Evaluation of the impact of plant extracts in different concentrations on the ecosystem of broilers’ intestine

Abstract

Modern research shows that several plant extracts containing tannins can improve the nutrition and the health status of farm livestock. In view of the fact that there is a certain dependence of the tannin activity on the source, geographical distribution, the assessment of their effects on changing the intestine microbiota is poorly studied. Experimental studies were conducted on 120 heads of 7-day-old broiler chickens (4 groups, n = 30, 4 replications). The control group received the main ration (MR); the first experimental group – MR + extract 1 (1 ml/kg of live weight); the second experimental group – MR + extract 2 (2 ml/kg of live weight); the third experimental group – MR + extract 3 (3 ml/kg of live weight). An extract from Quercus cortex was additionally included in the composition of experimental groups’ rations. Sequencing the content of samples from the small and cecal intestine was carried out at the second generation sequenator MiSeq Illumina (the United States). As the concentration of the extract increased, micro-organisms of phylum Bacteroidetes shrunk (I) and then disappear (II, III). The maximum concentration found a decrease of phylum Firmicutes (p ≤ 0.05) and an increase of Proteobacteria (p ≤ 0.05). This group also revealed a decline of representatives of class Bacilli (p ≤ 0.05). In groups I and II, representatives of class Clostridia decreased by 14.6-50.5% in comparison with the control. The ratio of representatives of microorganisms in the intestine depends on the number of tannin-containing substances in the extract, which reveals the need for a more detailed examination of this factor as a source of such substances.