The milk-fed calf has a requirement for AA instead of CP; however, most milk replacers (MR) are formulated to a specific CP concentration. Previous studies have demonstrated that feeding a modified accerelated milk replacer MR (24:20; CP:fat) improved calf growth performance. The objective was to determine if a MR formulated using synthetic AA to achieve the same AA concentrations as a 24/20 MR, but allowing for reduced CP concentrations would enhance calf growth performance compared with more standard MR formulations. Eighty 3- to 5-d-old Holstein bull calves in 2 lots (40 each) were received within the same week and blocked by BW and randomly assigned to 1 of 4 MR treatments of: 20:20 (20), 22:20 (22), 24:20 (24) and a 22:20 with amino acid concentrations of the 24:20 (AA). Each experimental MR containing decoquinate was fed at 0.28 kg/calf/d at 2 ×/d for 14 d via bucket and then increased to 0.43 kg/calf/ d at 2 ×/d until 35 d. Feedings were reduced to 1 time/d with a 0.43 kg/calf/d feeding rate to facilitate weaning at 42 d. Calves were housed in bedded Calf-Tel hutches with ad libitum access to water and 22% CP pelleted calf starter (CS). All data were statistically analyzed using a randomized complete block design (RCBD) with block considered random and treatments considered fixed effects. Initial BW was similar across all treatments (42.4 kg), while 56-d BW for calves fed AA MR were greater compared with calves fed 24 MR with calves fed 20 and 22 MR being intermediate and similar (78.7, 78.8, 76.5, and 81.8 kg for 20, 22, 24, and AA, respectively). Dry matter intake of CS was greater for calves fed AA MR (0.74, 0.78, 0.65, and 0.81 kg/d) compared with 20 and 24 MR, but similar to calves fed 22 MR, while calves fed the 24 MR had lowest CS DMI. Improved BW gains can be achieved by feeding an AA fortified MR having a lower CP concentration.