Search

Diseases that occur in such a multifactorial system as animal husbandry are determined not only by internal factors of the body, for example, the composition of the microflora of the digestive system, but also by external factors, such as feed. The aim of the study was to analyze the similarity of the microbiota of silage fed to cows with the composition of the microflora of their rumen and milk using the NGS sequencing method. The experiment was carried out on one of the commercial farms of the Leningrad region. The bacterial community of the contents of rumen, milk and silage from perennial cereals and legumes was evaluated by NGS sequencing on the MiSeq platform (Illumina, Inc., USA) with primers for the V3-V4 region of the 16S rRNA gene. As a result of the study, 22 phylum of attributed microorganisms were found in the microflora of silage, 24 to 30 phylum of rumen, 18 phylum of milk. Similar taxa of microorganisms were identified in silage, rumen and milk, the main difference was noted in quantitative ratios (P≤0.05). For example, the amount of Firmicutes in silage was 52.9 ± 3.45%, in milk - 11.8 ± 0.78%. This suggests that there may be some relationship between the studied biotopes. Pathogenic microorganisms, including the causative agents of mastitis, were present in many samples. The genera Staphylococcus, Acinetobacter, Streptococcus and Fusobacterium were identified by us as the most represented (P≤0.05) in the composition of the milk microflora. Their content was 0.24±0.023, 1.8±1.23, 1.0±0.06 and 0.35±0.031%, respectively. Probably, the microflora of the rumen can influence the formation of the milk microbiota.

The aim of the study was to study the effect of different concentrations of glyphosate on meat productivity and differential expression of genes for immunity and broiler productivity. Broilers were divided into groups: Control I, who received a diet without the introduction of glyphosate, Experimental II, who received a diet with the addition of glyphosate at a dose of 10 mg/kg of feed (0.5 MPC for food); Experimental III, who received a diet with the addition of glyphosate at a dose of 20 mg/kg of feed (1 MPC); Experimental IV, who received a diet with the addition of glyphosate at a dose of 100 mg/kg of feed (5 MPC). Transcriptome analysis was performed by RNA-seq on the Illumina Miseq platform, using the TruSeq Stranded mRNA kit (Illumina, USA). In the 22-28-day period of broiler rearing, a decrease in live weight gain (83 g less) was observed in Experimental group III compared to Control I (P≤0.05). It has been shown that glyphosate at the level of 1 and 5 MPC for food causes activation (P≤0.05) of the proinflammatory response genes (IL15, IL1B, IL34, IL22) and apoptosis (Casp1, Casp2, Casp6, Casp7, Casp8, Casp9) up to 31.1 times, which probably leads to the redistribution of nutrients in in the body towards the immune system, reducing the functions of absorption in the intestine. In parallel, there is an inhibition (P≤0.05) of the expression of genes that have a direct effect on growth and development, which ultimately leads to a decrease in poultry meat productivity. Exposure to glyphosate is an important but unaccounted-for risk factor for reducing meat productivity in birds, acting through a change in gene expression.

Despite the attention given in the recent years to the microbiological causes of endometritis and the potential sources of uterine microbiota infestation, more questions than answers remain in this research field. This paper describes an experiment carried out at the livestock farm of the Leningrad region on 6 dairy cows of the Holsteinized Russian Black Pied breed of the second lactation in the period after calving. The animals were divided into two groups (n = 3): Group 1 included clinically healthy animals, Group 2 included animals diagnosed with purulent-catarrhal post-calving endometritis. Metagenomic sequencing was performed using the MiSeq genomic sequencer (Illumina, Inc., USA) with the MiSeq Reagent Kit v3 (Illumina, Inc., USA). Based on the next-generation sequencing of microbiota of endometrial scrapings, 7 phyla of microorganisms were detected in clinically healthy cows and only 4 phyla of microorganisms in cows diagnosed with endometritis. The increase in the proportion of Fusobacteriota taxon bacteria permanently present in endometrial scrapings and the decrease in Bacteroidota phylum bacteria in the group of animals with endometritis could be related to the occurrence of this disease. Bacteria Alloprevotella, Campylobacter, Caviibacter, Falsiporphyromonas, Veillonella present only in the endometrial tissue of sick cows may be the etiological origin of endometritis. In the rumen of animals with endometritis, there was an increase in Bacteroidota phylum microorganisms (p≤0.05) against a decrease in Firmicutes phylum bacteria (p≤0.05) compared to the clinically healthy group. Using the PICRUSt2 software package (v.2.3.0), it was shown that the microbiome of cows diagnosed with endometritis showed inhibition (p≤0.05) of the potential of 9 metabolic pathways compared to healthy animals. This could have negative consequences for the body of animals and be a consequence of metabolic disorders.

Methods of molecular genetic analysis are widely used to study the air microbiota. These methods make it possible to study all groups of microorganisms without the need for their cultivation. The purpose of the study was to analyze the microbiota of the poultry house air environment by the qPCR method and identify the presence of representatives of the normophlora, opportunistic and pathogenic microflora. The research plan included sampling of the air microbiota from a three-tier cage battery for poultry rearing for 42 days. The data obtained revealed an increase in the presence of microorganisms during the entire experiment, the largest number of them was detected on the 42nd day of cultivation on the lower tier. The results of the study emphasize the importance of timely detection and assessment of the microbiota of the air to prevent the spread of diseases and their impact on the health and productivity of birds.

Molecular genetic techniques (NGS sequencing and quantitative PCR) were used to determine the composition of the cecal bacterial community of broiler chickens fed with different mixed fodder. The cecal microbiome exhibited taxonomic diversity, with both typical inhabitants of avian intestine belonging to the families Clostridiaceae, Eubacteriaceae, and Lactobacillaceae and to the phylum Bacteroidetes, and new unidentified taxa, as well as bacteria of the families Lachnospiraceae and Ruminococcaceae, which were previously considered restricted to the rumen microbiota. Contrary to traditional concepts, enterococci and bifidobacteria were among the minor components of the community, lactate-fermenting species were absent, and typical avian pathogens of the genus Staphylococcus were detected but seldom. Members of the family Suterellaceae and the genus Gallibacterium, which are responsible for avian respiratory infections, were also detected. Significant fluctuations of abundance and composition of microbial groups within the cecal community and of the parameters of broiler productivity were found to occur depending on the feed allowance. Cellulose content in the feed had the most pronounced effect on the composition and structure of bacterial communities. Decreased cellulose content resulted in a decrease of bacterial abundance by an order of magnitude and in increased ratios of members of the phylum Bacteroidetes and the family Clostridiaceae, which possess the enzymes degrading starch polysaccharides. Abundance of the normal inhabitants of avian intestine belonging to the genus Lactobacillus and the order Bacillales decreased, while the share of Escherichia and members of the family Sutterellaceae increased, including some species capable of causing dysbiotic changes in the avian intestine. No significant change in the abundance of cellulolytics of the families Ruminococcaceae, Lachnospiraceae, and Eubacteriaceae was observed. [ABSTRACT FROM AUTHOR]