In Exp. 4, a total of 175 pigs weaned at 20.7 ± 0.4 d of age were fed 5 diets (5 pens per treatment) for 3 wk: a basal diet [15.5% crude protein without plasma protein and fermented soybean meal], 2 diets (18.4% crude protein) with 3.7% plasma protein or 4.9% fermented soybean meal, and 2 diets (21.2% crude protein) with 7.3% plasma protein or 9.8% fermented soybean meal. Concentrations of Lysine, Methionine, Threonine, and Tryptophan were kept consistent among diets with the same crude protein concentrations