| The experiment was conducted to investigate the effects of Astragalus polysaccharides(APS),Clostridium butyricum,APS and Clostridium butyricum compound bacteria in ducklings on the production performance,immunity performance and intestinal microorganism.The use of APS,Clostridium butyricum,APS + Clostridium butyricum and bacitracin zinc was compared,which provided a scientific basis for the rational application of Shaoxing duck in production.In this experiment,A total of 600 one-day-old shaoxing male ducks were randomly allocated to five groups(the control group I,groups II,III,IV,V).Each of which include 6 replicates of 20 male ducks.The control group were only fed a basel diet.The groups II,III,IV,V were fed with the basal diet supplemented with 40 mg·kg-1 of bacitracin zinc,800 mg·kg-1 of APS,5×108 CFU·kg-1 of Clostridium butyricum,800 mg·kg-1 of APS + 5×108 CFU·kg-1 of Clostridium butyricum,The results were shown as follows:(1)Three weeks before the experiment: There was no significant difference in average daily gain(ADG),daily feed intake(ADFI)and feed-to-weight ratio(F/G)between the blank control group and each experimental group(P > 0.05).Fourth week: Compared with group I and II,the ADG and ADFI of group III,IV and V increased significantly(P < 0.05)and the F/G decreased significantly(P < 0.05).0-28 days: Compared with group I,the ADG of group III,IV and V increased significantly(P < 0.05),the F/G decreased significantly(P < 0.05),and the ADFI of group II,III and V increased significantly(P < 0.05).Compared with group II,ADG in group III,IV and V increased significantly(P < 0.05)and F/G decreased significantly(P < 0.05).(2)On the 28 th day of the experiment,the triiodothyronine(T3)in group V was significantly higher than that in group I(P < 0.05),but there was no significant difference among other groups(P > 0.05);the tetraiodothyronine(T4)in group III,IV and V was significantly high er than that in group I(P < 0.05);and the growth hormone(GH)in group III,IV and V was significantly higher than that in group I(P < 0.05).(3)On the 28 th day of the experiment,the contents of Ig A in groups III and V were significantly higher than those in groups I,II and IV(P < 0.05).There was no significant difference in the contents of Ig G,complement C3 and complement C4 between groups,but the contents of Ig G in group V were higher than those in other groups(P > 0.05).The content of immunoglobulin M(Ig M)in group V was significantly higher than that in group I,group III and group IV(P < 0.05),but the difference was not significant(P > 0.05).There was no significant difference in serum cortisol(CORT)between the experimental group and the control group(P > 0.05).Interleukin-2(IL-2)in group IV and V was significantly higher than that in group I and group II(P < 0.05).The levels of IFN-gamma in group V were significantly higher than those in group I,II and IV(P < 0.05),but there was no significant difference between group I and II(P>0.05).The levels of IFN-gamma in group III were also significantly higher than those in group I,II and IV(P < 0.05).(4)On the 28 th day of the experiment,thymus index of group V was significantly higher than that of other groups on the 28 th day(P < 0.05);spleen index of group IV and V was significantly higher than that of group I and group II(P < 0.05);bursa index of group V was not significantly different from that of other groups(P > 0.05).(5)On the 28 th day of the experiment,the activities of superoxide dismutase(T-SOD)and glutathione peroxidase(GSH-PX)in serum of group V were higher than those of other groups(P < 0.05);the total antioxidant capacity(T-AOC)in serum of group V was higher than that of other groups,and there was a significant difference between group V and groups I and II(P < 0.05).The activities of T-AOC,T-SOD,GSH-PX in the liver of group V were significantly higher than those of group I and II(P < 0.05).The content of malondialdehyde(MDA)in serum and liver of group IV was the lowest,and there was a significant difference between group IV and group I(P < 0.05).(6)On the 28 th day of the experiment,duodenal recess depth in group V was significantly lower than that in other groups(P < 0.05),and there was no significant difference in the ratio of villus height to recess depth between groups(P > 0.05).The depth of jejunal recess in group V was significantly lower than that in group I,II and III(P < 0.05),and the ratio of villus height to recess depth in group IV was significantly higher than that in group I and II(P < 0.05).The depth of ileal recess in group III,IV and IV was significantly lower than that in group I and II(P < 0.05).The ratio of villus height to recess depth in group III,IV and IV was significantly higher than that in group I and II(P < 0.05).(7)On the 28 th day of the experiment,there was no significant change in the diversity of microbial flora among the cecum intestinal tract groups.Adding APS,Clostridium butyrate and their complex preparations could improve the abundance of microflora to a certain extent,but did not improve the diversity of microflora.To sum up: adding APS and Clostridium butyricum compound preparation in diet can improve growth performance and immune performance of ducklings more than adding APS or Clostridium butyricum alone,and improve intestinal morphology to some extent,can replace the addition of antibiotics,but the diversity of flora has not been significantly improved. |
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