Venn diagrams showing the number of observed operational taxonomic units (OTU) shared across 3 diet groups. A) Only 2,359 OTU were shared in combination across 3 diet groups, and each group was represented by numerous unique OTU. B) The number of observed OTU was normalized based on the smallest number of sequences in Silage/Forage. The number of shared OTU was lower between Silage/Forage and Moderate Grain (or High Grain) than between Moderate Grain and High Grain. See online version for figure in color.