Effects Of Different Oligosaccharides On Growth,Immunity And Intestinal Bacteria Flora Of Litopenaeus Vannamei

This thesis was studied the effects of different oligosaccharides of chitosan oligosaccharide,fructo oligosaccharide,oligosaccharides and mannan oligosaccharide on growth performance,immunity,resistance to ammonia nitrogen stress and intestinal bacteria flora of Litopenaeus vannamei.Outcomings of this study are presented as listed below:1.Effects of different oligosaccharides on growth performance,immunity and resistance to ammonia nitrogen stress of Litopenaeus vannameiFour experimental diets were formilated by supplementing the basal diet with COS,FOS,XOS and MOS(500mg/kg).The feeding trail lasted for 42 days.Each diet was fed to three replicate groups of Litopenaeus vannamei(initial body weight : averaging 0.33±0.00g).The result showed that: different kinds of oligosaccharides can improve the growth of Litopenaeus vannamei.COS group improved WGR significantly(P<0.05).The FCR in all groups were significantly higher than that in the control group(P<0.05).TG and TP in XOS group were significantly higher than those in the control group(P<0.05).FOS group also reduced TG significantly(P<0.05).Different kinds of oligosaccharides can improve SOD and CAT in serum of Litopenaeus vannamei(P<0.05).T-AOC in XOS group,PO in MOS group,AKP and ACP in COS group were significantly higher than those in the control group(P<0.05).XOS group can significantly reduce MDA(P<0.05).COS,MOS and FOS can significantly improve SOD in liver of Litopenaeus vannamei(P<0.05).CAT and GSH-PX in COS group,PO in XOS group,AKP in MOS and XOS were significantly higher than those in the control group(P<0.05).MDA in all groups were significantly lower than that in the control group(P< 0.05).After 24 h acute ammonia nitrogen stress test,SOD and PO in serum in COS of Litopenaeus vannamei,T-AOC in XOS,CAT and LZM in MOS,FOS and XOS,ACP in FOS were significantly higher than those in the control group(P<0.05).COS,MOS and FOS can significantly reduce MDA(P<0.05).After 24 h acute ammonia nitrogen stress test,SOD in liver in MOS,CAT and ACP in COS,PO in XOS,GSH-PX in MOS and FOS were significantly higher than those in the control group(P < 0.05).MDA in COS were significantly reduced(P<0.05).2.Effects of different oligosaccharides on intestinal flora diversity of Litopenaeus vannamei by high-throughput sequencingMainly through high-throughput sequencing(Mi Seq)Technical Analysis chitosan oligosaccharide,fructo oligosaccharide,oligosaccharides and mannan oligosaccharide as feed additives Litopenaeus vannamei intestinal bacterial diversity.Bacterial 16 Sr RNA sequence characteristic sequence fragment V4 after Mi Seq,found within Litopenaeus vannamei rich diversity of intestinal bacteria.The results show: alpha diversity analysis results,the test group of Chao1 index was significantly lower than the control group(P<0.05)and the experimental group ACE index of the control group was significantly reduced(P<0.05).The analysis accounted for the major categories of bacteria in the intestinal tract,where the control group Bacteroidetes higher than the experimental group.Proteobacteria and Actinobacteria accounted for 37.7% and 24.6% respectively in the control group.3.Effects of Xylooligosacchardes on growth performance,immunity and resistance to ammonia nitrogen stress of Litopenaeus vannameiA 42-day feeding experiment was designed to value the effect of xylooligosacchardes on growth performance,immunity and resistance to ammonia nitrogen stress of Litopenaeus vannamei with the initial boby weight of(0.33±0.00)g.A total of five treatments,supplement of 0,250,500 and 1000 mg/kg xylooligosacchardes were singularity added to the basal diet,and named as control group,XOS250,XOS500 and XOS1000 respectively.The result showed that:FCR was decreased significantly with the increasing dietary xylooligosaccharides levels(P<0.05).FCR in XOS1000 group was significantly decreased than that in control group(P<0.05).T-CHO and TG in serum were significantly reduced in XOS500group(P<0.05).TP and ALB were significantly improved in XOS500(P<0.05).SOD and CAT in serum were all significantly improved with the increasing dietary xylooligosaccharides levels(P<0.05).T-AOC and PO in XOS500,ACP in XOS250 were significantly higher than those in the control group(P<0.05).SOD and AKP in liver in XOS500 were significantly higher than those in the control group(P<0.05).MDA were significantly decreased with the increasing dietary xylooligosaccharides levels(P<0.05).After 24 h acute ammonia nitrogen stress test,SOD in serum in XOS250,T-AOC in XOS500,CAT in XOS250 and XOS500,PO in XOS500 and XOS1000,ACP in XOS1000 were significantly higher than those in the control group(P<0.05).After 24 h acute ammonia nitrogen stress test,SOD and PO in liver in XOS500,T-AOC in XOS250 were significantly improved than those in the control group(P<0.05).4.Effects of Xylooligosacchardes on intestinal flora diversity of Litopenaeus vannamei by high-throughput sequencingMainly through high-throughput sequencing(Mi Seq)Technical Analysis oligosaccharides as feed additives Litopenaeus vannamei intestinal bacterial diversity.Bacterial 16 Sr RNA sequence characteristic sequence fragment V4 after Mi Seq,found within Litopenaeus vannamei rich diversity of intestinal bacteria.The results show: alpha diversity analysis results,XOS500 and XOS1000 groups of Chao1 index were significantly lower than the control group(P<0.05)and the ACE index of XOS500 was significantly reduced(P<0.05).The analysis accounted for the major categories of bacteria in the intestinal tract,where the control group Bacteroidetes higher than the experimental group.Bacteroidetes in XOS500 were significantly reduced(P<0.05).The Vibrio in XOS500 group was significantly reduced and the Bifidobacterium in XOS500 group was significantly improved(P<0.05).