Sixty barrows from crossing between commercial hybrids with an average initial weight of 95.7 ± 0.80 kg and an average final weight of 109.8 ± 1.13 kg were used to evaluate different dietary lysine levels on performance and on carcass characteristics. The experimental design used was a randomized blocks with five treatments, six replicates and two animals per replicate. The treatments corresponded to a basal diet with 13.7% of crude protein, 3367 kcal DE/kg supplemented with five L-lysine-HCl levels, resulting in diets with 0.50; 0.60; 0.70; 0.80 and 0.90% of total lysine. The daily feed intake reduced by linear way with the increase of lysine level in diet. However, it was showed highest lysine consumption with increase of dietary aminoacid concentration. It was verified quadratic effect of treatments on the feed:gain ratio which improved until the level of 0.76% of lysine level and on feed:lean gain that reduced by linear way. However the adjusted data by Linear Response Plateau indicated the level of 0.79% to the best feed:lean gain. The weight gain, carcass lenght, backfat thickness, ham yield, lean growth yield and loin eye area were not influenced by treatments. For the genotype studied, it was concluded that barrows from 95 to 110 kg require 0.76% of total lysine in diet, corresponding to a daily lysine intake of 23.8 g.
carcass; requirement; finishing; genotype; feed
