A Grain-Based SARA Challenge Affects the Composition of Epimural and Mucosa-Associated Bacterial Communities Throughout the Digestive Tract of Dairy Cows

The effects of a subacute ruminal acidosis (SARA) challenge on the composition of epimural and mucosa-associated bacterial communities throughout the digestive tract were determined in eight non-lactating Holstein cows. Treatments included feeding a control diet containing 19.6% dry matter (DM) starch and a SARA-challenge diet containing 33.3% DM starch for two days after a 4-day grain step-up. Subsequently, epithelial samples from the rumen and mucosa samples from the duodenum, proximal, middle and distal jejunum, ileum, cecum and colon were collected. Ex-tracted DNA from these samples were analyzed using MiSeq Illumina sequencing of the V4 re-gion of the 16S rRNA gene.