Fourty-eight barrows proceeding from crossing between commercial hybrids were used in a study to evaluate the different lysine levels on the performance and the carcass characteristics. The swines average initial and final weight was 110.1 ± 0.72 kg and 125.3 ± 1.23 kg, respectively. The animals were distributed in an experimental design of randomized blocks with four treatments, six replicates and two animals per replicate. The treatments corresponded to a basal diet with 13.7% of crude protein and 3367 kcal DE/kg supplemented with four levels of L-Lysine-HCl resulting in diets with 0.50, 0.60, 0.70 e 0.80% of total lysine. The lysine levels influenced the feed:gain ratio and the muscle efficiency conversion that were reduced by linear form. The daily lysine intake increased with the elevation of diet lysine levels. There was no effect of the treatments on weight gain, carcass characteristics, carcass yield, lean yield, fat yield, and ham yield. For the studied genotype it was concluded that barrows from 110 to 125 kg require 0.80% of total lysine corresponding to a daily lysine intake of 23.9 g.
carcass; requirement; finishing; genotype; lean yield
