外源酶对不同加热程度菜籽饼体外养分消化率的影响

Effect of exogenous enzymes on in vitro nutrient digestibility of rapeseed cake with different heating degrees

试验旨在利用单胃动物仿生消化系统(SDS-Ⅲ)建立肉鸡体外模拟消化模型,测定不同加热程度菜籽饼体外养分消化率的差异以及额外补加外源酶(蛋白酶Proact和淀粉酶A酶)对不同加热程度菜籽饼体外养分消化率的影响。试验采用2×2双因素完全随机设计,以不添加外源酶的正常菜籽饼和过热菜籽饼为对照试验,以分别在两组对照试验基础上额外补加外源酶蛋白酶Proact 15 prot/g、淀粉酶A酶0.4 KNU/g作为试验组。利用SDS-Ⅲ模拟肉鸡全消化道消化过程,测定4组试验原料的体外干物质消化率(IVDMD)、体外表观粗蛋白质消化率(IVACPD)、体外标准化粗蛋白质消化率(IVSCPD)、体外脱脂干物质消化率(IVDDMD)、酶水解物能值(EHGE)、体外能量消化率(IVGED),每个样品均设5个重复,每个重复1根消化管。结果表明,正常菜籽饼的IVDMD、IVACPD、IVSCPD、IVDDMD、EHGE和IVGED均极显著高于过热菜籽饼(P<0.01),为更加优质的菜籽饼来源。添加外源酶过热菜籽饼的IVDMD、IVDDMD、EHGE、IVGED显著高于对照组(P<0.05),IVACPD、IVSCPD极显著高于对照组(P<0.01)。研究表明,额外补加外源酶对养分消化率的提高具有正面作用,尤其是对发生美拉德反应的饲料原料消化率改善作用更明显,可能是外源酶对美拉德反应产物有一定的降解释放作用。

The experiment was to establish a simulated digestion model of broilers in vitro using SDS-III,to determine the differences of nutrient digestibility in vitro of rapeseed cakes with different heating degrees and the effect of additional exogenous enzymes(protease Proact and amylase A)on nutrient digestibility in vitro of rapeseed cakes with different heating degrees.A 2×2 two-factor completely randomized design was adopted in experiment.Normal rapeseed cake and superheated rapeseed cake without exogenous enzymes were used as control experiments,and exogenous protease Proact 15 Prot/G and amylase A 0.4 KNU/g were added as experimental groups on basis of the two control experiments,respectively.SDS-Ⅲwas used to simulate the whole digestive process of broilers.The IVDMD,IVACPD,IVSCPD,IVDDMD,EHGE and IVGED of four groups were determined.Each sample was set up with five replicates and one digestive tube per replicate.The results showed that IVDMD,IVACPD,IVSCPD,IVDDMD,EHGE and IVGED of normal rapeseed cake were extremely higher than those of overheated rapeseed cake(P<0.01),which was a better source of rapeseed cake.The IVDMD,IVDDMD,EHGE and IVGED of superheated rapeseed cake supplemented with exogenous enzymes were significantly higher than those of control group(P<0.05),and IVACPD and IVSCPD were extremely higher than those of control group(P<0.01).The experiment indicates that the addition of exogenous enzymes has a positive effect on the improvement of nutrient digestibility,especially on digestibility of feed raw materials with Maillard reaction,which may be due to the certain degradation and release of exogenous enzymes on Maillard reaction products.