after microscopic confirmation of the absence of sperm in the sediment after centrifugation of an undiluted semen sample

The 1999 WHO classification system distinguishes four categories of sperm: category A includes sperm with rapid progressive movement; Category B includes slow or inert sperm; category C - sperm with non-progressive movement; category D - immotile sperm. The percentage of sperm categories is recorded. A normal semen sample contains at least 50% motile sperm, most with good progressive movement (modal class >2, WHO classes A and B). Asthenozoospermia is diagnosed when the number of sperm with good motility is less than 50%.

Methods of artificial insemination of mares.

When inseminating mares, sperm is injected into the uterus (uterine method insemination). In practice, two methods of sperm injection are used: manual and visual .

With manual this method uses a rubber catheter by I. I. Ivanov and a syringe with a capacity of 30-50 ml or ampoule. The catheter is a thick-walled soft rubber tube with a narrow internal channel. Its anterior end is narrowed, the posterior end has a protrusion. in the form of a ring and an expanded channel opening for connection to the syringe cannula. The catheter is inserted by hand into the mare's vagina. With your index finger, find the mouth of the cervix and, under finger control, advance the catheter into the cervical canal to a depth of 10-12 cm. A syringe with sperm is attached to the catheter and by pressing the piston, the sperm is injected into the uterus.

With visual This method uses a glass or ebonite catheter 50 cm long, a syringe and a vaginal speculum. Disinfected vaginal the speculum is inserted into the genital tract and placed so that the cervix is ​​clearly visible. Under vision control nia the catheter is directed through a speculum into the cervical canal. After insertion into the uterus, a syringe is attached to the glass catheter using a rubber coupling. An ebonite catheter with a syringe cannula is connected in advance using a metal clamp with a rubber gasket, the mare is brought into a special machine and fixed. Calm animals are held by the reins and their front leg is raised so that they cannot hit the inseminator. The groom bandages the mare's tail and takes it to the side: he washes the vulva with warm water and wipes it dry with cotton wool. After this, the insemination technician, with the participation of an assistant who hands him an insemination instrument, inseminates the mare. For Insemination of one animal requires from 20 to 40 ml of sperm. Large, old and pregnant mares should be given the maximum dose of semen.

Optimal time for insemination. In mares, heat lasts much longer than in other animals, on average 5 - 6 days. Throughout this period, the degree of manifestation of its symptoms progressively increases.