Effects Of Purified Dietary Fiber Mixture On Reproductive Performance And Intestinal Microflora Of Sows And Their Offspring

The reproductive performance of sows is closely related to the production efficiency of breeding farms.Dietary Fiber(DF)plays a important role in maintaining the intestinal health of sows.In recent years,there have been many researches which focus on the effect of dietary fiber on the reproductive performance of sows.However,the effects of DF on the intestinal microflora of sows and the resulting changes in sows' immune function are still scarce.Meanwhile,it is worth to study whether the effect of DF on the intestinal microflora of sows will further affect the composition of the intestinal microbiota of their offspring.In this study,the fermentation characteristics of purified DF were studied by in vitro fermentation test technology,and intestinal microorganisms and metabolomic were analyzed by high-throughput sequencing and metabolomics technologies,So as to investigate the effect of DF on the intestinal microflora and reproductive performance of sows and piglets.The main research contents were presented as follows:1.Study on the fermentative characteristics of purified DF by in vitro fermentation technique using fecal microorganisms of sowsIn this study,four sources of DF,lignocellulose,cellulose,guar gum and inulin with different physicochemical properties were used in the in vitro fermentation technique,so as to provide references for the application of purified DF in sows based on their fermentation properties.The results showed that the theoretical maximum gas production of inulin and guar gum were significantly higher than that of cellulose or lignocellulose with lignocellulose being the lowest(p <0.01).For the end products of fermentation,the yield of inulin acetic acid was the highest(p <0.01),and the yield of propionic acid,butyric acid and total acid of guar gum and inulin were higher than those of cellulose and lignocellulose(p <0.01).2.Effects of purified dietary fiber mixture supplementation during gestation on reproductive performance,intestinal microflora and immune function of sowsA total of 68 healthy sows(mean parity 3.2 ± 1.4)were selected.After mating,sows were divided into the control group(CON)and fiber mixture group(FM)based on parity and backfat thickness.The sows in FM group were fed the control diet with3% fiber mixture supplementation during the whole gestation.The results we found theat the addition of FM during pregnancy significantly increased the number of live born piglets,feed intake at 3rd week of lactation(p < 0.05),and trend to increase the weaning weight and litter weight gain(p < 0.1).The FM supplementation significantly increased the butyric acid concentration at d30 and propionic acid concentration at d110 in the feces of gestating sow(p <0.05),and also showed a trend of increasing fecal propionic acid at d30 and fecal total short chain fatty acids(SCFAs)at both d30 and d110 of gestating sow(p <0.1).The addition of FM showed no effect on serum immunoglobulin,estradiol,progesterone,tumor necrosis factor-?(TNF-?),and interleukin-6(IL-6)levels of gestating sows.Compared with CON group,the serum level of serotonin at d110 and IL-10 at d30 of gestation in sows of FM group increased(p <0.05),while the concentration of interferon-?(IFN-?)at d30 of gestation in the FM group was significantly decreased(p < 0.05).The relative abundances of Roseburia and Eubacterium-hallii-group in FM group were significantly increased and those of Spirochaetaceae,Spirochaetales,Treponema?2were significantly decreased on d30 of pregnancy.Meanwhile,FM addition markedly increased the relative abundances of Bacteroidales,Bacteroidetes,Bacteroidia,Bacteroides,Prevotellaceae,Roseburia and Eubacterium-hallii-group,but decreased those of Peptostreptococcaceae,Clostridiaceae?1,Clostridium sensu stricto?1 on d110 of gestation.3.Effects of purified dietary fiber mixture supplementation during gestation on intestinal microflora and immune fucntion of offspring pigletsOnce the sows in exp.2 farrowed,one newborn piglet with no colostrum intake and whose weight was close to the mean birth weight of the litter was selected from six litters.At d21 of weaning,one weaned piglet whose weight was close to the mean weaning weight of the litter was selected from the six litters.After blood collection,samples of spleen,mesenteric lymph nodes,colon and colonic content were collected to the determin the composition of intestinal microflora and Toll-like receptors(TLRs)expressions in their piglets.The results we found that,the level of TNF-? in serum of piglets at d21 in FM group was significantly lower than the CON group(p< 0.05).The levels of other serum cytokines,immunoglobulin and complement proteins were identical between groups(p > 0.10).FM addition during pregnancy significantly increased the relative abundance of genus Roseburia at d21 of lactating of sows(p<0.05).Meanwhile,FM supplementation significantly increased the relative abundance of genus Roseburia and Lactobacillus and decreased the relative abundance of genus Odoribacter in the colon content of the offspring piglets at 21 d of age(p <0.05).The addition of FM had no significant effect on TLR m RNA expression in mesenteric lymph nodes,spleen and colon of newborn piglets(p >0.10),but significantly decreased the m RNA expressions of TLR4 and nuclear factor kappa B(NF-?B)in the colon of piglets at d21(p <0.05).4.Effects of purified dietary fiber mixture supplementation during gestation on the growth performance and immune stress response of offspringAfter mating,24 multiparous sows were randomly allocated to four groups with6 replicates per group.The gestation diet of group?and? were typical gestation diet with no fiber added,and the weaned piglets from group?and?were injected with physiological saline and lipopolysaccharide(LPS),respectively.The gestation diets of group ? and ? were added with 3% FM,and the weaned piglets were injected with physiological saline and LPS,respectively.The results we found that the FM addition during gestation and LPS injection showed significant interactive effect on average daily gain(ADG)and serum TNF-? level of piglets,the ADG of group ? piglets was significantly higher than group?(p < 0.05),the serum TNF-? level of group?piglets was significantly lower than group?(p < 0.05).5.Effects of dietary fiber on intestinal microorganisms and metabolites of pigletsTwelve 23 d weaning piglets were randomly divided into control group(C group)and experimental group(F group),with 6 pigs in each group and fed in a single pen.The piglets in C group was fed a basic diet,while the diet of F group was supplemented with 1%FM.On the 14 th day of the experiment,rectal contents were collected aseptically to analyze intestinal microorganisms and metabolites.The results showed that adding 1%FM in the diet of piglets could reduce the abundance of Proteobacteria,Eschericha-Shigella and Faecalicoccus,and significantly increase Mogibacterium,Methanobrevibacter and Lactobacillus.A total of 93 metabolites were identified by using metabolomicsd,among which 9 metabolites were significantly increased and 4 metabolites were significantly decreased in F group compared with C group.The different metabolites are mainly concentrated in 6pathways of Serotonergic synapse?Alanine aspartate and glutamate metabolis?Tryptopha metabolism?Tyrosine metabolism?Butanoate metabolism?Valine,leucine and isoleucine biosynthesis.The results of this study indicated that FM supplementation to the gestation diet could promote the proliferation of beneficial microorganisms in the intestinal tract and inhibit the proliferation of potentially pathogenic microorganisms,thus contributing to the intestinal health.The mechanisms underlying the increased number of live born piglets may be linked to the increase in SCFAs production by gut bacteria with FM addition.Higher SCFAs concentration has been proven to enhanced serotonin secretion and a bias towards a Th2-based immune response in gestating sows,thereby improving the embryo survival.Furthermore,the FM addition during pregnancy will affect the composition of intestinal microflora of their offspring,and thus affecting the immune function of piglets.The addition of FM in the diet of piglets will affect the structure of intestinal microflora,and change the metabolomic characteristics of intestinal contents,which is shown in the up-regulation of 5-HT and glutamine levels,the promotion of butyric acid metabolism,and the down-regulation of branched-chain fatty acids and indoles metabolites.The changes of metabolomic are conducive to promoting the intestinal health of weaning piglets.