Rumen microbiota and microstructure of small intestine in specially fattened young Edilbay rams (Ovis aries L.)

Feeding without fundamental understanding the digestive function (especially in ruminants) and the occurrence of diseases due to disruption of digestive processes, including due to histological changes in the intestine, affecting its function. We have obtained new data on the effect of diets with feed additives containing I, Zn, Se with plant-born Si and a protein-carbohydrate complex on rumen microbiocenosis and gut microstructure in 7-month old rams (Ovis aries L.). The taxonomic affiliation of microorganisms to genus was assigned, representatives of normal microflora, opportunistic, pathogenic, uncultivated and transit microflora were identified. Histological studies of the small intestine of Edilbaev rams were carried out using light microscopy. We examined the rumen contents and state of the small intestine in four groups (n = 10 each) of 7-month old Edilbaev rams fed additives based on Ioddar-Zn and DAFS-25 preparations. A detailed analysis of the rumen microbiota composition at the level of genera was carried out using NGS sequencing; microstructural studies of the small intestine were performed using light microscopy. An assessment of the influence of diets enriched with essential microelements (I, Zn, Se) on the rumen microbiota in rams showed that the proportion of normal microflora was generally high in all samples, and the proportion of opportunistic and pathogenic microflora was quite low. Histological studies of the mucous membrane of the jejunum did not reveal significant differences when changing diets. When analyzing the rumen microbiome of rams, it was revealed that the feed additives used affect the composition of the microbial community, modulating the ratio of various microorganisms. In all experimental groups, a significant (p ≤ 0.05) increase occurred in the representation of cellulolytic bacteria of the phylum Bacteroidetes . With dietary Ioddar-Zn, the proportion of lactate-fermenting Selenomonadales , Bifidobacteriales and methanogenic archaea significantly increased, and the abundance of the order Clostridiales in the rumen decreased. When using DAFS-25, in addition to an increase in the proportion of the phylum Bacteroidetes , there was a significantly larger (p ≤ 0.05) number of the order Bacillales . We did not identify any significant differences in the abundance and composition of pathogenic and opportunistic microbiota between the experimental and control groups. The dynamics of bodyweight showed that at the age of 7 months the absolute average gain in the experimental groups was from 3.45 kg to 4.49 kg vs. 3.1 kg in control group, group IV fed both feed additives showed the greatest increase in body weight. Group IV had the highest meat coefficient of 3.9, cross-sectional area of m. Longissimus dorsi was 13.61 cm2. Microstructural features of the small intestine were revealed in rams fed diets enriched with iodine and selenium. In general, the morphological structure of the small intestine corresponded to the age morphological standards without significant differences between the studied groups, although it is necessary to note a clearer small intestine wall microstructure in group IV fed both additives. The greatest increase in body weight occurred in animals from group IV fed diets enriched with both additives. The excess relative to the control was 10.48 % (p function show_eabstract() { $('#eabstract1').hide(); $('#eabstract2').show(); $('#eabstract_expand').hide(); }