| We studied the effects of AMR dietary supplementation,on concentrations of branched-chain fatty acids in lamb meat,taking supplementation ratios and feeding time of the AMR into the consideration,and to determine whether concentrations of the branched-chain fatty acids could be decreased through regulating factors above mentioned.We also used the methods of metagenomics and metabonomics,to explore the effects of dietary supplementation of AMR on lamb rumen microbiota diversity,characteristics of their metabolites composition,and we also predicted the metabolic passways of rumen microbiota,finally correlation analysis between concentrations of the three branched-chain fatty acids and certain data from databases of metagenomics and metabonomics was handled,in order to better understand the closest related rumen microbiota,metabolites to concentrations of the three branched-chain fatty acids.The paper contained six experiments,and studing contents and results of each experiment were as follows:Experiment 1: Effects of dried powder,its water-and fat-soluble extracts of Allium mongolicum Regel(AMR)on lamb growth performance,serum metabolites,immune responses,antioxidant status,and meat quality were evaluated in experiment 1.The 75-day experiment comprised a 15-day adaptation and a 60-day feeding trial.A total of 32 male small-tailed Han lambs(5 months old;34.8 ? 0.40 kg initial body weight)were randomly divided into 4 groups(n = 8).One group was fed a total mixed ration(CON)and the other 3 groups were fed the total mixed ration supplemented with dried AMR powder at 10 g/d per lamb(AMR),or water-soluble AMR extract at 3.4 g/d per lamb(AWE),or fat-soluble AMR extract at 2.8 g/d per lamb(AFE).Blood samples were collected on days 0,30,and 60 of the feeding trials(n = 8).These results indicate that dietary supplementation with AMR extracts had no significant effect on lamb growth performance,antioxidant status,and immune responses,but could significantly improve meat quality without the occurrence of pathological kidney and liver lesions.Experiment 2: According to experiment one,we therefore hypothesized AMR added into basic diets would significantly decrease the concentration of the branched-chain fatty acids.The study was aimed to evaluate effects of different feeding dose and period of Allium mongolicum Regel(AMR),on concentrations of the three branched-chain fatty acids in longissimus dorsi muscle of fattening lambs,and finally to identify the potential of AMR to reduce the concentrations of the three branched-chain fatty acids(BCFAs)and its suitable supplementation ratio,and to explore the feasibility of reducing feeding time not only to decrease the feed cost of AMR supplementation,but also decreas the concentrations of BCFAs.Based on the studing contents in this paper,56 2-Mo weaned lambs were selected with similar body weight,including half male and half female,and divied into seven groups randomly(n = 8/each group).The first group was the control group(CON),and the other six groups were divided into 2 major sets,the 2 sets contained three groups,0.5(Low Ratio,LR),1.0(Middle ratio,MR)and 1.5%(High ratio,HR)supplementation of AMR based on dry matter of diet,respctively.Differently,feeding time of the first set was 2 Mo,while another one was last Mo of 2-Mo fattening period.The animal feeding experiment consist of 15-day adaptation period and normal feeding period.Results showed that dietary supplementation of AMR with a suitable amount could significantly decrease the 4-alkyl branched-chain fatty acids,and improve mutton flavor.The measurement of decreasing the feeding period of AMR,to reduce the feed cost of AMR,and concentrations of 4-alkyl branched-chain fatty acids,are not feasible.The adviced amount of AMR supplementation is 0.5% of dietary dry matter,and the suitable feeding time is two month,through which could significantly decrease the concentrations of the three4-alkyl branched-chain fatty acids.Experiment 3:According to results of experiment 2,concentrations of 4-alkyl branched chain fatty acids were significantly decreased under the cndition of 2 Mo feeding with 0.5% supplementation of AMR(L-ALP).Thus,results of L-ALP group were mainly displayed in the abstract.The paper was aimed to explore the changes of structure of rumen microbiota.Results showed that(1)ALP supplementation did not significantly change the diversity of microbiome to influence the concentration of the branched chain fatty acids in mutton.(2)The relative abundance of core microbiome were changes by the supplementaton of AMR,and finally affected the concentration of the branched chain fatty acids.Experiment 4: the metabonomics was used to analyze the characteristics of composition of rumen metabolites.Results showed that,lipids and their der ivatives were significantly influenced,and Anibiotc X 14889 A,Docosapentaen oic acid(22n-6),D-Phosphatidylglycerol,Dehydrovomifoliol,2-Hydroxy-2,6,6-tr imethylcyclohexanone,2-Pentylfran and(3b,7b,22X)-Cucurbta-5,24-diene-3,7,23-triol-7-glucoside were down-regulated in L-ALP,while others were up-regula ted.Experiment 5: The experiment was aimed to predict the functions of rumen with KEGG database using data of the rumen metabolomics,to analyze the changes of rumen functions after feeding the AMR.Results showed that Phenylalanine metabolism,Arginine and proline metabolism and Tryptophan metbolism were significantly influenced in L-ALP group.Conclusions: The metabolism pathway affected under long term supplementation of AMR was amino acids metabolism.Experiment 6: This paper was aimed to analyze the correlation of concentrations of 4-alkyl branched chain fatty acids with relative abundance of rumen microbiome and metabolites.The study focused on the results of biomarkers(pecific microbiome and metabolites)of 4-alkyl branched chain fatty acids in the L-ALP group.Results showed that(1)EOA in L-ALP was positively correlated with species belonging to Firmicutes which is capable of digesting the fiber.(2)MOA and MNA in L-ALP was significantly correlated with certain methane bacteria.(3)EOA and MOA in L-ALP was significantly correlated with some uncommon Protozoa.(4)As for rumen metabolites,biomakers for MNA were Dehydrovomifoliol and Spermine,while for EOA was Lyso PE(16:1(9Z)/0:0),and MOA was D-Urobilin.Above all,AMR may reduce the concentration of 4-alkyl BCFAs by affecting the rumen Amino acid metabolic pathway.Certain genera of fibrolytic bacteria and methane bacteria could be biomarker for 4-alkyl BCFAs.As for rumen metabolites,biomakers for MNA were Dehydrovomifoliol and Spermine,while for EOA was Lyso PE(16:1(9Z)/0:0),and MOA was D-Urobilin. |
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