Improving the nutritive value of full-fat rice bran for broiler chickens using a lipase-based enzyme preparation

Two experiments were conducted to test the hypothesis that a lipase-based enzyme preparation would increase the AME content of full-fat rice bran (FFRB) by increasing fat digestibility when fed to broiler chickens. Experiment 1 used FFRB from Australia and lasted for 35 days, while Experiment 2 used FFRB from Thailand and lasted for 14 days. Rice bran was substituted in a maize-soybean diet at levels of 90 g/kg (Experiment 1) and at 90 and 180 g/kg in Experiment 2. Total collections of excreta were used for determination of AME content and fat digestibility. In Experiment 1, the enzyme increased the AME content of FFRB between days 4-7, 18-21 and 32-35 by 6.1-16.1% (p>0.05), however this was not associated with improved fat digestibility. In Experiment 2, the enzyme enhanced the AME content of FFRB between days 4-7 (10.42 vs. 9.06, p=0.107) and 11-14 (11.94 vs, 9.93, p=0.041), but again, this was not caused by increased fat digestibility. Inclusion of 180 g/kg depressed the AME content of FFRB by 7.4-11.5% (p>0.10) in conjunction with decreased (p<0.05) fat digestibility between 0-14 days of age. Improvements in bird growth with the enzyme were seen in Experiment 2 but not in Experiment 1. Increases in AME content of FFRB per se were not caused by enhanced fat digestibility, suggesting that the side activities associated with the preparation must have acted singularly or in combination to improve AME content and bird performance. These data show that the response of FFRB to the lipase-based enzyme preparation was dependent upon the geographical origin of the rice bran and the level of FFRB substituted in the basal diet

Altos níveis de fitase em rações para frangos de corte

Avaliaram-se o desempenho, o coeficiente de digestibilidade da matéria seca (CDMS), da proteína bruta (CDPB), a retenção aparente de cálcio (Ca) e fósforo (P) e a energia metabolizável aparente corrigida para balanço de nitrogênio (EMAn) de dietas suplementadas com altos teores de fitase (FTU) para frangos, até 35 dias de idade. Foram utilizados 1848 pintos, distribuídos em delineamento inteiramente ao acaso, com sete tratamentos e oito repetições de 35 aves. Os tratamentos foram: T1: dieta-controle; T2: dieta com inclusão de 1.500FTU/kg; T3: 3.000FTU/kg; T4: 4.500FTU/kg; T5: 6.000FTU/kg; T6: 8.000FTU/kg e T7: 10.000FTU/kg de ração. No 10º e 28º dias de experimento, quatro e três aves, respectivamente, foram transferidas para gaiolas de metabolismo. A partir da inclusão de 4.500FTU/kg, o desempenho das aves de 1 a 35 dias foi semelhante ao das aves do grupo-controle (P>0,05). Não houve diferença (P>0,05) entre os tratamentos nos CDPB e nos valores de EMAn, porém, na fase inicial, observou-se maior aproveitamento da MS com os altos níveis de fitase (P<0,05). Em relação à retenção de Ca e P, houve efeito positivo da suplementação enzimática, com aumento significativo do uso desses minerais pelas aves. Concluiu-se que é possível suplementar altos teores de fitase valorando adequadamente os nutrientes da dieta