A study was conducted under commercial conditions to compare the effects of 2 different Cu sources [tri-basic copper chloride (Cu₂[OH]₃Cl) or Cu(HMTBa)₂] on growth performance and carcass traits in pigs and to evaluate a step-down feeding strategy when supplementing pigs with Cu(HMTBa)₂. Cu(HMTBa)₂ is a chelated Cu with 2-hydroxy 4-methylthio butanoic acid (HMTBa) at 1:2 ratio (Novus International Inc., St. Charles MO). A total of 2,300 weaned pigs (initial BW = 6.60 ± 0.34 kg, 21 d of age, mixed sex) were randomly allotted to 1 of 4 feeding programs with 23 replications and 25 pig/pen. Treatments included 1) control (16 mg/kg Cu in the premix); 2) (Cu₂[OH]₃Cl) at 150 mg/kg (wean-finishing); 3) Cu(HMTBa)₂ at 150, 80, and 60 mg/kg (Nursery-Phase-I, Nursery-Phases-II-III, and grow-finishing phases, respectively) and 4) Cu(HMTBa)₂ at 150 mg/kg in Nursery-Phase-I and 80 mg/kg from Nursery-Phase-II to finishing phase. Copper levels were chosen based on current industry practices. Data were analyzed using the Mixed Procedure of SAS. The model included treatment as fixed effect and replication as random effect. From d 7 to 21 post-weaning, the ADG and GF was greater (P = 0.03) for pigs fed Cu(HMTBa)₂ than that of the control pigs. Pigs fed (Cu₂[OH]₃Cl) were intermediate. From d 0–42, ADG tended (P = 0.11) to be greater for pigs fed Cu(HMTBa)₂ than control pigs. In the grow-finishing phase (d 42–153), by d 111, the BW of pigs fed Cu(HMTBa)₂ at 80 mg/kg was heavier (P < 0.05) than control pigs and pigs fed (Cu₂[OH]₃Cl) or Cu(HMTBa)₂ at 60 mg/kg were intermediate. Overall (d 42–153) the GF was greater (P < 0.05) for both (60 and 80 mg/kg) Cu(HMTBa)₂ treatments compared with control (0.377 and 0.378 vs. 0.370, respectively). Pigs fed (Cu₂[OH]₃Cl) were intermediate. On average, the hot carcass weight (HCW) of pigs fed both levels of Cu(HMTBa)₂ was 101.48 and 101.49 (60 and 80 mg/kg, respectively) vs. 100.44 kg in pigs fed control, whereas the HCW of pigs fed (Cu₂[OH]₃Cl) was 101.34 kg. In conclusion, growth performance was improved by Cu(HMTBa)₂ supplementation to a greater extent than (Cu₂[OH]₃Cl). Supplementing Cu(HMTBa)₂ either at 60 or 80 mg/kg resulted in similar performance in terms of feed efficiency.