Local cattle breeds are source of valuable genes and an important part of cultural heritage of the breeding regions, it is therefore important to take measures that promote a sustainable management of these genetic resources. In this regard, aim of our work is characterization of the present allele pool, an assessment of level of genetic diversity and a study of genetic relationships of populations of nine native and locally developed Russian cattle breeds (n = 835), including Bestuzhev (BEST), Kalmyk (KALM), Kostromsky (KOST), Red Gorbatov (RGBT), Suksun (SUKS), Kholmogor (HOLM), Yaroslavl (YARS), Yakut (YAKT) and Tagil (TAGL). Polymorphism of 10 microsatellite loci was studied on genetic analyzer ABI3130xl. Effective number of alleles varied from 2.78 in YAKT to 4.56 alleles in TAGL, while number of informative alleles ranged from 3.50 in YAKT to 5.30 alleles in KALM. In 8 of 9 breeds level of observed heterozygosity exceeded 0.66. Pairwise F_st values showed an insignificant (from 0.023 to 0.045) or moderate (from 0.050 to 0.106) genetic differentiation between local cattle breeds. YAKT was the most separated (D_N from 0.315 to 0.518, F_st from 0.70 to 0.106). The pairs RGBT and SUKS (F_st = 0.026), KALM and BEST (F_st = 0.023), as well as TAGL and BEST (F_st = 0.022) occupied the neighboring positions on the PCoA plot. The AMOVA showed that 89% of the genetic variability was due to variability within the groups, while 11% of variability was intergroup differences. Thus, our research represents the most complete information on the state of the allele pool, genetic diversity and differentiation of nine local Russian cattle breeds.

Intensive development of the Arctic zone of Russia and the countries of Fennoscandia, as well as a significant change in the natural and climatic conditions of the reindeer habitat, the forced change in migration routes led to a reduction in the populations of wild and domestic reindeer, which makes it necessary to take measures to preserve and study them. Deer products are of great economic and strategic importance. However, the level of breeding and reproductive qualities is decreasing in the herds of domestic reindeer. Therefore, it is necessary to actively introduce modern scientific methods and technologies to improve domestic reindeer in Russia and the semi-domestic reindeer of Fennoscandia. This will improve their productive qualities, including meat production. Active use of DNA technology will solve this problem and increase the productivity of reindeer. We need to search for and study polymorphisms in genes that determine the growth and development of the body, in particular muscle tissue. These variants of genetic polymorphism can have a reliable relationship with the increase in body weight. Subsequently, it is possible to create a group of molecular genetic markers to increase the level of breeding in reindeer husbandry and to conduct analysis of populations of the genetic structure of wild and domestic reindeer. The most promising for reindeer breeding can be genes that have a studied physiological role in the process of formation of muscle mass in animals. А growth hormone or somatotropin gene is one of the most important genes that determine the processes of formation, growth and development of muscle and bone tissue in the organism. Somatotropin is a hormone that participates in anabolic processes in the body. It enhances protein biosynthesis in the cell and reduces the amount of fat deposits in the subcutaneous tissue, thereby increasing the ratio between fat and muscle mass in favor of the latter. Studies of variants of polymorphism in the growth hormone gene have revealed their reliable association with an increase in the body weight in farm animals. Three single nucleotide polymorphisms C920T, C805T and A755G analyzed in the region of the growth hormone gene (size 422 bp), identified by sequencing. The linkage disequilibrium (LD) calculated between the three SNPs found. Such an analysis may show that the mutation is causal.

The paper deals of the problems associated with the resistance of fish to low temperatures. Methods of selection of cold-resistant organisms are less effective than transgenic technologies that allow the creation of genetically modified organisms that are resistant to cold habitats. The most interesting genetically modified object among fish is "Supersalmon", created in the firm AquaBounty Technologies. "Supersalmon" is a polytransgenic fish, because in its genome contains integrated foreign growth hormone genes and antifreeze genes. Only 20 years later this product was first introduced in the world to the commercial market, since it was approved by the screening committee of the Food and Drug Administration of the United States (FDA). The aim of this study was to determine the degree of influence of low temperatures on the development, morphology of embryos and larvae of tropical fish Danio rerio with regard to the survival. At the stage 16-64 cells, embryos were placed in cold water (10⁰ C) for two hours. Every day, the morphology of the embryos and larvae was analyzed and their viability was taken into account. The optimum temperature for this fish species is 26-29 °C. After 24 hours of cultivation, the developmental anomalies were observed in the experimental groups and in control, but their degree of expression was different in different groups. In the control group the survival rate of zebrafish embryos and larvae with normal development varies from 72% to 93% for the week. About 80% of the embryos had normal morphology, and the percentage of embryos with abnormal development was 15% after two hours of blastocyst treatment at a temperature of 10 °C. 24 hours of development was a critical period with a maximum embryo death rate of 66%. The percentage of larvae with normal development for 5-7 days averaged an average of 10.0%, and with an abnormal morphology - 6.2%. The most common anomalies are deformation of the skeleton and dropsy. Thus, in the population of tropical fish there may be individuals able to adapt to extreme environmental conditions. The presented work can be applied in studying and obtaining stress-resistant forms of fish.

Over the past 10 years, as a result of full genomic sequencing of cattle, a chip technology based on single nucleotide polymorphism (SNP) in the animal genome was created. With the help of a genome - wide comparative analysis of Holstein cattle of the Leningrad Region have been identified genes that can be responsible for potential QTLs. All animals were genotyped by the BovineSNP50 v.2 chip. The criteria for editing SNPs were as follows: The minor alleles frequency of SNPs was < 1%. The genotyping error of SNPs is not more than 5%. Reliability of SNPs genotypes deviation from Hardy-Weinberg equilibrium was (P <0.001). ANIMAL MODEL was used for breeding values evaluation. In carrying out the associative analysis, the Plink 1.9 and EMMAX programs were applied. Associative analysis was carried out on 280 bulls and 500 cows including traits of milk yield and milk fat yield, which were evaluated with ANIMAL MODEL. Five SNPs overcome the confidence threshold of 10^-8 for milk yield (DYD of the bulls) and 12 SNP for milk fat yield (YD of the cows and DYD of the bulls). In bulls, the genes 6-β-N-acetylgucosamintransferase and RASA1 are identified as the most likely candidates for QTL responsible for milk yield and the gene RASA1 for milk fat yield. It may be the result of a negative correlation between milk yield and milk fat yield. In cows, the localization of the ZNF704 gene coincides with QTL in the Animal Genome database affecting of the milk fat yield. Associative analysis of BV with SNP markers confirmed the expected lower reliability of cows' breeding value evaluation in comparison with bulls ones in case of milk yield, but not for milk fat yield. The obtained data indicate that QTLs affecting the of milk fat yield were detected both in bulls and in cows, and in different chromosomes or in different regions of chromosome 7. The data obtained should be considered as preliminary, since the sample of animals did not exceed 280 bulls and 500 cows.

Gene pool breeds of chickens around the world are considered as a source of valuable genes, which may be in demand in breeding programs when market conditions change and, accordingly, the requirements for the quality of poultry products will appear. Identification of genetic changes occurring when crossing such breeds is the subject of research, since these data can solve some aspects of the inheritance of valuable genotypes in poultry generations. In the laboratory of molecular genetics, using a number of modern techniques for many years, a gene pool poultry has been studied. This study is a continuation of such research. As a research object, two-breed hybrids of several gene pool breeds of the bioresource collection chicken were selected in the number of 45 heads, blood from under the porch vein was taken to vacuum tubes for subsequent DNA isolation. High-molecular genomic DNA was then analyzed by DNA fingerprinting with a labeled oligonucleotide probe to identify hypervariable regions in the chicken genome. The distribution of DNA fragments on nylon filters was studied by pairwise comparison in all samples with calculation of the number of common and different fragments. The data was recorded in a table and further calculations were made using the Gelstats ™ computer program. Knowing the genealogy of the original gene pool of hens, it was interesting to trace the inheritance of hypervariable regions of the genome when crossing these breeds in the next hybrid generation. Data on marker DNA fragments that are characteristic of individual populations are also presented. In addition, the results of intrapopulation genetic variability, expressed as the average heterozygosity, are presented. The probability of occurrence of identical genotypes in individuals in the population for all detected DNA fragments was extremely low, which indicates on high resolution of the method used.

Aging in in vitro-matured oocytes negatively affects its fitness. However, there are few data on aging-related changes in oocytes.. In this research for was to determine the mitochondrial pattern of distribution of the matured bovine oocytes during their prolonged culture in vitro. Bovine cumulus-oocyte complexes (COCs) were cultured for 20 h in maturation medium (TCM 199 supplemented with 10% fetal calf serum (FCS), 10 μg/ml FSH, and 10 μg/ml LH). After IVM, COCs and oocytes denuded of their CCs (DO) were transferred to the aging medium consisting of TCM 199 supplemented with 10% fetal calf serum and prolonged cultured for 12 h. After maturation (20 h) or prolonged culture MII oocytes (12 h) were studied to determine mitochondrial activity using MitoTracker Orange fluorescence. For oocytes analyzed just after IVM mitochondrial activity was low, while after 12 h prolonged culture of mature bovine oocytes the activity increased (P<0,05). At the same time the removal of CCs before prolonged culture affected mitochondrial activity reducing (P<0,05). The result obtained point to increasing the level of mitochondrial activity during in vitro aging of bovine oocytes and to that the removal of CCs is able to decelerate these age-associated alterations.

A significant obstacle in the further development of northern reindeer breeding are various infectious diseases, among which a special place belongs to brucellosis. The results of the conducted studies showed that in the reindeer breeding areas of the Asian North Brucellosis is registered, which not only causes significant economic damage, but also complicates epidemiological tension in the regions. In general, in the Russian Federation in 2016, there were 52 unsuccessful brucellosis points, including 42 points in the Republic of Sakha Yakutia, 6 in the Yamal-Nenets Autonomous District, 1 in the Taimyr Municipal District and the Chukotka Autonomous District. On the Yenisei North, the Republic of Sakha (Yakutia), the Chukotka and Evenk Autonomous District, natural foci for brucellosis infection were formed. The epizootic chain of the disease includes domesticated and wild northern reindeer and carnivorous animals, regular seasonal migrations and permanent pastoral contacts which create favorable conditions for the spread of brucellosis infection. The results of the research showed that the use of anti-brucellosis measures in reindeer husbandry without the use of specific prevention means does not have the proper anti-epizootic effect, especially in the presence of a natural focus of brucellosis infection. The concept of optimization of specific prevention of brucellosis of reindeer is developed on the basis of modern theories of the epizootic process, self-regulation of parasitic systems and natural focality, taking into account the specific features of technology in the industry. It has been established that for the specific prevention of brucellosis in reindeer, the optimal dose of the vaccine from the B. abortus strain is 19 - 2.5 billion mt, and for a vaccine from the B. abortus strain 82, a dose of 10 billion mt. The effectiveness of optimal doses of vaccines from strains B. abortus 19 and 82 for specific prevention of brucellosis of reindeers in experimental and production conditions was proved.

The analysis of breeding value was carried out by 24 sire with a large number of daughters (more than 40), daughters were lactated in 22 herds in the Russian Federation. The breeding value of bulls is influenced by the method of breeding their daughters, and their distribution according to the level of breeding value. Most first-calves obtained by the cross-line method (over 90%), the average breeding value of the bull is determined by the level of breeding value of crossed daughters. Most of the bulls of a daughter, regardless of the method of their elimination, have the same orientation in assessments. It was revealed that the crossed daughters of Kazbek concede 4 kg, while the intra-linear ones outweigh 47 kg of milk, and Olympus - on the contrary +2 and -107 kg of milk, respectively. Daughters of bulls, deduced by different methods, are divided into three categories according to the level of the breeding value by milking: less than 100 kg (worst), -100 to +99 kg (neutral) and +100 kg of milk and more (best). In the group of bulls with an average positive breeding value, producers with a high proportion of the best daughters - Alku, Hialu and Oliver (More than 40%) were identified, as well as among producers with negative breeding value - with a high proportion of the worst daughters Accord, Unto and Centaur. For breeding work, the best producers are those whose high relative number of the best daughters does not depend on the breeding method, for example, Hial and Oliver. When using Kazbek and Etude, an intra-linear method should be used, and it is undesirable to use this method to obtain the descendants of Oliver and Lassie. In order to achieve a positive result with repeated use of the estimated bulls, it is necessary to test them not only in terms of breeding value by the milk yield of their daughters, derived by different methods, but also by the frequency of occurrence among them of offspring with a breeding level +100 kg of milk or more.

Identification of a food supply and assessment of fodder value of cervine pastures - the relevant directions based on need of obtaining basic characteristics of quality of pasturable grounds for timely adoption of economic decisions. At the choice of the direction of a research were considered: a problem of lack of information on a food supply of left-bank territories the Yenisei River and demand of results farms which are engaged in cultivation of a domestic reindeer. A left bank of the Yenisei River - historically developed region of the Yenisei North with intensive conducting northern house reindeer breeding of which distribution of cervine pastures with a large supply of green forages is characteristic. A research object - a food supply (vegetation of cervine pastures). Object of research - the fodder value of the main the kormosoderzhashchikh of types of vegetable communities. In the territory of a research the maximum fodder advantages during the summer period pastures of shrubby and marsh types have. Besides, the olkhovnikovy, ivnyakovy and ernikovy tundra has considerable fodder resources. The dwarfish birch and willows - valuable types in the fodder relation are a constant component of all pastures and meet everywhere. The Teoretiko-metodologichesky value of a research consists in the analysis and assessment of fodder advantages of green cervine pastures. The main evaluation criterion - structure, qualitative structure of forages and stocks of phytoweight. The practical importance of work is defined by the staticized data transferring the modern specifics of a condition of a food supply necessary for rational use of pasturable grounds. The data on the fodder value of cervine pastures reflecting stocks of green forages and the admissible period of their use can be recommended to reindeer-breeding farms. The received results of a research have high level in comparison with the best achievements of other researchers in this area.

The freshly excreted feces of the reindeer introduced into the Leningrad Region from the Murmansk region (2 farms) were studied by the methods of flotation and sedimentation ovooscopy, as well as by methods of larvae- and helminthoscopy at the Department of Parasitology, St. Peresburg State Academy of Veterinary medicine in February 2018. The study of the preparations was carried out using light microscopes MBS-10 (LOMO) and Mikmed-6 (LOMO). To obtain pictures an optical-mechanical adapter and camera 5D Mark II (Canon) were used. The oval eggs were found using modified Darling’s method in samples from a farm in the south of the Leningrad Region. Their length was 0.045-0.050 mm and the width was 0.022-0.030 mm. The content of the eggs is granular, the shell is relatively thick, multilayered. Eggs are clearly bipolar-plugeed. Based on their morphology, eggs can be attributed to the genus Capillaria. In samples from a farm in the north of the Leningrad region, Weid’s method revealed mobile larvae, the tail ends of which were curved and had spines. The length of the larvae was about 0.350 mm with a width of about 0.015 mm. Based on their morphology, the larvae can be attributed to the family Protostrongylidae. The physiological characteristics of the larvae, epizootic and clinical data suggest that the causative agent is the helminth of the genus Elaphostrongylus. Life-time identification of nematodes requires the use of molecular biology, serology, allergology and other tools. The need for such clarification is both of practical activities (the strategy of treatment and prevention) and of fundamental parasitology. The question of morphological differentiation of nematodes of the family Protostrongylidae based on their larvae L1 requires further study.

Evaluate the effectiveness of two visual research methods in the combined method of diagnosis of abnormalities of the limbs in horses, based on the obtained results of the generated comparative characteristics of application of radiography and ultrasonography in sporting horses. The study included 60 horses of the Trakehner breed at the age of 8-12 years, the average live weight =350-400kg. All horses in the period of the research work performed daily training sessions under the current regulations training. Training and competition were regulated according to the schedule eventing tests, which include: dressage, field tests (cross-country) and show jumping (overcoming obstacles). This type of equestrian sport is characterized by high risk of injury, unlike jumping and dressage. Conducted complex diagnostic tests according to current standard techniques, which includes collecting a General medical history, initial clinical examination, thermometry and instrumental examinations (ultrasonography and radiography). The clinical examination included: palpation of the affected limb, examination in a calm state and under stress, flexion tests, palpation of the pulse on the limb and determination of the type of lameness. Limb ultrasonography reveals soft tissue, tendon and ligament injuries, but is of no value in the diagnosis of bone and joint pathologies. Radiography, on the contrary, carries valuable information for the diagnosis of fractures, inflammatory diseases of the joints, but does not reflect the state of the tendon-ligamentous apparatus. On the basis of the conducted researches we have found that the use of only one method of functional diagnosis can lead to a false logic of the development of the pathogenesis of diseases of the musculoskeletal system of horses, and as a consequence iatrogenic, and further to the culling of high-value horses from the sport. For the production of a verified diagnosis of diseases of the musculoskeletal system of horses, in our view, it is necessary to use complex diagnostic studies, which must include data of the anamnesis, clinical examination, laboratory blood tests and the results of ultrasonography and radiography of the limbs.

Reindeer husbandry is a strategically important industry providing the population of Russian Arctic regions with food. An important role in the life of Rangifer tarandus is played by ruminal microorganisms-symbionts, which enable animals to effectively use scarce nutrient resources of the tundra and forest-tundra. However, the reindeer ruminal microbial community and its age-related changes are the least studied among other ruminants. In this study, the comparative analysis results of rumen bacterial community composition of calf (4 months), young (1-2 years) and adults (3-6 years) Rangifer tarandus of the Russian Arctic are presented for the first time. Samples of ruminal contents were selected in the summer-autumn period in 2017 from three animals of each age group in the Yamal-Nenets Autonomous District. The reindeer ruminal bacterial community composition was analyzed in the laboratory of the "BIOTROF +" Ltd. by T-RFLP method. In the ontogenesis, significant changes in the microorganisms’ representation were noticed, the greatest of which was noted in microorganism involved to carbohydrates fermentation. The content of cellulolytic bacteria of the Clostridia class and the acid-utilizing species of the Negativicutes class (P <0.05) decreased with age, bacteria with the amylo- and cellulosolytic properties of the phylum Bacteroidetes increased (P <0.05). A wide range of microorganisms, which traditionally belong to the pathogens of various animals’ and humans’ diseases was revealed. With age, a tendency to increase the number of pathogens, including the bacteria of the families Campylobacteraceae, Burkholderiaceae, phylum Fusobacteria, and the genus Staphylococcus was noticed. The greatest percent of opportunistic microorganisms, including of phylum Actinobacteria and the family Enterobacteriacea, was detected in young animals.

The production of roughages is the most important industry of agricultural production. The economic efficiency of dairy cattle breeding and the agricultural enterprise as a whole depends critically on the level of its development. Highly productive cattle breeding and the process of crossing cattle with Holstein breed, which began in recent years in the country, can developed successfully only when the quality of fodder, and especially the rough ones, is significantly improved. World experience confirms that if these conditions are not executed, achievement of selection progress is not used. Moreover, the farms are being economically damaged because their fodder base, and primarily the production of roughages, has a low level of development. Under such conditions, the genetically determined productivity of livestock, especially Holstein, is not showed. Fiber is of great importance in providing the energy needs of ruminants. Numerous studies have established that 40 to 75% of the crude fiber of fodder is digested in the gastrointestinal tract of cattle. The accessibility to the digestion of crud fiber and its fractions (NDF) and (ADF) in artificial rumen in fodders: hay, silage, haylage, dry beet bagasse. It has been established that certain fodders with a high NDF concentration may have a higher energy value than fodders with a low concentration of NDF. The content of NDF, ADF, crude fiber in haylage of perennial grasses ranges from 14.35 to 23.71%; from 7.53 to 10.27%; from 8.50 to 11.86%, respectively, with practically the same disintegration in the rumen. In the silage of perennial grasses, the NDF content is 8.4% higher than in the silage of annual grasses, its disintegration in the rumen is also higher by 13.97%. The content of crude fiber and its fractions, NDF and ADF in the hay, as well as disintegration in the rumen, varies within wide limits: content - from 16.38 to 35.93%; from 34.83 to 65.68%; from 21.91 to 39.02% respectively; disintegration - from 10.38 to 33.54%; from 24.63 to 34.58%; from 17.04 to 19.86% respectively.

Studying the peculiarities of the biology of the hypodermic and epipharyngeal gadfly in the Murmansk region, it should be noted that the duration of the gadfly’s fly is very long and depends on the weather conditions, the most important of which are air temperature and wind speed, and as a consequence the climatic zone in which animals are grazing. Estimating the dynamics of summer and activity of hypodermic gadfly in reindeer-breeding brigades in the tundra and forest-tundra zones, it should be noted that the first occurrence of flies in the forest-tundra was recorded 13-20 days earlier than the tundra, and the end of summer, respectively, 5-10 days later. It should be emphasized that the number of days of mass fly of insects in the forest-tundra is 11-12 days longer than in the tundra zone, all this determines the higher affect incidence by hypodermic gadfly larvae of reindeers grazing in the forest-tundra zone. With a comparative assessment of infection by hypodermic gadfly larvae depending on the grazing zone, it should be noted that reindeer grazing in the tundra zone is less affected by hypodermic gadfly larvae than in the forest-tundra zone (54.9-86.0% in the tundra zone and 94.1-96 , 0% in the forest-tundra climatic zone). The greatest invasion was noted in the groups of transport deer and calves of the current year of birth (83.3% - 96.6%, respectively). This is due to the regular use of transport bulls in cargo transportation and weak immunogenic protection of calves. Sires and she-reindeers (females) are affected by gadfly invasion larvae with lesser extent - (54.5% -81.1% and 48.6-82.1%, respectively).

The article is devoted to the current state of four breeds of domestic reindeer in Russia and the problems of organization of breeding work in reindeer husbandry. The existing breeds are developed as a result of long-term "national selection", which retains its priority in the practice of modern reindeer husbandry. Scientists have studied the main morpho-biological indicators species standards and guidelines for the evaluation and breeding for all breeds of deer. It is established that the largest breed - Nenets, over the past 10 years it has the highest growth rates of livestock - more than 33%. The Chukchi and Evenki breed had a growth rate of 3.5-11.2 per cent, the Evenki negative dynamics of growth of 12.5%. Since 2007 there has been an increase in the number of breeding farms in the Northern reindeer herding from 2 to 28. the most important criterion for the selection of deer was their size, expressed in terms of live weight and linear body size. The data of the author and other researchers do not confirm the effectiveness of this direction of reindeer breeding due to the strong press of natural selection, low and unstable level of animal nutrition in pastures. The strong influence of the medium and the presence of a large number of random factors disrupt the optimal balance of the "genotype environment", prevent the implementation of polygenic quantitative features and expand modification variability. Analysis of heritability and repeatability coefficients showed that the reindeer of the Nenets breed had the most efficient selection by their own productivity (live weight) in 0.5 and 1.5 years. Individual selection in reindeer husbandry is not carried out due to the group system of male producers and the use of mats during the gon period(fertilization of females). Breeding work and integrated assessment reindeer in breeding farms are in most cases formal due to organizational and technical reasons and a shortage of qualified personnel. It is proposed to strengthen the role of genetic research in reindeer husbandry in order to solve such problems as evaluation of calves by origin and evaluation of producers by quality of offspring.

The analysis of reproductive qualities of domestic sheep at purebred cultivation and crossing in the conditions of the Central Yakutia is carried out. The studies were carried out on the basis of the existing laboratory of agricultural products processing and biochemical analyses at the Institute. Production experiments were performed in the farm "Mayak" Namskiy ulus on the Romanov sheep and the Transbaikal fine-wool breeds. It is established that the lambing the ewes of Romanov breed took place in January - March, the Transbaikal fine-wool - in December - February. It was found that the highest multiple pregnancy, when crossed with argali × chubuku × Romanov sheep differed sheep of Romanov breed in an average of 2.66 sheep3 lambs 1 the uterus. The duration of the preparatory stage of childbirth in the Transbaikal sheep averaged 75.8 minutes, while during the first lamb they mostly had one, twins during the second lamb were born from 4 ducks (6.5% of the entire uterine population), during the third lamb from 5 heads (16.6% of the uterine population). The Romanov sheep breed, the duration of the preparatory stage lasted an average of 54.5 minutes. The stage of removing fruit of the Transbaikal fine-wool continued to average 16.9 minutes, Romanov sheep and 12.1 minutes. The intervals between the appearance of the fruit ranged from 3.4 to 27.5 minutes. Milking ewes amounted 165.5 - 178 liters per lactation. The study of the chemical composition of milk of experimental sheep revealed quite high rates of dry matter and fat in milk. The use of hybrids, bighorn sheep when crossed with the Romanov sheep and the TRANS-Baikal fine-wool breeds allows to obtain new genetic combinations of domestic sheep in the conditions of Central Yakutia. For three periods of agneya received 12 argali × the shank × Romanov, 58 Transbaikal fine-wool and 15 zabajkale × Arkhar × Chubuku× Romanov lambs.

The results of research of productivity and reproductive traits in Black-and-white holsteinized cows and Ayrshire cows of Leningrad region. Since the violation of reproductive functions inhibits the increase in milk production, an analysis was made of data on the reproductive ability of cows.In comparison with Black-and-white holsteinized cattle in cows of Ayrshire breed the best indicators for reproduction: service period and calving interval are much shorter, and the fertility index has a higher value. It was revealedthat with the increase in the fertility index, the value of the multiple-factor EBVC₆ is rise. This is due to a reliable high and positive correlation of these traits: so in the «Grazhdansky» the coefficient of correlation r = +0,40***, in the «Petrovsky» r = +0,41***, in the «Novoladozhsky»r = +0,52***. A reliable negative correlation between milk yield and fertility index in the «Grazhdansky» r = -0,33***, in the «Petrovsky» r = -0,25***, in the «Novoladozhsky» r = -0,23***. In the course of the research, two options for selecting cows were proposed, taking into account the plus and minus variants of the multiple-factor EBVC₆, as well as indicators of productivity and reproduction. It was found that, in the second variant, the breeding differentials of the polyfactorial index EBVC₆ in all three farms ("Grazhdansky", "Petrovsky", "Novoladozhsky") exceeded the first option for 34, 22 and 28, and also by milk yield by 256, 199 and 233 kg respectively. The effect of selection for milk yield was 43 kg in the "Grazhdansky", 82,3 in the «Petrovsky» and 48,8 kg in the «Novoladozhsky».

The most important element of the ecosystems of the North and an integral part of indigenous life and culture of the peoples of the Republic of Sakha (Yakutia) is a reindeer (rangifer tarandus). This species is the only representative of the genus reindeer (Rangifer), belonging to the cervids family of the suborder of ruminants, and one of the few species whose wild form coexists with domesticated ones [Baskin, 1970, Davydov, 1997]. Derived from folk selection by different nationalities of northern Russia, the species composition of the northern reindeer has been proved and tested by scientists of the Yakut Scientific Research Institute of Agriculture and approved by the Ministry of Agriculture of the USSR Order № 212 of 23.08.1985. There are bred 3 of 4 approved breeds of northern domestic reindeer (Even, Evenk, Chukchi and Nenets) in Yakutia: Even, Evenk and Chukchi (hargin). These breeds differ by the direction of productivity, exterior-constitutional features and adjustment to the specific climatic conditions. The thoroughbred breeding is widespread, the task of which is to fix the institutional type of animals, their adaptation to local conditions and to further increase their productivity. The Evenk breed of deer is the most numerous breed of northern domestic reindeer bred in the Republic of Sakha (Yakutia), they are bred in Abyisky, Bulunsky, Verkhnekolymsk, Verkhoyansky, Kobiai, Momsky, Oymyakonsky, Srednekolymskiy Tomponsky, Eveno-Bytantaisk, Ust-Yansky uluses. As from 01.01.2016, there are 87579 heads or 56.1% of the total number of deer in the Republic. The Evens breed is a deer of meat-and-transport type of build, on the exterior it is a quite high-legged animals, with a long, relatively narrow body. Live weight of adult males reach up to 135-145 kg, females 91-110 kg, slaughter yield of 48-50%. The Evenk deer can be divided into ecotypes depending on the natural climatic zone of breeding - tundra, forest tundra and mountain taiga deer, the largest number of livestock is in the mountain taiga and forest-tundra. Each ecotype of the Evenk reindeer is formed under the influence of certain natural and economic conditions, feeding and maintenance, zootechnical work and is characterized by high adaptive and reproductive abilities. Despite the relative study of ecological and ethological features, issues of thermoregulation and bioenergy of reindeer, ecological and physiological adaptation [1, 3, 4], scientific and methodological information on adaptation reactions of deer, depending on natural and climatic zones, is extremely limited and remains practically unexplored. For this reason, research was carried out on zootechnical parameters, rut and calving periods as an adaptation reaction of the northern domestic reindeer of the Even breed in mountain taiga natural and climatic zone of the Northeast of Russia.

The study of factors affecting reproductive health is the main direction of effective use of bioresources. Despite the vast natural resources are concentrated in the Arctic, the problem of their rational use remains relevant. The work is aimed at studying the possibility of using advanced assisted reproductive technologies in reindeer herding. Reindeer velvet antlers at an early stage of growth are often used for the preparation the medicines. They contain: 17 amino acids, taurine, hormones and insulin. The antlers often are cut off in the beginning of the rut. The aim of the work was to study the effect of cutting of the antlers on the efficiency of semen collection in reindeer. We take into account the efficiency of semen collection and erection. 17 reindeers were caught in the rut 2017 in Taimyr. The reindeers were divided into 2 groups (males with antlers (G1) and males without antlers (G2)). In the G1 group, sperm was collected in 90% of cases. The males in G2 had no erection. The volume of the ejaculate varied from 0.2 ml to 2 ml in G1and from 0,1 to 0,5 ml in G2. Thus, cutting off the antlers before rut has a significant effect on the efficiency of sperm collection in reindeer.