| The study chose DLY weaning piglets as test materials to analyse the effect of the interaction of different amino acid and immunopotentiator(astragalus polysaccharide, probiotics)on growth and immune performanc, swine fever antibody level and development of immune system in intestinal mucosa.We also use Lipopolysaccharide(LPS)to simulate the stressed situation,try to find the immunological mechanism that cause the different premunition and anti-stress ability under the interaction of different amino acid and immunopotentiator.lt aims at confirming the optimal composition of those two aditives,and lay the fundation of using immune indices to implement the research of immunonutrition.So that,we can offer theory basis to explore a healther and safer way of feed management and to find the replacement of antibiotic.Our experiment was constitute with three parts.Part1:Effect on immune performance and anti-stress ability of weaning piglets under the using of different amino acid and immunopotentiator675health weaning piglets with the age of31±1days old were selected to the test.They were separated into9groups randomly,each of the groups has3repeats(bars),and each repeat(bar)has25pigs,with closed male and female ratio.This trial designed completely randomize with2×4double-factor.We added0.14%threonine(Thr),0.15%methionine(Met),0.86%arginine (Arg),1.0%glutamine (Gln) and0.03%astragalus polysaccharide(APS),0.15%probiotics into the basic ration. By mutual combining those aditives,we achieved8test groups and1control group with nothing added in. The period of this experiment last for30days,made up by feed experiment(25d)and immunological stress experiment(5d).The results show that:①Growth performance:There is no obvious effect in improving the piglets’average daily gain by using the Thr、Met、Arg combined with APS、probiotics (P>0.05); While,The interaction of Gln,APS and probiotics can improve the growth performance significantly (P<0.05)②Biochemical criterion:Each of those group have no significant effect on the level of urea nitrogen, total cholesterol and triglyceride etc.in piglets before the stress (P>0.05).But,the group with Gln+probiotics and Arg+APS can restrain the increase of urea after the stress obviously (P<0.05)③Serum enzyme activity:Before the stress, adding Met+probiotics, Arg+APS can promote the increase of r-glutamyl transpeptidase(GGT) significantly(P<0.05).And,Gln+APS can increase the level of glutamic-pyruvic transaminase(AIL) highly significantly(P<0.01), while after the stress,group with Gln+APS has a decrease in GGT、AIL highly significantly (P<0.01)④Antioxidant index:Befroe the stress, every groups all have increased the level of malondialdehyde (MDA) in the serum in a certain degree,and the effect of the group with Thr+APS in it was highly significant (P<0.01).The effect of the groups with Thr+probiotics, Gln+probiotics,Gln+APS,Met+APS and Arg+APS are significant (P<0.05).While after the stress,every test groups have held up the increase of MDA highly significantly (P<0.01), and the group with Met+APS in it has the best effect than others.⑤Humoral immune indexes:There is no significant effect on the total protein,albumin and globulin etc.for any of these group before or after the stress (P>0.05),while added with Arg+probiotics,Gln+probiotics,Gln+APS and Thr+APS can highly significantly improve the level of immune globulin G (IgG), and meanwhile restrain the decline of IgG after the stress (P<0.01)⑥Physiological indices:There is no signficant effect on the levels of hemameba, basophilic granulocyte, erythrocyte and the index of HCT (P>0.05)⑦Growth hormone and somatomedin:Before the stress,each of the test group can highly significantly increase the level of growth hormone (GH) and somatostatin(SS)(P<0.01),while the group with Gln+APS and Arg+probiotics have the best effect on that increase of GH and the group of Gln+probiotics was best for the SS.For the effect on the insulin-like growth factor1(IGF-1),there is no obvious influence (P>0.05).After the stress,every test group can still significantly accelerate the increase of GH(P<0.05),and added with Met+APS,Met+probiotics and Arg+probiotics may achieved the best result.Adding with Gln+APS、Gln+probiotics and Met+probiotics have highly significantly restrained the rise of SS and adding with Thr+APS,Arg+APS and Met+APS may also increase the IGF-1in that way (P<0.01)。⑧Inflammatory cytokines:Before the stress,test group with Gin or Arg+probiotics can obviously facilitate the going-up of Gamma interferon (y-IFN) in the blood.while the combination of Met+APS or probiotics may obviously control the rise of it (P<0.05).Each of all the test group can decrease the interleukin1β(IL-1β) in the blood obviously.and the best effect comes to those groups with adding Arg+APS or probiotics, Gln+APS and Met+APS.Adding Thr+APS,Arg+APS or probiotics can significantly improved the level of tumor necrosis factora (TNF-a)(P<0.05); After the stress,the combination of Met+APS or probiotics can highly significantly increased level of y-IFN (P<0.01). Except the group with Thr, others can obviously increased the content of IL-1β(P<0.05).While groups add with Thr,Arg can highly obviously restrain the increase of tumor necrosis factora (P<0.01)Those results show that,there is no obvious improvement in growth performance of pigs in any of those test groups.But the interactions between Arg,Gln and APS,probiotics can obviously improve the immune performance of piglets,and meanwhile.In terms of regularing the the humoral immunity and resisting the stress,the APS is better than probiotics.Part2:Effect on the development of small intestine and the microorganism in cecum of weaning piglets under the interaction of different amino acid and immunopotentiatorExperiment design is the same as the part1.After the feed experiment,chose1health pig from each repeat to slaughter and collect the samples of duodenum, jejunum,ileum bowel, intestinal mucosa and feces in cecum to analyse the intestinal morphology, SIgA and the number of microorganism.The consequent indicates that:①There is an obvious effect on the length, breadth and ratio of villus height/crypt depth of duodenal intestinal villu under the interaction among different amino acid and astragalus polysaccharide, probiotics (P<0.05).Among them,the groups with Gln+APS,Gln or Arg+probiotics have the best effect on improving the those indexes.②Each of those group can facilitate the secretion of SIgA by intestinal tract significantly,and the groups added with Gln or Thr or Arg+probiotics, Gln+APS have the highly significant effect (P<0.01).③Every groups could restrain the reproduction of escherichia coli and accelerate the movement of lactobacillus.While the group with Gln or Arg+probiotics have the most obvious work (P<0.05)。It indicated that,the interaction of Gln,Arg and probiotics can improve the development of immune system of intestinal mucosa and it’s function comprehensively.Part3:Effect on the variation trend of swine fever antibody level of piglets under the using of different amino acid and immunopotentiator Experiment design is the same as the part1.Based on the specific immune procedure in the farm,we immunized those piglets with swine plague vaccine at the first time at the age of28days.Sampled the blood from precaval vein3days before the first immunized and7d,15d,22d after that(That is when the piglets in their25d,35d,42d and49d). Separated the serum and detected the swine fever antibody level in it.The results indicated that:There is an significant difference between test groups and control groups before the first immunized and two weeks after that (P>0.05).And the difference is getting larger in the third week(That is49d) after the first immunized.For the positive groups(antibodys tend to be positive before immunized) before immunized, each of those groups have a tend of slowing down in block-up value of antibody level,while for the negative groups before immunized,the interaction of Gln+APS, and Thr+APS can facilitate the generate of swine fever antibody obviously (P<0.05)。... |
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