Functional disorders of the ovaries of cows and heifers. Distribution of ovarian hypofunction in cows. Preparatory measures for local treatment
Ovarian hypofunction- this is a decrease in their hormonal activity, causing a weakening of the clinical manifestations of signs of the sexual cycle. Anaphrodisia- absence of clinical manifestations of signs of the sexual cycle for a long period, due to functional disorders or morphological changes in the ovaries.
Etiology and pathogenesis. The most common causes of G. and A. are insufficient and inadequate feeding, unsatisfactory living conditions - placing them in rooms with high air humidity, low temperature and the presence of constant drafts, lack of active exercise, insufficient exposure to sunlight, excessive exploitation of working animals . These causes cause certain metabolic disorders and disorders of the hypothalamic-pituitary regulation of ovarian function.
As a result of exposure to unfavorable factors, the process of growth and maturation of follicles slows down. The living body is not saturated with the necessary amount of estrogen hormones, therefore morphological changes characteristic of a normal sexual cycle do not occur in the endometrium. Signs of estrus - estrus, heat and sexual arousal - occur in a mild or subclinical form.
The degree of functional disorder is most often in direct relationship with the nature, strength and duration of the influence of the negative agent on the body. With mild and short-term exposure to the agent, ovarian cancer usually develops; with its strong influence, which can cause some structural changes in the ovaries, A usually develops. With a long course of the process in the ovaries and the surrounding area. The uterus develops degenerative changes in structural elements.
Symptoms. With G., estrus, heat, and sexual arousal appear in a mild form, and the intervals between estrus lengthen significantly, i.e. the rhythm of the sexual cycle is disrupted.
A rectal examination reveals weak rigidity of the uterus or it cannot be detected at all. The ovaries are slightly reduced in volume, sometimes it is possible to identify the corpus luteum.
A characteristic sign of A. is a prolonged absence of estrus, possibly severe emaciation or obesity.
With rectal examination It is established that there is no uterine rigidity, the consistency of the ovaries is homogeneous, and they are reduced in volume. No corpus luteum or follicles are detected.
Research biopsied endometrium allows us to determine the nature and depth of changes in the ovaries. Insufficient intake of estrogen hormones into the blood without subsequent progesterone influence causes characteristic changes in the endometrium. The endometrium is covered with multirow epithelium. The glandular and integumentary epithelium is low and in a state of mild proliferation. Signs of gland secretion are not detected, their lumens are narrowed. The stromal cells of the glands are closely located. Certain areas of the endometrial stroma undergo fibrosis and hyalinosis, the walls of the vessels are thickened, their lumen is narrowed.
Diagnosis. G. and A. of nutritional origin are diagnosed on the basis of a thorough analysis of diets, laboratory results. research food and blood of the living. For diagnostic purposes, in addition to general clinical and gynecological examination, an endometrial biopsy is performed, if possible.
Forecast. With G. and A. ovaries of functional origin, occurring without degenerative changes in the ovaries and uterus, the prognosis is favorable. Typically, the ability to fertilize is restored relatively quickly. after eliminating the causes of the disease. If there are structural changes in the endometrium and ovaries, then the restoration process. the rhythm of sexual cycles is significantly delayed, and the living organism is fertilized only after the indicated changes disappear.
Treatment. In case of G, caused by nutritional reasons and poor living conditions, it is necessary, first of all, to introduce into the diet food with a sufficient content of nutrients, vitamins, macro- and microelements necessary for the body. The diet should be individualized for highly productive animals, taking into account their body’s needs for various nutrients. It is also necessary to eliminate the identified violations in the keeping of animals. At the same time, treatment is prescribed, which should help normalize the regulatory mechanism of the sexual cycle, stimulate the growth and maturation of follicles, and form a normal rhythm of sexual cycles with their clinical manifestation.
FFA or SCFA is widely used to stimulate reproductive function. These drugs are administered to cows at a dose of 2.5-3 thousand units, to first-calf heifers - at a dose of 2.5 thousand units, and to heifers - 1.5-2 thousand units.
FFA or SCFA is recommended to be administered in combination with neurotropic drugs (0.1% carbacholine, 0.5% proserine and 1% furamone). A very good stimulating effect on ovarian function is observed with the introduction of gravohormone. Gravohormone is a gonadotropic drug purified from proteins. The drug is administered subcutaneously in the neck area at a dose of 9 units per 1 kg of body weight once 3-4 days before the onset of estrus. Various tissue preparations have been successfully used to stimulate estrus. A good therapeutic effect is observed with three or four injections of folliculin, 20 thousand units each. Massage of the uterus and ovaries through the rectum is very effective for ovarian hypofunction. It is produced once a day for a period of time. 5-6 minutes, repeating every 1-2 days. Sometimes massage is alternated with vaginal irrigation with hot water (45°C) or 1% sodium chloride solution. Massage and vaginal irrigation significantly increase the circulation of blood and lymph in the genital organs, cause irritation of nerve endings, causing the normalization of metabolic processes in these tissues, and lead to the restoration of ovarian function.
34. Follicularcysts- thin-walled, spherical, fluctuating formations. Externally, they differ from mature follicles only in that they are larger in size. The contents of young follicular cysts are straw-yellow or yellow liquid, rich in estrogens. Later, due to degeneration of the cellular elements of the cyst wall and, to a certain extent, their lutenination, the concentration of estrogen in the contents of the cysts sharply decreases. With follicular cysts, especially with their long-term development, endocrine function is disrupted, which is accompanied by endometrial hyperplasia.
LYuT New cysts differ from follicular cysts only in that their inner surface is partially or entirely lined with a layer of luteal tissue, the thickness of which varies from barely noticeable to 0.5 cm. Therefore, luteinization of individual sections of the cyst wall is not always accompanied by thickening its walls. The sizes of luteal cysts, like follicular ones, vary from 2.0 to 4.5 cm. The contents of luteal cysts are yellow or intensely yellow liquid rich in progesterone. Luteal cysts, as a rule, in their physiological effect on the body, including the uterus, do not differ from the corpus luteum of the reproductive cycle and do not affect its duration. Cysts are most often single, less often multiple. In these cases, several follicles are found in one or both ovaries
polar or simultaneously follicular and luteal cysts, which are at different stages of development or regression. Often in cows, a cyst and a corpus luteum are found simultaneously, located in one or both ovaries. This indicates restoration of ovarian function. Ovarian cysts are dynamic formations that retain their hormonal activity for a certain time. Then they become hormonally inactive and undergo reverse development. Most cows recover without treatment. The interval from cyst formation to recovery varies from 13 to 28 days. However, in 35 - 40% of cases, anovulatory cycles reappear and cysts form.
Etiology. Cysts should be considered as a sign of various forms of infertility, in which disorders of neurohumoral processes in the body occur. Most often, cysts in dairy cows form in the first 60 days after birth, especially in animals that had complications during the birth and postpartum periods. Often the formation of cysts is promoted by inflammatory processes in the uterus, less often in the ovaries and oviducts. Ovarian cysts in cows can occur at any time of the year and at any age, but most often they are recorded in winter in cows of the 3rd-7th lactation. Errors in feeding and husbandry and exploitation of animals are very significant predisposing factors in the appearance of cysts. In animals kept in stalls, with limited exercise, when fed feed poor in microelements and vitamins (iodine, carotene), ovarian cysts are much more common. Their occurrence is facilitated by missed sexual cycles and delay timing of insemination of cows after birth.
Cysts often occur when using hormonal drugs (FFA, estrogens, progesterone, etc.).
Clinical signs. At the beginning, the onset of the disease does not manifest itself clearly enough, since the formation of cysts during this period, as a rule, is not accompanied by a disorder of the reproductive cycle and cows often recover without treatment. In cases of deep disorders in the neuroendocrine system that regulates the hormonal and generative functions of the ovaries, multiple formations are observed in animals cysts, which is accompanied by irregular sexual cycles, or anaphrodisia, in which the development of cysts occurs without the phenomenon of sexual heat. In some animals, relaxation of the sacrosciatic ligaments is noted. In animals, prolonged development of cysts can lead to nymphomania or virilism. Nymphomania- a neuroendocrine disorder in which sexual estrus occurs over a short period of time and lasts for several days in the presence of strong signs of estrus and sexual arousal. When jumping on other living things and especially when lying down, copious secretion of mucus is observed from the genitals, sometimes containing streaks of pus. Near nymphomaniacs, other living things with signs of the stage of arousal usually gather.
Treatment. First of all, create normal conditions for living, feeding and exploitation. Treatment is aimed at stimulating ovulation or luteinization of the cyst. Communication of cows with vasectomized test bulls in combination with active exercise and insolation works well. From the city. drugs, it is recommended to use human chorionic gonadotropin, gravohormone, serum gonadotropin and gonadotropin-releasing hormone, which regulates the secretion of endogenous LH.
MINISTRY OF AGRICULTURE OF THE RUSSIAN FEDERATION
FEDERAL STATE EDUCATIONAL INSTITUTION
HIGHER PROFESSIONAL EDUCATION
IZHEVSK STATE AGRICULTURAL ACADEMY
Department of Internal Medicine and Surgery
COURSE WORK
Topic: Therapeutic and preventive measures for ovarian hypofunction in cows
Checked by: Associate Professor, Ph.D.
Davydov A.A.
Completed by: student 841 gr.
Semakina E.Yu.
Izhevsk 2008
CONTENT
INTRODUCTION………………………………………………………………………..3
- LITERATURE REVIEW…………………………………………………………….4
1.2. PHYSIOLOGICAL BASES AND REGULATION OF REPRODUCTIVE FUNCTION IN COWS………………………...…10
2. OVARIAN HYPOFUNCTION………………………………………………………......... 12
2.1. Reasons…………………………………………… ……………….12
2.2.Pathogenesis…………………………………………… ……………………13
2.3. Signs……………………………………………………………… ………………….14 2.4. Diagnosis……………………………………………………………… …… ……………...…14
2.5.Forecast………………………………………………… …………….…..15
2.6.Treatment………………………………………………… ………………………15
2.7. Prevention…………………………………… ………………………26
CONCLUSIONS AND SUGGESTIONS……………………………………………………27
LIST OF REFERENCES USED…………………………………...30
INTRODUCTION
The successful solution of the food program in our country largely depends on the development and accelerated implementation of effective methods for intensifying livestock production and, to a large extent, on measures to prevent infertility and barrenness in cattle. However, over the past 5-7 years, due to various objective and subjective factors, the yield of calves per 100 cows in most farms in our country does not exceed 75-77 calves, which is completely insufficient.
It is known that the economic damage caused by infertility exceeds the losses caused to livestock by all animal diseases combined. Losses from it consist of loss of offspring, milk, premature culling of infertile animals and unproductive costs for their maintenance, feeding and treatment.
Therefore, one of the main tasks in livestock farming is the intensive use of breeding stock and the annual production of at least 90-95 calves per 100 cows.
1. LITERATURE REVIEW
1.1. BRIEF INFORMATION ON THE ANATOMY AND PHYSIOLOGY OF THE COW'S GENITAL SYSTEM
The genital organs of cows and heifers are divided into external and internal. The external ones include the vulva, consisting of two labia and the genital fissure and the vestibule of the vagina with the clitoris, and the internal ones include the vagina, cervix, oviducts and ovaries. The uterus consists of a body and two horns that curl downward. Thin, winding oviducts (oviducts) extend from the tops of the uterine horns, which expand at the ends in the form of a funnel and are adjacent to the ovaries.
The length of the vestibule of the vagina is 10-12 cm, the vagina 25-28 cm, the cervix 10-12 cm, the body of the uterus 1.5-2 cm, the horns 15-20 cm and the oviducts 20-25 cm. In the cervical canal of cows there are 3-4 ring folds, the tops or ridges of which are directed towards the vagina. The cervical canal in cows and heifers is usually tightly closed and contains a small amount of dense mucus that performs a protective function. The cervical canal opens during hunting and childbirth. In heifers and young cows, the cervix and horns of the uterus are located in the pelvic cavity. In older cows, the size of the uterus is larger and its horns partially descend into the abdominal cavity. The lining of the uterus is called the endometrium. On its surface, ruminants have special formations called caruncles. On average, cows have 100-120 caruncles. During pregnancy they increase to the size of a chicken egg. On the surface of each caruncle there are depressions (crypts) that connect to the villi of the cotyledons located on the outer shell of the fruit. The caruncles represent the maternal part of the placenta, and the cotyledons (special clusters of villi) represent the baby part of the placenta. One maternal caruncle and one fetal cotyledon together form the placenta. The size of the placenta is one of the signs by which the age of the fetus or the month of pregnancy is judged. In the mucous membrane of the uterine horns there are numerous uterine glands that open on its entire surface, with the exception of the caruncles. These glands in pregnant cows form and secrete the so-called royal jelly, which serves as nutritional material for embryos in the first month of their intrauterine life. It reaches the embryo through its outer layer of cells (trophoblast) by diffusion and osmosis. Atrophy of the uterine glands or their hypofunction is one of the main reasons for the early death of embryos and unsuccessful insemination of cows.
The vestibule of the vagina and the vagina itself serve as organs of copulation in cows during their natural insemination and as a receiving site for sperm secreted by the sire in the terminal part of the vagina near the cervix. During artificial insemination, a vaginal speculum, catheter syringes, a hand with a device, or pipettes are inserted into the vagina for subsequent injection of sperm into the cervical canal.
The cervix serves as the site for the introduction of sperm during artificial insemination and the passage of sperm from the vagina into the uterus during natural insemination. In addition, the cervical canal performs an extremely important protective function. Mucus, produced by epithelial cells of the mucous membrane and secreted out by cows during estrus and heat, has the ability to kill many types of microbes and weak sperm that enter the cervical canal during insemination. Because of this, the bactericidal nature of mucus prevents the penetration of microbes into the horns of the uterus, protecting it from the development of the inflammatory process, which, in turn, is necessary for the normal development of embryos.
The uterus is the place for the growth and development of the fetus and its membranes throughout the entire intrauterine period. This is where the embryos attach to the uterine wall and the placenta develops. Most often, fetuses develop in the right horn of the uterus.
The oviducts are the site of fertilization; it is here, in the upper third of the oviducts, that the meeting of the egg and sperm occurs, the penetration of sperm into the egg, the fusion of the nuclei of the head of the sperm and the egg, the formation of a zygote (the initial stage of embryo development) and its advancement into the uterine horn.
The ovaries of cows are oval in shape, their length is 3-4 cm, thickness is 1.5-2 cm, they are most often located in the pelvic cavity near the tops of the uterine horns. The ovaries perform two important functions - generative (development of egg cells) and hormonal. They contain the growth, development and maturation of egg cells and follicles, as well as the formation and release into the blood of female sex hormones - folliculin and progesterone, which have a significant impact on the functional state of the entire body and the uterus of female farm animals. Secretion of folliculin occurs in the follicles, and progesterone in the corpus luteum, which is formed after ovulation at the site of the follicle from which the egg cell was released.
Sexual function in heifers and bulls manifests itself after reaching puberty, which occurs at 7-8 months of age. At puberty, full-fledged germ cells and hormones are formed in the gonads (ovaries and testes), and animals become capable of fertilization. However, insemination of heifers is carried out only upon reaching body maturity (physiological maturity), which occurs in them at 15-18 months of age. The live weight of heifers at this time should be 70% of the average live weight of adult cows (340-350 kg).
It has been established that reproductive cycles in cows can be complete or incomplete. A full-fledged cycle is one in which the animal exhibits all four phenomena (estrus, general reaction, heat and ovulation) during the excitation stage. If any of the phenomena does not manifest itself, then the sexual cycles will be incomplete. There are four of them: aestrous (without flow), areactive (without sexual arousal), alibid (without hunting) and anovulatory (without ovulation).
Incomplete sexual cycles due to various reasons are often observed in cows and are the cause of infertility. They are especially dangerous during artificial insemination. For example, during anestrous and areactive cycles, it is difficult for the artificial insemination technician to determine the time to inseminate animals. Even with timely insemination, it is difficult for sperm to move into the uterus during the aestrous cycle, since the mucus in the cervical canal acquires a denser consistency and an acidic reaction, causing the sperm to lose motor ability.
There is evidence that during normal estrus, mucus fibers (mucin protein molecules) in the cervical canal are located in parallel and this facilitates the movement of sperm into the horns of the uterus. During hunting, antiperistaltic contractions of muscle fibers are observed in the uterine horns, which play a major role in the movement of sperm along its horns. During alibid cycles, muscle contractions in the uterine horns will be insufficient to ensure the movement of sperm to the oviducts. It goes without saying that fertilization will be impossible even during anovulatory sexual cycles.
It should be noted that many artificial insemination technicians, milkmaids and specialists often regard estrus and heat in cows as equivalent phenomena and do not make a clear distinction between them. It is not right. Hunting is a positive sexual response of a female to a male. It can be established in cows and other animals only with the help of male testers.
The direct regulation of sexual cyclicity in farm animals is carried out through a neurohormonal pathway. A variety of environmental stimuli (olfactory, visual, auditory, tactile, etc.) are perceived by the cerebral cortex, which sends corresponding impulses to the hypothalamus, which is the control center of sexual function. The latter is located in the hypothalamic part of the diencephalon and secretes neurosecretion (gonadotropin, a hormone-releasing factor, or releasing factor), under the influence of which in the anterior lobe of the pituitary gland the formation and release of three gonadotropic hormones into the blood occurs: follicle-stimulating hormone (FSH-follitropin), luteinizing hormone (LH- lutropin) and luteotropic (LTG), also known as lactogenic hormone or prolactin. Under the influence of follitropin, follicles mature in the ovaries and egg cells develop in them. If the pituitary gland secretes lutropin, then ovulation and the formation of the corpus luteum occur. Prolactin controls lactation, maternal instinct and supports the secretion of follitropin and lutropin.
Under the influence of gonadotropic hormones of the anterior pituitary gland, folliculin (follicle hormone) or progesterone (corpus luteum hormone) is formed and released into the blood in the ovaries, which have a decisive influence on the morphofunctional state of the uterine mucosa. Under the influence of folliculin, proliferative processes occur in the endometrium, expressed in cell proliferation, the formation of uterine glands and capillaries, and under the influence of progesterone, secretory processes occur in which royal jelly, necessary for the development of embryos, is formed in the uterine glands and released onto the surface of the uterine mucosa. The normal course of proliferative and secretory processes provides the necessary conditions for the development of embryos in the uterine cavity.
Folliculin is an estrogenic hormone (which causes estrus) and consists of three fractions - estrone, estriol and estradiol. The most active fraction of the estrogen hormone is estradiol. The hormones vasopressin and oxytocin are deposited in the posterior lobe of the pituitary gland, which have vasoconstrictor, antidiuretic and stimulating uterine contractile effects. The posterior lobe of the pituitary gland secretes the hormone relaxin, which causes relaxation of the pelvic ligaments in animals before birth. Oxytocin is released into the blood and enters the mammary gland every time cows are milked. At the same time, it stimulates the contractile function of the myoepithelial cells surrounding the alveoli and regulates milk flow.
In addition to gonadotropic hormones, three general-action hormones related to the regulation of reproductive function are formed in the anterior lobe of the pituitary gland. These include growth hormone (somatotropin), adrenocorticotropic hormone (ACTH), which regulates adrenal function, and thyroid-stimulating hormone, which regulates thyroid function.
It has been established that gonadotropic hormones of the pituitary gland interact with ovarian hormones (female sex hormones) according to the principle of direct and feedback (plus or minus interaction). Follitropin has a direct stimulating effect on the growth of follicles and the formation of the hormone folliculin in them. Upon reaching the peak of folliculin secretion, it has an inhibitory effect on the secretion of follitropin in the pituitary gland and a stimulating effect on the secretion of lutropin, which is responsible for ovulation. Lutropin stimulates the formation of the corpus luteum and the secretion of progesterone. After reaching the peak of progesterone secretion, it inhibits the secretion of lutropin and stimulates the secretion of follitropin in the pituitary gland. Similar changes in the activity of the pituitary gland and ovaries are observed with each sexual cycle.
In addition to the hormones of the hypothalamus, pituitary gland and ovaries, hormones of the thyroid gland and adrenal glands take part in the regulation of sexual function. The posterior lobe of the pituitary gland releases oxytocin into the blood, which regulates the contractile function of the uterus.
1.2. PHYSIOLOGICAL BASES AND REGULATION OF REPRODUCTIVE FUNCTION IN COWS
Research by veterinary obstetricians has established that in cows under normal living conditions, the involution of the reproductive system after birth ends within 15-20 days. Therefore, the fertility rate of cows inseminated in the first month after birth is quite high on many farms. Based on this, scientists recommend planning to produce offspring from cows every 10.5 months, or 315 days. This intercalving period consists of 285 days of fertilization and 30 days of the postpartum period, during which cows come into heat and are inseminated. The fertility potential of cows is determined as follows. The number of cows on a farm or farm is multiplied by the number of days in a year and the total number of cow days is obtained. For example: 100 cows x 365 = 36,500 cow days. This number is then divided by 315 to get 115.6 calves per 100 cows.
However, the conditions for feeding and keeping animals are not yet sufficient and adequate in all farms. This leads to the fact that in many cows, uterine involution does not end within 30 days after birth and their first heat appears at a later date. In this regard, it is advisable to consider both a 30-day service period and a 60-day one as normal. In the second case, the intervals between calvings will be not 315, but 345 days, and from every 100 cows during the year, you can plan to produce 105 calves (100 x 365 = 36,500 cow days; 36,500: 345 = 105 calves).
When analyzing the state of work on herd reproduction on farms to determine the potential number of lost calves and the amount of loss, the total number of days of infertility in cows and heifers should be taken into account. For this purpose, the duration of the intervals between calvings in cows is determined, the value of the normal calving interval (315 days) is subtracted from them, the difference is recorded in the column “days of infertility”, they are summed up, divided by 315 (or 345) and thus find out the number of lost calves (see Table 1). If the calving interval (CAI) of an animal is less than 315, then a dash is added in the “days of infertility” column. For heifers, the IMI value is taken from the time between the first scheduled insemination and calving dates.
Table. 1Taking into account calving intervals and days of infertility
When determining the economic damage from infertility, they mainly take into account the cost of lost offspring and milk. At the same time, the cost of a calf at birth should be equal to the cost of not 1.5 c. milk, as required by official reporting, but to 3.6 c., because the cost of feed spent on the intrauterine formation of a calf, according to the staff of the Department of Obstetrics of the Kazan Veterinary Institute, is equal to the cost of 3.6 c. milk. Thus, one newborn calf, taking into account the selling price of 1 kg of milk at 4 rubles, costs 1,440 rubles.
It has been established that for every day of infertility, a cow loses 5 liters of milk, or 20 rubles, to the farm. Consequently, the losses from keeping each infertile cow for a year amount to 7,300 rubles. The total damage from the loss of the calf and milk will be 8,740 rubles, not counting the costs of care and treatment. Therefore, the prevention of infertility and barrenness in cows is one of the most important tasks in animal husbandry.
2. OVARIAN HYPOFUNCTION (Hurofuncto ovario)
The disease is characterized by impaired development and maturation of follicles, ovulation and formation of the corpus luteum, in which defective sexual cycles (areactive, aestrous, alibid, anovulatory) or anaphrodisia are observed.
More often, ovarian hypofunction is diagnosed in first-calf heifers.
Hypofunction of the ovaries should be understood as a condition in which, as a result of unbalanced feeding (especially carotene), unfavorable living conditions and under the influence of other factors, the growth, development, maturation and timely ovulation of follicles is disrupted. At the same time, the level of vitamin A in the blood sharply decreases, collagenization of the tissues of the gonads and a weakening of redox reactions in the endometrium are observed, accompanied by low contractility of the uterus. As a result, sexual cyclicity is disrupted or stops altogether; unfavorable conditions are created in the genital organs for the advancement of sperm, implantation of the zygote and the further development of the embryo, which in most cases is manifested by infertility of animals.
2.1. Reasons. Theoretical data on the etiology of ovarian dysfunction in cows indicate a wide and varied range of causes of its occurrence. In particular, three groups of factors are distinguished: endocrine, stress, and nutrition. The concept that long-term ovarian dysfunction after calving is a protective reaction of the body against the next pregnancy due to improper feeding, maintenance and exploitation deserves attention. When carrying a fetus under unfavorable conditions, the cow’s body gives it the main supply of energy and plastic materials. After the birth of a calf, neurohumoral changes occur aimed at reducing ovarian function and persistence of the corpus luteum, which, in turn, is necessary to preserve vital materials during the critical postpartum period.
The immediate cause of hypofunction is a decrease in the synthesis of gonadotropic hormones of the pituitary gland and a weakening of the ovarian response to their action. Corticosteroid hormones have a significant effect on ovarian dysfunction, the synthesis of which increases under various stress effects on animals. On rectal examination, the ovaries are small (about the size of a bean), but can increase in size and have a smooth surface. In this case, cows do not have sexual cycles and persistent infertility occurs.
Also, hypofunction of the ovaries can occur in animals as a result of insufficient and inadequate feeding (protein-carbohydrate starvation, deficiency of minerals in the diet, vitamins), which contributes to its occurrence in the second half of winter housing, unsatisfactory living conditions (dampness, insufficient illumination of premises against the background of lack of active exercise). Hypofunction of the ovaries occurs in cows with high milk production, inflammation of the genital organs, as well as pathology of the gastrointestinal tract (osteomalacia, ketosis, etc.).
In some cases, ovarian hypofunction also occurs as a result of pathological childbirth, atony of the proventriculus, traumatic reticulitis, untimely launch, and physiological old age.
2.2.Pathogenesis. Sexual function in the animal's body is controlled by the hypothalamus, which produces specific substances - releasing factors that stimulate or inhibit the function of the pituitary gland. The pituitary gland itself, or rather its anterior lobe, controls ovarian function by secreting follicle-stimulating (follitropin) and luteinizing (lutropin) hormones. Therefore, when the hypothalamic-pituitary system is disrupted in the ovaries, the number of maturing follicles decreases, and then their growth stops.
With ovarian hypofunction in cows, the histogenesis of primordial follicles does not stop. However, secondary follicles are almost absent; only single follicles in the atresia stage are found. Histological and histochemical studies have established that with ovarian hypofunction, dystrophic processes occur in the tissues of the gonads and endometrium, which are based on metabolic disorders.
2.3. Signs. The general condition of the animals is satisfactory. If the generative function of the ovaries is impaired, when the level of sex hormones and gonadotropins in the body is low, the stage of arousal of the sexual cycle does not appear clearly. The follicle does not reach maturity and undergoes atresia or then develops into a cyst (anovulatory sexual cycle). Ovulation abnormalities are caused by insufficient secretion of luteinizing hormone and prolactin by the pituitary gland. The egg dies. A rectal examination reveals a follicle with a flaccid wall in the ovary. When pressed, it breaks. The ovary may decrease in size, and sometimes even become enlarged (hyperplasia) due to the presence of non-developing primordial (primary) follicles in the cortical zone.
Ovarian hypofunction is accompanied by significant changes in the hormonal status of the female body. He experiences a deficiency of follicle-stimulating hormone, and accordingly the follicular apparatus
the ovaries do not produce sex hormones (estrogens: estradiol, estrone, estriol). The cortical zone of the ovaries is replaced by connective tissue. In animals, anaphrodisia is clinically manifested. Rectal examination
a decrease in the size of the ovaries (hypoplosia) is established. In first-calf heifers, they sometimes reach the size of a pea, i.e., even their atrophy occurs. Pathological examination reveals an increased amount of connective tissue in the cortical zone of the ovaries, which indicates sclerosis of the gonads. The ovaries thicken, become hard, and their surface is uneven.
The configuration of the ovaries varies: from bean-shaped they become elongated, flat, like a convex disk the size of 1-2 Soviet kopecks.
2.4.Diagnosis. When making a diagnosis, anamnestic data, data from primary zootechnical records, and general clinical and gynecological examination of the animal are taken into account. The information obtained can be confirmed by histological and histochemical examination of biopsied uterine material.
2.5. The prognosis depends on the nature and duration of action of the etiological factor. If the etiological factor does not last long and morphological changes have not yet occurred in the gonads, the prognosis is favorable and sexual function is restored soon after the main cause is eliminated. This happens more often in young animals. When ovarian hypofunction occurs under the influence of a long-term etiological factor and deep dystrophic changes occur in the reproductive area (ovaries, uterus), the animals become unsuitable for reproduction and are subject to culling.
2.6. Treatment. In case of ovarian hypofunction, it is necessary to eliminate errors in feeding animals, organize daily active exercise and use drugs that stimulate ovarian function. When the generative function of the gonads is impaired, sometimes one improvement in the care of cows and a single massage of the genitals is enough for the females to show a full stage of arousal of the sexual cycle. The duration of the massage session is up to 5 minutes. Massage of the genital organs increases their blood circulation, which is an important point in the competition of blood supply to the mammary gland in highly productive cows. The ovaries are massaged by lightly kneading them with the crumbs of the fingers, and the uterus is massaged by stroking from front to back, pulling into the pelvic cavity, lightly squeezing with the hand and kneading the horns.
If the hormonal function of the ovaries is disrupted, great efforts are required to restore the reproductive function of females with ovarian hypofunction. Along with improving feeding and organizing active exercise, genital massage can be used. The duration of the massage is 5 minutes with an interval of 4 – 5 days. More frequent massage may damage the rectal mucosa, causing bleeding.
To stimulate ovarian function, it is recommended to use gonadotropins containing follicle-stimulating and luteinizing hormones in combination with neurotropic drugs: 0.5% solution of proserin, 0.1% solution of carbocholine in a dose of 2-3 ml, and after 3- 5 days FFA or its derivatives.
Vitamin preparations are prescribed: trivit, tetravit in a dose of 7-10 ml every 7-10 days 2-3 times.
Valyushkin K.D. and Medvedev G.F. To stimulate sexual function, it is recommended to use massage of the ovaries and uterus, physiotherapy techniques, hormonal and pharmacological drugs, vitamins in their pure form, in combination with each other or with hormonal and neurotropic drugs.
Of the hormonal drugs, the most widely used are FFA and SCFA, as well as the gravohormone developed on their basis. G.A. Cheremisinov believes that the direct sexual cycle in animals occurs in the first 6 days after the administration of FFA or SCFA as a result of the direct effect of the drug on the ovary, and the induced one occurs after 15-20 days due to the influence of hormones on the hypothalamic-pituitary system. Therefore, FFA can be reintroduced no earlier than after 3 weeks.
When treating first-calf cows with ovarian hypofunction, a good result was obtained using a 0.1% solution of carbocholine in a dose of 2 ml and 2000 IU of SCFA against the background of three preliminary injections of vitamin E. This increased the fertility of treated animals by 25.4% (Valyushkin K. D., Medvedev G.F.).
Vitamin A oil concentrate, injected intramuscularly at a dose of 200 thousand IU per 100 kg of body weight three times with an interval of 10 days, leads to normalization of the acid capacity of the blood, the disappearance of collagenization phenomena in the ovaries and uterus and the occurrence of morphological changes corresponding to the shift in sexual cyclicity. In the ovaries and endometrium of treated animals, glycogen, acid and alkaline phosphatases accumulate. The fertility rate of cows increases by 16.5%.
Vitamin E, injected intramuscularly into infertile cows with ovarian hypofunction three times with an interval of 5 days at a dose of 200 mg per 100 kg of weight, causes morphological and histochemical changes in their genitals, similar to those that occur under the influence of vitamin A, only less pronounced, and increases the fertility of treated animals is 12.1%.
The combined use of vitamins A and E for ovarian hypofunction is more effective than using them separately and is even more effective when administered with 1-2 ml of folliculin.
Yu.E. Kharlamov, S.N. Khilkevich and A.M. Chomaev carried out biotechnical measures for ovarian dysfunction in cows, so they tested two domestic drugs: surfagon and mepregnol acetate (MAB).
Surfagon, an analogue of natural GnRH (gonadotropic releasing hormone), the synthesis of which was developed in the peptide synthesis laboratory of the All-Russian Cardiology Research Center, is tens of times more active than similar foreign drugs. After its intramuscular injection, the concentration of LH (luteinizing hormone) is attempted within 0.3 hours, reaching peak values after 1.9 hours.
In large doses, surfagon is recommended for the treatment and prevention of ovarian hypofunction in animals and humans, and in small doses for the treatment of anovulatory conditions and stimulation of ovulation.
Mepregnol acetate (MAB), the synthesis of which was developed by the Bioengineering Center, is currently being tested under production conditions. The first results showed that MAB for the prevention and treatment of infertility in farm animals is much more effective than some similar drugs.
The use of bioregulators for functional disorders of the ovaries is more effective with simultaneous effects on the uterus, since ovarian pathology is often accompanied by latent inflammation of the endometrium (V. Madison, 2001).
Considering the above, the authors studied the effect of surfagon on ovarian hypofunction in cows. For this purpose, 80 dairy cows of the black-and-white breed with the initial form of this pathology were selected, from which four groups were formed according to the principle of analogues. The average milk yield per cow was 3-5 thousand kg of milk per year. Feeding and use of animals during the experiments complied with the standards. Animals were inseminated using the rectocervical method, once and twice frozen and thawed sperm (pellets).
Cows of the first group, which were administered HSFA and estufalan, served as a control; the second - surfagon against the background of gestogenization with progesterone, and before insemination - estufalan at a dose of 500 mcg; the third and fourth - similar biological products, but instead of progesterone they injected MAB. In the fourth group, before the start of treatment with hormonal drugs, sanitation of the internal genital organs was carried out for 5-8 days using transrectal laser exposure in the following mode: exposure 1-2 minutes, number of oscillations 64 or 512 Hz. For this purpose, a laser device “RIKTA-01 (M2V)” was used. When analyzing the indicators, we paid attention to the comparative effectiveness of progesterone and MAB, and also studied the possibility of replacing GSFA (used for the treatment of hypofunction) with the surfagon-gest complex
etc.................
Neurohumoral regulation of reproductive function in cows
Control over the physiological mechanisms of controlling the reproductive function of females is carried out by the nervous and endocrine systems of the body, which closely interact with each other. Various external stimuli act on the senses (touch, smell, vision), which send analyzer signals to the cerebral cortex. From here, nerve impulses are transmitted to the hypothalamus (subthalamus region of the diencephalon, which, through neurosecretion or gonadotropin-releasing hormones (Gn-R-G), stimulates the pituitary gland to release hormones that affect the reproductive system of the animal (N. I. Polyantsev, 1986; I I. Rodin et al. 1974) It has now been established that the hypothalamus is the control center for the formation of various hormones through the transfer of short-distance neurohormonal substances through the pituitary system to the sinuses of the anterior pituitary gland (M. I. Prokofiev (1983)). However, there is another way for neurosecrets to reach the endocrine glands - this is a direct connection between the hypothalamus and the ovaries, bypassing the pituitary gland (B.V. Aleshin, 1978).
The anterior lobe of the pituitary gland secretes three hormones: follicle-stimulating hormone (FSH), luteinizing hormone (LH), luteotropic hormone (LTG) or prolactin. It has been established that FSH promotes the growth and maturation of follicles. The peak of FSH activity is observed at a low concentration of LH, which stimulates ovulation and the formation of the corpus luteum at the site of the ovulated follicle. LTG is necessary for the attachment of the embryo to the wall of the uterus, the normal course of pregnancy, stimulation of the activity of the mammary gland and the secretion of progesterone by the corpus luteum. The posterior lobe of the pituitary gland does not secrete hormones, but is connected with the supraoptic and paraventricular nuclei of the hypothalamus, where the formation of the neurosecretion oxytocin occurs, which enters the blood and contracts the smooth muscles of the uterus and oviducts (N. I. Polyantsev 1986, I. I. Rodin et al., 1974).
The hypothalamic-pituitary-ovarian system is a strictly coordinated mechanism that has direct and feedback connections. The essence of negative feedback is to block the synthesis and entry into the blood of any gonadotropic hormone when the level of a particular steroid hormone reaches a certain value. Chemoreceptors of the higher and lower hypothalamic centers sense the increased production of estrogen and transmit information to the ovary through the pituitary gland. With positive feedback, steroid-sensitive cells of the higher center of the hypothalamus increase the activity of tubular oral neurons of the hypothalamus, which affect the secretion of gonadotropins, if the level of steroid hormones in the blood is not high (N. I. Polyantsev, 1986, I. I. Rodin et al., 1974).
The main hormones involved in the reproductive function of females are FSH and LH, secreted by the anterior pituitary gland. Their ratio at different periods of the sexual cycle fluctuates and depends on many factors. Maturation of follicles, stimulation of mitosis, and formation of follicular fluid occur under the influence of FSH. The peak of FSH is observed after 13 days of the sexual cycle, at the same time there is a decrease in progesterone levels. The second FSH peak was observed 28 hours after the preovulatory luteinizing hormone surge. The ratio of androgens and estrogens found in the follicular fluid changes in favor of the latter as the follicle matures, which leads to the release of LH (L. K. Ernst, N. I. Sergeev 1989). During the luteal phase of the sexual cycle, the concentration of LH in the blood ranges from 1.2 to 4 mg/kg. The peak of LH is observed before ovulation and its concentration reaches 50-60 mg/kg, then a sharp decrease in its level occurs. Ovulation occurs 25-30 hours after the start of the hunt. According to some researchers, secondary LH peaks occur between days 8 and 13 of the cycle and 2-5 days before the start of heat.
The female's ovaries produce steroid hormones - estrogens (estrone, estradiol, estriol) and progesterone. Estrogens are synthesized in the follicle wall. The peak concentration of estrogen is observed during the hunting period. Functionally, they are responsible for the animal’s estrus and sexual estrus, and also influence the formation of antibacterial acidic mucopolysaccharides and specific hormone-binding proteins. The corpus luteum of the ovary, the adrenal cortex, and the placenta of pregnant cows are a source of progesterone, which inhibits the growth of follicles, promotes the attachment of the embryo to the wall of the uterus, weakens or turns off the effect of oxytocin and various biologically active substances (N. I. Polyantsev, 1986). An important role in the body is played by prostaglandins, the “progenitors” of which are unsaturated fatty acids (arachidonic, linoleic, linolenic). Prostaglandin F2-alpha is formed in the membranes of epithelial cells of the uterine mucosa. Prostaglandin type P stimulates, and type E inhibits uterine contraction. Their release into the blood is noted two weeks after ovulation, and the function of the corpus luteum, which produces progesterone, is completely blocked (N. I. Polyantsev, 1986; P. G. Boroyan, 1983). The mechanism of this luteolytic action is still unclear.
However, according to some authors (B.V. Aleshin, 1978), prostaglandins block the flow of blood to the corpus luteum of the ovary. With increasing gestational age, the synthesis of prostaglandins F2cx and E2 by the embryo also increases, which contributes to a decrease in the uterine secretion of prostaglandin F2aL. These interdependent processes probably determine the time of maternal recognition of pregnancy and the preservation of the corpus luteum, suppressing the secretion of prostaglandin F2aL by the uterus, which is confirmed by a decrease in the concentration of prostaglandin F2alpha after injection estradiol E2. Thus, the mechanism of maternal recognition of pregnancy is complex and requires further research. The endocrine glands involved in reproductive function include the thyroid gland and the adrenal cortex. Thyroid hormones (thyroxine and its derivatives) are involved in maintaining the gonadotropic activity of the pituitary gland. Hypofunction of the thyroid gland leads to the appearance of anovulatory cycles. Thyroid hormones take part in the preovulatory release of LH, and hormones of the adrenal cortex (glucocorticosteroids) influence the sexual cycle of females during unfavorable conditions for reproduction, turning off the ovaries from the hypothalamic-pituitary system (N. I. Polyantsev, 1986).
Analysis of literature data shows that the regulation of sexual function is carried out through the hypothalamus, pituitary gland, gonads and uterus. An important role is played by the cerebral cortex, subcortical and spinal centers, sympathetic and parasympathetic trunks innervating the genitals. Cyclic impulses are transmitted from centers located in the suprachiasmotic region of the hypothalamus to the nuclei at the base of the gray tuberosity. Pituitary gonadotropins are released into the blood, which affect the growth and development of follicles, rupture of the follicle and release of the egg, and the formation of the corpus luteum at the site of the burst follicle. Hormones of the ovaries, thyroid gland, and adrenal cortex have a direct effect on the genitals and are involved in the function of the hypothalamic-pituitary system.
Classification of ovarian pathology in cows
Ovarian diseases are a common cause of sometimes long-term, difficult-to-treat infertility in animals, since this eliminates the possibility of pregnancy due to dysfunction of the gonads - the process of formation and maturation of eggs. Ovarian diseases lead to disorders of the hormonal and endocrine systems, which are clinically manifested by changes in the nature of the sexual cycles.
The following classification of ovarian pathology is considered the most convenient (K. D. Valyushkin, 2002).
1. Anomalies in the development of the ovaries:
ovarian hypoplasia,
absence of an ovary.
2. Neoplasms in the ovaries
3. Ovarian dysfunction:
hypofunction,
persistent corpus luteum
4. Inflammation of the ovaries.
5. Complications of ovarian dysfunction and inflammation:
Ovarian hypoplasia refers to the underdevelopment and afunctional state of the gonads of females who have reached the age of puberty. This anomaly is recorded in 17.5-26.7% of infertile heifers and gilts.
The absence of ovaries can be unilateral or bilateral. This is a congenital phenomenon, most often caused by closely related breeding of animals. To prevent it, breeding work should be established, and animals with this pathology should be culled.
Neoplasms in the ovaries can be in the form of fibroma, adenoma, sarcoma, carcinoma, etc. Malignant tumors are accompanied by progressive emaciation of the animal, absence of estrus and sexual heat. The presence of neoplasms in both ovaries is incurable and the animal is discarded.
Hypofunction of the ovaries is accompanied by a violation of follicular oogenesis, defective (usually anovulatory) sexual cycles or their absence (anophrodesia) and accounts for about 41% of all causes of infertility in cows. At the same time, the ovaries are somewhat reduced in size, have a smooth surface, and do not contain either maturing follicles or corpora lutea. Therapeutic measures are limited to stimulation of sexual function.
Persistent is the corpus luteum that lingers in the ovary of a non-pregnant animal for more than 25 days. It can be a persistent corpus luteum of pregnancy or a persistent corpus luteum of the reproductive cycle. Animals with a persistent corpus luteum do not exhibit sexual cycles. During the year, 18% of infertile cows have persistent corpus luteum in their ovaries, and in the second half of the winter stall - over 50%. Treatment is by compression (enucleation) or the use of prostaglandins.
Cysts are cavity formations in the ovarian tissues from unovulated follicles (follicular) or corpus luteum (luteal). Occurs in 3.9 - 4.8% of infertile cows, mainly in the spring. A follicular cyst, while maintaining the function of the follicular epithelium, is manifested by virilism, nymphomania, and a luteal cyst by anophrodesia.
Inflammation of the ovaries can occur acutely or chronically and be serous, hemorrhagic, purulent or fibrinous. It is registered in 3-12% of infertile cows. For therapeutic purposes, antibiotics and sulfonamide drugs are used in standard doses.
Ovarian atrophy is accompanied by a decrease in the volume of the gonads with a simultaneous decrease in their functions. It is more often diagnosed in cows and can be unilateral or bilateral. Occurs as a consequence of oophoritis, prolonged intoxication, and insufficient and unbalanced feeding.
Ovarian sclerosis is characterized by the replacement of their parenchyma with connective tissue. Occurs in 3.8-6.5% of infertile cows.
Consequently, among diseases of the genital organs that lead to infertility and barrenness, functional disorders of the ovaries (ovarian dysfunction) are most often identified.
Dysfunctional conditions of the ovaries are characterized by impaired growth of follicles, ovulation, formation of the corpus luteum and can manifest itself in the form of delayed ovulation (persistence of the follicle), anovulatory sexual cycle, functional failure of the corpus luteum, ovarian hypofunction, cysts (follicular and luteal).
Follicle persistence. Ovarian dysfunction, manifested in the form of persistence of the follicle, is characterized by a delay in ovulation up to 24–72 hours after the end of heat (normally, ovulation in cows and heifers occurs 10-12 hours after the end of heat).
Anovulatory sexual cycle. Anovulation is a disruption or absence of the final phase of folliculogenesis. In this case, the dominant follicle undergoes atresia, and in some cases transforms into a thin-walled cyst.
Functional deficiency of the corpus luteum. Morphological and functional inferiority of the corpus luteum is characterized by the formation of defective luteal tissue of the corpus luteum.
Functional insufficiency of the corpus luteum is most often recorded in the first sexual cycle after calving (initial) and in later periods the frequency of this pathology decreases.
Ovarian hypofunction. Ovarian hypofunction is a weakening of ovarian activity, which is accompanied by arrhythmia or incomplete sexual cycles, as well as their long-term absence after childbirth.
Corpus luteum in the ovaries are formed at the site of burst follicles and can be of three types: corpus luteum of the reproductive cycle; corpus luteum of pregnancy and persistent corpus luteum.
Persistent corpus luteum. The persistent corpus luteum has no special clinical and morphological differences from the corpus luteum of pregnancy or the sexual cycle. If it is present, animals do not show signs of sexual arousal.
Ovarian cysts. Cysts are spherical cavity formations that arise in the tissues of these organs from unovulated follicles as a result of the anovulatory sexual cycle and, according to their functional state, are divided into follicular and luteal.
Follicular cysts are thin-walled, less often thick-walled, intensely or gently fluctuating spherical formations with a diameter of 21.0–45.0 mm. The cyst has a thin shell and can be easily crushed. The size of the cysts ranges from the size of a pea (small cystic ovary) to a goose egg or more.
Luteal cysts - as a rule, have one spherical cavity, the wall of which is formed by several layers of proliferating cells of the connective tissue membrane of the follicle, thick-walled, and difficult to squeeze out. Luteal cysts have a rim of luteal tissue on the inside that produces progesterone. There are no sexual cycles.
Distribution of ovarian hypofunction in cows
One of the causes of infertility in cows is ovarian hypofunction. According to the results of many studies, this pathology is registered in 30-40% or more of infertile cows. In most cases, ovarian hypofunction is detected in cows of the first and second lactation, as well as in animals with pathology of childbirth and the postpartum period. This pathology is becoming widespread in farms with a poor food supply and with violations of the standards for keeping and exploitation of animals at the end of the winter housing period. Violation of reproductive function in highly productive cows is expressed in inferiority or prolonged absence of sexual cycles after calving.
Hypofunction of the ovaries in cows should be understood as a condition in which, as a result of unbalanced feeding (especially carotene), unfavorable living conditions and under the influence of other factors, the growth, development, maturation and ovulation of follicles is disrupted. At the same time, the level of vitamin A in the blood sharply decreases, collagenization of the tissues of the gonads and a weakening of redox reactions in the endometrium are observed, accompanied by low contractility of the uterus. As a result, sexual cyclicity is disrupted or stops altogether; unfavorable conditions are created in the genital organs for the advancement of sperm, implantation of the zygote and further development of the embryo, which in most cases is manifested by infertility of animals (K. D. Valyushkin, 1987).
The greatest prevalence of ovarian hypofunction in cows occurs in February-April; a decrease in incidence was noted in May-June. Such dynamics during ovarian hypofunction are observed in farms where it is caused by the influence of unfavorable external factors (G.V. Zvereva, S.P. Khomin, 1976).
V.A. Genn (1965) diagnosed ovarian hypofunction in 17.6% of infertile cows, V. S. Dudenko (1964) - in 27.1% of cows, in 13% (cited from G. V. Zvereva et al., 1976).
K. D. Valyushkin (1987) diagnosed ovarian hypofunction in 40.8% of cows. The degree of manifestation of hypofunction depends on the strength and duration of action of etiological factors.
K.D. Valyushkin (1970,1981) came to the conclusion that the most common is hypofunction, caused by inadequate feeding and keeping animals without walking in the second half of the winter-stall period. Therefore, ovarian hypofunction in cows makes up a large percentage of gynecological diseases and is largely determined by the season of the year and the associated conditions of feeding and keeping animals.
A. A. Osetrov (1969), recorded ovarian hypofunction in 34.9% of infertile cows in winter, and in 19.9% of infertile cows in summer.
Etiology of ovarian hypofunction in cows
The reasons that cause ovarian hypofunction have interested many researchers.
Thus, G.V. Zvereva et al. (1976) note that the causes of ovarian hypofunction can be divided into two groups.
The first group of reasons is associated with the effect of unfavorable environmental factors on the body. These include quantitative and qualitative insufficiency of feed rations: vitamin, mineral and protein starvation, as well as low lighting in the room due to lack of exercise.
Therefore, this pathology is more often observed in cows in winter, as well as in early spring. At this time, feeding deteriorates, there is not enough feed, and the diet is not always balanced.
In many farms, ovarian hypofunction in cows occupies a large place and is widespread. A high percentage of the disease occurs in those years when the winter is harsh, cold, and there is little sun in winter and spring.
The second group of reasons for the development of ovarian hypofunction should include internal factors associated with diseases.
Ovarian pathology in these cases is usually sporadic in nature and develops in cows with diseases of the gastrointestinal tract (traumatic reticulitis, rumen atony), acetonymia, tuberculosis, foot-and-mouth disease, etc.
I. A. Bocharov (1956), A. P. Students et al. (1986) observed ovarian hypofunction in cows after severe pathological births, uterine prolapse, and retained placenta.
A. Yu. Tarasevich (1936), P. I. Shatalov (1960), I. A. Bocharov and others (1976), K. D. Valyushkin (1969, 1971, 1987), E. A. Akatov and others (1977), V.P. Goncharov and V.A. Karpov (1981) believe that insufficient and inadequate feeding and non-walking in the second half of the winter stall keeping, as well as when keeping animals in damp, cold, dimly lit rooms are the causes of hypofunction ovaries.
A. Yu. Tarasevich (1936), A. P. Students et al. (1986) explain the occurrence of ovarian hypofunction by nutritional reasons, stress, insufficient hardening and general oppression under the influence of an unusual environment. Hypofunction of the ovaries can occur in cows during inflammatory processes in the genital organs, with ketosis and other disorders of the body (P. A. Voloskov. 1940, V. P. Goncharov and V. A. Karpov, 1981).
K. D. Valyushkin (1987) believes that the cause of the disease can be constant underfeeding of livestock, when the body does not receive enough of a number of substances, especially carbohydrates, proteins, vitamins, minerals and other ingredients. In this case, vital functions are supported by existing reserves, and then animals begin to consume substances from skeletal muscles and other tissues. This is manifested by metabolic disorders and weakening of almost all body functions, and a decrease in the fatness of animals. Dystrophic changes occur in the genital organs of females and throughout the animal’s body, accompanied by infertility.
In the studies of I.A. Bocharov et al. (1967) B.A. Akatova et al. (1977), V.P. Goncharova and V.L. Karpov (1981) concluded that if animals are placed in rooms with high air quality, low temperature and in the presence of drafts, with insufficient exposure to sunlight rays, this causes metabolic disorders and a disorder of the hypothalamic-pituitary regulation of ovarian function.
From the entire list of reasons that lead to ovarian hypofunction in cows, it is clear that the occurrence of this pathology is etiologically diverse and in most cases depends on the living conditions of the animals. The main cause of ovarian hypofunction in cows is reduced activity of the pituitary gland due to nutritional disorders (imbalance of diets, especially in carotene, vitamin E and iodine).
Clinical signs of ovarian hypofunction in cows
N.I. Polyantsev (1986) defines ovarian hypofunction as a violation of the steroid-synthesizing and gamete-forming functions of the ovaries under conditions of chronic stress. This disease is clinically manifested in the initial period by disturbance of the sexual cycle, later by anaphrodisia (lack of estrus, sexual arousal, hunting). A rectal examination reveals: the rigidity of the uterus is weak or absent, the consistency of the ovaries is homogeneous, their shape is flattened or rounded, their surface is smooth, their volume is reduced, the corpus luteum or follicles are not detected. It has been established that with hypofunction of the ovaries in cows, ovogenesis does not stop, however, the follicles do not develop to ovulatory maturity, but undergo atresia (K. D. Valyushkin., G. F. Medvedev, (2001))
Ovarian hypofunction can manifest itself in the form of persistence of the follicle and delayed ovulation, anovulatory sexual cycle, hypoplasia and insufficient function of the corpus luteum, prolonged anaphrodisia.
Hypofunction of the ovaries, manifested in the form of persistence of the follicle, manifests itself in the form of repeated infertile inseminations and postlibidinal metrorrhagia (uterine bleeding on the second or third day after the end of sexual estrus). The rhythm of sexual cycles is not disturbed.
A rectal examination reveals an elastic-fluctuating follicle, ovulation of which occurs 24-72 hours after the end of heat (normally, ovulation in cows occurs 10-12 hours after the end of heat).
Hypofunction of the ovaries, manifested in the form of an anovulatory sexual cycle, is accompanied by repeated infertile inseminations. The rhythm of sexual cycles is not disturbed. A characteristic sign is the absence of the corpus luteum on one of the ovaries 10-14 days after the end of signs of sexual heat.
With ovarian hypofunction, accompanied by developmental disorders and insufficient function of the corpus luteum, the rhythm of sexual cycles may be disrupted. Cows experience multiple unsuccessful inseminations.
Rectal examination 6-8 days after the onset of the stage of excitation of the sexual cycle reveals a hypoplastic corpus luteum (small size, dense consistency).
Ovarian hypofunction, accompanied by anaphrodisia, is characterized by a prolonged absence of sexual cycles.
Rectal examination reveals ovaries reduced in size, dense in consistency, with a smooth surface, without growing follicles and corpora lutea.
Treatment for ovarian hypofunction in cows
Many researchers have dealt with the treatment of ovarian hypofunction in cows. Various techniques and methods have been proposed. Most often, in practice, hormonal drugs are used - progesterone and gonadotropic hormones, vitamin preparations, both in pure form and in combination with hormonal and neurotropic drugs, and physiotherapeutic methods of treatment.
A number of researchers (I. A. Bocharov et al. (1967). V. M. Voskoboynikov. et al. (1976). G. V. Zvereva, S. P. Khomin, (1976). V. A. Akatov and others (1977). V. P. Goncharov, V. A. Karpov, (1981) recommend starting all treatment procedures only after improved housing and feeding conditions have been created, active exercise has been provided to the animals. G. V. Zvereva and others (1985) recommend organizing walks with a test bull for 1-1.5 hours.The diet is supplemented with food containing sufficient nutrients necessary for the body, vitamins A, D, E and group B, macro- and microelements.
Currently, among the hormonal preparations, the serum and blood of pregnant mares (SZhK and KZhK), gravo-garmon, blood of pregnant cows and progesterone have been used.
Follicle-stimulating and luteinizing hormones are the active principles of FFA and SCFA, therefore the administration of FFA to non-pregnant females activates the role of follicles and accelerates the ovulation process.
According to G. A. Bocharov and other co-authors (1967), G. A. Cheremisinov (1975), V. A. Akatov and Yu. A. Skripitsin (1976), FFA can be used once subcutaneously. FFA activity must be at least 100 IU in 1 ml. The serum is recommended to be used in doses - for cows - 2500-3000 IU, for first-calf heifers - 2500 IU. Fertility was 65-70%. At the beginning, inject I-2 ml, then after a 2-3-hour break, inject the rest of the serum. This is done in order to avoid the phenomenon of anaphylactic shock in sensitized animals.
For hypofunction of the ovaries in cows with a similar effect, SCFA is used in the same doses,
Recently, they have often resorted to the combined use of small doses of FFA or SCFA and neurotropic drugs.
A. S. Bibilashvili (1970) pointed out that the complex use of FFA in a dose of 2000 IU, Proserpine 0.5% - 2 ml and, against their background, vitamin E in a dose of 3 ml for hypofunction of the ovaries in cows, ensured the fertility of cows by 90 .3%.
For first-calf cows, a 0.1% solution of carbacholine is used in a dose of 2 ml and KJK - 2000 M.E. against the background of preliminary three-time injections of vitamin E 125 mg with an interval of 5 days (K. D. Valyushkin, (1976)). This combination of drugs, the author points out, increases fertility by 25.4%. Carbacholine solution should be administered with the third injection of vitamin E.
Low activity FFA is used in combination with choriogonin in a ratio of 1.5:1, which ensures polyovulation in 87.5% of cows, with most animals ovulating from 60 to 100 mature follicles (N. A. Martynenko et al. 1966).
V. A. Zhelev, G. A. Cheremisinov, A. G. Nezhdanov, P. K. Shatalov (1975) established that the optimal dose of gravo-hormone, which has been widely used recently (it is prepared on the basis of FFA and the pituitary gland of farm animals ) with hypofunction of the ovaries in cows, it should be considered 4000 IU. With a reduced functional state of the ovaries and thyroid gland, gravo-harmone causes follicle-stimulating, ovulation and thyroid-stimulating effects.
V. A. Akatov and other researchers (1977) indicate the use of gravo-garmon and recommend administering this drug subcutaneously in the neck at a dose of 9 IU per 1 kg of animal weight once 3-4 days before the onset of the estrus phase.
Data from V.I. Nikolaeva and R.Ya. Shishko (1979) established that the use of gravo-garmone for ovarian hypofunction in cows ensures fertility in the last two sexual cycles of up to 88%.
Among other hormonal drugs for ovarian hypofunction, folliculin, pituitrin, progesterone are currently successfully used, and among vitamin preparations - trivitamin, tetravit.
K. D. Valyushkin (1981) believes that the greatest effect is achieved by three injections of vitamin E with an interval of 5 days, 4 ml (1000 mg), as a result, sexual heat appears 11 days faster, the time from completion is reduced by 9.1 days injections before fertilization, the fertility rate of the first insemination and the pregnancy of animals increases by 12.1% compared to the control group.
The use of vitamin A promotes the appearance of signs of sexual cyclicity and increases the fertility of animals by 12.6% compared to the control group (K. D. Valyushkin, (1970,1981,1987)).
A. S. Bibilashvili (1970) indicates that one or two doses of vitamin E to cows with infertile insemination and ovarian hypofunction in a dose of 3-3.5 ml after 5-6 days ensures fertilization in the first heat by 88%.
K.D. Valyushkin (1969, 1971, 1974,1981,1987) in experiments on the complex use of vitamins and microelements for hypofunction of the ovaries in cows established the following:
Vitamins A and E, administered intramuscularly to first-calf heifers three times, 50,000 units and 50 mg, respectively, have a general stimulating effect on the body and affect the reproductive function;
Vitamin A (150,000 IU), vitamins C (20 solution - 8 ml) and E (1000 mg) affect reproductive function and increase fertility by 22.5%;
Trivitamin in a dose of 10 ml is used with an interval of 5 days, sexual heat appears within 2 months in 80.5% of cows, trivitamin shortens the service period by 12 days;
Trivitamin in combination with microelements - manganese, zinc, copper, cobalt has an effect on sexual activity in case of hypofunction of the ovaries, fertility increases by 36.1%.
P. A. Voloskov (1960) conducted research on the combined administration of small doses of FFA in combination with neurotropic drugs (carbacholine, proserin solution). The course of treatment was as follows: a 0.1% solution of carbacholin was administered at a dose of 1.5-2 ml subcutaneously, on days 2-4 a solution of proserine was administered at a dose of 2 ml, then there was a break of 4-5 days, then SZhK 1500 was administered - 2000 M.E.
V.M. Voskoboynikov et al. (1976) injected vitamin E three times at a dose of 125 mg with an interval of 5 days. First-calf cows receive 2 ml of 0.1% carbacholine solution in combination with 2000 IU SCFA. After these injections, the fertility rate increased by 25.4%.
V. A. Akatov, Yu. A. Skripitsin (1976) used an aqueous solution of proserin in a dose of 2 ml together with a 10% oil solution of sinestrol in a dose of 2 ml for hypofunction of the ovaries in cows, this mixture was administered intramuscularly.
V.P. Goncharov, V.A. Karpov (1981) suggested doing massage and vaginal irrigation. This increases blood and lymph circulation in the genitals, causes irritation of nerve endings, normalizes metabolic processes in tissues, and restores reduced ovarian function. V.P. Goncharov (1979) used a massage using a 1% solution of progesterone, 100 ml for 2 days and on the 5th day he used gravo-garmon at a dose of 2337 IU in combination with 0.5 % solution of prozerin in a dose of 3 ml and trivitamin in a dose of 10 ml twice with an interval of 5 days. Fertility rate in the first heat was 71.5%.
Also effective is massage of the uterus and ovaries through the rectum once a day for 5-7 minutes for 3-5 days (V.P. Goncharov et al. (1985), G.V. Zvereva et al. 1985).
To stimulate ovarian function, V.P. Goncharov and V.A. Karpov (1991) used tissue preparations from the liver, spleen, ovaries, etc. at a dose of 5 ml per 100 kg of animal weight three times with an interval of 3–5 days in combination simultaneously with the first injection of a hormonal drug (one of the drugs: FFA, gravohormone, ovaritropin) at a dose of 1000-2000 IU.
To normalize ovarian function, BelNIIEV specialists recommend the use of colostrum from cows in the first 6-9 hours after calving with antibiotics subcutaneously in a dose of 20-25 ml once or colostrum in a dose of 20 ml with 2 ml of 0.5% proserin solution subcutaneously and 10 ml trivitamin (tetravit) intramuscularly once. A good therapeutic effect is provided by subcutaneous injection of an animal's own blood or the blood of a pregnant cow with proserin. It is recommended to administer surfagon to cows 30-33 days after calving during the normal course of the postpartum period at a dose of 10 ml intramuscularly and repeat the administration of surfagon after 10-12 days at a dose of 2 ml (B. Ya. Semenov et al. (1997)). M.I. Prokofiev et al. (1978) recommend administering surfagon in a dose of 5 ml, and after 10-12 days - prostaglandin in a dose of 2 ml. In this case, sexual arousal appears 40-50 days after birth, fertility increases by 25%, and the service period is reduced by 23 days.
Experiments by V. P. Goncharov (1991) on the treatment of ovarian hypofunction at cows using massage of the ovaries, oviducts, uterus and the introduction of a 1% solution of progesterone (100 mg) every other day for 2 days and on the 5th day - gravo-hormone (2500 IU) in combination with a 0.5% solution Proserin (3 ml) and trivitamin (10 ml) twice with an interval of 5 days showed that all cows came into heat on average on the 9th day after the start of treatment. Fertility in the first heat averaged 71.5%. A single application to cows of a 2.5% oil solution of progesterone (400 mg) in combination with trivitamin (10 ml), and after 3 days of gravohormone (2500 IU) with 0.5% progesterone (2 ml) contributed to the manifestation hunting after a course of treatment on average on the 8th day. Fertility after the first course of insemination is 69.2% of cows (V.P. Goncharov et al. 1985).
Cows with ovarian hypofunction V.P. Goncharov and V.A. Karpov (1985) were injected intramuscularly with prostaglandin once in a dose of 10 ml and tetravit twice with an interval of 5 days. Hunting in the experimental animals appeared on average 4.8 days earlier. 63.6% of cows were fertilized after the first insemination; the service period averaged 58.8 days.
The administration of these drugs to experimental animals affected not only the ovary directly, but also the function of the hypothalamic-epiphysial-pituitary system was restored, which contributed to the manifestation of full sexual cycles, ovulation with subsequent insemination and fertilization both in the first heat and at a later date (Goncharov V. P. and Karpov V. A. 1991).
Prevention of ovarian hypofunction in cows
For correct and systematic work to prevent ovarian hypofunction in farms, it is first of all necessary to eliminate the causes that cause this disease. Organize systematic daily walks in the fresh air during the dry period and after calving, a complete balanced diet. Timely detection and treatment of cows with endometritis (K. D. Valyushkin., G. F. Medvedev, (2001), Semenov B. Ya., et al. (1999)).
Of medications, Semenov B. Ya., and others (1999) recommend:
On the 10-15th day after calving, use reduced doses of GSZHK (serum gonadotropin or sergon, 1000 I.U.) in combination with tetravit and ASD f2 (tetravit 8 ml + 2 ml ASD f2) intramuscularly + 20-25 ml of colostrum subcutaneously . Emulsion of tetravit and ASD f2 should be used only in freshly prepared form;
On the 10-15th day after calving, surfagon 50 mcg (10 ml) intramuscularly + a mixture of ASD f2 (2 ml) with tetravit (8 ml) intramuscularly, after 10 days – 10 mcg (2 ml) surfagon;
Complex fortification with tetravit in doses: A – 0.7-1.5 million, I. E.; D 3 – 100-200 thousand I.E.; E – 6001200 mg. 6 injections are performed sequentially:
1st – two weeks before calving;
2nd – one week before calving;
3rd – 5-7 days after calving;
4th – 12-13 days after calving;
5th – on the day of insemination of animals;
6th – 10-12 days after insemination of animals.
The above and other data on the treatment and prevention of cows with ovarian hypofunction allow us to conclude that currently there are a number of effective drugs that are successfully used for ovarian hypofunction in cows.
Functional disorders of the ovaries, causing long-term infertility in cows and heifers, manifest themselves, as a rule, in the form of their hypofunction, cysts and persistence of the corpus luteum.
Ovarian hypofunction is characterized by impaired development and maturation of follicles, their ovulation and the formation of the corpus luteum. This pathology can manifest itself in the form of persistence of the follicle and delayed ovulation, insufficient function of the corpus luteum, or complete depression of the function of the gonads and prolonged anaphrodisia.
Etiology. The causes of ovarian hypofunction are a decrease in the synthesis and incretion of gonadotropic hormones by the pituitary gland or a weakening of the ovarian reactivity to the action of gonadotropins. The latter is observed, as a rule, with increased synthesis of corticosteroid hormones under stress, as well as with a lack of thyroid hormones in the body of animals.
Symptoms and course. The initial form of ovarian hypofunction, manifested by persistence of the follicle, is characterized by a delay in ovulation up to 24-72 hours after the end of the heat (normally, ovulation occurs 10-12 hours after the end of the heat), postlibid uterine metrorrhagia (bleeding on the second or third day after insemination) and low fertility animals.
Ovarian hypofunction, manifested by anovulation, is characterized by impaired development and maturation of follicles in the ovaries. Such animals are characterized by a lack of fertilization and multiple inseminations. A rectal examination of a cow during the period of anovulatory sexual cycle reveals growing small or medium-sized follicles in the ovaries that do not reach the preovulatory state.
With ovarian hypofunction, accompanied by developmental disorders and insufficient function of the corpus luteum, cows experience multiple unsuccessful inseminations, sometimes with disruption of the rhythm of sexual cycles (the manifestation of the arousal stage after 12-15 days). A rectal examination 6–8 days after the onset of the stage of initiation of the sexual cycle reveals a small, dense corpus luteum in the ovaries. The concentration of progesterone in the blood during this period does not exceed 1.6 - 1.8 ng/ml (versus 2.5 - 4.0 ng/ml during a normal sexual cycle). There are usually no changes in the uterus. Most often, this disorder of sexual function is observed in hot summer months, as well as with insufficient or inadequate feeding of animals.
With complete depression of the function of the gonads, clinically accompanied by anaphrodisia, the ovaries are reduced in size, dense to the touch, with a smooth surface, without growing follicles and corpora lutea. The horns of the uterus are located in the pelvic cavity or hang over the pubic edge, are weakly rigid, and atonic.
Treatment and prevention. Cows with ovarian hypofunction, manifested by delayed ovulation or anovulation, are injected intramuscularly with surfagon at a dose of 20 - 25 mcg or ovogon-TIO-1 - 1.5 thousand IE on the day of manifestation of the phenomena of the arousal stage of the sexual cycle (before or after the first insemination of the animal).
Animals with anovulatory sexual cycles are also prescribed serum gonadotropin, which is administered subcutaneously 2 - 3 days before the expected onset of the next stage of arousal (17 - 19 days after the previous sexual cycle and insemination) at a dose of 2.5 thousand IU. (5 - 6 IU per 1 kg of body weight). During an anovulatory sexual cycle, accompanied by luteinization of a non-ovulated follicle, determined in the ovary during rectal examination on days 6-8 in the form of a cavity formation with a “tight” fluctuation, one of the prostaglandin F 2-alpha preparations (estuphalan, bioestrophan, clatraprostin, gravoprost) is administered intramuscularly once or gravoclathran in a dose of 2 ml), and when the stage of excitation occurs (during insemination) - surfagon - 20 - 25 mcg or ovogon-TIO - 1-1.5 thousand IE.
In case of ovarian hypofunction, accompanied by anaphrodisia, cows are given a single dose of gonadotropin FFA at a dose of 3-3.5 thousand IU. (6-7 m.u/kg body weight). To ensure normal ovulation, on the day of the initiation stage of the sexual cycle (during insemination), surfagon is injected at a dose of 20 mcg. In animals that have not shown the stage of arousal of the sexual cycle, 21 - 22 days after a gynecological examination and confirmation of the initial diagnosis, gonadotropin FFA is reintroduced in the same dose.
Animals with insufficient function of the corpus luteum, when the next cycle appears on the day of insemination, are administered a single dose of 2.5 thousand IU subcutaneously. gonadotropin FFA (4 - 5 IU/kg body weight).
For the treatment of animals with depression of sexual function, it is recommended to administer gonadotropic drugs, which should be combined with the use of aqueous solutions of neurotropic drugs: carbacholin (0.1%) or furamone (1.0%). Any of these drugs is administered twice with an interval of 24 hours, 2 - 2.5 ml, and after 4 - 5 days, gonadotropin FFA is injected once at a dose of 1.5 - 2 thousand IU.
Ovarian cysts, as functioning formations, are formed from unovulated follicles and, according to their functional state, are divided into follicular and luteal.
Follicular cysts have one or more spherical cavities, the walls of which at the beginning of their formation and functioning are represented by hyperplastically modified hormonally active granulosa, vascularized theca, hyperplastically modified outer connective tissue membrane and reduced granulosa.
Symptoms and course. Rectally, they are determined in the form of one or several thin-walled blisters with gentle fluctuations, with a diameter of 2 to 4 - 6 cm or more. The ovaries acquire a round or spherical shape and increase in size to the size of a chicken or goose egg. The horns of the uterus are somewhat enlarged and hang over the edge of the pubic bones. At the beginning of the formation and functioning of cysts in cows, nymphomania is clinically observed, which subsequently, with the onset of degenerative changes in the cyst wall, is replaced by anaphrodisia.
Treatment. To treat cows with follicular ovarian cysts, different schemes for prescribing hormonal drugs are used. According to one of them, treatment is carried out by a single injection of gonadotropin FFA in a dose of 5 - 6 thousand IU. or human chorionic gonadotropin - 4 - 5 thousand units. Animals that have not shown the stage of arousal of the sexual cycle after a gynecological examination and if signs of luteinization of the cyst walls are detected are injected with one of the above-mentioned prostaglandin preparations in a dose of 2 ml on days 10 - 12. In another case, for treatment you can use gonadotropin-releasing hormone (surfagon), which is injected 10 mcg 3 times with an interval of 24 hours, or the luteinizing hormone ovogon-TIO once - 3 thousand IE. In the third treatment regimen, cows are parenterally injected with 50-75 mg of progesterone daily for 7-8 days, while 50-100 mg of potassium iodide is given orally, and after two to three days they are injected once with gonadotropin SFA-3-3.5 thousand. m.e.
Luteal cysts, as a rule, have one spherical cavity, the wall of which is formed by several layers of proliferating cells of the connective tissue membrane of the follicle.
Symptoms and course. With this pathology, the ovaries are diagnosed through the rectum in the form of spherical formations up to 6-8 cm in diameter with a dense wall and mild fluctuation. The presence of such cysts in animals is accompanied by anaphrodisia. The horns of the uterus and cystic ovaries hang into the abdominal cavity, the uterus is atonic. In the blood plasma, a low content of estradiol and a high level of progesterone are detected.
Treatment. It is carried out by a single intramuscular injection of estufalan in a dose of 500 - 1000 mcg, bioestrophan 2 ml, or clatraprostin 2 - 4 ml with simultaneous subcutaneous injection of 2.5 - 3 thousand i.u. gonadotropin FFA. When using gravoprost or gravoclathran in a dose of 4 ml, gonadotropin FFA is not prescribed. For ovarian cysts accompanied by atony and hypotension of the uterus, neurotropic drugs can be used as additional therapeutic agents.
Ovarian hypofunction - Hypophunctio ovarium is the most common dysfunctional condition of the ovaries in animals, occurring with a weakening of the hormonal and generative function of the ovaries, accompanied by defective sexual cycles or anaphrodisia.
Ovarian hypofunction in animals, especially cows, is one of the causes of infertility. This disease is especially often recorded in first-calf heifers (up to 50% or more) during the winter stable period.
Etiology. The cause of ovarian hypofunction in animals can be divided into two groups. The first group of reasons is directly related to the impact of unfavorable factors of existence on the animal’s body. This group should include quantitative and qualitative insufficiency of feed (mineral, vitamin and protein starvation), violation of living conditions (poor lighting in livestock buildings, lack of walks). Hence, ovarian hypofunction is more often observed in cows at the end of wintering, as well as in early spring, when there is a sharp deterioration in the quality of feed prepared for wintering. In some agricultural enterprises, peasant farms and private household plots with a low food supply, ovarian hypofunction is observed in the majority of cows, especially in years with cold and weakly sunny winters and springs.
Inadequate feeding of highly productive cows among owners of peasant farms and private farms can often lead to a sharp decrease in ovarian function - their hypofunction.
Hypofunction of the ovaries in animals can be caused by a disorder in the functioning of the pituitary gland and other endocrine glands.
Hypofunction of the ovaries in cows often occurs after severe pathological births.
Pathogenesis. Decreased ovarian function in animals develops gradually. In this case, the number of maturing follicles in the ovaries decreases, and subsequently their growth stops completely. Sometimes, as a result of the sudden impact of a whole complex of unfavorable factors, an animal may experience rapid depression of ovarian function.
P.A. Voloskov and co-authors (1960) believe that inadequate feeding of an animal, especially when there is a lack of protein and microelements (cobalt) in the diet, leads to a decrease in the functional state of the rumen with a simultaneous decrease in the synthesis of many vital substances in the rumen. All this ultimately leads to disruption of protein, carbohydrate and mineral metabolism in the body, changes in hormonal balance and a decrease in the hormonal function of the pituitary gland.
Many animal diseases lead to disruption of the hormonal function of the pituitary gland. This change entails a decrease in the functional state of the ovaries.
When conducting a microscopic examination of the ovaries from cows with ovarian hypofunction, we find a decrease in the number of secondary and tertiary follicles and a large number of atretic ones.
V.M. Lukyanenko and E.V. Shchirba (1974) during histochemical studies of the ovaries, uterus and oviducts established a decrease in the hormonal activity of the gonads (ovaries) and a sharp decrease in the secretory function of the mucosal epithelium.
When conducting a gynecological examination of cows, a veterinarian usually diagnoses hypofunction of both ovaries, at the same time, the degree of their response to unfavorable factors may be different.
The greatest prevalence of ovarian hypofunction in cows is recorded by veterinary specialists in February-April, and in May-June there is a sharp decrease. Similar dynamics during ovarian hypofunction in cows are usually expressed in farms in which it was caused by the influence of unfavorable external factors.
Clinical picture. The clinical picture of hypofunction of the ovaries in an animal varies from complete depression of ovarian function to the manifestation of mild signs of estrus and sexual heat in the animal.
In most cows, ovarian hypofunction begins with an incomplete sexual cycle and its rhythm is disrupted. In this case, the follicles, while developing, do not fully mature and undergo atresia, as a result of which the animal does not ovulate the egg, the corpus luteum does not form, and in some animals the corpus luteum of the ovary develops from a non-ovulating follicle.
Due to the fact that with ovarian hypofunction, the hormonal function of the pituitary gland and ovaries decreases, estrus, general (sexual) arousal and hunting are weak or absent.
Subsequently, the inferiority of the animal’s reproductive cycles is replaced by anaphrodisia, which can continue, especially in first-calf heifers, for 2-6 months or more. In some cows, sexual cyclicity may be restored in the spring-summer period, but its course is incomplete.
If an animal has complete depression of ovarian function, especially after giving birth during the winter stall period, anaphrodisia is the main symptom of ovarian hypofunction.
Veterinary specialists, during a gynecological examination of cows that have not come into heat for a long time, during a rectal examination, the veterinarian palpates the ovaries, which are reduced in size (in cows to hazelnuts, beans), most often dense and smooth, in which there are no follicles or yellow tel. If a veterinarian conducts a study during the anovulatory sexual cycle, then growing follicles can be detected in the ovaries, but they usually do not reach the size of the follicles that are observed in cows with normal fertility. During rectal examination of such animals, the uterus is usually reduced in size, the horns are thin and usually relaxed, and contract weakly during rectal massage. The mucous membrane of the vagina and the vaginal part of the cervix during vaginal examination using a vaginal speculum is pale and dry.
Forecast with ovarian hypofunction, it depends on the cause that caused it; if the cause of ovarian hypofunction can be quickly eliminated by the animal owners and the duration of the pathology is short, one can hope for a favorable outcome. In this case, the veterinary specialist must take into account the condition of the whole organism and especially the condition of the ovaries (their size, consistency, presence of growing follicles). Young animals always have a more favorable prognosis.
Treatment Animals with ovarian hypofunction must begin with the creation and normalization of living conditions, care and feeding. The feeding diet of a sick animal must be balanced in all nutrients, must contain a sufficient amount of vitamins A, D.E and group B, macro- and microelements. Animals during the winter stable period should regularly use active walks with a mandatory run of 3-4 km for 2-3 hours, during the grazing period - summer grazing.
After the owners of agricultural enterprises, peasant farms and private household plots have created normal feeding and housing conditions for the sick animal, veterinary specialists begin to use hormonal, pharmacological drugs, vitamins in pure form or in combination with hormonal and neurotropic drugs, tissue therapy, autohemotherapy, and physiotherapeutic methods of treatment.
When treating an animal with ovarian hypofunction, it is necessary to take into account that the effectiveness of treatment depends not only on the method, but also on the condition of the ovaries, uterus and oviducts, vagina, the duration of the pathology, the condition of the whole organism, as well as on the quality of the drug.
At the initial stage of ovarian hypofunction in cows, massage of the uterus and ovaries through the rectum once a day for 5-7 minutes is effective, the course of massage is 3-5 days. It is advisable to alternate massage of the genital organs with irrigation of the vagina with hot (45° C) weakly disinfecting solutions (furacillin, rivanol, bicarbonate of soda, potassium permanganate, etc.) or 1% sodium chloride solution. Carrying out massage and irrigation of the vagina significantly enhances blood and lymph circulation in the genital organs, causing normalization of metabolic processes in tissues, and leads to the restoration of ovarian function.
To stimulate ovarian function, practical veterinary specialists use FFA, SCFA, gravohormone, ovaritropin at a dose of 2500-3000 IU, for first-calf heifers - at a dose of 2000-3000, for heifers - 1000-2000 IU. These drugs are administered alone, as well as in combination with neurotropic drugs (0.5% solution of proserin, 0.1% solution of carbocholine) - two to three injections of 2-4 ml every other day.
The hormonal method of increasing the fertility of farm animals was developed in 1936. at the All-Union Research Institute of Animal Husbandry under the leadership of M.M. Zavadovsky. The drug from the blood of pregnant mares (FFB) can be used not only to stimulate multiple pregnancy, but also to normalize and activate the function of the ovaries and uterus.
FFA and KZHK are preparations obtained from the blood of pregnant mares (pregnancy period 40-120 days); contain gonadotropins, which have follicle-stimulating and luteinizing effects on the ovaries.
The immediate sexual cycle in an animal is detected in the first 6 days after the administration of FFA or SCFA as a result of the direct effect of the drug on the ovary, and the induced sexual cycle in the treated animal occurs 2-3 weeks later due to the indirect function of the hypothalamic-pituitary system.
The different effects of FFA and SCFA depend on the dose of the drug. A dose of 1000-2000 IU ensures the manifestation of the immediate sexual cycle, stimulating the growth of a small number of follicles and the release of folliculin, which leads to the restoration of the gonadotropic function of the pituitary gland with the subsequent onset of an induced sexual cycle without the development of pathological processes in the ovary.
With minimal pathological changes in the ovaries, the administration of 3000 IU of FFA to a cow causes an induced sexual cycle in cows. Through the experiments of G.A. Cheremisinov found that a single administration of FFA affects the functional state of the ovaries in cows for three weeks and excludes repeated administration of FFA during this period. It has also been established that SCFA has a prolonged effect and differs from FFA in having significantly fewer side effects.
Most authors believe that large doses of FFA (4500 IU or more) not only inhibit ovarian function, but also lead to cystic degeneration in the ovaries (A.I. Sergienko, 1972; G.A. Cheremisinov, 1972; M.V. Kosenko , 1974, and others).
Veterinary specialists, taking into account that the administration of FFA can cause an anaphylactic reaction in cows, recommend administering this drug using the Bezredka method - first, 1-2 ml of FFA is injected subcutaneously, and after 1-2 hours, if the animal does not react to the administration of serum, the cow is injected the remaining dose of FFA. G.A. Cheremisinov (1972) recommends administering 2500 IU of FFA. A two-month observation showed that sexual cycles after the introduction of FFA appeared in 97.5% of cows, of which 70% of the animals were fertilized.
In 1968-1970. Soviet and Bulgarian scientists developed a new hormonal drug - gravohormone, purified from ballast proteins. This drug was prepared on the basis of FFA and the pituitary gland of farm animals.
G.A. Cheremisinov and A.G. Nezhdanov (1972) established a dose of gravohormone for cows - 9 units. per 1 kg of animal weight. Gravohormone is most often administered once. If it is necessary to re-introduce gravohormone, the interval should be at least 3 weeks, due to the fact that induced sexual cycles in an animal occur within 7-21 days.
Gravohormone for ovarian hypofunction was administered once; within a month, sexual cyclicity was restored in 95% of cows, within 2 months of which 75% of inseminated animals were fertilized.
M.N. Trostyanetskaya (1963) found that gonadotropic hormones accumulate in the blood serum of pregnant cows. Taking this into account, the author recommends using serum from pregnant cows (3-6 months of pregnancy) to normalize reproductive processes in cows; dose 20-25 ml or 1800-2000 IU.
For ovarian hypofunction, veterinary specialists use progesterone, as well as its combined administration with FFA.
G. Trimberger and W. Hansell (1955), Evert (1973) used progesterone in doses of 50, 75 and 100 mg from the 15th day of the sexual cycle and obtained a fertility rate of 62.5% in cows.
A single application to cows with ovarian hypofunction of a 2.5% oil solution of progesterone (400 mg) in combination with trivitamin (10 ml), and three days later - gravohormone (2500 IU) with 0.5% proserin (2 ml) contributed to the manifestation of heat after treatment on average on the 8th day. The fertility rate of cows after the first insemination was 69.2%; the period from the first insemination to the fertile one averaged 37.2 days (V.P. Goncharov, 1980).
Recently, with ovarian hypofunction in cows, veterinary specialists have increasingly begun to use injections of a 1% progesterone solution in a dose of 10 ml three times with an interval of 2-3 days; on the 8th day from the start of treatment, the cow is given 2.5-3 thousand IU FFA or gravohormone, or ovaritropin in combination with proserin.
In order to increase the overall resistance of the body, stimulate the processes of regeneration of tissues of the uterus and ovaries, along with hormonal drugs, autologous blood is used in increasing doses (25,50, 75 ml), intramuscular administration of trivitamin, tetravit in a dose of 10 ml, 2-3 injections.
In case of hypofunction of the ovaries, practical veterinary specialists use colostrum obtained from healthy animals, especially those with infectious diseases (including r.s. leukemia), which is obtained from fresh cows no later than 12 hours after calving. First, add 80 ml of a 0.5% proserine solution and 2 million each to a liter flask. Units of penicillin and streptomycin (tricillin is possible). The volume is adjusted to 1 liter with colostrum, which must be obtained in compliance with the rules of asepsis. This drug, heated to the animal’s body temperature, is administered subcutaneously in 25 ml doses 2-3 times with an interval of 6 days. The therapeutic effect of colostrum in case of ovarian hypofunction is due to the presence of gamma globulins, enzymes, vitamins, hormones, microelements, etc.
The use of the following medicinal mixture has good therapeutic effectiveness for ovarian hypofunction:
Hydrolysine -100ml, ASD-2 -5ml, novocaine (powder) -0.5g. This medicinal mixture in a dose of 15-20 ml is administered in the neck area. The interval between injections is 48 hours. The course of treatment consists of 4-5 injections.
It is advisable to combine hormonal and drug therapy for ovarian hypofunction with massage of the uterus, ovaries and oviducts.
Conducted experiments on the treatment of ovarian hypofunction in cows using massage of the ovaries, oviducts and uterus and the administration of 1% progesterone at a dose of 100 mg every other day for 2 days and on the 5th day - gravohormone (2500 IU) in combination with 0.5% - solution of prozerin (3 ml) and trivitamin (10 ml) twice with an interval of 5 days showed that all cows came into heat on average on the 9th day after the course of treatment. At the same time, the fertility rate in the first heat averaged 71.5%.
Treatment of cows with ovarian hypofunction can also be carried out using prostaglandins, which are administered intramuscularly once at a dose of 10 mg and tetravit twice at a dose of 10 ml with an interval of 5 days. After this treatment, cows go into heat on average on the 5th day. Fertility after the first insemination is about 63%.
During an anovulatory sexual cycle, accompanied by luteinization of a non-ovulating follicle, which is determined by a veterinarian on days 6-8 using a rectal examination in the form of a cavity formation with a “tight” fluctuation, one of the prostaglandin F-2-alpha preparations (estuphalan, bioestrophan, clatraprostin) is administered intramuscularly once , gravoprost or gravoclathran in a dose of 2 ml), and when the stage of excitation appears (during insemination) – surfagon – 20-25 µg or Oogon-20-25 µg or Oogon – TIO-1-1.5 thousand IE.
In case of ovarian hypofunction, which is accompanied by anaphrodisia in the animal, cows are given a single dose of gonadotropin FFA in a dose of 3-3.5 thousand. IU (6-7 IU per 1 kg of body weight). To ensure normal ovulation of the follicle, on the day of the initiation stage of the sexual cycle (during insemination), an injection of surfagon is given at a dose of 20 mg. Cows that have not shown the stage of initiation of the sexual cycle, 21-22 days after a gynecological examination performed by a veterinarian and the diagnosis of ovarian hypofunction established by rectal examination, must be re-administered gonadotropin FFA at the same dose.
The administration of drugs to animals with ovarian hypofunction not only has a direct effect on the ovary, the function of the hypothalamic-epiphysial-pituitary system is restored, which ultimately contributes to the manifestation of full sexual cycles, maturation of follicles, ovulation of the egg, subsequent insemination and fertilization in the first heat, and in a more distant period (V.P. Goncharova, 1985).
If cows with ovarian hypofunction have damage to other organs, a veterinarian must carry out appropriate treatment for these diseases.
Prevention of ovarian hypofunction. Prevention of ovarian hypofunction in animals should be based on proper, intensive rearing of replacement young animals. Heifers in agricultural enterprises, peasant farms and private household plots must be adequately fed and provided with normal living conditions. So that by the age of 15-18 months they have a live body weight of 300-400 kg. cows and heifers should exercise daily at a distance of 2.5-3 km. In the summer they should use pasture. One of the important methods of combating infertility and barrenness in cows and heifers is obstetric and gynecological medical examination. See the corresponding article on our website - “”. Semenov B.Ya. and others (1999) in order to prevent ovarian hypofunction recommend:
- 10-15 days before calving, use reduced doses of GSZHK (serum gonadotropin or sergon, 1000 IU each) in combination with tetravit and ASD-2 (tetravit 8 ml plus ASD-2 (2 ml) is administered intramuscularly to the animal. Additionally, 20-25 ml is applied subcutaneously colostrum Veterinary specialists, when using emulsion from tetravit and ASD-2, should use only freshly prepared emulsion.
— A calving cow, 10-15 days after calving, is administered intramuscularly with 10 ml (50 µg) of surfagon and additionally an emulsion consisting of a mixture of ASD-2 (2 ml) with tetravit (8 ml). After 10 days, 10 µg (2 ml) of surfagon.
- preventive fortification with tetravit, trivitamin twice before calving and three times after calving with an interval of 7-10 days. The dose of tetravit is 10 ml intramuscularly.
