The Proportion Of The Combination Of Five Enzyme Preparations In The Wheat-Based Diet Of Broiler Chickens

The main aim of this study was to investigate the effects of five monomeric enzymes preparations supplemented to wheat-based diets on the digestibility of non-starch polysaccharides(NSP) and performance of broiler chickens.The five monomeric enzymes included xylanase,β-glucanase,celluase,phytase and mannanase.The study included two parts and the results were presented as follows:In the first part:An in vitro experiment was designed to study the effects of wheat-based diet supplemented with the five monomeric enzymes preparations on the digestibility of dry matter(DM) and NSP.The group 1 was wheat-based diet supplemented with only xylanase.The group 2 was wheat-based diet supplemented with xylanase +β-glucanase,analogizing later for group 3,4 and 5.The results showed that in all groups, the digestibility of DM(P＜0.01) and NSP(P＜0.05) were increased.The five monomeric enzymes were designed by uniform design in the second experiment.There were 13 groups in the second experiment,and the 13th group was the control.The results showed that in all groups,the digestibility of SNSP(soluble non-starch polysaccharides,SNSP) and INSP (insoluble non-starch polysaccharides,INSP) were increased.In the same time,the effects were various in different groups.The best group was the group 8,and its proportion of the enzymes was xylanase 400 U·kg^-1;β-glucanase 158 U·kg^-1;celluase 200 U·kg^-1;phytase 315 U·kg^-1;mannanase 192 U·kg^-1.In the second part:The in vivo study was conducted to examine the effects of wheat-based diet supplemented with the five monomeric enzymes preparations on the digestibility of NSP,calcium,phosphorus and phytate phosphorus,some organ's relative weight and performance of broiler chickens.Six hundreds and twenty four 1-day-old broiler chickens were randomly divided into 13 groups.The 13th group was the control.The broiler chickens were fed to 21-day-old.The results showed that the compatibility enzymes can increase the performance of the broilers with varied effects in different groups.The group 10 increased the feed intake significantly(P＜0.05),and the group 5,7,9,10 increased the body weight,weight gain and feed/gain significantly(P＜0.01).On 14-day-old,the digestibility of NSP was increased in all groups except group 1 and 2.The group 8 and 9 were more significant than others(P＜0.01),and the proportion of group 9 was xylanase 450 U·kg^-1,β-glucanase 47 U·kg^-1,celluase 333 U·kg^-1,phytase 135 U·kg^-1 and mannanase 153 U·kg^-1.On 21-day-old,the digestibility of NSP was increased in all groups(P＜0.01),but the effects were various in different groups.Group 1,4,5,7,10,11 increased the digestibility of calcium,phosphorus and phytate phosphorus on 14-day-old, with group 10 demonstrating the best result.Its proportion was xylanase 500 U·kg^-1,β-glucanase 95 U·kg^-1,celluase 33 U·kg^-1,phytase 540 U·kg^-1 and mannanase 115 U·kg^-1. The digestibility of phosphorus and phytate were significantly increased in all groups on 21-day-old(P＜0.01),and the best group was group 10.The results showed that the relative weight of jejunum,ileum and small intestine were decreased in all groups,and the group 9 was more significant than others both 14-day-old and 21-day-old.For both 14-day-old and 21-day-old,the heart relative weight was increased and the liver relative weight was decreased in all groups.