| Bacillus amyloliquefaciens is a non-pathogenic microorganism named for its highly active amylase,which is widely isolated from soil and plants.It is characterized by having strong resistance and many metabolites.The TL106 was isolated from cold and disease resistant Tibetan pigs in Linzhi,Tibet,aiming to study in vitro characteristics as a potential probiotic.We explored the effects of Bacillus amyloliquefaciens TL106 on growth performance,weaning stress,intestinal development,intestinal microbiota and metabolism of weaned piglets.Also,we explored the relieving effect of Bacillus amyloliquefaciens TL106 on stress at different health levels and immunosuppressed physiological state of perinatal sows as well as the impact on the production performance and nutritional metabolism of sows and piglets.Our findings provided a basis for studying how TL106 works in pigs with strong probiotic ability.It provides some research support for the development of animal husbandry under the background of "Limit and ban on antibiotic use" and healthy and efficient breeding.The primary study results are as follows:The milky white TL106 colonies with uniform size were isolated and confirmed through blue-purple gram staining.The growth was found fast,having 4h log growth phase.It could not only survive in an acidic environment,with high bile salt concentration and high temperature conditions,but also had certain tolerance and antagonistic effects on various antibiotics such as Penicillin,Streptomycin,Tetraamycin,E.coli,Staphylococcus Aureus,Salmonella,Haemophilus parasuis,and Streptococcus.It shows that Bacillus amyloliquefaciens TL106 had the basic condition of probiotics.TL106 significantly improved the growth performance of weaned piglets for two weeks,with a significantly lower diarrhea rate.There was no significant difference in diarrhea rate and growth performance as compared to the oxytetracycline calcium group.TL106 significantly improved the apparent digestibility of crude fiber and ash in weaned piglets(p < 0.05),with increased activity of cecal digestive enzymes,serum antioxidants and immunoglobulin level(p < 0.05).Oxytetracycline calcium,and TL106 significantly reduced serum pro-inflammatory cytokines and increased anti-inflammatory factors.Moreover,it significantly reduced Toll-like receptor key protein expression,following improved immune performance of weaned piglets.From the perspective of intestinal HE staining,the structure and function of the intestine of piglets in the oxytetracycline calcium group showed developmental delay,with decreased number of lymph nodes.The results of 16 S r RNA sequencing conveyed that antibiotic and TL106 had no significant effect on the diversity of intestinal microbes in weaned piglets,but TL106 stabilized gut microbiota disturbed by weaning of piglets,including increasing Lachnospiraceae,Peptococcaceae.rc4＿4,Erysipelotrichaceae.L7A＿E11 and Mollicutes.RF39.In this study,we have proven that Bacillus amyloliquefaciens TL106 can be regarded as an alternative to antibiotics to prevent weaning stress in Duroc×Landrace×Yorkshire weaned piglets.Metabolomics studies have shown that the TL106 group can up-regulate pathways related to nutrient digestion,absorption and transmembrane transport,amino acid anabolism,lipid metabolism,hormone synthesis,and genetic material translation in sows in late pregnancy.Improved tryptophan metabolism pathway and sphingolipid signaling pathway in lactating sows.Improved histidine metabolism,protein digestion and absorption and other pathways in suckling piglets.The display results corroborate with the results of improved production performance,improved nutrient utilization,anti-oxidation,and enhanced immunity.The TL106 group almost achieved a similar effect to the oxytetracycline calcium group,which improved production performance,decreased diarrhea,antioxidant,and enhanced immunity results of the TL106 group.The study of Bacillus amyloliquefaciens TL106 to perinatal sows,lactating sows and suckling piglets found that TL106 improved the stool score of sows with gestation period of 90 days(p < 0.05),reduced abnormal tires and improved daily weight and diarrhea.TL106 increased ATTD of feed nutrients in pregnant and lactating sows with increased oxidation resistance and immunoglobulin.Significantly reduced the serum levels of proinflammatory cytokines IL-1,IL-6 and TNF-αin pregnant sows(p < 0.05).The serum levels of IL-10 of pregnant sows,lactating sows and suckling piglets were significantly increased(p < 0.05).TL106 reduced Toll-like receptor key protein expression in piglet cecum,indicating that TL106 can alleviate the inflammation of sows in late pregnancy,improve the anti-inflammatory ability of suckling piglets,and balance the immune status of sows and piglets.16 Sr RNA sequencing showed that TL106 increased the species diversity of cecal flora in suckling piglets and increased the proportion of intestinal Firmicutes in sows.By analysing microflora species differences,in sow feces,TL106 increased in Clostridium＿sensu＿stricto＿1,Treponema,Turicibacter,Romboutsia,Ruminococcus,Eubacterium,Veillonella.These bacterial genera produce large amounts of short-chain fatty acids such as butyrate during growth.These inhibit intestinal inflammation via different mechanisms,maintaining the intestinal barrier,and regulating intestinal movements.In the cecal contents of suckling piglets,TL106 increased the abundance of Christensenellaceae＿R-7＿group,Cloacibacillus,Phascolarctobacterium,Prevotella,g＿＿Butyricicoccus,g＿＿unclassified＿f＿＿Clostridiaceae.These genera are related to fermentation production of lactic acid,digestive resistant starch and fiber,short-chain fatty acids such as butyric acid,stabilization of intestinal barrier,reversing diarrhea,negative correlation with metabolic diseases such as inflammation,and healthy mucosal markers.Metabolomics studies showed that the TL106 group can upregulate nutrient digestion and absorption and transmembrane transport,amino acid anabolism,lipid metabolism,hormone synthesis,and genetic material translation in late gestation.It improved the tryptophan metabolism pathway and sphingolipids signaling pathway in lactating sows.While in suckling piglets’ it improved histidine metabolism and protein digestion pathways.Hence according to all findings,Bacillus amyloliquefaciens TL106 improved performance,nutrient utilization,antioxidant,and enhanced immunity.The studies show that TL106 has the biological characteristics as a probiotic for animal use,which can obviously colonize in the pig ileum and cecum.It plays a positive role in the production and health of sows and piglets to relieve piglets weaning stress and sow perinatal syndrome,reduce the use of antibiotics.TL106 is available as a probiotic in pigs and has good use prospects. |
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