Ruminant nutrition symposium: Improving rumen fermentation through altering rumen microbiota
Written by ADSA Graduate Student Division member April White of The Ohio State University.
ADSA’s Ruminant Nutrition Symposium: Improving Rumen Fermentation Through Altering Rumen Microbiota demonstrated that the rumen microbiome is a complex ecosystem affected by the host diet, genetics, and the environment. In turn, the microbiome influences host health and performance phenotypes.
Ruminant nutrition relies on the rumen microbiome to supply a dairy cow’s energy (70% from volatile fatty acid fermentation) and protein (from microbes). The rumen microbiome remains a desirable target for modifying an animal’s efficiency and production performance, but complex feeding and cross-feeding networks exist in the rumen that require further study in order to manipulate the composition of the rumen microbiome and drive efficiency in production.
Inhibiting predation in the rumen may be one viable option for improving efficiency. Protozoa make up around half of the microbial biomass in the rumen and engulf up to 24% of the total rumen bacteria, consuming microbial protein. Protozoa, in turn, die and are degraded by rumen bacteria, driving a futile nitrogen-recycling loop that decreases nitrogen and feed efficiency. Defaunation corrects this, but is impractical in a production setting, so identifying targets in the protozoal genome to inhibit predation is necessary moving forward.
Controlled rumen viruses may be used to reduce protozoa, or targeted enzymes such as peptidases may offer control points. Similarly, the volatile fatty acid profile produced by rumen bacterial fermentation may be modified by targeting enzymes in the alternative pathways that microbes use. However, the current understanding of the biochemistry behind microbial fermentation doesn’t represent rumen microbes well. Combining modern genomics, proteomics, and enzyme activity assays will allow researchers to identify key steps in the fermentation pathways of rumen bacteria, potentially allowing for modifications of rumen volatile fatty acid concentrations in the future.
Exploring the relationships between microbiome composition and function and host performance may also provide opportunities to improve animal agriculture in the future. In addition to contributing to public health goals, such as reducing methane emissions and halting the development of antibiotic-resistant bacteria, modifying the rumen microbiome may help improve growth and resilience in calves or production in adult animals. Identifying the microbes that are prevalent in efficient, healthy animals may allow for the development of tools to improve animal performance by modifying the composition of the microbiome.
For this technology, dairy scientists should be reminded that great strides have been made in human medicine to characterize, modify, and perfect the human gut microbiome to treat disease, and animal agriculture stands as an industry that has consistently adapted and adopted new technologies to improve production, performance, and sustainability. Rumen microbiome research will continue to develop strategies to benefit dairy animals and the dairy industry.
Recommended by LinkedIn
Three key takeaways from the presentations
Zhongtang Yu: Protozoa offer many potential targets for inhibiting predation in the rumen, including targeting functional proteins such as peptidases and lysozyme. The growing knowledge and characterization of the rumen virome will likely provide opportunities in the future to use phages to control protozoal populations in the rumen, thereby increasing efficiency.
Tim Hackmann: The alternative fermentative pathways that rumen microbes use to make volatile fatty acids are relatively poorly characterized compared with their aerobic cousins, which grow readily in research labs. However, increases in genomics research are beginning to allow us to find and characterize novel fermentation types in rumen bacteria, pointing toward future targets for modification.
Peixin Fan: Host-microbiome interactions are important considerations for study, especially in production agriculture. Genetics, diet, and the environment all impact the microbiome, which in turn affects the host phenotype. Future research is needed to characterize how the host and microbiome interact, especially as production demands increase and antibiotic-resistant microbes continue to evolve.
ADSA Annual Meeting
As a dairy professional, staying up-to-date with the latest research and industry trends is essential to your success. Attending ADSA’s conferences gives you face-to-face, personal access to cutting-edge dairy science and the people behind the breakthroughs. From symposia to poster sessions, networking events to hallway conversations, ADSA’s in-person and virtual conferences offer the keys to groundbreaking dairy science and to advancing your career. ADSA members enjoy reduced registration rates to the ADSA Annual Meeting (over $100 off each year) and all Discover Conferences.
Laboratory Technician- Fiji National University
1yIs there any difference in the rumen microbiota of cattles's and goats? Do goats have a stronger rumen microbiota which enables them to synthesize more ADF and NDF.
Rumen microbiome, host, diet, genetic, environment, phenotype, their interaction are meaningful keywords. Gut microbiota is a new organ.