PSXV-7 - The mixture of herbal extracts that change the microbiome of the cattle rumen

Today, the search for new antibacterial natural agents based on plant raw materials is relevant. These raw materials have promising secondary metabolites that reduce the formation of methane in the ruminant scar. The aim of this study was to evaluate the effect of the following extracts: oak bark+birch leaves (I group) (250 ml/head per day), oak bark + St. John's wort grass (250 ml / head per day; II group) and birch leaves + St. John's wort grass (III group; 250 ml/head per day) on the rumen microbiota of large cattle, against the background of control (C). Extracts added to the water of calves with rumen fistula (dairy breed, age 12 months, diet -70 % of hay, 30 % of grain feed, duration is 14 days). The microflora analyzed using high-efficiency 16S rRNA (Illumina) gene sequencing. Plant extracts prepared by purification, grinding (1-2 mm) and extraction in a water bath (for 30 min, 70 ° C) and filtration. According to the study results, the inclusion of extracts led to increase of the Bacteroidetes phylum for 1.11-3.69 % in the practical groups in comparison with C. A decrease was obtained for Firmicutes for 2.06-3.55 % (p 0.05) and Proteobacteria. In the I group bacteria of the class Bacteroides increased by 0.9-5.64% and Candidatus Saccharibacteria increased by 0.25% (P = 0.05). In the III group the value increased by 0.64 % (P = 0.05). Compared to C at the level of the family Prevotellaceae dominated in all experimental groups by 1.04-9.11 % (P ≤ 0.05), in group III Bacteroidaceae dominated by 0.27 % and Rikenellaceae by 0.14 %. This contributes to the regulation of opportunistic microorganisms without harmful effects on the rumen microbiota. This research was performed with financial support from the project 0761-2019-0005.