Transcriptomics analysis of host liver and meta-transcriptome analysis of rumen epimural microbial community in young calves treated with artificial dosing of rumen content from adult donor cow

Authors: Li, Wenli; EDWARDS, ANDREA - University Of Wisconsin; RIEHLE, CHRISTINA - University Of Wisconsin; COX, MADISON - University Of Wisconsin; RAABIS, SARAH - University Of Wisconsin; STEINBERGER, ANDREW - University Of Wisconsin; SKARLUPKA, JOSEPH - University Of Wisconsin; Walling, Jason; Bickhart, Derek; SUEN, GARRET - University Of Wisconsin

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/25/2018
Publication Date: 1/28/2019
Citation: Li, W., Edwards, A., Riehle, C., Cox, M., Raabis, S., Steinberger, A., Skarlupka, J., Walling, J.G., Bickhart, D.M., Suen, G. 2019. Transcriptomics analysis of host liver and meta-transcriptome analysis of rumen epimural microbial community in young calves treated with artificial dosing of rumen content from adult donor cow. Scientific Reports. 9. Article 790. https://doi.org/10.1038/s41598-018-37033-4.
DOI: https://doi.org/10.1038/s41598-018-37033-4

Interpretive Summary: It is thought that bacteria that grow in the developing stomach of cows impacts the further development of the cow’s gut, and resultant production efficiency changes. However, little is known about how the colonization of bacteria can change the animal. Chemical changes in the animal are caused by enzymes and are in turn controlled by the expression of specific genes. This experiment introduces adult rumen content to new born calves to see if this treatment introduces physiological changes in the host by looking at a whole array of genes in calf liver. In turn, it is possible to figure out how these genes lead to specific developmental characteristics. Ultimately, our experiment will facilitate the design of probiotic treatment in young dairy calves with the aim to give the cow a highly active and efficient working gut that leads to good health, and production efficiency.

Technical Abstract: In mammals, microbial colonization of the digestive tract (GIT) occurs right after birth by several bacterial phyla. Numerous human and mouse studies have reported the importance of early gut microbial inhabitants on host health. However, few attempts have been undertaken to directly interrogate the role of early gut/rumen microbial colonization on GIT development or host health in neonatal ruminants through artificial manipulation of the rumen microbiome. Thus, the molecular changes associated with bacterial colonization are largely unknown in cattle. In this study, we dosed young calves with exogenous rumen fluid obtained from an adult donor cow, starting at birth, and repeated every other week until six weeks of age. Eight Holstein bull calves were included in this study and were separated into two groups of four: the first group was treated with rumen content freshly extracted from an adult cow, and the second group was treated with sterilized rumen content. Using whole-transcriptome RNA-sequencing, we investigated the transcriptional changes in the host liver, which is a major metabolic organ and vital to the calf’s growth performance. Additionally, the comparison of rumen epimural microbial communities between the treatment groups was performed using the rRNA reads generated by sequencing. Liver transcriptome changes were enriched with genes involved in cell signaling and protein phosphorylation. Specifically, up-regulation of SGPL1 suggests a potential increase in the metabolism of sphingolipids, an essential molecular signal for bacterial survival in digestive tracts. Notably, eight genera, belonging to four phyla, had significant increases in abundance in treated calves. Our study provides insight into host liver transcriptome changes associated with early colonization of the microbial communities in neonatal calves. Such knowledge provides a foundation for future probiotics-based research in microbial organism mediated rumen development and nutrition in ruminants.