Association of <i>FGF2</i> gene polymorphism with economically significant traits of Holstein cows of the Republic of Tatarstan

Abstract

Improving the reproductive functions of dairy cows may be possible through the use of marker-associated breeding. The FGF2 gene is a candidate gene for bovine fertility, in early pregnancy and affects fetal embryonic development and embryonic mortality. The study of the interaction of the gene of the basic fibroblast growth factor 2 (FGF2 – SNP11646 [A → G]) and economic indicators was carried out on 270 full-aged cows of Holstein population of indigenous selection of Breeding Farm Integrated Agricultural Production Center of the Republic of Tatarstan. In the observed population, the G allele (0.591) and the AG genotype (42.6%) are the most common, and the genetic balance, according to the Hardy-Weinberg law, is preserved. Pearson's consensus criterion is 2χ=3.84, respectively, the expected distribution of FGF2 gene alleles in the study group coincides with the observed one. The maximum live weight at the first fruitful insemination was in full–aged cows carrying the homozygous allele A at the FGF2 gene locus – 435.5 kg, which is higher than in livestock with the GG genotype – by 17.7 kg (4.2 %; p < 0.01). The Doha fertility index for the studied population is average. It was revealed during the study that the level of fertility, with a high degree of reliability, is higher in individuals with the AG genotype – 6.2%, for the same group the earliest age of the first fruitful insemination was noted. A high level of maleness leads to milk losses in cows heterozygous for the FGF2 gene locus, exceeding milk losses observed for the AA genotype by 32.7 % (p < 0.001). There is an inverse correlation between high milk productivity and reproduction traits of cattle, which affects the economic efficiency of dairy production.