The diagnostics of FH4 haplotype in the Simmental cattle breed using the system of PCR in real time

The aim of the study was to develop real-time PCR test system for diagnosing and studying the distribution of FH4 in the population of Simmental cattle. Using the real-time PCR method, the distribution of the mutation in the SUGT1 gene associated with the decrease in the fertility and embryonic mortality of progene in the population of cows (n = 180) and sire (n = 239) Simmental breed of Voronezh, Oryol, Lipetsk, Kaluga, Moscow Regions, the Republics of Tatarstan, Khakassia and Altai Region was studied. The testing system’s work is based on the Taq Man principle. According to the results of genotyping in the studied group of Simmental bulls, 15 latent carriers of FH4 were identified, originating from the lines Redad 711620016730, Honig 803610032, Strike 979322326, Polzer 803608138 and Celot 929105907; in the group of cows - 4 hidden carriers, whose fathers were bulls-producers Walter 644662345 (l. Florian 374), Myilnyiy 1405 (l. Façadnik 642), Mars 3659 (l. Neolit 8593). The homozygous GG variant was not diagnosed in the claimed sample of animals due to the embryonic mortality of the progene. The frequency of the AA genotype was 93.7±0.016 % and 97.7±0.011 % in the groups of bulls and cows, respectively, with an average of 95.5±0.010 % in the sampling. The frequency of occurrence of the G allele was fixed at the level of 0.032±0.011 in the bulls and 0.012±0.008 in the cows, respectively, and mean value for the studied sample was 0.023±0.007. Thus, our studies have shown the effectiveness of the developed test system in detecting polymorphism (А→G in the position 11102143 (rs110793536, ARS-UCD1.2) in the SUGT1 gene associated with fertility. Systematic organization of screening activities will allow identifying lethal genetic defects in the reproductive part of the herd before the breeding company. This approach ensures that only those animals not having genetic load will participate in the breeding process.