Analysis results of cow rumen microflora composition under the probiotics influence by NGS sequencing method

The purpose of research is to study the effect of the probiotic Profort-T on the composition of the rumen microbiome of dairy cows using NGS sequencing, productivity and hematological parameters of the animals' blood serum. The experiment was carried out on black-and-white cows for 60 days. Analogue groups of 20 animals each were formed: control group I (received the basic diet (BD)) and experimental group II (received the BD diet and the Profort-T probiotic). The BD consisted of: silage - 42.26 kg; hay - 1.97; mixed feed - 14.67 kg; salt, chalk, soda. The cows of experimental group II received the probiotic Profort-T at the rate of 0.03 kg per 1 head from the day of admission to the new calving group. The feed additive was distributed manually to each head of experimental group II during the new calving period and partially during milking. The animals were kept under the same conditions. Animals are kept in tethered conditions. The rumen bacterial community was assessed by NGS sequencing using a MiSeq sequencer (Illumina, Inc., USA). The use of a probiotic (experimental group II) made it possible to increase the average daily milk yield from 14.9 to 22.0 % compared to the control (P ≤ 0.05) and reduce the content of somatic cells in cows’ milk from 21.6 to 33.5 % (P ≤ 0.05). NGS sequencing demonstrated that 21 phyla of microorganisms were found in the rumen microflora of the studied cows. The most represented (P ≤ 0.05) bacteria in the rumen were bacteria of the phylum Bacteroidetes - from 46.6 ± 4.48 to 58.1 ± 5.52 %. The proportion of cellulolytic bacteria Candidatus Saccharibacteria increased in experimental group II at the end of the experiment compared to the control by 1.9 times (P ≤ 0.05). Microorganisms Proteobacteria and Fusobacteria decreased in experimental group II compared to the control by 5.7 and 1.8 times, respectively (P ≤ 0.05), i.e. the use of the Profort-T probiotic led to an improvement in the structure of the microbial community of the cow rumen.