Идентификация гаплоблоков, потенциально ассоциированных с эмбриональной смертностью крупного рогатого скота черно-пестрого корня

Abstract

Abstract. In modern realities, the problem of cattle reproduction is becoming one of the most important issues in managing a large herd. The long-term desire of breeders in all countries of the world to increase milk productivity in dairy cattle has led to the degradation of their reproductive capacity. The service period has increased by more than 40 days, the insemination index has increased almost 2 times, the intercalving period has become 3 months longer than a year. Due to intensive selection aimed at milk production and a decrease in reproductive capacity, a cow does not give birth to a calf every year, and the percentage of pregnant animals after the first insemination has sharply decreased to 30%. In terms of the degree of loss of reproductive function in cows, embryonic mortality ranks first, due to which up to 70% of pregnancy losses occur in the first 45 days after fruitful insemination. Accelerating the pace of breeding progress requires the use of genomic selection in animal husbandry, which will make it possible to conduct genome-wide association studies (GWAS) with indicators of productive longevity and fertility of cows and to identify genomic regions subject to the greatest selection pressure for indicators of productive longevity and reproductive function of dairy cattle. Purpose of the work: Identification of haplotypes responsible for reproductive function of cattle. Research methods. The studies were conducted on the Holstein breed of cattle. Identification of homozygous haplotypes was carried out using the GHap package in R software. The scientific novelty of the work lies in the identification of homozygous haplotypes responsible for early embryonic mortality and affecting fertility in a population of Holstein cows of the Ural type, Results. During the processing of the data obtained, chromosomes with haploblocks were identified, which may be responsible for early embryonic mortality and affecting the fertility of cattle.