This study was conducted to evaluate nutritional plans of digestible lysine for boars 67 to 165 days of age, immunocastrated at their 107 and 135 days. Two hundred and forty animals, with initial body weight of 27.73 ± 1.57 kg, were sorted in a randomized block design with four nutritional plans of digestible lysine for immunocastrated pigs (0.9-0.8-0.7; 1.0-0.9-0.8; 1.1-1.0-0.9 and 1.2-1.1-1.0%, respectively from 67 to 107 days, from 108 to 135 days and 136 to 165 days) with four replications and a control plan for barrows (1.1-1.0-0.9% of digestible lysine) with eight replications and ten animals each. The nutritional plan with the sequence containing 1.1-1.0-0.9% digestible lysine improved feed conversion, reduced backfat thickness and increased the amount of lean meat of pigs carcass when compared to other nutritional plans. The other performance and carcass variables were not affected by nutritional plans. Nutritional plans with the sequence 1.1-1.0-0.9% of digestible lysine for periods of 67 to 107 days, 108 to 135 days and 136 to 165 days, respectively, meet the nutritional needs of immunocastrade boars 107 to 135 days old.
amino acids; ideal protein; growth performance; nutritional requirements
