Cow genome instability in connection with milk productivity

The Object of the work: cytogenetic analysis was performed on 20 cows from LSMU VA practice and research centre, 10 productive cows and 10 unproductive cows. The research was performed by standard citogenetical laboratory. The aim of the work: to evaluate the influence of chromosomal aberrations on cow high productivity. The tasks of the work: collect and analyze scientific literature on bovine chromosome number and structure of the environment and their relationship with performance traits. Prepared bovine chromosome preparations. To investigate the chromosome number and structure changes in high and low productivity of dairy cows. Calculate the number of chromosomes and structural changes in the frequency and range of high and low productivity of dairy cows. Determine the relationship between chromosome number and structure changes and milk production levels. The results and their discussion: after the examination of the unproductive cows the structural and numeral variations of chromosomes were identified. Most part of structural variations in chromosomes, i.e. 37,5 proc., consisted of gaps in one chromatid (S1), 15,6 proc.of gaps in both chromatids (S2), 17,2 proc. of cracks in chromatids (D1) .There were 10,9 proc. of poliploidies (P) found in numeral variations of chromosomes. There were also identified both the structural and numerical variations of chromosomes after examining the productive cows. These structural variations of chromosomes were identified: 34,6 proc. of gaps in one chromatid (S1), 19,2 proc. of cracks (D1) in chromatids. There were 15,4 proc. of poliploidies (P). A number of productive and variations in the cells in the group of unproductive cows is 2,9 times bigger (p