Dairy productivity of holstein cattle with different genotypes of the kappa-casein gene (CSN3)

Abstract

The purpose of research was to study the polymorphism of the CSN3 gene and its effect on milk yield, fat and protein mass fractions in milk, as well as on the lactation curve characteristics in the first lactation of Holstein cows. The experiment was carried out on the biological material of 146 cows of of Integrated Agricultural Production Centre “Stud farm named after Lenin” of the Atninsky district of the Republic of Tatarstan in the laboratory of agrobiological research of Tatar Research Institute of Agriculture of FRC KazanSC of RAS. DNA diagnostics by PCR-RFLP method of the CSN3 gene testified that the livestock under study is genetically diverse. The herd contains animals of all genotypes: АA – 41,1%, АВ – 47,9%, ВВ – 11,0%. The frequency of occurrence for allele A was 0.651, for allele B – 0.349. The genetic equilibrium in the population is not disturbed, the chi-square criterion is below the critical value. The analysis of milk productivity indicators of cow-heifers with different genotypes of the CSN3 gene shows the superiority of animals with the AB genotype in milk yield per standard lactation (6908.5 kg), with the BB genotype in the content of the protein mass fraction (4.05%) and protein yield (267.8 kg). Individuals with the AA genotype are characterized by an increased mass fraction and milk fat yield (3.65% and 244.4 kg). Cows have different lactation curves depending on the genotype of the CSN3 gene.