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An experiment was conducted to determine the lysine regime required to maximize growth performance for high-lean-growth potential barrows and gilts beginning at 45 lb and concluding at approximately 260 lb. There were four growing-finishing phases and four lys treatments within phase (Grower-1, 44 lb to 79 lb; Grower-2 79 lb to 132 lb; Finisher-1, 132 lb to 189 lb; and Finisher-2, 1891b to 260 lb). Dietary treatments were corn-soybean meal based supplemented with 0.15% crystalline lysine. The formulation of 2 dietary treatments was aimed to provide lysine below the requirement, while the other 2 dietary treatments provided lys above the requirement. The lysine regimen (requirement) to maximize growth performance of barrows and gilts appears to be approximated by 1.14%, 1.04%, 0.94%, and 0.86% total lysine, respectively, but greater dietary lysine concentrations (similar to the greatest lysine regimen) may be warranted to maximize carcass leanness. However, it should be noted that the highest lysine regimen (1.30, 1.20, 1.10, and 1.00%, respectively) may reduce feed intake and daily gain.