Ruminal Microbiome Manipulation to Improve Fermentation Efficiency in Ruminants

Abstract

The rumen is an integrated dynamic microbial ecosystem composed of enormous populations of bacteria, protozoa, fungi, archaea, and bacteriophages. These microbes ferment feed organic matter consumed by ruminants to produce beneficial products such as microbial biomass and short-chain fatty acids, which form the major metabolic fuels for ruminants. The fermentation process also involves inefficient end product formation for both host animals and the environment, such as ammonia, methane, and carbon dioxide production. In typical conditions of ruminal fermentation, microbiota does not produce an optimal mixture of enzymes to maximize plant cell wall degradation or synthesize maximum microbial protein. Well-functioning rumen can be achieved through microbial manipulation by alteration of rumen microbiome composition to enhance specific beneficial fermentation pathways while minimizing or altering inefficient fermentation pathways. Therefore, manipulating ruminal fermentation is useful to improve feed conversion efficiency, animal productivity, and product quality. Understanding rumen microbial diversity and dynamics is crucial to maximize animal production efficiency and mitigate the emission of greenhouse gases from ruminants. This chapter discusses genetic and nongenetic rumen manipulation methods to achieve better rumen microbial fermentation including improvement of fibrolytic activity, inhibition of methanogenesis, prevention of acidosis, and balancing rumen ammonia concentration for optimal microbial protein synthesis.

A Review of Effect of Saponins on Ruminal Fermentation, Health and Performance of Ruminants

“…Benchaar et al [ 39 ] reported that saponins have no effect on total protozoal populations or on generic composition. It is interesting to note that the antiprotozoal activity of saponins is only transitory [ 20 , 43 ]. The antiprotozoal effects of Sesbania sesban in sheep were observed [ 44 , 45 ].…”

Nutrient intake, digestibility, and utilization in goats fed graded levels of hempseed cake finisher diets

“…The increase in OM intake and digestibility has been reported to result in high total VFA and acetate in lambs (Tadayon et al 2017 ). Feed organic matter is the main substrate for rumen microbial growth and VFA production (Faverdin 1999 ; Soltan and Patra 2021 ). However, Neto et al ( 2016 ) suggested that the acetate concentration is more related to NDF intake and digestibility.…”

The Effect of Adding Thymol on Rumen Fermentations, the Digestibility of Nutrients and Bacterial Count of Arabi Lamb’s Rumen Fluid in Vitro

“…Table (3) indicates that there were no significant differences (P> 0.05) in the pH of the rumen fluid and in the concentration of ammonia nitrogen after 24 hours of in vitro incubation. Table (3) showed that there was a significant superiority (p<0.05) in the metabolizable energy, total fatty acids and total gas in favor of the addition of 200, 300, 400 mg thymol compared to the control treatment (zero thymol). The value of metabolizable energy for the four treatments were 7.87, 10.50, 10.18, 10.59 MJ/kg dry matter respectively.…”

“…Rumen fermentation plays an important role in feed digestion and microbial production. However, microbial fermentation can lead to significant energy and protein losses through the production of methane and ammonia, which are environmental pollutants [3]. Therefore, rumen microbial fermentation can be diversified to improve productivity and mitigate adverse environmental effects.…”