UDC 636.2.082:575.22

https://doi.org/10.61562/mgfa2023.20

STUDY OF BETA-CASEIN GENE POLYMORPHISM IN DAIRY CATTLE POPULATIONS OF UKRAINE
Ladyka Volodymyr Ivanovych1,
ORCID: https://orcid.оrg/0000-0001-6748-7616
Sklyarenko Yuriy Ivanovych2 e-mail: Sklyrenko9753@ukr.net
ORCID: https://orcid.org/0000-0002-6579-2382
Pavlenko Yulia Mykolayivna1,
ORCID: https://orcid.org/0000-0002-4128-122X
Malikova Alona Ivanivna1
1Sumy National Agrarian University, Sumy, Ukraine
2Institute of Agriculture of Northern East of NAAS, Sad, Ukraine
Abstract: Using real-time polymerase chain reaction methods, we have researched the CSN2 polymorphism gene in 2 populations of cows in the North-East of Ukraine. The
observed distributions of genotype frequencies А1А1, А1А2, А2А2 and A1 or A2 alleles varies considerably in different cattle populations of cows: population of brown cattle – 1.7%, 38.5, 59.8% (0.209 and 0.791); black and spotted population – 18.3%, 44.7%, 37.0% (0.406 and 0.594). The ratio of genotypes were found significant differences when comparing genotypes A1A1 (p<0.001) and A2A2 (p<0.001). The results of DNA testing of the beta-casein locus for A1 and A2-allelic variants in stud bulls of the studied populations have shown that the highest frequency of the A2A2 desired homozygous genotype is characteristic of the breeders of brown cattle (46%). The obtained results indicate the prospects of breeding work to create herds with genotype A2A2 animals - specifically with the brown cattle.
Keywords: genetic polymorphism, beta-casein A2, genotype frequency, cattle breeds.