NSP Complex Enzyme Optimization And Study On Its Super Dose Effect In Broiler Diet

The study was conducted to determine the enzymolysis relationship between different NSPenzymes and different feedstuffs by in vitro digestion method after the optimum NSP enzymes wereselected, and establish a prediction model of complex enzyme formula correspond to different feedformulations. An experiment was also conducted to study the effects of super dose complex enzyme onthe growth performance, nutrient availability, organ indexes, serum hormones concentration, smallintestinal mucosa, digesta viscosity and microbial community of broilers. The study had threeexperiments.The experiment1was to determine optimum enzymes among three different sources of xylanase,cellulose, β-mannanase,-galactosidase and pectase by studying the properties of temperature (30,37,40,45,50,55,60,65℃), pH (3.0,3.5,4.0,4.5,5.0,5.5,6.0,6.5,7.0,7.5,8.0) and tolerance toacid-base, pepsin and trypsin. The results showed that the optimum enzymes are xylanase-I, cellulose-Ⅱ, β-mannanase-I,-galactosidase-I and pectase-Ⅲ which optimum temperature and pH are45,50,55,40,45℃and6.0,4.5,4.5,4.5,6.0, and have high relative activity treated by acid-base, pepsin andtrypsin.The experiment2was to determine the optimal enzymatic hydrolysis dose of different NSPenzymes to different feedstuffs by gradient in vitro digestion method simulating broiler, and therelationship between added complex enzyme and different feed formulation. The enzymatic hydrolysiscurves of different NSP enzymes to different feedstuffs were also deduced by testing the enzymatichydrolysis products based on the content of non-starch polysaccharides in different feedstuffs. Theresults showed that the enzymatic hydrolysis curves of different enzymes to different feedstuffs havenormal linear relationship. The amount of product, which degraded from different feedstuffs by differentenzymes, and its percentage of substrate are calculated. The optimal enzymatic hydrolysis dose ofxylanase, β-mannanase, cellulose,-galactosidase and pectase to maize, soybean meal, wheat, wheatbran, cottonseed meal, rapeseed meal, rice bran meal and DDGS are0.336,0,6.0,1.22(3.66),2.24,0,0.44and5.0(20.0) U/g,1.68,3.90,0.276,6.28,4.08,1.72,7.04and0.84U/g,4.98,28.62,8.88,19.44,44.48,27.78,22.8and9.72U/g,1.11,27.78,1.94,1.48,13.34,5.37and4.45U/g,0.234,37.3,0.474,4.26,7.56,10.68and0.64U/g. The broiler trials showed that enzymolysis effect was no longersignificant increase after added enough enzyme and there is proportional relationship between in vitroand breeding broiler test. The results provided theoretical data for complex enzyme added to differentfeed formulae.The experiment3was conducted to investigate the effects of low energy diets supplemented withdifferent dosage of compound enzyme on the growth performance, nutrients utilization, organ index,serum hormones concentration, intestinal mucosa morphology, digesta viscosity and microbialcommunity of broilers. Three hundred and twenty broilers (1day-old) were randomly assigned to fourtreatments with eight replicates with ten broilers each. The positive control (PC) treatment was fed a corn-soybean meal diet. The diet of negative control (NC) treatment was reduced by210KJ ME/kg, andthe content of miscellaneous meal and wheat was increased in this treatment. The conventional dose ofenzyme (CDE) and super dose of enzyme (SDE) treatment was respectively fed the NC diet withdifferent dosages of compound enzyme0.02%and0.2%. The trial lasted for42d. The results showedthat the FCR of broilers fed the SDE treatment was significantly lower than those fed the NC (P<0.01);the FCR of broilers fed the CDE and PC treatment was significantly lower than the NC (P<0.05). TheCP, EE and energy apparent metabolizability of the SDE treatment diet were higher than the NC diet(P<0.01); the DM apparent metabolizability and AME of the SDE treatment diet were higher than theNC diet (P<0.05). There were no significant differences in the organ index of small intestine and spleenof broilers fed different diets (P>0.05); the organ index of stomach and bursa of fabricius of broilers fedthe SDE diet had difference significantly with those fed the NC diet (P<0.01). The thyroxine of broilersfed the NC treatment was significantly lower than other three treatments (P<0.05); the insulin ofbroilers fed the SDE diet was significantly higher than other three treatments (P<0.05). As for villiheight, the PC and SDE treatment were significantly higher than other two treatments (P<0.01); the NCtreatment was significantly lower than the CDE treatment (P<0.05). As for crypt depth, the NCtreatment were significantly lower than other three treatments (P<0.01); the SDE treatment wassignificantly lower than the PC and CDE treatment (P<0.05). As for V/C ratio, the SDE treatment weresignificantly higher than other three treatments (P<0.05); the NC treatment was significantly lower thanthe PC and CDE treatment (P<0.05). As for mucosa thickness, there was no significantly difference(P>0.05). As for digesta viscosity, the SDE treatment was significantly lower than the NC treatment(P<0.05). As for Lactobacillus of microbial community, two added enzyme treatments weresignificantly higher than the NC and PC treatment (P<0.05). The experiment prove that the growthperformance, nutrients utilization, organ index, serum hormones concentration, intestinal mucosamorphology, digesta viscosity and microbial community of broilers were improved significantly as thebroilers fed the diet (reduce210KJ ME/kg) containing complex enzyme at the level of0.02%and0.2%.The effect of complex enzyme was increased significantly while the dosage of enzyme was enhancedfrom0.02%to0.2%.