Dynamics of the cows’ endometrial microbiota composition against biological feed additives use

The aim of the study is to investigate the effect of the feed additive AntiKlos, which was introduced into the diet during the transition period of lactation, on the composition of the endometrial microbiota of highly productive Holstein cows and the reproduction indices of the cows. Objectives: to conduct a scientific and economic experiment on a herd of dairy cows by feeding them the natural feed additive AntiKlos® (OOO BIOTROF, Russia); to analyze the composition of the endometrial microbiota using quantitative PCR, to analyze a number of reproduction indices with and without the additive. Two groups of animals were formed (n = 20): the control group I consumed the basic diet (BD), the experimental group II consumed BD with the addition of the probiotic AntiKlos. The composition of endometrial microorganisms was analyzed in three clinically healthy cows from the control group I and the experimental group II. The composition of endometrial bacteria was analyzed using qRTPCR. On the 21st day after calving, in the control group I and experimental group II, compared with the result obtained during sampling before calving, an increase of 15.7 and 14.3 times, respectively, in the number of representatives of the Enterobacteriaceae family was noted (P ≤ 0.05). During this period, the appearance of bacteria of the Fusobacteriaceae family in the control group I in the amount of (2.5 ∙ 104 ± 1.3 ∙ 103) genomes/g and in a lower amount – (4.2 ∙ 103 ± 1.1 ∙ 102) genomes/g (i.e., 6.0 times lower than in the control, P ≤ 0.01) – in the experimental group II was also noted. Improvement of the structure of the microbial community of the endometrium of cows in the experimental group II contributed to the subsequent reduction of the service period and a decrease in the insemination index.