An experiment was conducted to evaluate the levels of exogenous fibrolytic enzymes (EFE) on in vitro digestibility of dry matter (DM) and organic matter (OM), net gas production (NGP), metabolizable energy (ME) content, microbial biomass production (MBP) and efficiency of microbial biomass production (EMP). | An in vitro dose optimization of exogenous fibrolytic enzymes in total mixed ration for crossbred cows