Abstract
The aim of the research was to metabarcode the microbiocenosis of the gastrointestinal tract of young Romanov sheep raised with and without «Yarosil» probiotic use. The research was carried out on lambs of the Romanov breed of Yurievskoye LLC in the Pervomaisky district of the Yaroslavl region. Samples of the mucous membrane of the rumen, cecum, and feces of lambs from the control and experimental groups served as the material for the research. The proportion of various OTE (operational taxonomic units) of mixed samples from various parts of the gastrointestinal tract of young sheep was analyzed. High–throughput sequencing of the V3-V4 region of the 16S rRNA gene has shown the dominance of representatives of the Bacillota, Pseudomonadota, Verrucomicrobiota and Actinomycetota phyla. The microbiota of the lamb rumen of the control group was characterized by a significant predominance of bacteria of the genus Latil Lactobacillus, reaching almost 75 %. Such a high concentration of these bacteria may indicate their important role in the processes of fermentation and absorption of nutrients in the rumen. Unlike the rumen, the intestinal microbiome was dominated by bacteria of the genera Nanosyncoccus and Faecousia, indicating the specialization of microbial communities in different parts of the digestive system. There have been calculated the indices of biological diversity: the Shannon index ranges from 2.55 to 5.76 in the control group, from 4.65 to 6.13 in the experimental group, the Berger–Parker index ranges from 0.11 to 0.55 and from 0.09 to 0.23 in the control and experimental groups, respectively.