The objective of the study was to investigate the effect of dietary concentrate levels on nutrition digestibility, blood parameters, rumen fermentation and growth performance of Chinese Holstein bulls.Sixteen bulls were randomly allocated to four groups and given different levels of concentrate(0.8%, 1.0%, 1.2% and 1.4% of the body weight). Results showed that the CP and NDF intake were significantlyincreased as the dietary concentrate level increased(P<0.05).Bulls which received the 1.4% and 1.2% concentra...