The Regulation Effects Of Allium Mongolicum Regel Extracts On Rumen Microbial Community,Fatty Add Composition,and Its Mechanism In Mutton Sheep

The mid-vestern desert steppe of Inner Mongolia is affluent in Allium mongolicum Regel(A.mongolicum Regel)resources,and its extracts hold the regulatory function on the average daily gain,fat distribution,fatty acid composition of fat tissues,and decrease the 'mutton'flavor in mutton sheep;as well as optimizing the rumen fermentation pattern and rumen microbial community simultaneously.Thus,it hypothesized that the effects of A.mongolicum Regel extracts on liponertabolism may through the regulation of rumen microbial community approach,assuming that the linkages between rumen microbial community and average daily gain or fatty acid profiles.In order to prove this hypothesis,this study designed two feeding experiments:dietary supplementation of A.mongolicum Regel extracts on small-tailed Han,male sheep;and Dorper x small-tailed Han crossbreed,female sheep.On the basis of the evaluation of the regulation effects of A.mongolicum Regel extracts on rumen microbial community,average dail gain(ADG),and fatty acid profiles of fat tissues,it explored the linkages between rumen microbial community and the ADG,or fatty acid composition,and or medium-branched chain fatty acid(MBCFA).This dissertation composed of 5 parts,and the results were concluded as follows:1.The effects of A.mongolicum Regel extracts on rumen bacterial or archaeon community,and ADG in small-tailed Han sheep,as well as the linkages between rumen microbial community and ADG Forty,healthy,male,and small-tailed Han fattening sheep,with similar body weight and age of months,were randomly assigned to one of the following four dietary treatments:basal diet as control group(CK),basal diet supplemented with 3.4 g·sheep-1 d-1 A.mongolicum Regel powder water-soluble extract as PAM group(PAM),basal diet supplemented with 10 g·sheep-1·d-1 A.mongolicum Regel powder as AM group(AM),and basal diet supplemented with 10 g·sheep-1·d-1 A.mongolicum Regel water-soluble extract residue as RAM group(RAM).The results showed that,the rumen microbial community composition and structure changed in AM or RAM group,while the ADG increased significantly(P=0.0171).The abundances of Tenericutes and Mollicutes([p]=0.5021,P=0.0124)were positively correlated with ADG.The main negatively correlated bacteria were Saccharibacteria([p]=-0.4762,P=0.0187)and Betaproteobacteria([p]=-0.5669,P=0.039).Thus,it indicated that the rumen microbial holistic structural change may lead to the increase of ADG effectively.2.The effects of A.mongolicum Regel extracts on rumen bacterial or fungal diversity and fatty acid composition of greater omental fat or subcutaneous fat in Dorper x small-tailed Han crossbreed sheep,and the linkages between the rumen microbes and fatty acid composition in fat also explored.Sixty,healthy,female,and Dorper x small-tailed Han crossbreed fattening sheep,with similar body weight and age of months,were randomly assigned to one of the following four dietary treatments:basal diet as control group(CT),basal diet supplemented with 10 g·sheep-1·d-1 A.mongolicum Regel powder(AM),basal diet supplemented with 3.4 g·sheep-1·d-1 A.mongolicum Regel water-soluble extract(AWE),or basal diet supplemented with 2.8 g-sheep-1 d-1 A.mongolicum Regel fat-soluble extract(AFE).As a result,AWE or AFE group significantly decreased rumen microbial Shannon index,and AM group significantly increased the SFA/PUFA(P=0.012).Saturated fatty acid(SFA)in greater omental fat was greater than that of subcutaneous fat(P<0.0001).In contrast,monounsaturated fatty acid(MUFA)in subcutaneous fat greater than that of greater omental fat(P<0.0001).Similarly,n6 polyunsaturated fatty acid(PUFA)in subcutaneous fat greater than that of greater omental fat(P=0.0248),yet both C18:2n6c in greater omental fat and subcutaneous fat negatively correlated with Rikenellaceae_RC9_gut_group and Bacteroidales_S24-7_group_norank,while SFA was positively correlated with the genus within Neocallimastigomycota both in the two fat depots.Thus,although the fatty acid composition of greater omental fat and subcutaneous fat were different,their linkages with the rumen bacteria or fungi were tended to be the same.3.The effects of A.mongolicum Regel extracts on the structure of rumen microbial community,structure of the microbial genes,fatty acid composition,and MBCFA of muscle in Dorper x small-tailed Han crossbreed sheep.The results demonstrated that rumen microbial community,the genes of EggNOG,the enzymes of CAZYs,and KEGG pathways cluster changed by the supplementation;compared to CT group,AWE or AFE significantly decreased the SFA(P=0.0525)in longissimus dorsi muscle,while significantly increased the MUFA(P=0.0448)and PUFA(P=0.0326);it also significantly decreased the contents of MBCFA in muscle.Thus,it indicate that A.mongolicum Regel water-soluble or fat-soluble extract resulted in the holistic microbiome structural changes that may altered the fatty acid composition and the MBCFA contents in muscle.4.The linkages between rumen microbial species and fatty acid profiles of muscle were also explored in Dorper x small-tailed Han crossbreed sheep.The results showed the linkages between fatty acid groups in muscle and rumen microbial communities dominated by negative correlations,especially that for MUFA that scattered for Bacteroidetes,Firmicutes,Proteobacteria,and Actinobacteria.The association of SFA or PUFA in muscle and rumen microbes were relatively little,and the correlated microbes scattered for different microbial orders.Muscle MBCFA negatively associated rumen microbes mostly assigned for Bacteroides,Deltaproteobacteria,Lactobacillales,and Actinobacteria;while positively associated rumen microbes mostly assigned for Clostridia,Gammaproteobacteria Ascomycota and Euryarchaeota.5.The linkages between the microbial gene abuidance and MBCFA of muscle in Dorper x small-tailed Han crossbreed sheep.The results showed that 16 genes within EggNOG annotation exhibited negative correlation with MBCFA,including ENOG4111M92,COG0096,ENOG410XR97 and COG3617 associated with all the MBCFA.In terms of GHs within CAZYs,GH16,GH73,GH25,and GH23 exhibited negative correlation,while CBM2 and CBM20 exhibited the positive correlation.Furthermore,9 KEGG pathways exhibited a positive association with MBCFA in muscle.On the other hand,there were more frequent linkages were observed for the association of MBCFA with rumen microbiota than fatty acid group in muscle.Overall,dietary supplementation with A.mongolicum Regel extracts can regulate the structure and composition of the rumen microbial community and which related to ADG and fatty acid composition and contents Dietary supplementation of A.mongolicum Regel and its extracts can increase the average daily gain,improve the fatty acid composition in longissimus dorsi muscle,and significantly decrease the MBCFA contents that related to the'mutton' flavor.These phenotypes exhibited the significant association with the specfic rumen microbes in mutton sheep.