PSVII-19 - Change in the taxonomic composition of ruminal microflora against the background of copper and plant extract

Plant extracts are used in cattle diets to stimulate growth and immunity, while the unstable biochemical composition of plants contributes to the search for effective compositions that exhibit a synergistic effect. Objective of the study is the effect of an aqueous extract of oak bark (0.7 ml/kg of live weight) - group I, copper particles specific surface area 24 m2/g; 0.06 mg/kg of live weight - group II, their compositions (group III) on the taxonomic composition of the bacterial community of the rumen of cattle. Bulls had rumen fistulas Bos taurus at the age of 13 months (n = 5). Test samples of feed components were given with a concentrated portion of the main diet. Diet contain 60% - roughage (hay of Sudanese grass and alfalfa), 35% - concentrated feed (mixture of barley, wheat, sunflower husk, bran). The taxonomic composition of ruminal content was determined by NGS sequencing on a MiSeq device (Illumina, USA). It was found that the combined use of the extract and copper UFPs increases the concentration of representatives of Bacteroidetes in the rumen by 5.6%, the separate use of copper UFPs is by 20.7% (P ≤ 0.05), at the same time the values of representatives of Firmicutes decreased - by 7.2 and 24.7% (P ≤ 0.05) in comparison with the control. At the taxon level, the following classes prevailed: Bacilli (2.6%) in group I; Bacteroidia (17.0%) in II, in III - Bacteroidia (5.0%) in comparison with the control. In the experimental groups, at the genus level, a lower content of Streptococcus and the absence of Faecalibacterium were registered. Thus, the composition of plant extract and copper has an inhibitory effect on certain representatives of pathogenic bacteria. The results obtained indicate that the combined use of these substances is promising. This research was performed with financial support from the RSF (20-16-00088).