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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Cell Wall Biology and Utilization Research » Research » Publications at this Location » Publication #412451
Research Project: Developing Strategies to Improve Dairy Cow Performance and Nutrient Use Efficiency with Nutrition, Genetics, and Microbiology

Location: Cell Wall Biology and Utilization Research

Title: Rumen microbial inoculation effects on the liver transcriptome and meta-transcriptome in weaned calves

Author
item FREGULIA, PRISCILA - Oak Ridge Institute For Science And Education (ORISE)
item Zanton, Geoffrey
item Li, Wenli

Submitted to: Ruminant Physiology International Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/14/2024
Publication Date: 8/26/2024
Citation: Fregulia, P., Zanton, G., Li, W. 2024. Rumen microbial inoculation effects on the liver transcriptome and meta-transcriptome in weaned calves [abstract]. International Symposium on Ruminant Physiology. Paper No. 27.

Interpretive Summary:

Technical Abstract: Rumen microbial inoculation in calves may impact rumen fermentation and animal metabolism, but the impact on the liver is largely unexplored. Thus, our objective was to evaluate the effects of dosing three types of rumen microbial inoculum on the liver tissue transcriptome (LT) and meta-transcriptome (LM) of dairy calves. Fifteen Holstein bull calves were enrolled at birth and randomly assigned to one of the three inoculum treatments dosed once weekly from three to six weeks of age, weaned at seven weeks, and euthanized at nine weeks with liver tissue collected for LT and LM analysis. The treatments were prepared from rumen fluid collected from four adult cows and processed as autoclaved (control; C), bacteria-enriched (BE), or protozoa-enriched (PE) inoculum. We used Cufflinks for differentially expressed gene (DEG) analysis (p < 0.05, fold-change > 1.5), DAVID for Gene Ontology (GO), LEfSE for microbial signatures unique to each treatment, sPLS-DA for microbial community structure analysis, and the rarefied read count to calculate the diversity. Compared to C, 132 genes were differentially expressed (DE) in BE and 112 in PE. Between BE and PE, 67 genes were DE. For downregulated genes in BE compared to C, several GO terms were related to response to microbes and immune response (e.g. GO:0009617), and in PE compared to C most of the GO terms were in the category Biological Process (47%) (e.g. GO:0005520). In both BE and PE, the upregulated genes compared to C were enriched in GO terms related to cellular components (e.g. GO:0001558). For the LM analysis, we found a lower alpha-diversity in PE compared to the other groups (Simpson's index, p < 0.05). LEfSe detected that microbial signatures specific to C were composed of Acinetobacter and Hydrogenophaga. No unique microbial signature was detected for BE and PE. We found a higher abundance of Clostridium in BE and PE and a higher abundance of Paraglaciecola in BE. The sPLS-DA showed that BE community structure largely overlapped with C and PE, while C and PE showed nearly distinct microbial profiles. Our findings suggested that the dosing differentially enriched ruminal microbes can affect LT expression profile and potentially introduce disruption to its native microbial communities.