The soybean meal (raw and thermal processed) from soybean cultivar BR 36 with conventional trypsin inhibitor activities levels (standard) and the soybean line BRM95-5262 that was genetically selected to contain low trypsin inhibitor activities were used in a biological assays with chicks. The BR 36 and BRM95-5262 soybean meal (thermal processed), used in the assays contained, respectively, 40 and 20, and 30 and 20% of relative residual trypsin inhibitors activities. The mean values of PER, NPR and feed: gain showed that the treatments with raw soybean meals were lower than the treatments with thermal processed soybean meals. However, thermal processed soybean meal treatments with 20% of relative residual trypsin inhibitor activities did not show significant differences between them and in relation to the standard, soybean meal. However, when the final residual trypsin inhibitor activities were 8.61 and 8.44UIT/mg of samples or 20 and 30% of relative residual trypsin inhibitor activities of the BR 36 cultivar and BRM95-5262 line soybean meal, respectively, it was observed that the mean values of PER, NPR and F: G were not significant. So, the values of PER, NPR and F: G obtained with soybean meal was dependent of initial relative residual trypsin inhibitor activities and of its respective thermal treatments. There was advantage to use the BRM95-5262 soybean meal line with low relative residual trypsin inhibitor activities.
chicks; biological assays; trypsin inhibitors; soybean
