Interestingly, from those bacteria that showed a significant effect of sampling day, many that were increased(Alkalibaculum, Coprobacillus, Coprococcus, Gelria,Ethanoligenes, and Dethiobacter) in the forage feeding period were gram-positive bacteria and not the LPSproducing gram-negative bacteria. Therefore, the role of the rumen epithelial bacteria in host gene expression with regard to commensal versus opportunistic pathogens requires further research and the development of reliable assays for other TLR targets such as TLR2.