The trial used 135 average weight (7.2±0.2) kg of Duroc×Landrace×Yorkshire crossbred weaned piglets,using 3×3 crossing design trial, studied the dietary levels of neutral protease 3 (0,40mg/kg and 80mg/kg) and three levels of acid protease (0,40mg/kg and 80mg/kg) on growth performance, nitrogen and amino acid apparent digestibility, blood biochemistry indexes, to find the best of the neutral and acid protease with the program. A total of nine experimental groups of three replicates of five pigs. A trial per...