Screening Of Compound Enzyme Preparations In Vitro And Its Application In Low Energy Diet Of Laying Hens

In this study,the optimum formulation of cellulase,xylanase and glucose oxidase was screened by in vitro digestion test.The selected compound enzyme formulation was applied to the diet of laying hens to study the effect of compound enzyme preparation on laying hens Performance,egg quality,nutrient utilization and blood index.The test results are as follows:Experiment 1:Screening of complex enzyme formulations in vitro1.In this study,the activity of three enzymes was determined by GB method.The three enzyme activities were as follows:xylanase 46863.47u/g,cellulase 8452.608u/g,glucose oxidase 1000u/g.2.In this study,3×3 complete crossover design test,the use of in vitro digestion method to simulate the digestion of feed in the body,access to metabolites,determination of dry matter and crude protein digestibility.The three enzymes had a significant effect on the dry matter digestibility.The best single enzyme dosage for the digestibility of dry matter:xylanase low 4500u/g,cellulase 250u/g,glucose oxidase 300u/g.In summary,the screening compound enzyme formula:cellulase 250u/g,xylanase 4500u/g,glucose oxidase 300u/g.Experiment 2:Effects of different levels of compound enzyme preparation on performance,egg quality,nutrient digestibility and blood index of laying hens in low energy diet.1.Production performance:Reducing energy can affect the performance of laying hens,adding compound enzyme preparation can improve the performance of laying hens.Compared with positive control group,the average egg weight of negative control group decreased by 1.22%(P<0.05),and the average egg weight of test 1 was increased by 2.63%(P<0.05),and the average egg weight of test 1 was significantly higher than that of test 2 and test 3(P<0.05).Compared with positive control group,the egg production rate was reduced by 10.01%(P<0.01),and the egg production rate was increased by 7.53%(P<0.01).Compared with positive control group,the ratio of egg to egg was decreased by 16.11%(P<0.05),but the difference was not significant(P>0.05).2.Egg quality:Test 1,test 2,test 3 compared with positive control group and negetive control group,there were no significant differences in the thickness of egg shell,strength,egg weight,protein height,huff unit and egg yolk color(P>0.05).3.Nutrient metabolism:The addition of complex enzyme preparations to low energy diets has the effect of promoting dry matter metabolism,but not significantly different from the negative control group(P>0.05),which was significantly higher than the negative control group,increased by 8.76%(P<0.05),and there was no significant difference between the two groups(P>0.05).The addition of complex enzyme preparation had the tendency to promote the use of crude protein,compared with the positive control group,the crude protein metabolism ratio of the test group 2 increased by 5.77%(P<0.05),The experimental group 3 increased by 10.60%(P<0.01).Compared with the negative control group,the experimental group 2 increased by 6.92%(P<0.05),And the trial group 3 increased by 11.80%(P<0.01).The addition of enzyme preparation in low energy diet can promote the apparent metabolic energy of feed(P<0.05),but the experimental group 1 and the experimental group 3 were significantly lower than the positive control group(P<0.01).The experimental group 1 and the control group were increased by 8.73%and 9.04%respectively(P<0.05).Therefore,the test group with better effect in nutrient utilization rate is the experimental group 3.4.Blood indicators:Compared with the negative control group,the serum albumin in the experimental group 1 and the experimental group 3 was significantly higher than that in the control group(P<0.01),and significantly higher than the negative control group(P<0.01);the levels of serum globulin in group 2 and group 3 were significantly higher than those in control group(P<0.05),and significantly higher than the positive control group;The total protein content of serum in test 1 was significantly higher than that in negative control group(P<0.05).The total protein content of serum in test group 2 and group 3 was significantly higher than that in negative control group(P<0.01),and significantly higher than the positive control group(P<0.01).The serum triglyceride in the experimental group 2 and the experimental group 3 was significantly lower than that in the control group and the negative control group(P<0.05),and significantly lower than the positive control group(P<0.01).There was no significant difference between the two groups(P>0.05)in serum and triglyceride group,but significantly lower than the positive control group(P<0.01).The effect of enzyme preparation on serum calcium was not significant,the difference was not significant(P>0.05).The phosphorus content of test group 1 was significantly higher than that of positive control group and negative control group(P<0.05).The phosphorus content of the three groups was significantly higher than that of the positive control group and the negative control group(P<0.01).