The microbiome of the digestive system of ruminants – a review

Abstract

This review aims to explain the influence and characterization of the microbiome in the ruminant digestive system by presenting the knowledge collected so far. The knowledge presented in this work is focused on the main factors affecting the microbiome and the main dependencies that have been found in it so far. The microbiome in the rumen is the first to come into contact with the biomass of the forage and its main purpose is to decompose into smaller particles or compounds. With the gradual increase in knowledge about the microbiome, there is a chance to manipulate it so that the animal continues to live in a symbiotic relationship with it, while reducing greenhouse gas emissions to the environment as well as increasing feed efficiency. Therefore, understanding the influence of the ruminant microbiome is the main step to achieve such results. However, learning the relationship between microorganisms is only at an early stage, because research focuses mainly on taxonomy. Future research should focus on interactions in the ecosystem which is the microbiome, on explaining individual functions and on influence of environmental factors.

Development of Swine’s Digestive Tract Microbiota and Its Relation to Production Indices—A Review

“…Microorganisms act as a specific ecosystem, which is adapted to the habitat and physiological status of the host. Populations of microorganisms include saprophytic microorganisms, commensals and incidentally pathogenic microorganisms [1][2][3].…”

Evaluation of Changes in the Levels of Firmicutes and Bacteroidetes Phyla of Sheep Feces Depending on the Breed

“…The obtained results may suggest that although the Romanov sheep as a breed was in the past formed and selected for desirable traits in Russia and was then subject to conditions prevailing in this country, this could have affected the composition of its current microbiome. Despite being maintained in Poland, this could still contain the features of the microbiome from the time of breed formation in Russia [ 6 , 18 , 19 , 20 ].…”

“…In addition, studies conducted so far have shown a significant impact of the microbiological composition of the digestive system on the health status of the animals and the quality of the products obtained from them, i.e., milk and meat, as well as the amount of methane produced [ 3 , 4 , 5 ]. Anaerobic and relatively aerobic bacteria (mainly Firmicutes and Bacteroidetes) are the most abundant, along with much smaller quantities of Proteobacteria, Fibrobacteres, Tenericutes, and Actinobacteria, followed by archeons (mainly Methanobacterium , Methanosarcina , and Methanobrevibacter species), protozoa (i.e., genus Isotrichia , Dasytrichia , Entodidium , Diplodinium , Endidiplodinium ) and fungi (e.g., Anaeromyces , Caecomyces , and Cyllamyces [ 6 ].…”

“…According to the literature, the microbiological composition is mainly influenced by factors such as the environment, age, physiological state, and nutrition, and even geographical differences [ 1 , 6 ]. However, ruminants (cattle, sheep, goats) differ not only in terms of species but also breed, and this may be one of the factors differentiating the microbiological compositions of their digestive systems.…”

“…However, ruminants (cattle, sheep, goats) differ not only in terms of species but also breed, and this may be one of the factors differentiating the microbiological compositions of their digestive systems. Not much is known about the influence of breed or even genotype on the microbiological composition of the gastrointestinal tract [ 6 ]. Recent studies have shown the influence of the host itself on microbial composition.…”