Fifty barrows with high genetic potential for lean gain averaging initial body weight (BW) of 15.4 ± 1.02 kg were used to determine the digestible lysine requirements, considering performance and carcass protein deposition rate. The experiment was analyzed as a complete block design with five treatments, five replicates and two animals per replicate. Treatments consisted of five digestible lysine levels (0.80, 0.90, 1.00, 1.10, and 1.20%) obtained with different dietary amounts of corn and soybean meal. Animals were kept in the experiment until they reached final BW of 30.0 ± 1.93 kg. It was observed quadratic effect of treatments on daily weight gain, that increased until the 1.10% estimated level. Linear effect of dietary digestible lysine levels on feed:gain, protein deposition and daily lysine intake was observed. No treatment effect on daily feed intake was noticed. Barrows with high genetic potential for lean gain in the carcass from 15 to 30 kg require 1.10% of dietary digestible lysine that is correspondent to a 12.05 g/day digestible lysine intake.
initial phase; genotype; protein deposition
