The ME value of the basal diet was determined to be 2.32 Mcal/kg of DM in a previous experiment (McLeod et al., 2001). Additionally, the basal diet was formulated to meet the rumen-digestibleintake protein requirement for steers in the R-SH treatment and the MP requirement for steers (250 kg of BW) gaining 0.84 kg/d (NRC, 1996).