When selecting bulls, it is important their age and the method of breeding to obtain of the new generation. The Breeding Value (BV) of bulls was studied depending on their age (up to 10 years, 11–15 years, over 15 years) and the method of breeding their daughters (cross lines with inbreeding and intralinear). It was found that with an average BV of 92 bulls -11±3 kg of milk the best BV of milk yield + 14±3 kg of milk in middle age (n=45) in contrast to bulls of older and younger ages (n=26, -60 ± 6 kg; n=21, -4±2 kg, respectively). Distributing the bulls by the level of the BV, there is a decrease in improvers in the older group compared to the average group of bulls. When calculating the BV bovine, depending on the method of breeding daughters, it was found that the proportion of cross-offspring decreases on average from 78,8% in the middle age group to 61,8% in the older age group. Among improvers, the percentage of such animals is still more than 87,2 against 43,8% respectively. The average-grade improver BV are higher than the representatives of the other two groups by 47 and 93 kg of milk, respectively.
The share of intralinear daughters is greater in the group of bulls of the old selection (27,1% versus 20,3 and 17,0%). By the value of BV, their number increases among bulls of the new genetics and old selection from 12,3 to 26,6 and from 24,7 to 53,3%, respectively. The BV of the improvers of the old selection (85±7 kg of milk) is higher than the bulls of the other two groups. When selecting the best bulls, it was found that the best in the middle BV, as well as in the BV cross and intralinear daughters in the group of young bulls were three producers, and the middle and older groups correspond to the same bulls. Therefore, when reusing an estimated bulls, it is necessary to calculate the BV depending on the method of breeding their daughters.

It is necessary to determine through the correlation variability the direction of changes in the relationship between the signs of the exterior and milk yield in the process of age development of bulls and their daughters. Type traits of four age groups of 45 bulls taken at different periods of their life (12, 16, 18, 24, 36, 48 months), their daughters in the first lactation (8366 heads) were analyzed and founded relationship between the measurements of father - daughter and economically useful traits. Young bulls at the age of 7.2 years from the group (5 to 9 years) are the best in all measurements in all evaluation age periods the estimates exterior compared to other groups. High and reliable relationships were found for stature, body depth, girth of pastern and selectively for other measurements of bulls taken at different measurement times, which gives the right to predict the body type of animals during ontogenesis. Calculated 92 correlation coefficient of measurements of bulls and the same of daughters, as well as their milk yield, taking into account the age of the manufacturer and the date of measurement. Reliable correlation coefficients were obtained from the stature and body depth in bulls of different ages. The relationship measurements of a body of bulls with milk yield of their daughters in most cases low, but reliable (as a large number of daughters). Milk yield of daughters for 305 days of lactation significantly correlates with their body depth and girth of pastern 0,428*** and 0,307***. The relationship between mother and daughter on a number of exterior features is established. The largest - milk yield with stature 0,153 **, body depth 0,173 **, girth behind the shoulder blades 0,154 **, slanting body length 0,157 **. For daughters, milk yield for 305 days of lactation reliably correlates with their body depth and girth behind the shoulder blades 0.428 *** and 0.307 ***. The measurement of the body depth has been established: the body depth bull - daughters 0.156 **; body depth mother - daughter 0,707 **; body depth daughters with a yield 0.428 **; the body depth of bull with daughters milk yield 0.173 **.

The main selection and genetic parameters of the linear and classification traits of the exterior of 1,438 first calving cows of the Leningrad, Kirov and Vologda regions of the Russian Federation. Most variable indicators were "udder cleft" in all three populations (30.65; 36.67; 30.47 %) and "body depth" in the Vologda and Leningrad populations - 35.57 and 23.40 %, respectively. The “rump width” in the Vologda population at Cv = 41.6% had a rather low absolute score (2.31 ± 0.08 points), therefore more careful selection is needed. The soft pasterns (26.8%), additional teats (26.2%), and slack back (8.3%) were the most common deficiencies. Less common were a peaked rump (6.2%), a high-set tail (4.8%), and a pterygoid scapula (4.1%). The construction of linear profiles of bulls Geyser, Lepa, Landskape using the standard transmission ability (STA) for each linear and classification types was carried out. The largest positive correlation values of the rear udder width (0.30, P≤0.001), front length udder (0.24, P≤0.001), body depth (0.12, P≤0.001) and dairy form (0, 10, P≤0,001). Reliability negative relationship between the corner rump and milk yield -0.09 (P≤0.001).

The Finnish population of the modern Ayrshire breed is known to have been formed as a result of a complex reproductive crossing of the Ayrshire breed with a number of northern breeds. The Russian Ayrshire population is a reflection of global trends in working with livestock in different countries, namely Scandinavia, Finland and Canada. The purpose of the research is to assess the ratio of the breed component in the Ayrshire herd of Public Company "BP of V.I. Chapaeva" for the last 10 years and the dynamics between the closest generations (the dairy herd and the replacement population).

With the help of electronic databases of bulls and mothers of Ayrshire breed bulls of the Selection Breeding Center (RRIFAGB) 13820 pedigree records were studied, including 2324 heifers, 2741 cows of dairy herd, 8755 archival records of the breeding stock.

It has been established that fathers of mothers and fathers of mothers of mothers in the herd pedigree are most often represented by bulls with simple blood characteristics: usually Finnish, less often Finnish-Swedish, even less often Canadian selection.

The sum of the component pedigree, approved by the FABA, a herd of PC "BP of V.I. Chapaeva" on average since 2013 meets the requirements of section A (Main book). During this period, the share of Finnish Ayrshire is growing and the share of Canadian Ayrshire is decreasing, with constant weight of red Swedish and Norwegian red breed components. Other components of the breed are partially found. Consequently, in the south of Russia, a herd of Ayrshire breed with Finnish-Canadian genetics is used, selection is conducted against the background of climatic and feeding conditions that are not typical for breeding history.

In the stables and pasture system, the success of the formation and development of herds on new farms is determined by the adaptive response and viability of cattle obtained in different countries and breeding systems, which was the purpose of the work. The object of the research was a herd of Ayrshire cattle, originally formed by heifers from 15 farms of the Leningrad region (n=843), Finland (n=684), Swedish red cattle of Sweden (n=115), as well as their reproduction - the first and second generation. Cattle of the Leningrad selection, with a similar duration of productive life (41,7…42,7 m.) and the number of calving (3.10...3.29) exceeded the Finnish and red-Swedish breeds in the number of effective daughters of the first reproduction introduced into the herd by 9.9...17.9%. The advantage of domestic genotypes is provided on the one hand by the increased number of cows of mothers by 4,9...6,8%, and on the other by the smaller share (-7,6...-8,1%) of cows with only one effective daughter. Milk productivity on average for all lactation and the number of offspring of female have a positive conjugation. Thus, cows that had no daughters or one daughter in the herd on average for all lactation were inferior in milk yield to mothers by -3553...-1103 kg (P≤0.95...≥0.999), as well as peers who had several daughters by 167..406 kg (P≤0,95...≥0,99). Thus, the Ayrshire cattle of domestic selection surpasses import on reproductive ability, relative number of effective mothers and daughters. In selections for cultivation it is necessary to use bulls with high adaptive value having disposal of young growth to 3 months no more than 6%. During the period of adaptation and acclimatization, the conditions of keeping and feeding should ensure the productivity of cows at the level of mothers, with an acceptable reduction in milk yield of not more than 12%.

The results of the study on the influence of cows age and the genotype of Ayrshire sires on the absolute (ANSC) and logarithmic (scoring estimation, SENSC) number of somatic cells in milk (24,800 individual milk samples were tested) are presented. It is established, that cows have a minimum NSC (106.4-103.2 thousand / cm³) in the first lactation. As animals mature, the number of somatic cells increased and reached a maximum in the fifth lactation and older (326.5-413.2 thousand / cm³), that is 3.1-3.8 times more than that of first-calving cows. The presence of cows of a given age in a herd can be a risk factor for increased udder inflammation. The hereditary effect of 36 bulls on NSC in milk of daughters was evaluated (24362 tests). The absolute value of ANSC for the daughters of the best and worst bull varied from 65 to 547 thousand / cm³, logarithmized (SENSC) - from 1,260 to 3,789 points. These differences indicate a significant effect of the fathers' genotype of on somatic cells content in milk of daughters. In the first lactation, the heritability coefficient of the NSC scoring was relatively low, but reliable (h² = 0.0369; P <0.001). The value of h² for this trait is rather high when taking into account all lactations of daughters (0.1267; P <0.001) and it agrees with the data of other researchers. The heritability coefficient of the absolute number of somatic cells was much lower (0.0497), what confirms the conclusion about the worst suitability of ANSC for use in breeding. With an increase in the multiplicity of testing during lactation, the h² value for the indicators of content and milk properties increased significantly. The presented materials show the possibilities of using the NSC scoring in breeding for increasing the resistance of cattle to mastitis.

In each climatic zone are engaged in cultivation of the breeds of the dairy or combined direction of efficiency which are well adapted for local conditions. However, the research of a possibility of instilling in the local cattle of the best manifestations of other breeds or its gradual replacement, with preservation of adaptive opportunities, gains the scientific and practical importance. For increase in production of milk it is necessary to try to obtain fuller realization of genetic potential of the cattle, both at thoroughbred cultivation, and when crossing with highly productive breeds. When crossing the dress should seek to keep improvement of economic and useful signs of breed local animal’s adaptive qualities of the initial, zoned breed. Comparative assessment of efficiency of hybrids of the different krovnost zoned in a droughty zone of Dagestan of red steppe breed with highly productive ayrshire is relevant. It is established that hybrids of the first generation authentically surpass initial red steppe breed in amount of milk for a lactation and to contents in it valuable nutrients (fat, protein, etc.). In the second generation characteristics of efficiency concerning the first generation also improve a little. With age animals adapts to specific economic conditions better that brings to fuller manifestation of hereditary potential of animals (heredity of the improving ayrshire breed) what fat content in milk for the third lactation at cows of two adjacent generations of hybrids testifies to. For the first lactation of difference between generations on the fat content of milk makes 0.04%, and on the third - 0.36%, and on milk fat for a lactation - 4.0 and 13.0 kg, respectively. In general, it is possible to note that in process of increase in a share of blood of ayrshire of a hybrid are more and more preferable, than the red steppe breed of the dairy cattle zoned for a droughty zone. From the first to the second generation on indicators for the third lactation reliable essential advantage on the milk fat content, milk fat and milk protein. The more heredities of ayrshire, the more they approach on efficiency the improving breed in this zone of cultivation.

Currently, the state program for the development of agriculture is aimed at the implementation of the main measures - for livestock breeding to form a breeding base that meets the needs of domestic agricultural producers in breeding products. The key aspects of increasing the productivity of dairy breeds of cattle are the effectiveness of the use of breeding material (bulls) of domestic and foreign breeding. The conducted studies on the population of Ayrshire cattle breed in the Vologda oblast revealed the directions of the breeding process using bulls of different breeding. The superiority of the used bulls of foreign selection in terms of milk yield of mothers is 2546 kg of milk compared to domestic selection. However, the milk yield of daughters of bulls of different breeding has no significant difference-242 kg of milk, and the realization of the genetic potential of milk yield of animals of foreign selection is only 77.0%, which is inferior to domestic - 7.9%. A distinctive feature of domestic breeding cows is a high fat content of 4.40%, which exceeds foreign by 0.10%. According to the genealogical units animals different breeding revealed a different pattern: in foreign, if you increase the milk yield of mothers and fathers of the genetic potential productivity of daughters is reduced; in the country it is noted the inverse relationship. According to foreign breeding revealed prepotent bulls Urho 430 and Anatolia 711 line Urho Erranta 13093 with milk yield daughters 8338 kg, 8181 kg of milk with an average yield of mothers of fathers at the level of 10,000 kg of milk. On domestic breeding the best results are received from the bull singer 418 lines O. R. Lichting 120135 with milk yield of daughters 8409 kg, at milk yield of mothers 9736 kg of milk. Consequently, the use of bulls of foreign selection with high rates of milk yield of mothers and, accordingly, high genetic potential of their daughters does not increase the productivity of cows of the modern herd of Ayrshire breed. Bulls are domestic breeding have a high prepotente qualities and fast transfer of high yields and daughters.

The choice of breed used in the farm depends on the goals pursued by the owner, and the efficiency of animal use. Not only obtaining high productivity is now a priority, but also the efficiency of using animals, their reproducibility and quality of cattle. To assess the prospects for the use of Ayrshire cattle in the Murmansk region, a comparative analysis was carried out of animals of this breed with Holstein-Kholmogory breed in one of the farms - Polar Star LLC. The estimate of the milk yield showed that Ayrshire breed animals are slightly inferior before Holstein-Kholmogory, but despite this they are able to achieve a high level of productivity - 9-10 thousand kg of milk. They are superior in milk quality composition of the Holstein-Kholmogory, even despite its high productivity. The milk fat content of Ayrshire cows is 4-4.2%. Ayrshire cows have a shorter service period and lactation duration, which has a positive effect on the herd reproduction rate. The study of genealogical groups allowed us to identify the best in reproductive qualities - the line Yuttero Romeo. A similar analysis was carried out among families. The one fairly numerous family of Ayrshire breed (family Lomka 1076) was among the best. Evaluation of bulls by fertilizingcapacity did not allow unequivocally distinguish representatives of the Ayrshire breed as leaders. Both the Ayrshire and Holstein bulls had different reproductive abilities. Thus, the analysis made it possible to identify good prospects when using the Ayrshire breed in the conditions of the Far North and them high competitiveness. However, it is necessary to continue to improve the breed, especially in the direction of improving reproductive abilities.

The article is aimed to the assessment and analysis of breeding and genetic parameters of milk production for first-calving cows in Russian dual-purpose cattle population. As initial information, SELEX software databases for breeding animal of five regions in Russian Federation were used: Belgorod, Orel, Kursk and Voronezh regions, as well as the Altai Territory. The total amount of records was 72394, including 21078 individuals of the Simmental breed and 51316 of the Red-and-White breed. To determine the differences and similarity of the variability values and their relationship for milk production traits in each breeds and the common data set have been studied. Based on the obtained results, the breeding equations indices of animals in the combined population of dual-purpose cattle, as well as separately in the Simmental and Red-and-White breeds were constructed. Revealed a significant advantage of the Red-and-White cattle breed for milk yield with a lower content of fat percentage. Evaluation of phenotypic and genetic values of variability and correlations between studied traits revealed same values in the compared breeds, as well as the equal directionality of correlations between them. At the same time, the structures for constructing selection indices differed significantly, which was due not so much to the absolute values of variability (covariance) of traits in the Red-and-White and Simmental breeds, but to differences in their relative values. As a preliminary assessment, a comparative analysis was carried out based on the sires’ estimated breeding values (5 best individuals in milk yield selection index and 5 best individuals in terms of fat percentage), assessed by the developed indices. The analysis showed that the rank correlation coefficients of bulls, estimated by different structures of indices were very high (r= + 0.94…+0.95 by comparing breeds under the whole population and r= + 0.99 in comparing between Simmental and Red-and-White populations). The results obtained provide actual information for choosing the optimal way for breeding control and management in Russian dual-purpose cattle in the future.

The purpose of this study was to identify the relationship of the body condition score (BCS) of first-calving cows with different physiological condition before and after calving with milk production and reproductive performance. Evaluation of the BCS of Holsteinized black-and-white first-calving cows (n = 509) was carried out using a five-point scale with a step of 0.25 point two weeks before calving, in the first days after calving, during the period of maximum milk yielding, at the end of lactation, during the dry period. The first-calving cows were divided into groups in the period before calving with a BCS of 3.50, 3.75 and 4.00 points, in the period of the pick of milking with a BCS of 2.50, 2.75, 3.00, 3.25 and 3.50 points, loss of BCS - without loss of points, with a loss of 0.50, 0.75, 1.00 and higher points. As a result of the research, it was established that the first-calving cows, who had a BCS before calving, above the norm, were fed 305 and 100 lactation days less by 368 (p <0.05) and 288 (p <0.001) kg of milk and had a shorter service period (16 days at p <0.1) than animals with a BCS of 3.75 points. It was revealed that primary first-calving cows with BCS during the period of the pasture above the norm (3.50 points) were fed for 305 and 100 days of lactation by 1005 and 217 kg of milk less (p <0.01) than animals with a fatness of 2.50 points. In first-calving cows with a BCS in the maximum milk yield period of 3.50 points, the service period is shorter by 40 days with p <0.05 than in animals with a BCS of 2.75 points. It was established that with the loss of BCS during the maximum milk yield period of 0.75, 1.00 or more, primary first-calving cows have higher milk productivity for 305 and 100 days of lactation by 526 and 624 kg of milk and 185 and 201 kg of milk with p <0.05 than animals without loss. First-calving cows, who lost the most in BCS, have the largest service period (178 days) with a difference of 37 days with p <0.05 with a group of animals that had no losses. The phenotypic correlation between the BCS of the cows during the maximum milk yield period and milk productivity over 305 and 100 days and the service period revealed a negative reliable (-0.216, -0.193, -0.228). Thus, for stable reproduction in the herd, it is necessary to create conditions for feeding and housing, contributing to the maintenance of BCS up to calving at the level of 3.75 points, and in the pick of milking, to prevent its decline by more than 0.5 points.

The article discusses the prospects of improving reproductive performance and longevity of animals in the improvement of commercial herd “Ryazhskaya MTS” Ryazan region through the use of Holstein bulls with genetic evaluation of fertility and longevity indices. A preliminary analysis of the impact of high and low values of bull indices on the number insemination of heifers, age of the first calving, as well as the number of insemination per conception, the interval from calving to conception, the interval between calving cows and their survival to 3 lactation. It was found that the daughters of bulls with a negative value of the HCR index (from -1.5 to -1.3) and the DPR index (from -4.3 to -2.3) had the highest sperm consumption for fruitful conception of 1.9 and 2.0 doses, respectively. With increasing index HCR and DPR bulls the number of insemination for conception heifers decreased. The lowest index (1,2) was observed in heifers whose fathers had the highest index of HCR (from +1,3 to +5,7) and DPR (from +1,0 to +5,0). The daughters of bulls with negative values of HCR indices (from -1.5 to -1.3) and DPR indices (from -4.3 to -2.3) had age of 1 calving of 25.7 and 27.1 months, with positive values of HCR (from +1.3 to +5.7) and DPR (from +1.0 to +5.0) - 23.2 and 23.0 months respectively. Among the bulls (fathers) of imported livestock, carriers of haplotypes affecting reproduction were mainly in groups with negative values of HCR and DPR. Among the daughters of bulls with a high DPR and PL index, 21.8% of cows survived to the third lactation, among the daughters of bulls with low values only 5%. Daughters of bulls with high index values showed a tendency to reduce the number of insemination per conception, the number of days from calving to conception and the interval between calving.

The article presents an overview of the current state of sturgeon farming in the Northern regions. The European North is characterize by optimal parameters for the development of aquaculture, but difficult climatic conditions inhibit the development of warm-water fish farming, in particular, sturgeon breeding. However, despite this, the use of sturgeon aquaculture in the North is quite relevant, as the sturgeons are characterized by high nutritional value and good commodity indicators (fast growth, low feed costs, high survival). When creating optimal conditions in fish farms, these objects show considerable potential and show high cultivation efficiency. The largest producer of sturgeon products in the European North is an enterprise in the Vologda region - «Diana» Fish and Commodity Farm, where production volumes reach 23 tons of caviar and 150 tons of marketable fish per year. Such results were obtaining due to the optimal location of this farm, good climatic conditions, developed infrastructure and other factors. In other regions of the North, growing volumes of sturgeon farming is much lower. In the Leningrad region, several farms grow commercial sturgeon and have reproductive fish. An increase in the production of sturgeon products may be promising with the use of industrial growing methods, for example, in installations with closed recirculating systems of water supply (CRS). In the Murmansk region and the Republic of Karelia, good results of sturgeon rearing up to commercial weight were also obtained and reproductive herds were formed. Evaluation of fish-biological, morphometric and reproductive indicators (the coefficient of fatness and wide-spinnability) of these species showed the high quality of Lena sturgeon producers. Research results indicate good growing conditions and prospects for the use of sturgeon in aquaculture of the Northern regions.

The reindeer's rumen microbiota plays an important role in the digestion of feed with enzymes produced by rumen microsymbiotes. In this regard, the study of reindeer adaptations, the possibility of effective use plant feed resources of the Arctic are of wide interest. This study presents for the first time the results of the assessment of the population structure of the microbial communities of the Rangifer tarandus rumen in the winter period according to high-throughput sequencing data. A special feature of the reindeer ration in the winter-spring period is the high proportion of lichens in the diet (up to 70%) as compared with the summer-autumn (no more than 10-15%). Samples of the rumen content were collected in the winter-spring period in 2018 in the Yamalo-Nenets Autonomous District from calves (6-8 months, n = 3), young (1-2 years, n = 3) and adults (3-6 years, n = 6) reindeer of the Nenets breed. The composition of the bacterial community of the reindeer rumen was analyzed in the laboratory of the company BIOTROF + by the method of NGS sequencing (next-generation sequencing). The results showed that representatives of Firmicutes and Bacteroidetes occupied a dominant position in microbial communities like in other ruminants. The total content of this bacteria in animals of different age groups was not significantly different. The composition of the microbiota in calves was presented with a higher content of cellulolytic microorganisms of the genera Ruminococcus, Buturivibrio, Coprococcus compared with young and adults (p <0.05). The share of acid-utilizing bacteria of the genera Succiniclasticum and Selenomonas in calves was lower compared with young and adult individuals (p <0.05). The taxonomic analysis for the composition of microbial communities is confirmed by the results of biodiversity assessment using environmental indices. According to the results of assessment of α and β-diversity of the microbial communities of the rumen, the greatest uniqueness was found for the microbiomes of adults in comparison with calves and young. In general, the obtained results confirm the opinion of researchers that the microbial community can reflect the physiological state of animals.

Budenny horse breed was obtained as a result of the crossing of Don and local Black Sea mares with Thoroughbred stallions during 1920-1920. To improve the athletic qualities of Budenny horses Thoroughbred stallions are regularly used in breeding, which inevitably affects the breeding qualities of the received offspring. The task of the research was to study the genetic features of the polymorphism of microsatellite loci in Budennny horses, taking into account the origin and Thoroughbred horses’ blood propotion. Tested on 17 loci of microsatellites, horse DNA of the Budenny breed (n = 155) were subdivided into 5 groups, taking into account the type of selection and the proportion of blood. In the 5th experimental group horses with unregistered ancestors in the pedigree from the “Pobeda” farm were included. A comparative genetic-population analysis of different groups of horses was performed on a number of indices, including the level of polymorphism (Ae), the observed (Ho) and the expected (He) heterozygosity, as well as Wright's F-statistics indices using Microsoft Excel 2010. As a result of testing 127 alleles of STR loci were identified in Budenny breed that evidences a sufficient reserve of genetic diversity. The number of alleles in the studied loci varied from 3 to 13, the most polymorphic ones were the ASB17 (13), VHL20 (9) ANT4 (9) and LEX3 (9) loci. Horses of the all 5 groups differed both in the spectrum of alleles and in the degree of heterozygosity. The highest level of the main parameters (MNA, Ae, Ho and He) had horses of a consolidated origin and Thoroughbred blood proportion at the level of 5/8. The practiced crossing with Thoroughbred stallions led to an increase in the proportion of blood and the decrease in Ae polymorphism level from 3.803 to 3.588, the degree of heterozygosity lowed from 0.737 to 0.703. The results of phylogenetic analysis indicate that the four groups of Budenny horses form a common cluster, in the center of which are horses with a consolidated origin. Microsatellite markers used to control the origin of horses can be additionally used for genetic control of breeding processes in populations and breeds of horses.

The results of the research experiment on resection of growing antlers in males in the herd of domestic reindeer on Yamal are presented. In June, two groups of animals similar in age were formed: the experimental group with cut and the control group with preserved antlers. The comparison between the groups was carried out on the basis of eye assessment of deer and biochemical blood parameters. Blood was taken for the study in July and October. It showed that the resection of antlers affected the total protein content of the blood serum of deer in the direction of increasing its concentration. By the ratio of protein fractions between groups, the picture is more diverse. Thus, in the experimental group the albumin content was higher-by 2.44 g / l, but lower - globulins, while the difference in α1 - fraction was statistically significant (p≤0.01). For α2 - and β-globulins the difference is insignificant, for γ-globulins no difference was found. The experimental group of deer exceeded the control group by almost 24% in the content of amylase., but the difference has not reached the minimum level of confidence. The superiority of the control group in the content of cholesterol (P ≤ 0.01), which is known to serve as a material for the formation of sex hormones-androgens, was reliable. The biochemical picture of deer blood in autumn, before the chase, showed a significant advantage of the animals of the experimental group on the content of total protein at a reliable level (p ≤ 0.05), but due to the superiority in the content of globulin fractions. The relative albumin content in the blood serum of deer in October is higher than in July, the amylase content in the serum of animals in the control group fell by almost two, the experimental - three and a half times. The content of calcium and phosphorus in the blood of animals of both groups during the study period was almost the same. At the same time in the body of males in October decreases cholesterol, but the difference between the groups is negligible. Lowering cholesterol in the blood of males after resection of the antlers can slow the formation of sex hormones-androgens.

A scientific and analytical review of experimental research with the use of rats as biological test systems and electrocardiogram (ECG) parameters assessment was conducted. The data on various methods of ECG recording in anesthetized and unanesthetized animals (including the advantages and drawbacks of such methods) were presented. Both invasive and non-invasive approaches to recording the cardiac electrical activity in unanesthetized rats (including the method of telemetric ECG monitoring), which allow EEG monitoring in freely-behaving animals, were described. The review widely presents the studies with ECG registration in anesthetized animals. The data on influence of various types of anesthesia on electrical manifestation of cardiac activity in rats as well as hemodynamic parameters and activity of the vegetative centers regulating them was systematized. The review analyzes the parameters of rat’s ECG recorded in experimental studies in comparison with the parameters of human’s ECG and assesses the possibilities of extrapolating the data obtained to humans. The literature data analysis revealed a fairly wide range of scientific studies and preclinical trials of drugs based on the use of the electrocardiography method in rats. The most significant ECG parameters in rats were identified: PR interval, QRS complex (RS or Rs), T wave amplitude and corrected QT interval, which are of practical importance for adequate interpretation of the data of experimental research of integral characteristics of cardiovascular system and intersystem regulatory mechanisms activity.

Resistance to chronic technological stress is one of requirements to keep the stable productivity of animals. Stress level depends on both external factors and genetic traits of animals. Reaction on chronic stress was estimated in different housing technologies (floor and cage) of meat breed laying hens’. Behavioural, hormonal and physiological state changes can be performed as indicators of stress. Pair bone asymmetry may be connect with animals’ susceptibility to stress. Illustrated that for estimation of animals’ state the complex approach is essential when detected differences and trends permit to compare housing conditions in poultry or in husbandry. High corticosterone concentrations and high individual differences, increase levels of triglycerides and cholesterol are indicated higher unit of stress in cage housing system. Morphological traits’ variability is small and generally not related with asymmetry level of laying hens. Some tibia and femoral bones length reduction can be associated with chronic technological stress level increasing of laying hens located in cages. There are no detected significant differences through summary skewness between groups. Alongside there is substantially minor percent of symmetrical individuals located in cages. Thus, biochemical and hormonal state, morphological traits estimation showed decreased chronic stress levels on laying hens across floor housing technology. Despite the observed signs of homeostasis instability, there are high reserves of adaptive abilities inherent in the selection of initial forms and hybridization scheme demonstrated by hens.

For several years, strengthened state support measures domestic livestock has reached on many qualitative and quantitative indicators of the European level. First of all, we are talking about industrial poultry farming and pig breeding, as well as dairy and beef cattle breeding in terms of increasing the genetic potential. At the same time, the direction of dairy cattle breeding remains one of the most problematic. Annually, purchases of expensive animals experiencing stress during transportation are carried out, which leads to a decrease in the vital energy and functional-physiological reserves of the body. In this regard, many questions arise related to the need to preserve these functional reserves, which can be studied using non-invasive methods. One of such methods is cardiointervalometry of heart rate variability. The method allows to assess the physiological state of the organism of an animal, on which factors, both exogenous and endogenous, can act. The obtained indicators can be used in conducting practical and lecture classes at veterinary faculties of universities, as well as serve as material for further research and discoveries.