Fig. 4

Unconstrained NMDS ordination analysis was used to visualize beta diversity based on OTU (a) and viral population (b) abundances across samples. PERMANOVA results indicate that structuring of bacterial communities is best explained by diet (diet: P = 0.001, R ² = 0.365; period: P = 0.188, R ² = 0.140; steer: P = 0.312, R ² = 0.166). Both dietary and host animal effects were found to significantly explain the variation in viral populations (diet: P = 0.002, R ² = 0.266; period: P = 0.096, R ² = 0.145; steer: P = 0.048, R ² = 0.290). 27CDS—27% condensed distillers solubles; 40MDGS—40% modified distillers grains plus solubles; 55CS—55% corn silage. 222, 259, 346, 3244, and 3257 represent animal identifiers