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Aim. The unique gene pool of indigenous breeds in the Dagestan Caucasus is threatened by the increasingly widespread use of commercial breeds, which in turn risks narrowing the genetic base necessary to increase and maintain existing genetic diversity. For this reason, our research aimed to study the polymorphism of the PRL, PIT‐1, GH genes in red steppe and Caucasian brown cattle raised in the conditions of Dagestan.Methods. Genotyping of red steppe and Caucasian brown cattle was carried out using PCR‐RFLP methods. Using these methods, genetic analysis was carried out and polymorphism of the prolactin, somatotropin and pituitary‐specific transcription factor genes was studied.Results. As a result of the genotyping of an experimental group of red steppe cattle, it was found that the distribution of two alleles and three genotypes (PIT‐1A and PIT‐1B; PIT‐1AA, PIT‐1BB, PIT‐1AB) of the PIT‐1 gene has a specific character. The specificity of the allelic spectrum of the PRL gene is expressed in the high (0.84) frequency of occurrence of the PRLA allele and low (0.16) frequency of the PRLB allele. This is reflected in the presence of homo‐ and heterozygous genotypes with a frequency of occurrence of 73.0; 23.0; 4.0 %, respectively.Conclusion. Applied genetic approaches to improve the productive and breed qualities of livestock, which are modern and based on a more complete analysis of the genetic diversity and genotype of the studied populations, contribute to the conservation of zoned breeds. At the same time, intrapopulation variability and good adaptability should ensure the sustainable development of dairy cattle breeding in various climatic zones.

Aim. One of the important tasks in solving the problem of improving the efficiency of sheep breeding is the rational use of fodder lands in the North Caucasus and the South of Russia, a significant part of which is located in different natural and climatic conditions. The complexity of solutions lies in insufficient knowledge of the mechanisms of adaptation of farm animals, in particular sheep, to the ecological and geographical features of these regions. The purpose of this research was to study the genetic polymorphism of genes, the degree of genetic variability and immune status in sheep of different breeds, since genetic polymorphism is a measure of its adaptability and the hematopoietic function of blood is the basis of the life of the organism.Material and Methods. The genetic structure of the GH/Hae III, GDF9/AsplEI genes and immune status, was studied by the methods of genetic‐statistical and immune analysis in sheep of different breeds kept in different climatic zones of Dagestan and the Krasnodar Territory.Results. As a result of DNA genotyping of the studied samples of sheep of different breeds, it was found that polymorphism of GH/HaeIII, GDF9/AsplEI genes is represented by three genotype variants: homozygous GH/HaeIIIАА, GH/HaeIIIВВ; GDF9/AsplEIАА, GDF9/AsplEIGG; heterozygous GH/HaeIIIAB; GDF9/AsplEIAG and two alleles: A and B – of the GH/HaeIII gene; A and G – GDF9/AsplEI gene with different frequency of occurrence, respectively.Conclusion. For the first time, genetic variability has been studied in the context of the immune status of sheep populations of different breeds bred in the foothills of the Republic of Dagestan and Krasnodar Territory. The information obtained about the role of the degree of genetic variability and the immune status of sheep of different breeds is answered in the formation of adaptive‐compensatory mechanisms to specific conditions of the breeding environment. A deeper study of the adaptive characteristics of sheep of different breeds for their further improvement allows the use of molecular genetic and hematological methods.

Aim. To study the polymorphism of the genes calpastatin (CAST), somatotropin (GH) and differential growth factor (GDF9) of sheep of the Dagestan mountain breed.Material and Methods. Studies on the genetic typing of Dagestan mountain sheep according to CAST, GH and GDF9 genes were carried out in conditions of distant pasture farming in the Republic of Dagestan by the Genetics and Breeding Laboratory of the Federal Agrarian Scientific Centre of the Republic of Dagestan, an accredited laboratory of immunogenetics and DNA technologies of the All-Russian Research Institute of Sheep and Goat Breeding and a branch of the North Caucasus Federal Scientific Agrarian Centre. These investigations were undertaken by the PCR-RFLP method (polymyrase chain reaction - restriction fragment length polymorphism) on a Tersik four-channel programmable thermal cycler from DNA-Technologia (Russia) using specific primers synthesized in the SYNTHOL research and production laboratory (Moscow).Results. Carrying out PCR-RFLP revealed breed-specific alleles with different frequency of occurrence, which was: in the locus of the CAST gene - allele CASTN - 0.03; allele CASTM - 0.97; at the GH gene locus - GHA allele - 100.0, GHB allele - 0; in the locus of the GDF9 gene - the GDF9A allele - 0.25, the GDF9G allele - 0.75, which determined the frequency of occurrence of the homo- and heterozygous genotypes: CASTNN, CASTMM and CASTNM - 93.0; 0 and 7.0%; GHAA, GHBB and GHAB - 100.0 and 0%; GDF9AA, GDF9GG and GDF9АG- 16.0, 66.0 and 19.0%, respectively.Conclusion. The regularity revealed can be considered as an ecological factor that optimizes the adaptive functions of the sheep's organism, on the one hand, an evolutionary selection process that contributes to the creation of a specific way of genetic structures in the population, on the other. The assumption is made that the information obtained can serve as the beginning of a more in-depth study of the unique gene pool of sheep of the Dagestan rock breed for its further improvement. Variants of genetic marker profiles of parental pairs are proposed for accumulation in breeding herds bred in different ecological-geographical zones and genotypes of carriers of selection-significant genetic structures.

Aim. The rational use of North Caucasus forage lands, a large part of which is located in the mountains, is one of the important tasks in addressing the issue of improving the efficiency of cattle breeding. This appears quite challenging, as the mechanisms of adaptation of farm animals, in particular cattle, to the environmental and climatic peculiarities of a certain region have not been sufficiently explored. Since hematopoietic function of blood is the basis of organism’s vital functions and genetic polymorphism is the measure of its adaptability, the present study is aimed at examining haematological profile and the degree of genetic variation in the Brown Caucasian cattle.Materials and Methods. Haematological, genetic and statistical methods of analysis were used to examine the haematological profile and genetic structure of genes GH, PIT‐1, PRL in Brown Caucasian dairy cattle, bred in different ecological and climatic zones of Dagestan.Conclusion. This was the first time that hematopoietic function was studied in the context of genetic variation in Brown Caucasian dairy cattle bred in the foothills (100‐200 m above sea level) and mountains (650‐1,250 m above sea level). The information obtained gives an idea of and an answer to the question about the role of haematological profile and the degree of genetic variation in the development of adaptive and compensatory mechanisms to specific environmental conditions. The use of haematological, molecular and genetic methods allows the further exploration of the adaptation traits of Brown Caucasian dairy cattle for their further improvement.

Aim. The widespread use of so‐called commercial breeds leads to the loss of a unique gene pool of native breeds and the narrowing of the genetic base that is necessary to preserve and to increase the genetic diversity of cattle breeds which are still preserved. These breeds include the Caucasian Brown. In connection , the aim of this research was to study the polymorphism of PIT‐1, PRL and GH genes in dairy cattle bred in different ecological climatic zones of the Republic of Dagestan to identify the genotypes of carriers of selection‐significant marker alleles for their preservation and further use in the selection process.Material and Methods. Genotyping of the Caucasian brown breed cows bred in different natural climatic zones was carried out using PCR‐RFLP methods. The polymorphism of PIT‐1, PRL and GH genes was studied, population analysis of their distribution in the cattle stock studied was carried out and the features of the genetic structure in the researched populations were studied in relation to the conditions of their habitat.Results. The specific allelic PIT‐1, PRL, and GH gene spectrum, characteristic for each animal population studied has been established. Homozygous and heterozygous carrier genotypes of the desired marker alleles with frequency of occurrence depending on both the gene and the animal population were identified. The genetic structural features of the genes studied in the researched populations were revealed.Conclusion. The data obtained indicate the genetic uniqueness of the Caucasian Brown breed bred in different natural climatic zones in the Republic of Dagestan and are probably associated with the manifestation of adaptations, the nature of which has developed under the influence of the prevailing ecological, natural climatic conditions of its habitat.