Utilização de enzimas exógenas em dietas com diferentes fontes e níveis de proteína para leitões na fase de creche

Two experiments were carried out to evaluate the inclusion of exogenous enzymes in diets with different protein levels and sources for pigs during the nursery period. In the first experiment, 80 pigs from 21 to 51 days of age, weaned at 14 days of age, were assigned to a randomized blocks experimental design, in a 2x2x2 factorial (two protein levels; with or without meat and bone meal; with or without enzyme), with five replicates and two pigs/box, and fed a corn (C), soybean meal (SBM) and dried whey (DW)-based diets. In the second experiment, 40 pigs from 28 to 45 days of age, weaned at 21 days of age, were assigned to a randomized blocks, with four treatments, five replicates and two pigs/box, fed a control diet (C, SBM and DW-based diet with 18% crude protein - CP) and three diets with different levels of enzymatic complex (0.2, 0.4 and 0.6%). In the first experiment, no interaction was observed among protein level, presence or absence of meat and bone meal (MBM) and presence or absence of enzyme. Reduction of ADG and ADFI was observed at the dietary level of 18% CP. No effect of MBM inclusion and 0.2% enzyme in the diet was detected. In the experiment II, it was observed increasing linear effect for ADG and ADFI, as the enzyme level increase. The addition of 0.4% of exogenous enzymes provided the best economical return for the ration cost. It was concluded that the level of 21% CP and the addition of increasing exogenous enzyme levels in corn and soybean meal-based diets improve pig performance, that is not affected by the inclusion of 5% the meat and bone meal in the diets.