In Brazil, the slaughter of boar is prohibited, however this category presents economic advantages when compared with the barrows. Some experiments have demonstrated that differences exist in the nutritional requirement among these categories. The present experiment was carried out at the Federal Universty of Santa Maria, where 96 animals were evaluated concerning performance when fed with diets containig 100, 90, 80 and 70% of the maximum levels recommended for lysine, threonine, methionine + cystine and tryptophan (1.25, 0.81, 0.75 and 0.22%, respectively) until they reached an average weight of 70kg. No significant differences (P > 0.05) were observed for food intake, daily gain and feed conversion efficiency during the whole period, being the levels of 0.87% lysine, 0.57% threonine, 0.52% methonime + cystine and 0.16% tryptophan enough to provide good performance, and showed to be more economic between tested levels.
nutrition; lisyne; threonine; methionine; cystine; tryptophan; swine
