Lysine requirements of crossbred barrows (AG-PIC 412 X C-22), using 40 animals in a completely randomized block design with five dietary treatments (.50; .60; .70; .80 and .90% of total lysine), four replicates and two animals per experimental unit were estimated. Synthetic amino acids were added to keep amino acids levels according to the ideal protein profile. Quadratic effect of treatments on average daily gain, on feed conversion, on 10th rib fat depth and on last rib fat depth were observed. Linear effects of treatments on daily lysine intake and on daily lean gain, were observed. No effects of lysine level on daily feed intake, P1 backfat thickness, P2 backfat thickness, loin depth, lean percentage, carcass yield, carcass length, carcass length measured by Brazilian method and ham percentage were found. The total dietary lysine requirement for 95 to 122kg high lean barrows is .76%, which corresponds to approximately 25.99g/day of lysine intake.
swine; lysine; requirement; late finishing; performance; carcass
