POLYMORPHISM OF PARAOXONASE-1 GENE (PON1) AND ITS ASSOCIATION WITH ECONOMIC TRAITS OF HOLSTEIN CATTLE

Abstract

The purpose of the research was to study the polymorphism of the paraoxonase-1 gene with the replacement of A with G in the promoter region, as well as to evaluate the growth, milk productivity and reproductive ability of Holstein heifers with different genotypes on this gene. The work was performed in 2018–2019 in the Republic of Tatarstan on 148 first-calf cows. Genotyping was conducted by PCR-RFLP in Bsc4I locus of PON1 gene. The studied population was polymorphic, the genetic balance was not disturbed. The distribution of alleles and genotypes was as follows: A – 0.564 and G – 0.436; AA – 31.8 % (48 animals), GA – 49.3 % (75 animals), GG – 18.9 % (28 animals). Animals with GA genotype of PON1 gene were not significantly better in terms of growth dynamics (kg) in control weighing from 6 to 18 months and of daily gain (g) in 6-18 months period. The cows from the same group were statistically significantly superior to heifers with AA and GG in terms of reproductive ability: fertility index of Dohi (56.2), calving interval (395.7 days), service period (122 days), and were distinguished by the early age of the first successful insemination (17.1 months). It was found that first-calf heifers with the GG genotype were better in milk yield per 305 days of lactation (7339.6 kg), milk fat yield (291.1 kg) and milk protein yield (254.6 kg). The identified associations of PON1 gene polymorphism can be used for the selection of parental pairs for targeted breeding to improve economically useful signs of Holstein cattle