The dissertation work presents the results of investigations on toll-like receptor 1 (TLR1), toll-like receptor 4 (TLR4), membrane protein А1 (SLC11A1), tumor necrosis factor α (TNFα), mannose-binding lectin 1 (MBL1) and interferon gamma receptor 2 (IFNGR2) loci polymorphism and the analysis of productivity parameters of Ukrainian selection breeds of Ukrainian Black-and-White and Ukrainian Red-and-White dairy breeds according to the identified polymorphic loci to preserve the gene pool of these breeds and increase its productivity due to the use of promising PCR-RFLR-markers of economically valuable traits of local cattle breeds. According to the results of the researches, for the first time, the genetic structure of the experimental cattle populations of Ukrainian Black-and-White and Ukrainian Red-and-White dairy breeds was estimated by marker mutations 1596G>A in the first exon of the TLR1 gene; 8732G>A, 8834G>C and 2021C>T in the third exon of the TLR4; 7400C>G, 7808A>T in the eleventh exon of the SLC11A1; -824A>G in the promoter fragment of the TNFα gene; 2651G>A in the second exon of the MBL1 and 1008A>G in the seventh exon of the IFNGR2. Three possible genotypes are found in Ukrainian Black-and-White and Ukrainian Red-and-White dairy breeds. In Ukrainian Black-and-White breed, frequencies of AA, AG, and GG genotypes are 0,12; 0,64; 0,24 respectively; in Ukrainian Red-and-White – 0,13; 0,54; 0,33. The frequencies of A and G alleles are: in Black-and-White breed – 0,44 and 0,56; in Red-and-White – 0,40 and 0,60 respectively. The results of the study demonstrated that in all the experimental populations, the locus TLR4 by mutations 8732G>A, 8834G>C, and 2021C>T in the third exon was monomorphic. For the MspI polymorphism by 8732G>A mutation, only individuals with genotype BB were found; by 8834G>C (RsaI polymorphism) – with genotype GG; by 2021C>T (BsiHKAI polymorphism) – with genotype CC. In Ukrainian Black-and-White and Ukrainian Red-and-White dairy breeds the predominant genotype is СС with the corresponding frequencies for each of them – 0,66; 0,57. The most common allele in all cattle breeds is C (0,83-0,79). In both experimental populations of cows, the most common are AA genotype, which frequencies are 0,68 and 0,83 respectively. During the investigation of the haplotype distribution features in the membrane protein A1 gene (SLC11A1) in experimental populations CC-AA, CGAT, CG-AA, CG-TT haplotypes were revealed. According to results of the polymorphism of the tumor necrosis factor α locus by -824A>G mutation, significant differences between experimental populations of cows in the genotypes and alleles frequencies revealed. It was determined that, in Black-and-White breed the frequencies of homozygous genotypes are found at a fairly low level and with the same indicators (AA = GG = 0,17), while in Red-and-White dairy breed, the frequency of the genotype GG is 3,5 times higher compared to the genotype AA. The frequencies of alleles A and G are: in Black-and-White breed – 0,5 and 0,5; in Red-and-White – 0,39 and 0,61 respectively. The results of the study demonstrated that in both the experimental populations, the mannose-binding lectin gene by mutation 2651G>A in the second exon is polymorphic. Frequencies of AA, AG and GG genotypes were determined in Black-and-White breed – 0,35; 0,57 and 0,08; and in Red-and-White breed – 0,13; 0,76 and 0,11 respectively. The study of genetic structure of the populations of Ukrainian Black-andWhite and Red-and-White dairy breeds by 1008A>G mutation in the seventh exon of the interferon gamma-receptor 2 locus indicate a similar trend in the distribution of genotype and allele frequencies between experimental groups of animals. According to the results of conducted comparative analysis of populationgenetic parameters of two experimental populations of Ukrainian Black-and-White and Red-and-White dairy breeds on five genes (TLR1, SLC11A1, TNFα, MBL1, IFNGR2), it was determined that significant differences between the experimental groups of cows are not observed. Predominant genotypes in Ukrainian Black-nd-White breed are: АG (0,64) by mutation 1596G>A (TLR1), CC (0,66) – by 7400C>G (SLC11A1), AA (0,68) – by 7808A>T (SLC11A1); AG (0,66) – by mutation -824A>G (TNFα); AG (0,57) – by mutation 2651G>A (MBL1); АG (0,51) – by 1008А>G (IFNGR2). Alleles are characterized by the highest frequencies: G (0,56) by mutation 1596G>A (TLR1), C (0,83) by 7400C>G (SLC11A1), A (0,84) by 7808A>T (SLC11A1), A (0,64) – by 2651G>A (MBL1) and A (0,63) – by 1008A>G (IFNGR2). The analysis of productivity traits of experimental cattle populations with different genotypes by TLR1, SLC11A1, TNFα, MBL1 and IFNGR2 loci was conducted. Promising in the direction of increasing milk productivity are TNFα^(AА) and ІFNGR2^(GG) for Ukrainian Black-and-White breed; SLC11A1^(СG)SLC11A1^(АА), ТNFα^(AG), ІFNGR2^(АG) – for Ukrainian Redand-White dairy breed.
