Analysis Of Gut Microbiota Characteristics And Fungi Isolation And Identification Of Sows During Reproductive Cycle

The feeding of sow is key to determine the production level and economic benefit of farm in large-scale pig production,and pregnancy and lactation are the core period of sow management.Gut microbiota play an important role in many physiological metabolism and disease occurrence and development of the host,and are closely related to the health and physiological activities of the host.However,there are relatively few studies on the structural characteristics of gut microbiota in sows during the reproductive cycle,especially on fungi and overall metabolism.In order to explore the composition characteristics and changes of gut microbiota in sows at different stages of the reproductive cycle,12 sows were selected in this experiment.fecal samples were collected during five periods,including empty pregnancy(2 d before mating),early pregnancy(28,42,56 d after mating),late pregnancy(70,84,98 d after mating),delivery and lactation(7,14,21d after breeding).16S and ITS amplifiers were sequenced,metabonomic experiments combined with bioinformatics techniques were used to longitudinally analyze the characteristics and changes of gut microbiota of sows,and fungi were isolated and cultured by culture methods.The results of this study are as follows:(1)The bacterial flora belongs to 32 phyla,283 families and 633 genera.Theαdiversity of intestinal microflora in sows was significantly different in five periods,increased progressively with the beginning and progress of pregnancy,reached the highest value in the late stage of pregnancy,and then decreased sharply.It maintained a level similar to but slightly lower than that during lactation(P<0.05).There were significant differences inβdiversity among the five groups(R~2>0.2).Structurally,it was mainly composed of Streptomyces and Bacteroides,and the ratio of them(F/B)decreased gradually from empty to parturient,reached the lowest during parturition,and then increased(P<0.05).The dominant bacteria in sow feces in the five periods were Clostridiaceae,Peptostreptococcaceae and Oscillospiraceae.The relative abundance of Muribaculaceae and Tannerellaceae increased gradually with the progress of pregnancy and reached the peak during parturition.Similarly,the relative abundance of Prevotellaceae increased gradually with the progress of pregnancy and reached the peak in the third trimester of pregnancy.The relative abundance of Peptostreptococcales-Tissierellales increased from empty pregnancy to early pregnancy,and then decreased gradually.48 characteristic genera were obtained by difference analysis(Lef Se).(2)The fungal flora belongs to 18 phyla,267 families and 726 genera.Theαdiversity in early pregnancy was lower than that in empty pregnancy,but there was no significant change in the second trimester of pregnancy,then increased in parturition,but there was no significant difference between parturition and lactation.There were significant differences inβdiversity between pre-pregnancy and lactation sows(R~2>0.2).Structurally,it is mainly Ascomycetes,and there is a high abundance only in the first trimester,late pregnancy and parturition.The dominant family of fungi in the five periods is Aspergillaceae.In addition,the relative abundance of Neocallimastigaceae in early and late pregnancy was significantly higher than that in empty pregnancy and lactation.A total of 49 characteristic genera were obtained by Lef Se.There are complex interactions between bacteria and fungi,but the interactions between bacteria and fungi are not rich.A total of 148strains of fungi were obtained,belonging to 3 phyla,13 families,17 genera and 21 species,of which 70 strains were potential new strains(the similarity with the reference sequence in NCBI database<98.65%).The combination of ITS amplifiers sequencing and culture genomics methods can more comprehensively clarify the structure and composition of intestinal fungal communities.(3)784 metabolites were identified in pos mode and 735 metabolites were identified in neg mode.The main compounds were lipids and their derivatives.There were significant differences in metabolites among empty pregnancy,late pregnancy and lactation.Compared with empty pregnancy,the number of down-regulated metabolites during lactation and late pregnancy was more than that of up-regulated metabolites.There are 13 differential metabolic pathways between late pregnancy and empty pregnancy,mainly bile secretion and platelet activation,5 differential metabolic pathways,mainly ovarian steroid production,steroid biosynthesis and fatty acid degradation,and 17 differential metabolic pathways,mainly TRP regulation,linoleic acid metabolism and so on.In summary,this study systematically evaluated the changes of intestinal bacteria,fungal community and microbial metabolism in sows at different reproductive stages,and obtained fungal strains with research significance.During the reproductive cycle,sow intestinal microorganisms experienced stage-specific changes in composition and metabolites,which may be involved in maternal metabolic changes;the combination of culture methods and ITS amplifiers’sequencing method is more conducive to the complete display of the structure of intestinal fungal community.The data of this study provide data and theoretical support for the further study of the interaction mechanism between gut microbiota and host in the future.