Effect Of Probiotic Fermented Feed On Immunity And Gut Health Of Finishing Pigs

The probiotic fermented feed is a mixture of probiotic bacteria inoculated with the feed material to obtain a mixture comprising the feed material and their metabolites.In this study,a total of 48 growing barrow pigs(Duroc × Landrace × Large White)with similar body weights were randomly allocated into one of two feeding groups: one fed with commercial soybean meal and a second with fermented complete commercial soybean meal.Upon reaching slaughter weight,one pig from each pen was randomly selected and fasted for 12 h(with free access to water)before slaughter and sampling.The automatic blood cell analyzer was used to analyze the changes of blood routine physiological indexes of finishing pigs.The levels of immunoglobulin and inflammatory factors in the serum of finishing pigs were detected by ELISA.The expression of blood and intestinal immune related genes in finishing pigs were detected by RT-PCR.Hiseq high-throughput sequencing method was used to detect the composition of bacterial flora in duodenal and colon contents and mucosal samples of fattening pigs.The composition of metabolites in colon contents was detected by LC-MSbased non-targeted metabolomics.Get the following results:1.There was no significant difference in white blood cell count,absolute lymphocyte value,absolute value of intermediate cells,absolute value of granulocytes,number of red blood cells and platelet count between the treatment group and the control group(P>0.05).When compared to control pigs fed a standard diet,the results showed that serum levels of IgG,and IgM were significantly increased in FF pigs(P<0.05).In addition,serum levels of IgA and inflammatory factors(IL-10 and TNF-?)were not significantly affected(P>0.05).The expression of TLR3,TLR4,TLR6 and TLR8 in the blood of the treatment group were significantly higher than that of the control group(P<0.05).2.The expression levels of TLR5,TLR1,TLR2,TLR4,TLR9,PBD-1 and PR-39 in the duodenum of the treatment group were significantly higher than those in the control group(P<0.05).The expression levels of TLR2,TLR4,TLR5,TLR7 and PBD-1 were significantly higher than those of the control group(P<0.05).3.Statistical estimates of species richness for 5,000 subsets of each sample at a genetic distance of 3% showed that there was no difference in richness estimates(ACE and Chao)and the alpha diversity among the microbial communities was tested with the Shannon and Simpson indices.4.The results of non-targeted metabolomics found that 1351 metabolites were identified in the positive and negative ion mode between the probiotic fermentation feed group and the control group,of which 293 were up-regulated metabolites,down-regulated metabolism.There are 1058 species.The KEGG pathway enrichment analysis found that 14 metabolic pathways were influenced,and there were significant differences in C5-branched dibasic acid metabolism and purine metabolism(P<0.05).In summary,the fermented feed is beneficial to the health of finishing pigs,significantly improving their immunity.The above research results provide experimental basis for the promotion and application of fermented feed in the production of large scale pig farm.