December 19, 2019

Interpretive Summary: Metagenomic sequencing of rumen microorganisms of cattle

Interpretive Summary: Metagenomic sequencing of rumen microorganisms of cattle fed a corn stover-based diet

By: Anne Wallace

The authors of this ASAS-CSAS Annual Meeting and Trade Show abstract published in the December 2019 issue of the Journal of Animal Science evaluated how a corn stover-based diet (CSD) affected the rumen microbiota of Holstein cows.

Stover is an economical feed with a lower digestibility than traditional feed. Therefore, there is a need to identify changes in the rumen microbiome of cattle fed CSD to potentially identify microorganisms which may be able to more effectively degrade lignified forage like corn stover.

Cows were fed a corn silage and oat hay mineral premix diet during the first experimental period, and a CSD mineral premix diet for the second experimental period, each lasting 45 days. Ruminal fluid was collected at the end of each period and analyzed in a 16S gene sequencer.

With CSD feeding, there was a significant increase in the relative abundance of the following rumen bacteria: Prevotella ruminicola, Streptococcus luteciae, Clostridium aminophilum, Selenomonas ruminantium and Pantoea agglomerans. With CSD feeding, there was a significant decrease in the relative abundance of Propionibacterium acnes and Bacteroides ovatus.

Overall, this study identified specific changes to the rumen microbiome of cows fed a CSD. More in-depth studies looking at the ability of these identified microorganisms to degrade lignified forage may help to find ways to increase its digestibility.