PSVIII-21 The effect of medicinal extracts on microflora and enzymatic processes of calf rumen

Abstract

Abstract The fight against antibiotic resistance and a decrease in the greenhouse effect leads to the search for safe alternative substances for animals, special attention is paid to phytochemicals in medicinal plants. The aim of this study was to evaluate the effect of extracts of Oríganum vulgáre (OV) and Hypéricum perforátum (HP; 0.5 ml/kg body weight) on ruminal microflora and fermentation characteristics against the background of control (C). The extracts were added to water of bulls with rumen fistula (14-month, diet - 70% hay, 30% barley grain). The fermentation parameters (CH4, digestibility of dry matter of the grain) were analyzed daily, and the microflora was analyzed using highly efficient sequencing of 16S rRNA gene (Illumina). OV and HP were prepared by grinding, extraction in a water bath (30 min, 70 ° C) and filtration. According to the results, the addition of OV and HP reduces the formation of CH4 and the digestibility of CB did not differ compared to C (48.7 and 47.8%, against 50.6%). The phylum of archaea Euryarchaeota was small and dominant in OV and HP. The phylum of Bacteroidetes dominated and was higher than that of C, that of OV was 35.6% (P ≤ 0.05) and HP was 30.7% (P ≤ 0.05). The Bacteroidia class (30.0–31.5%) changed similarly due to the families Porphyromonadaceae (P ≤ 0.05), Prevotellaceae (P ≤ 0.05). OV showed a tendency towards a decrease in Firmicutes phylum, and increase in bacteria of the Clostridia class by 11.1% (P ≤ 0.05). Clostridia class prevailed in HP by 14.5% (P ≤ 0.05) in comparison with C, due to Ruminococcaceae, Clostridiales families. This study highlights the potential use of OV and HP in cattle diets aimed at decreasing methane production and increasing gram-negative bacteria. This research was performed with financial support from the RSF (16-16-10048) and project 0761-2019-0005.