Effect Of Non-starch Polysaccharidase Added To Wheat-type Diet On Growth,Immunity And Intestinal Microflora Of Weaned Piglets

Enzyme preparations are an important functional feed additive for improving the digestibility of feeds.Non-starch polysaccharides(NSP)are valued for their ability to improve intestinal microbial fermentation and reduce the anti-nutritional effect of fiber.The NSP enzyme with stronger screening effect has important significance for improving the utilization efficiency of feed resources and saving the cost of breeding.In this paper,weaned piglets were used as experimental animals to evaluate the effects of the two NSP enzymes Rovabio Advance(RA)and Rovabio Excel(RE)in wheat-soybean meal diets,as well as to immunize piglets and the gut.Microbiological effects.Three treatments were designed: the control group,the RA enzyme group,and the RE enzyme group,in which the control group was fed the basal diet,and the RA enzyme group and the RE enzyme group were fed with the RA enzyme or the RE enzyme in the basal diet,respectively.In the diet,the components of both enzymes were endo-1,3(4)-?-glucanase and endo-1,4-?-xylanase,and the enzyme activity was 1800 U/kg.A total of 240 male(castrated)and female piglets(Duroc × Large White × Landrace)were selected from the same batch of weaned piglets(21 days of weaning day weight,weight of 7.27 ± 0.09 kg),and each 80 piglets were randomly assigned to receive A test diet with 16 repetitions(half male and female)for each diet and 5 piglets per replicate.The trial lasts for 6 weeks and is divided into two phases.The first 2 weeks after weaning is the pre-test period,and the last 4 weeks are the later stages of the trial.The pigs were recorded for the weight of the test and the weight at the end of each stage.The health status of the pigs was observed and recorded on a daily basis.Feed intake was recorded weekly.On the day of the end of the experiment,feces and blood samples were collected from healthy and near-average weight pigs per treatment column.Serum biochemical indicators were measured using an automatic biochemical analyzer.Serum inflammatory factors and immune parameters were determined by ELISA.Faecal volatile fatty acids(VFAs),the relative viscosity of feces were measured using an Ostwald viscometer(?0.5-0.6 mm),and fecal microbial composition was determined usingthe 16 S rRNA method based on the Illumina HiSeq sequencing platform.The result is as follows:(1)Effect of adding NSP enzyme on production performance: Dietary treatment had a significant(P<0.05)effect on the feed-to-meat ratio in the pre-test(1-2 weeks after weaning),and the feed-meat ratio in the RE enzyme group was significantly lower(1.16±0.05)(P<0.05)than in the control group(P <0.05)(1.21±0.05)and RA enzyme group(1.22±0.04)groups.Dietary treatment had no significant(P> 0.05)effect on Average Daily Gain(ADG)and Average Daily Feed intake(ADFI).Dietary treatment and the interaction between NSP enzyme and sex had a significant(P<0.05)effect on ADG at the end of the trial(3-6 weeks after weaning),and ADG in the RA enzyme group was significantly(P<0.05).Compared with the control group and the RE enzyme group,the ADG of the RA enzyme sow was significantly higher(P< 0.05)than that of the control and RE enzyme groups.The interactions of dietary treatment and NSP enzyme with gender had no significant(P>0.05)effect on ADFI and feed-to-meat ratio at the end of the experiment.It is worth noting that during the third week of weaning(ie,week 1 of the post-test refeed),the frequency of diarrhea in the RA enzyme group(0.72%)was extremely significant(P< 0.01)lower than that of the control group(4.31%)and RE enzyme.Group(4.11%).In the later period of the experiment,the frequency of diarrhea in the RA enzyme group(1.43%)was also significantly lower(P<0.05)than in the control group(2.43%),and extremely significant(P<0.01)was lower than the RE enzyme group(3.12%).During the whole trial(1~6weeks after weaning),the interaction between enzyme and sex had a significant(P<0.05)effect on ADG in piglets.Specifically,the ADG of sows in RA group was significantly(P<0.05)higher than that of controls.Group and RE enzyme group sows.The interaction between enzyme and sex had no significant(P>0.05)effect on ADFI and feed-to-meat ratio during the whole period of the experiment.(2)The effect of adding NSP enzyme on serum biochemical indexes:Dietarytreatment had significant(P<0.05)effect on serum total protein and globulin levels in piglets.The serum total protein content in the RA enzyme group was significantly(P<0.01)higher than that in the control group and the RE enzyme group.The RA enzyme group globulin The content was significantly higher(P<0.05)than that of the RE enzyme group and was significantly(P<0.01)higher than that of the control group.At the same time,gender had a significant(P<0.05)effect on serum glucose levels in piglets,and serum glucose levels were significantly(P<0.01)higher in sows than in boars.Dietary treatment and the interaction between enzyme and sex had no significant effect on serum urea nitrogen and albumin(P>0.05).(3)the effect of adding NSP enzyme on serum inflammatory factors and immunoglobulin content:Dietary treatment had significant(P<0.05)effect on serum inflammatory cytokines interleukin-1?(IL-1?)and tumor necrosis factor(TNF-?),and serum IL-1 ? content in RA enzyme group was significantly lower(P<0.05).In the RE enzyme group,and lower than the control group,but no significant difference(P> 0.05).Serum TNF-? levels in the RA enzyme group were significantly higher(P<0.05)than in the control group,and significantly(P<0.01)higher than the RE enzyme group;dietary treatment and interaction between the enzyme and gender had no significant effect on serum IL-6 levels(P>0.05).At the same time,dietary treatment had significant(P<0.05)effects on serum IgG and IgM in piglets.Specifically,serum IgG levels in RA enzyme group and RE enzyme group were significantly(P<0.05)and extremely significant(P<0.05)higher than the control group,serum IgM levels in the RA enzyme group is also extremely significant(P <0.01)higher than the control group,dietary treatment has no significant effect on serum IgA content(P>0.05),and the interaction of the enzyme and gender on the piglet serum The levels of IgG,IgM and IgA had no significant effect(P>0.05).(4)Effect of adding NSP enzyme on fecal viscosity and VFA: The feces viscosity of RA enzyme group had a tendency to decrease compared with the control group and RE enzyme group(P<0.10).Dietary treatment and the interaction of enzyme andgender on fecal acetic acid in piglets,VFA levels such as propionic acid and butyrate had no significant effect(P>0.05).(5)Effects of adding NSP enzyme on fecal microorganisms: The 16 S pyrosequencing results showed that according to the Observed Species Index,the amount of sequencing of the sample basically covers all the species of the sample.Through the analysis of NMDS,we found that the points in the control group and the RA enzyme group were densely clustered,and the distance between the groups was increased,indicating that the effect of RA enzyme treatment on the species information has changed,changing the structure of intestinal flora of piglets.On this basis,we obtained the following results by comparing changes in bacterial structure:a)Analysis at the gate level revealed that the addition of RA enzyme significantly(P<0.05)reduced the Firmicutes abundance.At the same time,it was found that the abundance of Proteobacteria in the male rabbits of the RA enzyme group was extremely high(P<0.01)compared with the male piglets in the control group.b)Analysis at the genus level found that RA enzyme significantly(P<0.05)increased the abundance of the subordinates defined by Ruminococcaceae,a microorganism that is primarily involved in degrading NSP and producing butyric acid in inflammatory regulation;specifically,RA enzyme significantly(P<0.05)increased the abundance of Ruminococcaceae_UCG-010,Ruminococcaceae_UCG-013,Ruminococcaceae_UCG-002).At the same time,compared with the control group,RA enzyme significantly(P<0.05)increased the abundance of some of the subordinates defined by Prevotella,including Prevotellaceae_UCG-004 and Prevotellaceae_NK3B31_group,which can produce hydrolyzed cellulose.The enzyme required for xylan and xylan showed that the enzyme RA is selective for the regulation of microorganisms,so it was speculated that the enzyme RA specifically enhances the intestinal microflora that can secrete the NSP enzyme,for example,Prevotella and The genus Ruminococcaceae(Rubicinaceae)is a genus that reflects the role of RA enzyme in improving theperformance of piglets by promoting the proliferation of NSP-degrading bacteria.In summary,the addition of NSP enzyme RA enzyme or RE enzyme to wheat-type diets has a certain improvement effect on the performance of piglets;RA enzyme is more effective in reducing the rate of diarrhea in piglets,and it promotes proliferation and reduction of NSP-degrading bacteria.It is related to the expression of pro-inflammatory cytokines and increase of immunoglobulin secretion.