Initial effects of supplemental forages and feedstuffs on bovine rumen ecology in vitro as determined by DNA-based molecular procedures

Authors: Turner, Kenneth; BELESKY, DAVID - West Virginia University; Zobel, Richard; Fortuna, Ann Marie

Submitted to: Journal of Applied Animal Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2020
Publication Date: 6/22/2020
Citation: Turner, K.E., Belesky, D.P., Zobel, R.W., Fortuna, A. 2020. Initial effects of supplemental forages and feedstuffs on bovine rumen ecology in vitro as determined by DNA-based molecular procedures. Journal of Applied Animal Research. 48(1):268-280. https://doi.org/10.1080/09712119.2020.1781648.
DOI: https://doi.org/10.1080/09712119.2020.1781648

Interpretive Summary: Many different forages and feedstuffs are used in beef cattle production systems. The rumen contains a mixed community of bacteria, protozoa, and fungi that vary in response to diet and feedstuff supplementation. The interactions of bacteria, protozoa, and fungi with forages and feedstuffs creates a unique ecological, and end-product profile. We applied a standard DNA terminal fragment length technology to a laboratory-based rumen fermentation technique commonly used to evaluate forage and feedstuff nutritive value for cattle. Our results helped to identify groups of forages and feedstuffs which responded similarly during rumen fermentation by the bacteria, protozoa, and methane-producing bacteria in the rumen. Information can be used by livestock producers, nutritionists, and researchers to help identify and refine forage mixtures and supplements (energy, protein, or a combination) for improved nutritional management, feed use, and economics in production livestock.

Technical Abstract: Short-term shifts in bovine rumen community structure (bacteria, archaea, protozoa, and fungi) were measured using terminal-restriction fragment length polymorphism (T-RFLP) profile response to forages and feedstuffs added to an orchardgrass (Dactylis glomerata L.) hay in vitro rumen fermentation. This research aided in determining how supplemental forages and feedstuffs influenced rumen ecology after 48 h of in vitro rumen fermentation. We used a modified principle component analysis to remove artifacts from rumen T-RFLP data sets. The Tukey Vacuum Cleaner Analysis (TVCA) model for analysis of bacteria accounted for 66.3% of the treatment variance and operational taxonomic unit (OTU) clustered into 3 distinct pattern groupings. The model developed for TVCA analysis of archaea accounted for 76.6% of the treatment variance and OTU derived from DNA sequences clustered into 2 distinct pattern groupings. The TVCA treatment variance of protozoa accounted for 75.8% and OTU clustered into 3 distinct pattern groupings. Additions of various forages and feedstuffs did not result in shifts in fungal community structure evidenced by the TVCA model. The rumen contains a mixed microbial community of which the structure can vary due to diet and supplementation with a variety of feedstuffs that can modify microbial interactions, end products, and the overall ecological profile. Our results demonstrate that the ecology of initial T-RFLP profiles in bacteria, archaea, and protozoa can be examined and evaluated using a simplified TVCA analysis to identify pattern groupings of forages and feedstuffs. Groupings of forages and feedstuffs can be used to help identify combinations for improved nutritional management of ruminants.