Study On The Effect Of Red Yeast Rice On Methane Emissions?rumen Archaeal Diversity And Feed Efficiency In Goats

This experiment was conducted to evaluate the effect of red yeast rice on met hane emissions,rumen archaeal diversity and feed efficiency in goats.Ten goats we re selected for the experiment in a duplicate 2*2 Latin square design.The test was set up two treatments,including 1 basal diet(control,CT)and 1 experiment diets(containing red yeast rice,RYR).Each experiment period last 23 days,including a daption period(14days),metabolic trial(6days)and gaseous exchange measurements(3days).The feed efficiency was evaluated by metabolic trial,and the CH4 emissions were measured through indirect open-circuit respiration chambers.After 23days expe riment,the rumen content were sampled on day 24,Then we extracted total DNA of rumen content samples,individually.The universal primers for archaea(a forward primer 515F:A349F 5'-GYGCASCAGKCGMGAAW-3' and a reverse primer A806 R 5'-GGACTACVSGGGTATCTAAT-3')were used to amplify the V4-V5 region of 16S rRNA gene.We identified and characterized the overall ruminal microbiota,b y using the 16S rRNA pyrosequencing on the Illumina MiSeq 300PE sequencing pl atform.The results showed as follows:1)Red yeast rice supplementation had no significantly influence on dry matter intake and the apparent digestibility of DM,ash,EE,NDF,ADF and CF(P>0.05),fearfully significantly ruduced the apparent digestibility of OM and CP(P<0.01),but only with a reduction of 3.4%and 7.3%,respectively;2)Red yeast rice supplementation had no significantly influence on nitrogen deposition rate and net nitrogen utilization(P>0.05);3)Compared with CT,the DE/GE and ME/GE of RYR was fearfully significantly lower(P<0.01)and the significantly lower(P<0.05),respectively.But the NE/GE of RYR was fearfully significantly higher(P<0.0l)than CT.4)Red yeast rice supplementation fearfully significantly reduced the CH4g/d,CH4g/kgDMI,CH4g/kgOM intake,CH4g/kg digestible DM intake and CH4g/kgBW?0.75(P<0.01),and significantly reduced CH4/digestible OM intake.But there were no significantly difference in between CT and RYR in CH4/Digestible NDF intake(P>0.05);5)Red yeast rice supplementation fearfully significantly reduced blood levels of high density lipoprotein and low density lipoprotein(P<0.01),and significantly reduced blood levels of cholesterol and triglycerides(P<0.05);6)there were no significantly influence on the concentration of ruminal acetate,propionate,butyrate and ammonia nitrogen(P>0.05);7)A total of 227729 sequences across all rumen content samples were generated by pyrosequencing,and the total number of operational taxonomic units(OTUs)detected by the analysis reached 2364(an OTU was defined as a read sharing ?97%nucleotide sequence identity),which could cover a broad range of ruminal archaeal species.The Shannon index of RYR was significantly higher than that of CT(P<0.05).The chaol index and observed species index was also higher than those of CT,but did not differ significantly between the host species(P>0.05),but the differences were not significant(P>0.05);8)The most abundant phyla found in CT was Euryarchaeota(95.80%),which was highly significantly higher than that in RYR(P<0.01).And the abundant of Crenarchaeota found in RYR(19.44%)was highly significantly higher than that in CT(P<0.01).9)At a class,order,family and genus level,the abundant of Methanobacteria,Methanobacteriales,Methanobacteriaceae and Methanobrevibacter found in RYR was highly significantly lower than those in CT(P<0.01),respectively.All the phyla Crenarchaeota detected in RYR were able to classify into unclassified Thermoprotei,which had a significantly higher abundant than that in CT(P<0.01).In conclusion,red yeast rice supplementation was able to inhibit Methanobrevibacter.but not for all ruminal archaea.The result showed red yeast rice supplementation was able to highly significantly reduce CH4 emission and increase the efficiency of utilization of feed energy,but had no significantly influence on the efficiency of utilization of nitrogen and rumen fermentation parameters for goats.As a naturally fermented product,red yeast rice can be a good selection for mitigating rumen methane emission.