Characteristics of the lines of the Sibiryachka cattle breed by genes CSN3, BLG, LALBA, LEP and their relationship with dairy productivity

Abstract

The results of studies on productivity and genotypic structure of cows of the leading lines of Sibiryachka cattle breed, associative links of CSN3, BLG, LALBA, LEP genotypes with economically important traits are presented. Comparative evaluation showed that Reflection Sovering bull cows had the highest milk yield of 6851 kg, fat content of 4.05% and protein content of 3.15%. The Siberian bull lines Frank 937, Uragan 27 and Kursa 1949 which are being shaped are inferior to them in milk yield, fat and protein content with values of 5246-5504 kg, 3.92-3.94%; 3.10-3.12% respectively. The genotypic structure of the herd and the leading lines is identified. The Vis Back Aydiala bull line is characterized by a higher frequency of CSN3AA and LEPTT genotypes by 18.2 and 11.0%, in comparison with the Reflection Sovering line. For other genotypes, the differences do not reach the confidence threshold. The average level of homozygosity for the genes studied varies from 51.2% to 73.4%. The highest homozygosity was found for the CSN3 gene in the Vis Back Aydiala line at 79.6%. The number of effectively acting alleles is 1.66-1.72; the degree of genetic variability is 40.2-42.7%. The cows with CSN3AB genotype had 544.0 kg higher milk yield than homozygous animals for the A allele (p <0.05). The highest milk yield was observed in BLGAA animals - 6790.1 kg, which is 947.2 kg higher than in cows with the alternative BLGВВ genotype (p < 0.01). Animals with the LEPCC genotype outperformed LEPTT cows in milk yield by 718.7 kg. No priority genotypes were identified for the LALBA gene. Also, no connection has been established between genotypes and the quality indicators of milk.