As a result of long-term selection of Russian White hens in the RRIFAGB population for thermal resistance to low temperatures during chicks raising, as well as increased resistance to Marek's disease, carcinomas and diseases of the leukemia-sarcoma complex, genotypes with snow-white color of the down of day-old chicks appeared. Currently, a line of "snow-white" hens, homozygous for the recessive allele of snow-white down gene, has been segregated. Research objective was to study the traits of Russian white hens with yellow down at day-old age comparing to "snow-white" hens in embryonic and early neonatal periods for thermoresistivity in low temperatures of raising, and also at the output level and the biological activity of the allantoin-amniotic fluid of their embryos. The influence of a single cooling during the sensitive period of embryogenesis (+20^oC for 6 hours on 5.5 days of incubation) on the output of extraembryonic fluid of 12.5-day-old embryos was studied; the thermoregulatory capabilities of 7-day-old chicks under the influence of a stress factor (cooling at +10^oC for 30 minutes for 7 days) and raising at a low temperature (+22^oC) were studied. The level of allantois-amniotic fluid yield and biological activity of Newcastle disease viruses, infectious bronchitis and chicken reovirus infection in it in embryos of Russian White hens with different color of down was evaluated. In response to the dosed effect of low temperatures during the sensitive period of embryogenesis, 12.5-day-old embryos of hens with snow-white down color increased the volume of extraembryonic fluid. However, the incubation rates in the line of "snow-white" hens were worse than in hens with yellow color of down. "Snow white" chicks also responded more to hypothermic stress in the first week of raising and had less volume and biological activity of the extraembryonic fluid of their embryos. It is concluded that to use hens that are homozygous for the gene of snow-white down as producers of raw materials for the Bio-Industry is not advisable.

This article presents the analysis of the state of dairy cattle industry and its short-term development prospects in connection with the crisis of 2020.  For the purposes of objective assessment, we considered the period of 2015-2019 and presented the dynamics of the main statistical indicators with significant state support (grants, subsidies, etc.) for agricultural producers. In 2019 the total amount of disbursed funds was more than 1.4 billion rubles, most of which were directed to the development of dairy cattle breeding. According to the results of 2019, 73.9% in milk-production structure accrue to personal subsidiary farms, 19.6% - to agricultural organizations and 6.5% - to private farms. The significant share of produced milk in the Stavropol territory accrues to personal subsidiary farms; at the same time, the increase in milk production was 26.5% (643.8 thousand tons). Alongside the reduction of livestock in the general population of milk cattle in the Stavropol territory it is obvious that the genetic potential of cows increases due to the decrease of low-productivity animals and wide-scale import of high-producing breeding heifers, both from abroad and domestic market. The topical problems of the industry are low reproductive qualities of cows (the output of calves in agricultural organizations is only 75%), the violations of feeding technologies and animals housing due to insufficient availability of specialists. In general, industry development rate is quite high and has significant potential for production increase in short-term prospect, provided that the existing state-support programs continue. The most relevant trends are the increase of genetic potential of productivity in Stavropol livestock population, the adoption of state-of-the-art technologies for livestock keeping and feeding, as well as the development of farming and the niche of organic products.

Milk production and live weight of queens in mountain meat-coarse-wool sheep breeding, as one of the main quantitative traits in postnatal ontogenesis, are more susceptible to the influence of paratypical factors, that is, they have a large “rate of reaction” to the conditions of feeding and maintenance.

In order to resolve the question * how to select, what animals to leave for the tribe in the mountain meat coarse-wool sheep breeding *? We at OOO Dargan, a mountainous zone of the Kabardino-Balkarian Republic (KBR), according to the methodology, formed five groups of queens, with a class interval of 5 kg.

It was found that the milk production of the queens had a certain relationship with their live weight, and was 32.4 kg in group V, which exceeds the same indicator of group IV by 1.4 kg; III - by 3.0; II - by 7.6; I - by 8.5 kg, the difference between IV and III groups is 0.6 kg.

At 4 months of age, the rams of group V in live weight exceeded rams of groups IV and III by 0.7 and 0.4 kg, II - by 2.5 kg, I - by 5.3 kg, at 6 months of age - I at 7.9 kg, II - at 4.0 kg, III - 1.5 kg. There were no significant differences between IV and V groups - 0.7 kg.

Along with this, it should be noted that with an increase in the vertical zoning of pastures above sea level (above sea level), with steep slopes, the higher milk production potential of large queens is leveled.

The obtained research results indicate that in mountain meat and coarse-wool sheep breeding, selection for increasing the milk yield of ewes, in combination with the optimal live weight, is an effective method of increasing the live weight of young animals.

Currently first place in the number is a domestic black-motley breed, second place – Holstein. In the Sverdlovsk region, the Ural type of black-and-white cattle was created and officially registered in 2002 by crossing the breeding stock of the black-and-white breed of the Ural offspring with the Holstein bulls. In recent years, there has been a stable significant increase in milk productivity, as a result of which in five years the milk yield for the herd increased by 1388 kg of milk, and for full-aged cows by 1655 kg and reached 10257 kg. A significant increase in productivity was accompanied by a significant increase in the fat content in milk by 0.26% on average for the herd, and by 0.47% for first heifers. protein-Milk content has not changed much, but it is still not high enough. Over the past five years, there has been an increase in the variability of the main selectible trait – milk yield for both the first and third lactation. The selection boundaries for such an important quality indicator of milk as protein content have been slightly expanded. Coefficient of variability in protein content. The negative impact of milk yield on the level of fat content of the herd over the past more than 15 years has naturally changed from an average negative to an average positive in first-heifers, and in full-aged cows it has decreased from -0.17 to -0.08. The dependence of milk yield after the third calving on the results of the first lactation has decreased, but it is still quite significant, as evidenced by the corresponding correlation coefficient of 0.28. The increase in the correlation coefficient between the milk yield of mothers and daughters has almost doubled in ten years.

Age-related deterioration in female fertility is mainly associated with a decrease in the number and quality of ovarian follicles, which, in turn, leads to various endocrine disorders. In the present work, the steroidogenic activity of theca and granulosa layers from preovulatory follicles of laying hens of different ages was studied in vitro. Young hens aged 32-33 weeks with a long egg clutch and hens aged 74-76 weeks with a short egg clutch were used in the experiments. The granulosa and theca layers were isolated from the two largest preovulatory follicles F1 and F2 and cultured separately for 18 h. After culture, the concentration of sex steroid hormones in the media was determined by ELISA. The production of progesterone by the granulosa layer was 1.5-2.0 times higher in reproductively aged layers than in young layers. Concurrently, the secretory activity of granulosa cells increased with the development of follicles from the F2 stage to the F1 stage only in aged birds (from 74.0±7.5 to 97.0±10.9 pmol/mg tissue, P<0.05). Furthermore, testosterone production by the theca layer in aged hens was 2.0-2.8 times higher than that in young hens, but did not change significantly with the growth of follicles in birds of both groups. At the same time the ability of theca cells to secrete estradiol-17β was 1.6-2.3 times lower (P<0.001) in F1 than in F2 follicles, regardless of the age of the birds. The findings indicate that the processes associated with ovarian aging modulate the steroidogenic activity of follicular cells in laying hens, with the age-related reduction in the egg clutch being related to an increase in the basal production of progesterone and testosterone in the two largest preovulatory follicles.

Modified lipid metabolism has a negative effect on the fertility of cows. The aim of the research was to study lipid metabolism in the pre- and postpartum periods in primiparous cows with different signs of the impaired reproductive function. At 8, 6, 4 and 2 weeks before calving and 2 and 7 weeks after calving, the animals were bled to analyze the content of phospholipids and triglycerides. Based on the assessment of the functional state of the ovaries 7 and 9 weeks after calving, the cows were divided into three groups: I - without signs of ovarian hypofunction (n = 31), II - with moderate ovarian hypofunction (n = 13), III - with deep ovarian hypofunction (n = 14). After 12 months of lactation, animals without a diagnosis of deep ovarian hypofunction were divided into 3 groups: 1 - with an open days period of less than 125 days (n = 12), 2 - with an open days period of more than 125 days (n = 21), and 3 - cows that remained infertile (n = 11). The phospholipid concentration increased 1.6-1.9 times (p<0.001-0.05) between the 2nd and 7th weeks after calving in the blood of cows of all studied groups. Meanwhile, in groups II and 3, it decreased 1.4-1.5 times (p<0.05) between the 4th week before calving and the 2nd week of lactation. Seven weeks after calving, the phospholipid content in the blood of group I animals was 1.2-1.4 times higher (p<0.001-0.05) than in animals of groups II and III. In addition, this indicator after 2 and 7 weeks of lactation was 1.4-1.5 times higher (p<0.05) in group 1 than in group 3. The concentration of triglycerides decreased by 1.3 times (p<0.05) between the 2nd week before calving and the 2nd week after calving in the blood of group I cows and by 1.5-1.6 times (p<0.05) between the 6th week before calving and the 7th week after calving in groups II and III. In group 1, it increased 1.6 times (p<0.05) between the 8th and 2nd weeks before calving, and then decreased 1.5 times (p<0.05) by the 2nd week of lactation. This indicator decreased 1.4 times (p<0.01) between the 2nd week before calving and the 7th week of lactation in group 2 and did not change throughout the observation period in group 3. After 7 weeks of lactation, the content of triglycerides in the blood was 1.4 times higher (p <0.05) in group I than in groups II and III and was 1.3 times higher (p <0.05) in group 1 than in group 2. The data obtained suggest that the peculiarities of lipid metabolism during the pre- and postpartum periods are associated with various states of the reproductive system in primiparous cows.

In the present studies, we studied and tested various criteria for evaluating donors before carrying out fetal transplantation. The main objectives of the study were: to study the prevalence of gynecological pathology in cows, which are potential candidates for embryo transplantation, to determine the relationship between the concentration of carotene and the level of progesterone as a marker of ovarian activity. It was found that the greatest number of complications during childbirth were recorded during the period of fetal excretion, which were observed in 72% of animals, and in the subsequent stage of labor, which were observed in 68% of animals. In the postpartum period, inflammation of the genital organs was most often manifested in 23.6% and uterine subinvolution 13.89%. Further, in the postpartum period, the concentration of progesterone in milk in cows was investigated and the functional activity of the corpus luteum was determined. For the study, a group of 32 cows was formed whose genital involution had ended. The study of progesterone was carried out in dynamics, twice on the 35th and 45th days after calving. The study found that in 71.86% of cows the amount of progesterone was less than 5 ng / ml, which indicates a low activity of the corpus luteum. In 28.13% of animals the concentration of progesterone on the 35th day was higher than 5.67 ng / ml and averaged 8.22±3.83 ng / ml and significantly decreased to 1.86 ± 1.69 ng / ml. The number of cows with a consistently low P4 concentration in two measurements was 56.25% of the total number of animals in the group. Thus, it was found 12.5% with a reduced activity of the corpus luteum in the luteal phase. Also, in experimental animals, a biochemical study of blood serum was carried out and a pronounced relationship with the concentration of carotene in the blood was determined.

Reproduction and culling of productive animals are the main factors that affect the number of cows in a herd. Timely determination of fertility in replacement heifers with subsequent culling of problem heifers will help reduce direct economic losses in breeding dairy cattle. When making a diagnosis, veterinarians should exclude all forms of temporary or permanent infertility, including Congenital anomalies (infantilism, freemartinism, deformities, etc.).

In order to establish the hormonal status of heifers-freemartin in the blood serum, the concentration of sex hormones (progesterone, estradiol-17ᵦ, and testosterone) and anti-Müllerian hormone (AMH) was determined.

Studies of the level of AMH using an enzyme-linked immunosorbent assay in blood serum have proven the possibility of early assessment of fertility in heifers. This method will allow early culling of Freemartin heifers from a productive herd. The study of AMH levels showed that its amount directly correlates with fertility in cattle, regardless of the period of the estrous cycle. When the concentration of AMH in the blood serum is below 100 pg / ml, heifers are not capable of fruitful insemination, while a high level of anti-Müllerian hormone (more than 380 ng / ml) makes it possible to successfully fertilize animals on the first attempt. All clinically healthy replacements obtained during a single pregnancy were successfully inseminated. At low concentrations of anti-Müllerian hormone, Freemartin heifers were sterile, even after hormonal stimulation (Co-Synx) and sperm doses were administered without clinical manifestation of sexual desire.

The introduction of testing for the level of AMH by the ELISA method in the mandatory gynecological clinical examination of cattle in livestock enterprises is expedient and effective.

A preliminary test of two variants of the honey diluent, PP Pechnikov and PN Skatkin, for cryopreservation of the sperm of honey bee drones was carried out. The first option: honey 10% - 50 ml, lactose - 10 mg, sucrose 10 mg, egg yolk - 2.5 ml, glycerin 3% - 6 ml 250 μl. In the second variant, glycerin is replaced by DMSO 10% in a volume of 5 ml. A 10% working solution of honey was prepared in deionized water according to the method of P.P. Pechnikov and P.N. Skatkin on the basis of honey from white acacia. In a 1.8 ml Nunc cryotube, 80 μl of freshly prepared diluent was added, then 10 μl of semen, and everything was mixed. The samples prepared in this way were placed in visotubes, which, in turn, were immersed in a vessel with water at room temperature (24-26 ° C). After that, this vessel was placed in a refrigerator for 2 h at 3 ° C for equilibration. The cryostorage period was one day.

The samples were thawed in a water bath at 37 ° С for 1 min. After thawing, 1 ml of a diluent heated to 37 ° C was added to the sample, carefully pipetted and left for 5-10 min. Then, a single centrifugation was carried out for 3 min at 3000 rpm. After centrifugation, the supernatant was removed and sperm was collected from the bottom of the cryovial using the capillary of the syringe block for uterus.

The results of the analysis showed that the most optimal option for artificial insemination of queen bees is the option with DMSO. A single insemination with a volume of injected semen of 8-10 μL was used. For insemination, we used infertile queens aged 7–8 days. The printed brood was counted by direct counting of the number of bee and drone cells.

It was found that natural bee honey from white acacia showed the properties of a cryoprotectant, which in combination with egg yolk and DMSO made it possible to obtain brood of working bees over 50%.

The Arabian horse is the world's oldest cultural breed of hot-blooded horses. Traditionally, the Arabian horse has been bred “pure” for centuries, without using the blood of other breeds. Nowadays purebred Arabian horses are very popular in many countries. Arabian horses are bred for shows, equestrian sports, flat races and endurance races. In spite of the common origin of all purebred Arabian horses, the breed is subdivided into different types as historically selection criteria for breeding in some regions can vary significantly.  The modern population of purebred Arabian horses in Russia has been developed as a result of the breeding use of a limited number of animals imported in the 20th century, mainly from France, England and Poland. The Russian horse breeders distinguish 4 intra-breed types of purebred Arabian horses that differ in morphological and physiological characteristics: “Siglavi”, “Koheilan”, “Koheilan-Siglavi”, “Hadban”. The aim of this study was to investigate the genetic variability in 4 intra-breed types of purebred Arabian horses of the Russian population using DNA markers. A total number of 263 adult horses were genotyped by using 17 microsatellite markers: AHT4, AHT5, ASB2, ASB17, ASB23, CA425, HMS1, HMS2, HMS3, HMS6, HMS7, HTG4, HTG6, HTG7, HTG10, LEX3, VHL20. A total of 100 alleles were identified across all estimated loci. The highest level of genetic diversity was found in the group of “Hadbans”. The lowest level of genetic diversity was detected in the group of “Koheilan-Siglavies”

The Pechora zonal type (PH-1) was obtained by absorbing crossbreeding of local Northern komolog cattle with the Kholmogorsky breed. Currently, Kholmogorsky cattle are on the verge of extinction, which is due to the widespread metisation of domestic Holstein breeds. The paper presents the characteristics of the allelofond of the Kholmogorsky herd of the Pechora type (n=66) by 11 polymorphic loci of microsatellites. It was found that the polymorphism of tandem repeats in the Pechora type of Kholmogorsky cattle is observed in all 11 loci, the most polymorphic is the tgla53 locus (10 alleles). The most common allele SPS115 248 occurs with a frequency of 0.606. The average number of alleles for 11 loci was 6.2, and the number of effective alleles was 3.4. the obtained indicators were compared with the values published for Yakut [1], Holstein [2, 3] and Ayrshire cattle [4]. It was found that the Pechora type of Kholmogorsky breed has a higher number of effective alleles than Yakut cattle (by 1.0), and lower than other breeds (by 0.3...1.6). Analysis of F-statistics showed that on average, the deviation of the actual heterozygosity from the expected one is insignificant Fis=-0.004, while other breeds, excluding the sample of Holstein bulls, had a more significant excess of heterozygotes. The smallest genetic distance of the studied population was established with the Holstein breed (d=0.221 to cows and d=0.200 to bulls). A more detailed genetic analysis of individual loci showed that the frequency of occurrence of alleles BM2113 Pechora type is closer to the Yakut (r=0.935) and Ayrshire (r=0.875) than to the Holstein breed (r=316...357).

The clathrate complex of 3- (2-phenylethyl) -2-thioxo-1,3 thiazolidin-4-one with betadex was developed for the first time. 1: 5 ratio obtained by the solid-phase synthesis method, which has a crystalline form in the form of nanoparticles with an average size of 40.5 nm. In the present work, the effect of the created nanoscale form of 3- (2-phenylethyl) -2-thioxo-1,3 thiazolidin-4-one on protein metabolism, growth and development of Wistar rats was first studied. It was shown that the administration of 3- (2-phenylethyl) -2-thioxo-1,3 thiazolidin-4-one nanosized form in rats at doses of 10.0 and 20.0 mg / kg body weight activates the biosynthetic system and promotes an increase in protein deposition in their body. Nitrogen retention in rats of the experimental groups compared with the control increased by 20.0% (P≤0.05) due to a decrease in its endogenous losses, and the urea content in the blood serum was lower by 24.1 and 26.4%, respectively, compared to control. In rats of the experimental groups, the concentration of total protein (P≤0.05), albumin (P≤0.05) and globulins in the blood was higher compared to the control. It was found that in female rats of the experimental groups, in comparison with the control and intact animals, their growth and development were statistically significantly higher. In this case, the optimal dose of the nanoscale form of 3- (2 – phenylethyl) -2-thioxo-1,3 thiazolidin-4-one is a dose of 10.0 mg / kg of rat body weight.

The effect of the plant ecdysteroid-containing preparation of Leuzea extract on the metabolism and productivity of barrows (three-breed crossbreeds Landrace × large white × Duroc) during fattening on low-protein diets enriched with essential amino acids from 130 to 212 days old was studied for the first time. In the control and experimental groups, a low-protein barley-wheat diet with the addition of essential amino acids contained (g / kg) crude protein - 108 g, metabolic energy - 12.5 MJ, lysine - 7.6 g, threonine - 5.4 g, methionine - 5.2 g. In the experimental group, liquid extract of leuzea was introduced into the feed, at the rate of 190 mg / kg. Feeding the barrows during the fattening period of the leuzea extract contributed to an increase in the efficiency of the use of nutrients in biosynthetic processes in animals. In the barrows of the experimental group, the concentrations of total protein (P≤0.05), albumin (P≤0.05), creatinine (P≤0.05), lactate dehydrogenase, creatine kinase, alkaline phosphatase activity at a lower level were statistically significantly higher urea (16.1%, P≤0.05) and glucose (P≤0.05). In the experimental group, during the period of fattening, the average daily gain in live weight was higher (by 10.2%, P≤0.05), the yield in the carcass of muscle tissue (P≤0.05), the indices of lean and meatiness, and lower the cost of feed (P≤ 0.05), crude protein (P≤0.05) and exchange energy (P≤0.05) per 1 kg of gain in live weight, output of subcutaneous adipose tissue and internal fat in comparison with the control. It was concluded that the use of a leuzea extract containing phytoecdysteroids, while feeding low-protein diets enriched with lysine, methionine and threonine, corrects metabolic processes, stimulating the biosynthesis of meat components, and thereby contributes to an increase in the productivity of barrows during fattening.

It is difficult to objectively assess the functional state of the endocrine gland based on the level of hormones in the blood, since hormones vary significantly in absolute values during the day. Therefore, to assess the functional state of the endocrine glands in biological and medical practice, "load" is used. The criterion for evaluating the state of the gland is the change in the concentration of secreted hormone by the endocrine gland in response to the stimulation. As is known, the testis reacts relatively quickly to stimulation with chorionic gonadotropin. This allows us to determine the limiting features of the hormone-synthesizing and hormone activity of the testes and determine the maximum response of the testes to this stimulation. The object of the study was 6-month-old boars of large white breed, Landrace and tempo, 10 heads from each breed. In order to determine the functional endocrine reserves of the testes at 6 months of age, CG (chorionic gonadotropin) was administered intramuscularly at a dose of 1000 IU. HCG was administered 3 times every 72 hours. Blood for the determination of testosterone was taken before administration of HCG and 2.12,24,48 and 72 hours after its administration. Testosteron was determined by the enzyme immunoassay. Sperm counts in 18-month-old boars were studied using standard methods. Performed three-fold loads with an interval of 72 hours showed that the hormone level increased to 7.2±0.6 nmol/l in a large white breed 72 hours after the first administration of HCG, in the Landrace breed to 7.9±0.5 nmol/l, in the Duroc breed to 7.0±0.7 nmol/l, in the tempo breed to 7.0±0.6 nmol/l. After the second injection HCG the testosterone levels in large white breed boars increased by 1.2 nmol/l, and breeds Duroc 1.7 nmol/l, Landrace 0.1 nmol/L. In the boar breed, tempo increased the hormone by 0.4 nmol/l. In this regard, the increase in testosterone in experimental boars continued, which means that the reserves of endocrine function of the testes were not fully realized, so the 3rd stimulation of HCG was also performed. In a large white breed of boars and Duroc, the maximum concentration of testosterone was observed 24 hours after administration of HCG and was 9.2±0.7 and 8.9±0.5 nmol/l respectively. In the Landrace and tempo breeds, the maximum concentration of testosterone was 2 hours after 3 CG stimulation and was 8.2±0.6 and 7.5±0.6 nmol/l. respectively. In terms of sperm, its fertilizing capacity and the production of live piglets per Farrow, the indicators were higher for boars of large white breed and Duroc.

Cycloheximide and 6‐dimethylaminopurine (6‐DMAP) are widely used in protocols of somatic cell nuclear transfer (SCNT) for inhibition of maturation promoting factor (MPF) activity in SCNT-oocytes in the post-activation period of their culture. Nevertheless, you should remember that these agents have a wide range of activity and can conflict with other cell processes. Therefore, a definition of the optimal period of culture of SCNT-oocytes with the previously mentioned inhibitors may help to prevent the undesirable negative consequences. In this research the effects of cycloheximide (10 µg/ml) and 6‐DMAP (2mM) treatments duration (3.0, 4.0 or 5.0 h) on the reprogramming of somatic nuclear was estimated by the cleavage and blastocyst rates, and by the total cell number and a level of apoptotic cell in the obtained cloned blastocysts. The cleavage rate did not differ between the experimental groups, varying from 63.7 to 77.0 %. Also, there was not found an effect of treatment duration of the investigated factors on the development of activated SCNT-oocytes before blastocyst stage. For 3-hr treatment, the blastocyst rate was 19.6 ± 1.8%. The prolonged up to 4 and 5 hours duration did not change this rate. Meanwhile, we found out the effect of culture duration with сycloheximide and 6‐DMAP on quality of cloned embryos. In case of 3-hr treatment, the total cell number in cloned blastocyst was 58.8 ± 2.4. With prolongation of duration up to 4 hours the result was growing up to 76.6 ± 1.4 (p<0.05), but prolongation up to 5 hours reduced the total cell number in blastocyst as compared to that in 4-hr group (p<0.05). The apoptosis rate had no difference between the treated groups and had its variety between 5.4 to 7.0 %. Our date indicate that efficiency of bovine cloned embryo production depends on duration of 6-DMAP and cycloheximide treatment of the SCNT-oocytes in the post-activated period of their culture. The optimal duration according to the described protocol of SCNT for the best quality of embryos is 4 hours.

During cage keeping of minks, one of the important problems is the high level of stress of animals caused by a number of factors: microclimate, feeding, low locomotion, etc. High stress levels have a negative effect on the physiological status of animals and can lead to serious pathological changes. Stress reactions activate neuroendocrine mechanisms, while at the same time mobilizing the body’s protective functions and inhibiting the processes of growth, development and reproductive function. The level of cortisol in the body clearly shows the degree of its stress, since the adrenal glands are responsible for the regulation of the stress response and are a source of catecholamines and corticosteroids. The experiment was carried out on the young mink males. Under observation were 60 animal analogues. Blood was taken from 6 animals from each group at the beginning and at the end of the experiment. An autopsy of 6 male minks from each group was performed to assess the condition of the internal organs. The level of cortisol in male minks at the beginning of the experiment was increased (more than 700 nmol/l). It is shown that with the introduction of the Emidonol 20%, the stress of animals decreases, in comparison with the control. The adrenal mass in the control group was 29% higher than in the group where the additive was used. The cortisol level at the end of the experiment in minks that were the additive was input (541 nmol / L (p≤0,05) significantly decreased in comparison with the control (815 nmol / L). Also, a decrease in the level of stress may indirectly be indicated by a decrease in heart and liver (p≤0,05) and kidney mass, compared with the control group.

The study of indicators of Kaplan indices in dogs has not been previously conducted and their normal values are not described in the available literature. Given the subtlety of the mechanisms of autonomic regulation of the heart, there is a need to expand the diagnostic base for very common heart diseases in dogs.

The aim of the research is to study the Kaplan indices in dogs to assess the possibility of including them in an integrated approach to the analysis of the functioning of the heart in dogs. 74 healthy dogs were examined. The dependence of changes in the Kaplan indices on age was studied. An asymmetric distribution of Kaplan indices in the studied group of dogs was established. Intervalograms were recorded using a computerized polygraphic amplifier "MKS KARDi2-NP" (Russia). Recording was performed on dogs in a resting state, standing or sitting. To analyze the obtained intervalograms, to obtain the values of the Kaplan indices, the integrated instrumental-methodological complex "CONAN" was used.

The following Kaplan indices have been studied: Respiratory modulation index (IDM); Sympathoadrenal Tone Index (SAT); Slow-wave arrhythmia index (IMA).

The normal values of Kaplan's indices were established: IDM, SAT, IMA for dogs. In this regard, the assessment of these indices should be included in the basic set of methods for diagnosing heart disease in dogs. The absence of dependence of changes in indices on age in dogs was found. The lack of research on Kaplan indices requires additional research in groups of different weight on a representative sample.