41 Differential Gene Expression of the Bovine Rumen Epithelial Microbiota During a Sub-acute Ruminal Acidosis (SARA) Challenge

Abstract Sub-Acute Ruminal Acidosis (SARA) is a metabolic disorder in dairy cattle characterized by lowered ruminal pH, as result of high grain diets. Dairy cows experiencing SARA show decreased milk production and impaired health; thus, has major economic impacts. been associated with changes the rumen epithelial microbiota. Previously, we performed meta-transcriptome sequencing on biopsy samples from 3 fistulated Holstein before (baseline) after switching to concentrate feed induce analyze gene expression In this previous analysis, 1,607 features were detected using KEGG Ontology reference database, including wide variety genes, well stress response, motility, other functions. However, only differentially expressed between baseline conditions approach. Here, present re-analysis meta-transcriptomics data an improved bioinformatics pipeline reveal additional genetic diversity genes. We de novo transcriptome co-assembly Trinity, mapped reads assembled contigs, used RSEM determine read counts, DESEQ2 for detection genes (Q < 0.05). Features annotated EggNOG, providing taxonomic predictions GO, COG, KEGG-based functional prediction. Using method, total 76,861 transcripts assembled, 4,935 conditions, representing substantial improvement over analysis. Our preliminary analysis indicates levels central metabolism housekeeping oxidative response outer membrane proteins among bacteria. Differentially archaeal primarily upregulated under included involved methanogenesis. Further analyses are ongoing will provide insight into microbiota, their association SARA.