Reindeer husbandry is a historically established main branch of animal husbandry in the northern regions of the Russian Federation. Despite the active of domestic reindeer breeding within the northern latitudes of our country, the features of the biological processes of this animal species remain incompletely understood. The importance is a detailed study the reproductive system physiology, which is relevant in light of the prospects for introducing assisted reproductive technologies into reindeer husbandry practice in order to intensify the selection process. Assisted reproductive technologies in reindeer husbandry are currently not used even in breeding herds due to the low level of development, although their introduction can significantly reduce the time and financial costs of selection and breeding work carried out to improve the productive qualities of domestic reindeer breeds. In mammals, the sexual process is under the complex subordinate control of neurohumoral mechanisms, which are based on changes in hormonal status, that is, the levels and ratios of the hormones in accordance with the physiological cycle. Reindeer are the least studied productive farm animals in terms of reproduction. The current trend is to study the hormonal regulation of reproductive processes in female reindeer in different physiological states, such as anestrus, rut, pregnancy, and the post-calving period. We studied the concentration of estradiol, progesterone, and luteinizing hormone (LH) in the blood of female reindeer before the rut (early summer, early autumn, and at the beginning of the rut). The levels of hormones were determined using enzyme immunoassay. The study determined the level hormones in physiologically healthy female domestic reindeer in the early summer and early autumn periods and at the beginning of the rut. The results obtained showed a statistically significant decrease in the concentration of progesterone and estradiol. A decrease in LH was recorded in the warm period with an increase towards the breeding period.

As the amount of data on genomic variations increases, tools capable of assessing the functional impact of individual nucleotide sequences are becoming more relevant. There are several prediction servers available to interpret the effects of variants in the human genome, but few have been developed for other species, and none have been specifically designed for species of interest to veterinary medicine, such as dogs. [1] Mammalian glycopeptide hormone receptors are key regulators of reproductive development, and their homologues are widespread in the animal kingdom.[2]. The interest of our research group is aimed at finding gene variations promising for further research of associations in the field of dog reproduction. In this regard, a group of genes has been selected that potentially affect the sperm quality of males. Based on the GeneCards® human gene database, the following genes were selected: the INHBA (Inhibin subunit Beta A) gene, associated with the activation and inhibition of follicle-stimulating hormone by the pituitary gland, a protein encoded by this gene plays an important role in the development of eyes, teeth, and testicles [11], as well as the FSHR (follicle stimulating hormone receptor) gene, The protein encoded by this gene belongs to the G protein-coupled receptor family 1. It is a receptor for follicle-stimulating hormone and is involved in the development of the sex glands [11]. Mutations in this gene cause type 1 ovarian dysgenesis, as well as ovarian hyperstimulation syndrome in humans [11]. We hypothesized that the INHBA and FSHR genes may affect the quality of ejaculate in males. Studies in the field of INHBA and FSHR gene polymorphisms, which were included in this study, were previously conducted on sheep [3] and bulls [4].

Reindeer (Rangifer tarandus) are a polycyclic animal species with a limited breeding season. Although the main reproductive season for reindeer occurs in autumn, the onset of this period varies even within one geographical area, which is due to feeding factors related to the fatness of animals, as well as temperature, light and other climatic conditions. Therefore, a thorough understanding of the female reindeer reproductive cycles is important for managing reproductive processes, including through assisted reproductive technologies, and increasing the productivity of populations. Hormone levels is a critical aspect in the practice of artificial insemination of animals, since hormonal status has a significant impact on reproductive functions. The aim of our study is to study the hormones concentration: estradiol, progesterone, luteinizing hormone (LH) - in the blood of female reindeer in summer and autumn. The object of the study were clinically healthy female domestic reindeer (n = 3), that live in Pushkin. Blood was taken from June to October, the time interval between blood sampling was on average 1 week. The level of hormones was determined using enzyme immunoassay. Based on changes in LH and progesterone levels, the estrus cycles in the studied animals occurred from July to late October. The dynamics of changes in LH levels at the beginning of the rut season differed in all three animals. In all animals, cyclic increases in progesterone were observed on average every 14 days with the onset of the rut season. All the studied hormones in reindeer female demonstrated moderate and weak reliable correlations.

Reindeer herding is an important branch of animal husbandry in Russia, especially in the northern regions of the country. Genomic selection is a method based on the analysis of genetic data on animals in order to select individuals with certain genetic characteristics for breeding. By genetic selecting, it is possible to increase the efficiency of breeding programs, reduce the time to obtain the desired results and improve the quality of the offspring. The FSHR (Follicle-Stimulating Hormone Receptor) gene encodes a protein that is a receptor for follicle-stimulating hormone (FSH). Studying the FSHR gene is important for understanding the mechanisms of regulation of the reproductive system and searching for new genetic markers associated with reproductive functions in different animal species, including reindeer. The aim of the study was to study the polymorphism of the FSHR gene in female reindeer of the Yamalo-Nenets Autonomous Okrug of the Russian Federation. DNA samples from 43 reindeer females (Rangifer tarandus) belonging to the same herd were analyzed. We sequenced a 2208 bp FSHR region containing the fifth intron of the gene in females from the Yamal Peninsula. During the study of the region, we found two singlenucleotide polymorphisms: G28578A and G29110A. The first polymorphism was located in the second nucleotide of the codon and led to the replacement of serine with asparagine in the amino acid sequence of the protein. The second polymorphism was synonymous and did not lead to a change in the structure of the protein.

Despite the fact that reindeer (Rangifer tarandus) are an important commercial species for providing food for the population in difficult living conditions, they are currently poorly studied due to the complexity of conducting research. This is especially true for physiological characteristics associated with reproduction, the gaps in which complicate the implementation of modern assisted reproductive technologies. Deep knowledge of endogenous hormonal regulation in different physiological periods of female reindeer could allow us to manage the reproductive function. The work is devoted to the analysis of concentrations of steroid hormones 17β - estradiol and progesterone, as well as gonadotropins - follicle-stimulating and luteinizing hormones of females during the breeding season. The object of the study were female (female) reindeer (n = 31). The habitat is a reindeer farm in the north of Western Siberia, in the Yamalo-Nenets Autonomous Okrug of Russia. The total sample was divided into two groups: group 1 (n=16) did not calve and group 2 (n=15) did. The hormone levels in the blood serum were determined using enzyme immunoassay. The results of the studies show that in the group of does in the late calving period, the concentrations of estradiol and progesterone were significantly higher (p<0.01) compared to the group of does after calving. At the same time, a tendency towards an increase in follicle-stimulating hormone can be noted after calving. A negative correlation was recorded in the case of progesterone and luteinizing hormone in the group of does in the early calving period (r=-0.735, p<0.01). A positive correlation was found between follicle-stimulating and luteinizing hormones (r=0.811, p<0.01). In the group of animals in the late calving period, a positive correlation was found between progesterone and estradiol (r=0.641, p<0.01). The results obtained suggest that in female reindeer, the resumption of sexual cycles occurs according to a similar hormonal scenario, in which the level of steroid hormones decreases after calving, and the concentration of gonadotropic hormones, on the contrary, gradually increases with higher FSH dynamics, compared to LH.

The aim of the work is to assess the biological usefulness of bull semen when cooled to 5 °C and stored for a period of time.Sperm cooling is less traumatic for cells than deep freezing. The fertilizing capacity of chilled sperm is higher than cryopreserved sperm, but it persists for several days, which limits its use. The study was conducted using native sperm from black-and-white (n = 6) and Ayrshire bulls (n = 3). Two diluents were used in the experiment: OptiXcell commercial diluent (IMV) (France) was used as a control, and an experimental diluent based on Tris was developed as an experiment. There was no significant difference in overall and progressive mobility between the studied diluents. In most cases, the spermatozoa were alive for 10 days. If we take into account the progressive mobility of 40% as the minimum permissible for artificial insemination, on average, the studied bulls had it during storage for 120 hours. At the same time, there were individual ejaculates that had progressive mobility (40% and higher) even after 168 hours of storage. There were no significant differences in membrane safety when diluted with the studied diluents. When stored for 72 hours, there was practically no decrease in the number of intact cells when using an experimental diluent. The preparation and application of an experimental diluent are economically more profitable than using a Western analogue — OptiXcell (IMV). At the same time, the diluent developed by the authors is not inferior in characteristics (qualitative indicators of spermatozoa), and even surpasses the foreign one.

Purpose: to conduct a comparative description of the productive and morphological characteristics of domestic reindeer of the Nenets and Evenki breeds.Materials and methods. Study of the morphological, behavioral and reproductive characteristics of domestic reindeer of the Nenets and Evenki breeds, kept in various natural and climatic conditions of the tundra and northern taiga, during the calving and dairy periods. Experimental data were collected from clinically healthy animals. The research was carried out in accordance with the basic methods of zootechnical research (observation, examination). Their gender (visually) and age were determined (using ear tags and animal registration data, and, if necessary, based on the degree of tooth wear); An assessment of the exterior of the reindeer herd was carried out before the rut to select males and females for mating. Methods of visual assessment, linear measurements of animals, and field chronometry of calving were used.Results. The Evenki breed of deer is distinguished by its large size, height, high load-carrying capacity and endurance when transporting goods and people. It has been established that the dynamics of calving of domestic reindeer of the Evenki breed is identical to the dynamics of calving of Nenets reindeer, but there are some peculiarities. In the tundra zone, calving takes 3—5 days longer, and the initial phase begins (on average) 7-10 days earlier than in the taiga zone. The live weight of Evenki breed calves at birth is 0.8 kg higher than that of Nenets breed calves. The intensity of growth up to 3 months of age is higher in the early, mass and late periods of calving. It has been established that calves of the early calving period exceed in live weight at birth and its growth the calves of the mass period, and those, in turn, exceed the calves of the late calving period. This pattern can be traced up to 6 months of age. Calves of early and mass calving periods, having the potential for rapid growth, find themselves in more favorable nutritional conditions in the first months of life than late calves. This is expressed in the ability to receive green pasture food 15-25 days earlier and be stronger by the time the blood-sucking dipterous insects appear. Early calving Nenets calves are more active at night, since there is still a lot of snow in the tundra zone during this period and the temperature sometimes drops below 0ºC.

Cryopreservation is a widely used method of semen conservation in animal breeding programs. This process, however, can have a detrimental effect on sperm quality, especially in terms of its morphology. The resultant sperm disorders raise the risk of reduced sperm fertilizing ability, which poses a serious threat to the long-term efficacy of livestock reproduction and breeding. Understanding the genetic factors underlying these effects is critical for maintaining sperm quality during cryopreservation, and for animal fertility in general. In this regard, we performed a genome-wide association study to identify genomic regions associated with various cryopreservation sperm abnormalities in Holstein cattle, using single nucleotide polymorphism (SNP) markers via a high-density genotyping assay. Our analysis revealed a significant association of specific SNPs and candidate genes with absence of acrosomes, damaged cell necks and tails, as well as wrinkled acrosomes and decreased motility of cryopreserved sperm. As a result, we identified candidate genes such as POU6F2, LPCAT4, DPYD, SLC39A12 and CACNB2, as well as microRNAs (bta-mir-137 and bta-mir-2420) that may play a critical role in sperm morphology and disorders. These findings provide crucial information on the molecular mechanisms underlying acrosome integrity, motility, head abnormalities and damaged cell necks and tails of sperm after cryopreservation. Further studies with larger sample sizes, genome-wide coverage and functional validation are needed to explore causal variants in more detail, thereby elucidating the mechanisms mediating these effects. Overall, our results contribute to the understanding of genetic architecture in cryopreserved semen quality and disorders in bulls, laying the foundation for improved animal reproduction and breeding.

There are many publications revealing the physiological role of kisspeptin in the neurohumoral aspect in various species of wild and domestic animals. However, kisspeptin levels during puberty in cattle are still unclear. The purpose of the research was to study the concentrations of kisspeptin, progesterone and testosterone in the blood serum of Holstein bulls and heifers during puberty. Kisspeptin concentrations remained the same in bulls and heifers until the age of 4 months. Further, starting from 5 months, the concentration of kisspeptin increases in heifers, as does the concentration of progesterone. At the age of 9 and 10 months, the concentration of kisspeptin was significantly higher than in bulls. In bulls, testosterone concentration increased with age. Correlation analysis showed a significant relationship between the concentrations of kisspeptin and progesterone in heifers - a correlation coefficient of 0.797, P>0.01, and the concentrations of kisspeptin and testosterone in bulls - a correlation coefficient of 0.636, P>0.05. Kisspeptin most likely plays a role in puberty. Further research is needed on kisspeptin in relation to reproductive function in Bos Taurus.

Reindeer husbandry is the main branch of agriculture in the Arctic zone of the Russian Federation, and a form of traditional environmental management of the North peoples. To preserve and grow the industry, government support and the development of the principles of traditional management with the help of biotechnology are necessary. The article discusses the prospects for using reproductive technologies in fence keeping of reindeer. In reindeer breeding, none of the reproductive technologies are currently used, unlike other types of animal husbandry. The advantages of using assisted reproductive technologies in fenced reindeer herding are that reindeer herders obtain offspring of animals with favorable characteristics and manage reproduction. In addition, the development of technologies for working with sperm and embryos, the creation of cryopreserved biomaterial banks are important for the revival of endangered subspecies and intrabreed local genotypes. When keeping reindeer in a fenced area, it is possible to accustom animals to manipulations with an artificial vagina or electroejaculator. Free-range keeping of reindeer complicates the identification and fixation of individuals, observation and selection. With free-range keeping, uncontrolled mating may occur, it is impossibility of separating selected individuals, and creating harems. Fence keeping will allow to create necessary groups (recipients, synchronized females, females for artificial insemination, males for sperm extraction, etc.) and graze them separately, fix them, quickly find the necessary animals and carry out manipulations. Division into groups will also allow to carry out harem mating with selected males and females. Development and implementation of assisted reproductive technologies in northern reindeer herding will allow to intensify the selection process and improve the quality of reindeer products.

Reindeer remains one of the least studied animals from the point of view of genetics and reproduction of all animals that are use by humans in economic activities. In Russia, reindeer is use as a farm animal to produce environmentally friendly meat with high nutritional value. Reindeer is also the basis of economic activity for the indigenous peoples of the Arctic. Depending on the climatic zone, there are two methods of breeding reindeer - tundra and taiga. For more effective breeding and planning of reproduction work of this species of animals, it is necessary to have clear knowledge about the features of their reproductive cycle. Reindeer are animals with a pronounced seasonal reproduction; in addition, the timing of calving and rutting season can shift significantly depending on changes in weather conditions. According to researchers, the gestation period of northern females has a very high variability. The aim of this work was to conduct research on the differences in the timing of the beginning and end of the calving and rutting periods, their dynamics, as well as the duration of pregnancy in female reindeer in reindeer herding farms in the taiga and tundra climatic zones. To compare the dynamics and timing of calving and rutting, data were collected on the recording of matings and calvings in reindeer herding farms in the tundra zone of the Arctic regions of the Russian Federation (Taimyr Peninsula and Yamal Peninsula) and in the taiga zone (Buryatia). Because of the research, it was found that not only the timing of the rut, but also the timing of calving have differences in time in the tundra and taiga habitat zones of reindeer, in addition, they can shift even within the same climatic zone depending on weather conditions. The pregnancy period under unfavorable weather conditions can be shorten or extend.

The results of the studies (2019-2021) of increased incidence of genetic mutations, such as fertility haplotypes, in the population that result in lower reproductive rates in dairy cattle are presented. Semen quality of the Ayrshire breed bulls was evaluated for motility and morphological indices due to rs475678587 in the UBE3B gene locus associated with the AH1 fertility haplotype. Semen samples (n = 14) were obtained from the Center of Collective Use "Genetic Semen Collection of Domestic and Foreign Cattle Breeds" of the All-Russian Research Institute of Farm Animal Genetics and Breeding (ARRIFAGB) and belonged to the animals born in 2014 and older (average age of bulls was 6-15 years). Genotyping for rs475678587 of the UBE3B gene was performed by Sanger sequencing. Animals with the heterozygous CT genotype were defined as carriers of the AH1 haplotype (AH1-C), and those with the homozygous CC genotype were defined as free of the AH1 haplotype (AH1-F). Frozen-thawed semen was evaluated according to the following parameters: total and progressive motility, percentage of normal spermatozoa. Morphological indices of sperm quality were assessed after differential staining of cellular elements of spermatozoa using a commercial kit "Diakhim-Diff Quick" (ABRIS+ scientific and production company) in sperm smears. The following indicators were taken into account: acrosomal abnormalities, abnormalities in the head, tail, and neck of the spermatozoon. Data on the indicators of native semen (motility, concentration), obtained immediately after collection, were received from the archive of the technical service of the breeding enterprise. The results of the studies have shown that according to physiological and morphological indices the semen obtained from the bulls carrying the haplotype AN1 did not differ significantly from those of the bulls free of the mutation. In terms of total motility, the semen of the haplotype fertility carrier bulls was almost 2% higher than that of the haplotype free bulls. It can be noted that the haplotype carriers of fertility bulls were generally characterized by good sperm fertility indices.

Horses were domesticated later than other farm animals. Horse breeds have been selectively developed by humans to satisfy different needs and purposes. The factory and indigenous breeds are of particular interest, having been bred in purity for many centuries without the addition of foreign blood. Data from 31 stud farms, as well as ranches, located in fifteen regions of the Russian Federation were used in this work. DNA was sampled from 102 stallions of 11 breeds: Arabian, Akhal-Teke, Don, Orlov Trotter, Vladimir Heavy Draft, Russian Heavy Draft, Soviet Heavy Draft, Kabardin, Yakut, Tuva, and Vyatka. Data on the origin of each animal from which the material was collected were taken into account. DNA genotyping was carried out using GGP Equine 70 k ® array chips (Thermo Fisher Scientific, USA). Genetic diversity of horse breeds was estimated using Admixture 1.3. and PLINK 1.9 software. FROH inbreeding was computed via the R detectRUNS package. The minimum length for ROH was set at 1 Mb to reduce the occurrence of false positives. We conducted PCA analysis using PLINK 1.9, and used the ggplot2 library in R for visualizing the results. Indigenous equine breeds, such as Vyatka, Tuva, and Yakut, are very hardy, and well adapted to local environmental and climatic conditions. They are employed as draft power, as well as for milk and meat. Both the Akhal-Teke breed and the Arabian breed have retained a minimum effective population size over many generations. We note significant accumulations of homozygosity in these breeds. In equestrian sports, performance is a top priority. ADMIXTURE and PCA analyses showed similarities between Don equine breeds and Kabardin, as well as some Arabian breed animals. Earlier research indicated the presence of thoroughbred traits in Don stallions. The Orlov Trotter breed stands out as a separate cluster in the structural and PCA analyses. Considering the small population size of this breed, our study found high FROH in all tested animals. The general reduction in the diversity of the horse breed gene pool, due to numerous crosses for breed improvement with thoroughbreds, has lead to a decline in the differences between the top sporting breeds. Our study presents new opportunities for exploring the genetic factors that influence the formation of adaptive traits in indigenous breeds, and for finding ways to preserve genetic diversity for effective population reproduction.

Materials and methods. The semen of 53 bulls was collected at OJSC Nevskoe. A total of 110 bull semen samples were analyzed. Sperm quality was determined using Argus-CASA (ArgusSoft, Russia). Membrane integrity was determined by staining the samples with nigrosine-eosin dye (Diam, Russia) and a Motic BA 410 microscope. Spermatozoa respiration was determined using an Expert-001 instrument. The functional state of the energy system was assessed by the reaction of respiration to the addition of the uncoupler of respiration and phosphorylation, 2,4 dinitrophenol (2,4-DNF). DNA for genetic analysis was isolated from semen by the phenol-chloroform method. Sanger sequencing was performed on an Applied Biosystems 3500 Genetic Analyzer using commercial BigDye® Terminator v3.1 Sequencing Standard Kits (Applied Biosystems) according to the manufacturer's protocol. Results . Sperm quality were characterized by high individual variability. Thus, the volume of the ejaculate was from 2 to 15 ml, the concentration of spermatozoa was from 0.6 to 1.7 billion/ml, the total number of spermatozoa in the ejaculate was from 1.6 to 15 billion, and progressive motility was from 0 to 85%. Four SNPs were identified for the ESR1 gene. No significant associations of ESR1 gene polymorphism were found, except for a significant association of ESR1 665 G>C with spermatozoa concentration and the number of swollen acrosomes

One of the important factors affecting the reproductive function is the genotype of the animal. The method of genomic selection is based on the use of polymorphic single nucleotide substitutions (SNP) as markers for determining the value of the genotype of an animal or plant. The formation and functioning of the reproductive system of animals occurs as a result of the coordinated interaction of a wide range of genes. The search for genomic associations of GWAS (Genome-Wide Association Studies) with signs of fertility will allow further selection of animals based on these indicators at the genomic level. Sperm was obtained with the help of mares in hunting and on a phantom using an artificial Hannover vagina (Minitube, Germany). The sperm of each stallion was collected at least three times. The semen quality of 96 stallions of different breeds (Arabian, Akhal-Teke, Trakenen, thoroughbred horse, Oryol trotter, French trotter, Soviet heavy horse, Shetland pony, Welsh pony, horses of different breeds) was analyzed. High variability of sperm quality indicators was revealed. For example, the concentration of sperm in the ejaculate varied from 59 to 514 million /ml, progressive mobility from 20 to 87%, and the number of cells without damage from 21.6 to 95.6%. Such variability of the studied features makes it possible to assume that their formation in the process of ontogenesis occurs under the influence of genetic factors. The GWAS analysis of ejaculate volume, concentration and motility of stallion sperm revealed potential candidate genes associated with these indicators. The associations identified in our study are promising candidates for further identification of the biological mechanisms underlying the quality of stallion sperm.

The specifics of breeding and selection significantly affect genetic diversity and variability within a breed. We present the data obtained from the genetic analysis of 21 thoroughbred and warmblood horse breeds. The most detailed information is described from the following breeds: Arabian, Trakehner, French Trotter, Standardbred, and Soviet Heavy Horse. The analysis of 509,617 SNP variants in 87 stallions from 21 populations made it possible to estimate the genetic diversity at the genome-wide level and distinguish the studied horse breeds from each other. In this study, we searched for heterozygous and homozygous ROH regions, evaluated inbreeding using FROH analysis, and generated a population structure using Admixture 1.3 software. Our findings indicate that the Arabian breed is an ancestor of many horse breeds. The study of the full-genome architectonics of breeds is of great practical importance for preserving the genetic characteristics of breeds and managing breeding. Studies were carried out to determine homozygous regions in individual breeds and search for candidate genes in these regions. Fifty-six candidate genes for the influence of selection pressure were identified. Our research reveals genetic diversity consistent with breeding directions and the breeds' history of origin.

Reindeer husbandry is the leading branch of agriculture for the regions of the Far North. Reindeer (Rangifer tarandus) remains poorly studied from the point of view of genetics and reproduction, which hinders the intensification of development of the industry. Research is being actively conduct in the field of genetics of the productive qualities of reindeer, but the formation and functioning of its reproductive system has been little study. Hormonal regulation of the reproductive process and the formation of hormonal status at key stages of the reproductive cycle is a significant aspect of animal reproduction. Reindeer are characterized by a pronounced seasonality of reproduction, and the study of hormonal regulation of the reproductive cycle is the main aspect of the further use of assisted reproductive technologies. The work is devoted to the analysis of the level of anti-Mullerian hormone in females during the breeding season. The studies were carried out on reindeer farms of the MAU “Directorate of the Territory of Traditional Natural Resources Management of Soyots”, Buryatia, (female, n=29). The dependence of the concentration of anti-Müllerian hormone (AMH), which is a generally accepted indicator of the female ovarian reserve, on the concentration of sex hormones (progesterone, estradiol, testosterone and luteinizing hormone) in the blood serum of females was study. Hormone levels were determined by enzyme immunoassay. A higher content of sex hormones - testosterone, estradiol, progesterone and luteinizing hormone was revealed in the group of women with an AMH concentration of >1 ng/ml than in the group of women with an AMH concentration of <1 ng/ml. The significance of the differences in progesterone was p<0.05, and in estradiol – p<0.001. A low concentration of AMH (<1 ng/ml), characterizing a reduced ovarian reserve of female reindeer, corresponds to a reduced concentration of sex hormones that support reproductive function, and, conversely, a high concentration of AMH (>1 ng/ml), and, accordingly, a high ovarian reserve the reserve corresponds to an increased concentration of sex hormones - testosterone, estradiol, progesterone and luteinizing hormone.

Sperm morphology is an important indicator of sperm quality. We calculated the rank correlation coefficient between fertility and the number of cells with damaged acrosomes, which was r=-0.6, which is relatively high. The aim of the study was to find genetic associations with semen morphology after cryopreservation in bulls. The quality of spermatozoa was assessed by CASA and GWAS was used for genotype analysis. Calculations were carried out using PLINK and EMMAX programs and a Manhattan-type plot was obtained using the qqman package in R software. The localization of SNPs was determined and candidate genes were identified using the NCBI and Ensembl genomic browsers. The semen of 130 bulls was evaluated. Total sperm motility varied from 25 to 65% and progressive motility ranged from 15 to 60%. There were 13.6 to 39.2% of cells with damaged acrosomes and 1.2 to 14.1% of cells with damage in the tail and neck in frozen bovine semen. There were several significant SNPs associated with the number of missing acrosomes after cryopreservation. For example, a significant SNP on the fourth chromosome, BTB-00566744 (P-value=2.89E-15), is an intron variant of the POU6F2 gene, somatic mutations of which have been identified in human glaucoma and prolactinoma. Prolactin, in turn, significantly reduces the spontaneous acrosomal reaction. There were genomic associations with the percentage of swollen acrosomes after cryopreservation. Thus, the LPCAT4 gene is involved in the biosynthesis and metabolism of lipids and phospholipids. The identified genomic associations with disorders in the tail and neck region mostly repeated genes associated with disorders in the head region. These are the genes: FOXF1, ZBTB40, WNT4, FRMD4A, FAM107B, PTPRU, GLRA3, RABGAP1, EPC2, MBD5, TTK, BCKDHB, PPP3CA, MAP2K5, MAP2K6, CD59, DIP2B, AIG1, ADAT2, TTC29, POU4F2, ENDRA, GRIK1, NEDD4, C10H15orf61, WNT5A, RIMS1, RAD51B, KLHL1, PAPSS1, DKK2, RGS17, U6, ORC4. Thus, the RIM1α isoform can compensate for the lack RIM2α in calcium-induced acrosomal reaction. As a result, a large number of genome-wide associations that affect the preservation of spermatozoa after freezing-thawing have been identified. Authors acknowledge financial support from Russian Science Foundation, Grant No: 18-16-00071.

Purpose: to study the effects of subclinical ketosis on the hematological indicators of the blood of highly productive milk cows in the postal period. The studied animals are selected according to the principle of conditional analogues and divided into 3 groups of 5 goals each. Depending on the concentration in the blood of 3-hydroxybutirate, animals were divided into 3 groups: 1st group-less than 0.8 mmol/l; Group 2-1.2-1.4 mmol/l; 3rd group-more than 1.4 mmol/l. The conditions of their detention and feeding were the same for all groups. The determination of the level of 3-hydroxybutirates took place 2 times: on the 5th and 15th day after the hotel. Taking blood was carried out from the tail vein in front of the morning feeding. The blood serum was obtained by centrifugation (3000 rpm) with subsequent freezing at -20 ° C. The following indicators were determined in the samples: red blood cells, hemoglobin, hematocrit, the total volume of red blood cells, the average hemoglobin content in red blood cells, the distribution of red blood cells in the blood, leukocytes, granulocytes, monocytes, lymphocytes, thrombocytes, the average volume of platelets. Reliable differences have been established in the case of indicators of the level of red blood cells, hemoglobin and hematocrit in comparison of the 1st and 2nd groups with the 3rd group. A reliable correlation between the level of 3-hydroxybutirates and some hematological indicators (on various days after the hotel) has been established.