Existing approaches to in vitro maturation (IVM) of bovine oocytes do not take into account their specific demands during terminal phase of IVM including the need for increasing of their resistance to age-re-lated changes. In this work, we performed for the first time a comparative investigation of nuclear maturation and abnormal changes of MII chromosomes in bovine oocytes after their maturation in single-phase system and different two-phase systems and after the subsequent prolonged culture of the ova. When using the single-phase system, cumulus-oocyte complexes (COCs) were cultured for 24 h in the medium TCM 199 containing 10% fetal bovine serum (FBS), 10 μg/ml FSH, and 10 μg/ml luteinizing hormone (LH). In the two-phase system, oocytes matured in the same conditions for first 16 h and then in a new medium (TCM 199 containing 10% FBS (Control) or the same medium supplemented with 50 ng/ml progesterone) for the remaining 8 h of IVM. After maturation in the single-phase and the two-phase systems, a part of COCs were transferred to an aging medium (TCM 199 containing 10% FBS) and further cultured for 24 h. The state of the nuclear material (stage of meiosis and abnormal changes of MII chromosomes) in the matured and aged oocytes was assessed using cytogenetic analysis. The rate of oocytes being at the MII stage of meiosis after IVM in the single-phase and the two-phase systems was similar and amounted 82.7-86.3%. In addition, no effect of the culture system on the rate of MII oocytes with abnormal morphology of chromosomes was revealed. For the single-phase culture, this rate after the end of the IVM period was 32.2±0.5% and for the two-phase systems culture 38.5±4.0%. The prolonged culture of matured oocytes led to an increase the frequency of destructive changes in MII chromosomes to 56.9±2.9 and 68.4±3.0%, respectively. Progesterone in the IVM medium (during the last 8 hours) also did not effect on the rate of nuclear maturation, but reduced the rate of oocytes with abnormal changes in chromosomes: after IVM, as compared with the Control and the two-phase system; after 24-hours prolonged culture as compared to control (P <0.05). The results of the study suggest that the two-phase maturation of bovine oocytes may be used as an alternative to the conventional IVM protocol and that progesterone during the second phase of IVM causes an increase in the quality of ova and their resistance to subsequent age-related transformations.

Purpose: to assess the correlation of serum alkaline phosphatase with the live weight and growth rate of male lambs during the milk and post-milk growing periods.

Materials and methods. The study of indicators of serum alkaline phosphatase activity in 74 male lambs aged one and five months was carried out in connection with the intensity of growth and the peculiarities of metabolism. All the male lambs were born at the same time and were raised for up to six months under similar feeding and maintenance conditions. To study the dynamics of changes in the live weight of young animals, individual weighing was carried out monthly with an accuracy of 0.1 kg. Based on the results of weighing, the absolute, relative, and average daily live weight gains were calculated and the animals were divided into three groups. The analysis of the serum for the content of the studied parameters was performed by photometry with the help of the corresponding sets of reagents of the company «VitalDiagnostics SPb».

Results. During the observation period, the average increase in live weight of male lambs was 21,14 kg, or 136,75 g per day. At one month of age, the activity of alkaline phosphatase was 188,61±9.50 U/l, and at five months — 100,01±3,58, or 47% (P<0,001) lower. It was found that the activity of the enzyme during the suckling period was positively associated with live weight and growth intensity (r=0,35 and 0,49), and after weaning from mothers — negatively (r = -0,46 and -0,46, respectively). The activity of alkaline phosphatase was consistently increased in monthly male lamb when they moved from a group with lower productivity to a larger one — 160,5 — 191,4 — 214,9, and in five-month-olds, on the contrary, decreased — 121,0 — 98,1 — 80,2 E/l. At the age of one month, the increase in growth intensity was accompanied by an increase in the blood serum of male lamb values of gamma-glutamyltranspeptidase, glucose, calcium and phosphorus, and a decrease in urea and cholesterol levels. At the age of five months, both the list of links and their vector changed. In the serum of fast-growing animals, the de Ritis coefficient and gamma-glutamyltranspeptidase were higher, but the activity of lactate dehydrogenase and creatine phosphokinase was lower.

Conclusion. The presence of a correlation between alkaline phosphatase and growth makes it possible to use alkaline phosphatase in zootechnical practice and breeding work as an additional criterion for the growth potential of male lambs up to six months in the early stages of ontogenesis. However, the change in the nature of the relationship from plus to minus implies a differentiated approach in the use of this indicator, taking into account the age of the male lambs.

Purpose: Conduct an analysis of cardiac rhythm variability in the cows of the Jersey breed with a different vegetative status.
Materials and methods. Indicators of the electrocardiogram (ECG) and cardiac rhythm variability studied on cows of the Jersey breed (n = 103). For the analysis and removal of ECG, the animal studied used the program «Conan-4.5» in the system of frontal administrations according to the method of P. M. Roshchensky. Clinical research methods were carried out according to the methods of clinical inspection of animals B. V. Ears and included — inspection, palpation, percussion and auscultation of the heart area.
Results. Among the entire studied array of animals, the largest amount was sympathyone — 50,5%, normotonics — 24,3%, hypersympathicotonics — 16,5%. The smallest amount — vagotonic — 8,7%. For the vagotonic, the respiratory modulation index was 8,16±0,02%, the index of the sympathetic system is 43±0,1%, and the index of slowly wave arrhythmia is 0,8±0,1%. This group of cows parasympathetic (software) prevails over the sympathetic department of the vegetative nervous system. For normotonics, the value of the respiratory modulation index was 4,14±0,03%, the index of the sympathetic system is 96±0,2%, and im is 2,5±0,2%. This group is characterized by an equilibrium state between sympathetic department and VNS. The ids for sympathicotonists amounted to 2,78±0,03%, the index of the sympathetic system is 195±0,2%, and im is 8,2±0,1%. At sympathicotonists, which are characterized by a predominance with VNS above software. The hyper smpathetical respiratory modulation index was 1,34±0,02%, ICAS — 588±0,1%, and im is 11,4±0,3%. In hypersympathicotonists, which are characterized by the predominance of the super-viper vehicle of the vegetative nervous system over parasympathetic.
Conclusion. The separation of the entire array on the subgroups based on the vegetative status of animals was based on the indicators of the voltage index of regulatory systems. To confirm the correctness of the separation of the studied array of animals on the subgroup, statistical processing was carried out and a classification matrix was built. Also, to confirm the classification separation matrix, additional statistical processing of the material of the differences between the obtained groups in the square of the distance of the Mahalonobis D2 was carried out. In the course of further registration and mathematical analysis of the variability of the heart rate of cattle (cows of the Jersey breed) with the help of a modern complex electrophysiological laboratory «Conan-4.5» features of indexes of A. Ya. Kaplan were established.

Purpose: Determination of the peculiarities of the behavior and the flow of childbirth in females (wrenches) of the northern home deer of the Even Breed of the Republic of Sakha (Yakutia), depending on the natural climatic zone of breeding.
Material and research methods. Research of the reservation of the hotel's reservoir of the northern home deer was held from April to June in the reindeer herds of the mountain-taiga (FSUE «Yuchjuyuskoye») and the Tundrov zones (SHPZK «Taba-Yana») of the Republic of Sakha (Yakutia) in the conditions of nomadic home reindeer herding since 2013 2018 In the study, the method of observation is used with the registration of motor activity of animals and the activities of individual bodies in a certain living environment.
Results. To fix some patterns and species features of the generic process, 8 main elementary behavioral reactions spent venizables of northern domestic deer per day before childbirth: walking, feeding feed, chewing, leisure standing, rest lying, sleep, urination (how many times / total time), defecation (how many times / total time). Also marked 4 behavioral reactions on the hotel day: the exploitation time of the fetus, the licking of the calf, the time of the calf on his feet after delivery, the first reception of the mosper calf after birth. For each parameter, data reflected in tabular format is obtained.
Conclusion. It has been established that the degree of adaptation of the northern domestic deer to the harsh conditions of existence in various natural-climatic zones of the Republic of Sakha (Yakutia) is very high, which is manifested in a minor difference in the duration of the generic process and behavioral reactions at the vainer of the mountain and tundra and tundra dilution zones.

Purpose: to study morphometric parameters of absolute values of linear and weight body sizes, specific growth rate and relative (allometric) growth of chicken embryos of the «Lohmann Brown» egg cross at different stages of embryogenesis.
Materials and methods. The absolute values of linear and weight body sizes of chicken embryos were estimated using morphometric methods. The formula of I. I. Schmalhausen and S. Brody was calculated the specific growth rate of length and body weight of chicken embryos by the formula simple allometry — relative (allometric) growth of body length from body mass.
Results. This is manifested in the increase in the specific growth rate of body length of the embryo at 5 days of the late-fetal stage, 8th, 10th, 12th day of the early-fetal stage and specific growth rate of body mass for 6 days of the late-fetal stage of the late-fetal stage, 10-th and 12-th day of the early-fetal stage. At all stages of embryo development, there is a negative allometry of the relative growth rate of the embryo body length, except for 14 days of the mid-fetal stage, where negative isometry was observed (b=-1,000). Higher values of the power coefficient reflecting the slower growth of the embryo in length relative to their body weight, observed in late-fetal stage at 5-6 days (b=0,913-0,995), in early-fetal stage — 10-e (b=0,960) and 12 days (b=0,928), in mid-fetal stage — 13-th (b=0,821) and 15 days (b=0,981) and late-fetal stage — 20 days (b=0,836).
Conclusion. New knowledge derived from this study can be applied not only in research, but in the poultry industry to assess the impact of preincubation processing of eggs on the development of embryos and embryonic mortality at different stages of embryogenesis, the definition of normal and abnormal development of embryos, as well as to assess the impact of other factors, artificial incubation on embryo development, hatchability of eggs and safety of poultry.

Purpose: Assessment of the possibility of using ultrasonography for early prediction of the response of the functional activity of the ovaries to the introduction of some hormonal drugs at ET.
Materials and methods. The study was conducted on 42 cows of various breeds (Holstein, Ayrshire, Black-and-white breed of cows) — potential donors of egg and embryos in several farms of various organizational and legal forms of ownership of the Saratov and Volgograd regions of the Russian Federation. Cow donors are selected taking into account anamnestic data. To assess the full response of the ovaries, two experiments were produced to carry out the stimulation of supersuvulation: the first study was introduced on the 10th day of the estrous cycle, 9 animals of follitropine on the developed protocol, and 7-animals — «plus» and the second study — for 11 days of the estrous cycle 8 — animals injected follitropine, and 6 cows — «plus» in the 4-day protocol. The synchronization of the estrus was carried out according to the generally accepted protocol. For morphological studies, the donor cows were extracted by ovaries and studied their physical characteristics, such as volume, weight, thickness, width, gonad length, the size of yellow bodies and follicles. For a more detailed study, ultrasonography was carried out using a Mindray DP 10 VET portable scanner with a rectilinear rectal sensor 7.5 MHz by 10-11 (before the administration of the drug) and zero (after the introduction of the follicularity of the hormonal preparation) of the estrous cycle days.
Results. The average rate of ovaries before the introduction of drugs, on the 10th day of the estrous cycle, was 11.103±2.275 cm3, the volume of yellow bodies — 7,122±3.435 cm3. The average volume of yellow bodies to the ovary was 48.7±1.3%. The level of supervision reaction depends on the quality of the yellow body in the middle of the L-phase, at the time preceding the beginning of the gonadotropic stimulation from donor cows.
Conclusion. Based on the data obtained, it can be concluded that the visual analysis of sleepograms is an acceptable method for predicting the suitability of donor cows prior to the beginning of animal treatment with gonadotropic drugs and can be used as the animal selection criterion into a group of potential donors. Using ultrasound echography, relevant data reflecting the morphological and functional state of cows ovaries were obtained.

Purpose: study the phenotypic parameters of fertility, milk production and survival of the same cows during their lifetime in the herd (from birth to the fourth calving) depending on the age of the first calving to better understand the factors that will improve the productive longevity of cows.
Material and methods. Studies were conducted in a commercial herd with Holstein cattle located in the Central region of the Russian Federation. For the analysis, we used data from cows (culling and alive) of the same year of birth (2014), which were born, grew, calved and reached 4 calving (2019). The generated database contained complete information about the animal throughout its life in the herd (n=842). Depending on the actual age of the first calving (26 months), which reflects the growth rate, cows were grouped into groups: less than 23 months, 23–25 months, 26–29 months and over 30 months. In each group, we studied (1) reproductive parameters of heifers (number of inseminations per conception, age of the first insemination); (2) reproductive parameters of cows (number of inseminations per conception,, number of days from calving to first insemination, number of days from first to last insemination, conception rate at first insemination, number of days from calving to conception); (3) 305-day milk yield of first, second and third lactations; (4) lifetime milk production; (5) longevity index (proportion of days spent on milk production); (6) survival rate (proportion of cows surviving from first calving to the second, third and fourth calving, respectively). 
Results. Cows with an average age of the first calving of 22.1 (<23 months) and 23.7 (23–25 months) months during the growing period with a minimum interval from the first insemination to conception (68 days) had a high percentage of pregnancy from first insemination ≥84%. Survival rates from 1 to 2 calving ranged from 82.7% to 83.1%, to 3 calving-from 55.3% to 62.7%, to 4 calving — from 6.0% to 11.9%, respectively. Optimal intervals between inseminations allowed to finish 3 lactation, in general, 73% of cows and 45% were still alive and producing milk. For 3 lactation (for 305 days) they produced from 17280 to 17805 kg of milk. What was spent on from 45% to 48% of a productive life. Cows with an average age of the first calving of 26.9 (26–29 months) and 32.5 (≤30 months) months during the growing period had a low conception rate of 44% and 5%, long intervals between inseminations (from 113 to 219 days). In lactation, there was a tendency to increase the average days from calving to the first insemination (in 1 lactation — from 85 to 88 days, in 2 lactation — from 82 to 83 days), from the first insemination to conception (in 1 lactation — from 117 to 122 days, in 2 lactation — from 88 to 92 days), which led to an increase in the days from calving to conception (in 1 lactation — from 156 to 164 days, in 2 lactation — from 125 to 140 days). Such cows had the lowest fertility, survival rate, and therefore the short productive life.
Conclusion. Cows with the age of the first calving ≤25 months without serious problems during the rearing period were distinguished by the best indicators of reproduction and productivity. They reached the third lactation faster and ended it by producing the largest amount of milk, which spent 45 to 48% of their productive life.

Purpose: Identification of the dynamics of the mass of carcass and mass of muscle tissue in the carcass, as well as the speakers of the cost of feed for the increase in the purebred, two-rigorous and three-stenged young children, as well as the establishment of the degree of affect of the father's rock when crossing the increase in the growth of carcass in the fattening of animals from Live mass 100 kg to 125 kg.
Materials and methods: For the study, the method of regression analysis was used, the source material for which the data of the control fattening and the subsequent feasibility of descendants from the purebred breeding of the Belarusian large white (BKB), Belarusian meat (BM), two-rigorous crossing with their use and use and Three-rigorous crossing using at the first stage of the above-mentioned rocks, and at the final stage — boars of rocks (EB) Estonian bacon, Yorkshire of German (NY) and Canadian (ky) breeding, Landraz German (NL) and Canadian (CL) selection, as well as Durok Belarusian (database). German (ND) and Canadian (CD) selection. The costs of feed units per 1 kg of the growth of live masses, masses of carcass and masses of muscle tissue in a carcass in a fattening to the specified weight conditioning are determined. Revenue was calculated from the sale of carcass growth and the level of profitability is determined or the unprofitability of its production during the fattening of the young of each of the studied combinations to the above-mentioned weights.
Results. It has been established that fattening of the BKB purebred animals, two-rigorous young BKB X BM and three-rigorous youngsters using at the final stage of the crossing of the Estonian bacon rock to the living mass over 100 kg are not profitable due to a reduced level of meat qualities with increased consumption of feed for growth. The fattening of the young Belarusian meat breed and three-stenged places using at the final stage of the crossing of the landscape of the German and Canadian breeding breed of profitable only to a vibrant mass of 105 kg at a profitability level of 2.5%, 6.7% and 7.1%, respectively. The fattenings of three rigorous youngsters from the final breed of the Yorkshire of the German and Canadian selection of profitable to the vibrant mass of 105 kg with a profitability of 10.3% and 11.0% and up to 110 kg with a profitability of 1.9% and 2.8%. Application at the final stage of the three-stenged crossing of the droke breed turned out to be the most efficient. At the same time, the Belarusian type of Duxa provides profitable fattenings of young to the vibrant mass of 110 kg, which makes it possible from each head to additionally get 8.48 kg of masses of carcasses and 5.38 kg of muscle tissue, and the use of boars of the divok canadian and German selection provides profitable fattenings of young to the vibrant mass of 115 kg, and makes it possible to additionally obtain from each head of 13.11 and 12.84 kg of masses of the carcass and 8.16 and 8.13 kg of muscle tissue in comparison with the caution with a living mass of 100 kg.
Conclusion. When analyzing the data obtained, it was established that during the final fattening, the processes of increasing masses of the carcass, as well as the mass of muscle tissue in it in animals of different breed combinations, proceeded with different intensity, which was reflected in the efficiency of production of pig breeding.

Purpose: Install the influence of the «small diameter of the egg» on the living mass and the reproductive qualities of chickens of meat crosses and the quail of meat breeds.
Materials and methods. The selection was carried out along egg production and mass of eggs and additionally on the average small diameter of 5 eggs by value of ≥0.5σ from the average for the herd, while the evaluation on the basis of the «small diameter of the egg» was carried out in chickens aged 238 days of life, quails — 70 days of life. Calculated the average for each female and the average for the herd. For further reproduction, chickens carrying eggs with a small egg diameter ≥0.5σ from the average for the herd. Studies were held in SibNIP on quail and on the courses.
Results. In the initial period of the egg laying, the individual variability of the small diameter of the egg — more than 10% (in the future, the figure decreased). The close correlation rate of the small egg diameter in the first half of the egg laying with such at the end of the bird's operation period was revealed. It has been established that the large diameter of the egg has a positive reliable connection with a lively mass, but negative with egg production. The reliable correlation rate of the small diameter of the egg with a live weight at a 42-day age, as well as with the derivation of eggs. The inheritance coefficients of the small diameter of the egg are comparable to the inheritance coefficients of the mass of eggs and significantly exceed those for a large diameter of the egg. The selection according to the small diameter of the eggs by ≥0.5σ from the average for the herd led to the fact that the chickens of the experimental groups reliably exceeded the live weight in the SB level of 1.57%, in the line G8 — by 1.35%. The superiority of a lively mass of quail of experienced groups was more pronounced than that of the chickens: the Pharaoh breed — by 4.15%, the Texas white breed is 4.22%. In relation to the derivation of eggs, a similar trend was traced. The derivation of eggs in quails of experienced groups was more than 4.59–4.98%; Country, respectively, 4.57–5.22%. Egg production of females of comparable groups of both chickens and quail was almost on the same level, and the difference was unreliable.
Conclusion. It was established that a new method of breeding the poultry of the meat direction of productivity allows without decreasing egg production to increase the living mass of chickens of meat crosses by 1.5%, rewinds of meat breeds — by 4%, the derivation of eggs, respectively, by 4–5%. The method is intended for early prediction of females productivity during breeding selection.

Purpose: To assess the productive qualities of donor cows, taking into account the transmitting capacity of their families. To study the possibility of using this criterion to predict the breeding qualities of descendants.
Materials and methods. The assessment of the transmitting ability of animals was carried out according to the System for assessing the breeding qualities of dairy cattle by transmitting ability (2010). A genealogical database of first-calf heifers in herd «Petrovsky» (more than 9500 heads) has been formed. The estimation of the transmitting capacity of productive traits of 111 families, to which 132 cows from the donor herd belonged, was carried out.
Results. It was found that 44 donors belonged to the «best» families in terms of milk yield and 348 embryos were frozen from them. From 31 donors from the «worst» families in terms of milk yield, 199 embryos were frozen. Linear profiles of families were compiled according to the characteristics of their transmitting capacity for five indicators of milk productivity. It is shown that the probability that the descendants of cows from the «worst» families in terms of transmitting ability will have high rates for the trait we are interested in is approximately 18–20%. In families of the «best» category, this probability is 45% or more.
Conclusion. Evaluation of productive traits in terms of transmitting capacity is an important additional criterion when choosing the most valuable cows as embryo’s donor. Compilation of linear profiles of families allows you to obtain objective information about their breeding value in relation to productive traits.

The research goal is to carry out comprehensive studies to define the biological and chemical characteristics of the young Poltava Meat Breed boars’ bacon for further work with existing genotypes and creating new ones.
Materials and methods. The research was carried out on bacon samples taken from Poltava Meat Breed boars of different genotypes during the «control slaughter» at the age of reaching the live weight of 100 kg. Purebred Poltava Meat Breed boars were divided into two groups according to the principle of paired analogs: the group I (control) contained animals of «clean» breeding lines (16 heads), and the group II (experimental) contained animals with 12,5% of the Finnish Landrace blood (14 heads). The thickness of the bacon, its morphological structure and its chemical features were studied. All the results obtained were then processed by statistical methods.
Results. It was found that Poltava Meat Breed boars, regardless of the genotype, had bacon thickness values below the Poltava Meat Breed target standard after reaching the live weight of 100 kg, with very low variability of the indicator (1,05–1,69%). However, there was no significant difference between the groups. During the morphological study of the samples, qualitative differences in the bacon of animals from different groups were noted. In the first group, the subcutaneous tissue (bacon) is subject to more pronounced destructive changes due to the intensified process of fatty degeneration. The fat cells of animals with Finnish Landrace blood were slightly smaller, but no significant difference between the area of fat cells in boars of different genotypes was found. The variability of morphological parameters in both groups was average (23,91% and 16,23%). The infusion of Finnish Landrace blood to the Poltava Meat Breed boars led to a change in the chemical composition of bacon, such as: an increase in the amount of moisture by 8,58% (p≤0,01), protein by 3,62% (p≤0,01), a decrease in the amount of fat by 9,25% (p≤0,01), to a decrease in the saponification number by 8,36% (p≤0,01) and the iodine number by 10,48% (p≤0,01).
Conclusion. The bacon of Poltava Meat Breed boars is characterized by biological and chemical features due to both species and genotype. The established features of the bacon of Poltava Meat Breed boars indicate a significant decrease in its quality in the case of Finnish Landrace blood infusion. Intensive selection for meat content of Poltava Meat Breed pigs leads to a significant decrease in the thickness of the bacon and excessive selection pressure.