Genetic characteristics of producing bulls of the Kholmogorsky breed, depending on their linear affiliation and the level of Holstein

Abstract

Relevance. Genetic analysis using STR markers makes it possible to effectively use various techniques to control the breeding process in a population.Methods. The material for DNA research was the deep-frozen sperm of 103 bulls-producers of the Kholmogorsky breed, with different blood levels of Holstein cattle belonging to five main genealogical lines. Molecular genetic studies were conducted in the laboratory of DNA technologies at VNIIPlem.Results. The animals of the VBA (I = 1,557) and Nl (I = 1,556) lines had the maximum genetic diversity, and the Chl lines had the lowest (the indicator is lower by 0.229 (р ≤ 0.05) relative to VBA). A pronounced discrepancy between the observed and expected heterozygosity towards heterozygote deficiency was found among animals of the VBA line (F = 0.173), which is higher by 0.220–0262 relative to RS and Chl (р ≤ 0.01–0.001). The bulls of the Chl and RS lines have an equilibrium shift towards an excess of heterozygosity (F = -0.111 and F = -0.054 respectively). The most related lines are Nl and VBA (DN = 0.097), as well as Nl and Lm (DN = 0.101), and the least VBA and Chl (DN = 0.247), as well as VBA and RS (DN = 0.218). When differentiating the samples by the level of Holstein, it was found that the greatest genetic diversity was characterized by bulls with a blood density of 25–49% (1,633), and the minimum was animals with a degree of Holstein above 74% (which is lower by 0.299–0.334 relative to other samples, р ≤ 0.05–0.01). With an increase in the degree of Holstein, an increase in the level of genetic inbred was observed (in crossbreeds with a bloodline above 74%, the indicator was 0.142–0.229 more (р ≤ 0.05–0.001) compared with other samples).