Although the rumen microbiome is thought to impact feed digestion, the connection between microbiome and production in beef and dairy cattle remains unclear. The aim of this meta-analysis was to determine if the microbiome can serve as an accurate predictor of animal performance compared with predictions based on diet composition. To support this comparison, a set of models was derived and compared. Models predicted milk yield (MY), ADG, DMI, and feed efficiency (FE) using different sets of independent variables: diet (D), microbiome (M), and experimental methods (EM). Diet independent variables included dietary percentages of dry and organic matter, neutral and acid detergent fiber, crude protein, ether extract, non-fiber carbohydrate, starch, and forage. Microbiome variables included relative abundance of 3 major bacterial phyla, species richness, and species diversity. Experimental variables were publication year, breed type (dairy, beef, or Bos indicus), and rumen sampling fraction (fluid or solid). A second set of models used D and EM variables as predictors of the microbiome. Predictor variable sets were used individually and in combination. Linear mixed-effects regression, weighted by standard error, was used to derive models using data from 51 journal articles. Models were compared on the basis of CCC, root estimated variance associated with study and error, and AICc, where appropriate. The MY model using D+M+EM predictors outperformed all other MY models (CCC = 0.71). Average daily gain was most accurately predicted by D alone (CCC = 0.92). Interestingly, M+EM was more successful at predicting DMI than any model using D. Similarly, dairy FE was more accurately predicted by M+EM than D, albeit slightly (CCC = 0.69 vs. 0.65), while beef FE could only be modeled using D variables. Breed type proved a better predictor of phyla than D. Conversely, species richness and diversity indicators were unaffected by breed type, but could be predicted by D. This analysis concludes that, in some cases, the microbiome may serve as an accurate indicator of animal performance independent of diet.