| In this paper,three experiments were conducted to study the effect and mechanism of the addition of different non-starch polysaccharide enzymes on the performance of AA broilers while reducing the energy level of corn-soybean meal feed.Experiment 1: To study the effects of adding NSP enzymes X1～4 to the low-energy cornsoybean meal diet on the growth performance,nutrient digestibility and serum biochemical indexes of AA broilers.A total of 1188 broiler chickens were selected and randomly divided into 6 groups with 18 replicates in each group and 11 chickens in each replicate.They were fed with conventional diet(A),low energy diet(B),low energy diet + NSP enzymes X1(C),Low-energy diet + NSP enzymes X2(D),Low-energy diet + NSP enzymes X3(E),Lowenergy diet + NSP enzymes X4(F),feeding time is 42 days,the low-energy diet for 1～21days is reduced by 60 kcal per kilogram,and the low energy diet at 22～42 days is reduced by70 kcal per kilogram.The test results showed that:(1)the addition of NSP enzymes had no significant effect on the production performance of broilers(P>0.05),but the average body weight and average body weight of the C and F groups were higher than that of the positive and negative control groups during the whole test period The average feed intake and feedmeat ratio in group F were lower than those in negative control group B.(2)The addition of NSP enzymes did not improve the digestibility of nutrients in the experimental group.(3)The addition of NSP enzymes had no significant effect on the blood biochemical parameters of broilers(P>0.05),but groups C,D,and F had a tendency to increase the content of high density lipoprotein.Note: The addition of compound non-amylase can improve the production performance of broilers to a certain extent while maintaining economic benefits,and improve blood biochemical physiological functions.Experiment 2: To study the effects of adding NSP enzymes X1～4 to the lower-energy corn-soybean meal diet on the growth performance,nutrient digestibility,serum biochemical indicators,intestinal enzyme activity,relative intestinal length,relative intestinal weight,and immune organ index.A total of 702 broiler chickens were randomly divided into 6 groups with 9 replicates in each group and 13 chickens in each replicate.They were fed with conventional diet(A),low energy diet(B),low energy diet + NSP enzymes X1(C),Lowenergy diet + NSP enzymes X2(D),Low-energy diet + NSP enzymes X3(E),Low-energy diet + NSP enzymes X4(F),feeding time is 42 days,feeding time is 42 days,and low energy diet is reduced by per kilogram 110 kcal.The test results showed that:(1)from 1 to 21 days of age,the average body weight,average body weight,average feed intake,and feed-to-meat ratio of the experimental group C and F were significantly higher than those of the positive and negative control groups(P<0.05),from 22 to 35 days of age,the average body weight,average body weight gain,and feed-to-meat ratio of test group C were still higher than those of the positive and negative control groups(P>0.05),and the average feed intake of test F was less than that of the negative control group B(P>0.05).From 1 to 35 days of age,the average weight,average body weight gain,average feed intake,and absolute feed-to-meat ratio of C,F in the experimental group were higher than those in the positive and negative control groups(P>0.05).(2)The dry matter digestibility of the test groups D and F at 21 and 35 days of age was significantly higher than that of the positive and negative control groups(P<0.05),and the crude protein digestibility of the test groups D and F at 21 days of age was significantly higher than that of the positive and negative control groups(P<0.05),the digestibility of NDF was significantly higher in the group F at the age of 35 days than that in the other groups(P<0.05),and the digestibility of the ADF was significantly higher in the groups D,F and the positive control A group at 21 days of age than that in the other groups(P<0.05),the digestion rate of crude fat at 21 days of age was significantly higher in the experimental group D than those in the other groups(P<0.05),and the absolute values of energy digestibility were higher in the experimental groups D and F at 21 and 35 days of age.It was higher than the positive and negative control groups(P>0.05).(3)The addition of NSP enzymes had no significant effect on blood biochemical parameters of broilers(P>0.05),but in absolute terms,compared with the positive control group A,the NSP enzymes increased to a certain extent the he density lipoprotein content and reduced the low density lipoprotein content.(4)At 21 days of age,the lipase activity of the group F was significantly higher than that of the positive and negative control groups(P<0.05),and the chymotrypsin activity of the C and F groups was significantly lower than that of the positive and negative control groups(P<0.05).At the age,the chymotrypsin activity in test groups C and F was significantly lower than that in the positive and negative control groups(P<0.05).(5)NSP enzymes had no significant effect on the relative organ weight,relative intestinal weight,and relative intestinal length of broilers at10,21,and 35 days of age(P>0.05),but from the absolute value of the entire period,the F was high in the relative weight of the heart,the relative weight of the liver,the relative weight of the spleen,the relative weight of the jejunum,the relative weight of the ileum,the relative length of the jejunum,and the relative length of the ileum showed an increasing trend,and the absolute values were the highest at 35 days of age.The relative lengths and weights of the intestine and immune organ indexes in group D tended to decrease compared with other groups.Note: The addition of NSP enzymes had improved broiler production performance,improved blood physiological and biochemical functions,adjusted intestinal enzyme activities,and affected the development of the intestine and organs to a certain extent.Among them,by a comprehensive evaluation,NSP enzymes X4 works best.Experiment 3: To study the effects of adding NSP enzymes X4 to the different energy level of corn-soybean meal diet on the growth performance,relative intestinal length,relative intestinal weight,the index of immune organs,the PH of the stomach contents and the moisture content of the stool.6000 broiler chickens were randomly divided into 4 groups,10 repeated in each group,6 cages for each group,25 chickens for each cage,respectively,they were fed with conventional diet(A),low energy diet(B),conventional diet + NSP enzymes X4(C),and low energy diet + NSP enzymes X4(D).the feeding time was 42 days,and the low energy diet was reduced by 110 kcal per kilogram.The results show that:(1)From 1 to 12 days of age,the average body weight and average body weight of the experimental group D were significantly lower than those of the A,B,and C groups(P<0.05),and the feed-meat ratio was significantly higher than that of the A,C groups(P<0.05).At 13～25 days of age,group A was significantly higher than the experimental group D in terms of average body weight(P<0.05).At 26～42 days of age,the average body weight of group A and group C was significantly higher than that of group B(P<0.05),and the ratio of test meat to group C was significantly lower than that of group B(P<0.05).At 1～42 days of age,the absolute value of the feed-to-meat ratio in group D was smaller than that in group B,but the feed-to-meat ratio in group B and D was significantly higher than that in groups A and C(P<0.05).(2)The NSP enzymes X4 had a significant effect on the slaughter rate of broilers(P<0.05),but had no significant effect on other slaughter performance indicators,but the absolute values of dressing weight rate and eviscerated rate in group D were larger than those in group B and C.(3)At 12 days of age,the relative weight of the heart in the test group D was significantly higher than that in the group B,and the relative weight of the spleen was significantly smaller than that in the group B(P<0.05).At 27 days of age,the relative weight of the heart in the test group D was significantly higher than that in the group A,and the relative weight of the spleen was significantly lower than in the groups B and C(P<0.05).The NSP enzymes X4 had no significant effect on the relative intestinal weight and relative intestinal length of broilers aged 12 and 27 days(P>0.05).(4)NSP enzymes X4 had no significant effect on the intestinal morphology of broilers at 27 days of age(P>0.05).(5)NSP enzymes X4 had no significant effect on fecal water content and fecal p H of 28-day-old broilers(P>0.05),and had no significant effect on fecal water content,fecal p H,and gastric content ph of broilers at 41-day-old(P>0.05).Note: The addition of NSP enzymes X4 improved the production performance of broilers,improved the growth and development of immune organs to a certain extent,reduced the increase in intestinal compensation,and verified the role of NSP enzymes in broiler production. |
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