Effects Of Feeding Caragana Korshinskii Kom.on Serum Indexes,Rumen And Colon Microbiota Of Tan Sheep

Caragana korshinskii Kom.is one of the shrubs widely distributed in Northwest China,adding a certain amount of CK to the forage can improve the production performance of ruminant and regulate the microbial community structure of their rumen.The application of CK in animal husbandry production is still at an early stage,and most of the research focuses on the impact on production performance,lacking the experimental research on the physiological and biochemical impact.At present,the research on the correlation between CK on gastrointestinal microorganisms and cytokines in Tan sheep has not been reported.This study aimed to examine the effects of 10%Caragana korshinskii Kom.on blood lipids,immune indicators,and rumen and colon microbiota of Tan sheep.Twelve Tan sheep(4-month-old)with an initial average weight of 27.5±3.32 kg were randomly divided into 2 groups(6 in each group):NC group was fed with 30%concentrate and 70%alfalfa;CK group,with 30%concentrate,60%alfalfa and 10%CK.The preparatory experiment was 10 days and the formal experiment was lasted for 60 days.At the end of the 60 days,blood was collected to measure blood indexes,and rumen fluid,colon contents were collected to detect the changes of flora in rumen and colon,respectively,by 16S rRNA sequencing and qPCR.After the formal experiment,all were slaughtered,rumen fluid and colon contents were taken for microbial genomic DNA extraction,and DNA fragments were amplified using the universal primer set(341F/805R)of microbial 16S rRNA V3-V4 region.After quantitative purification of the PCR products,they were sequenced by Beijing Jianyunkang Technology using the Illumina HiSeq2500 sequencing platform,and further verified the differences of related bacterial genera by qPCR.Through the above experiments to study the effect of CK on the gastrointestinal flora of sheep,and then study the effect on blood lipids and the secretion of immune factors in blood.The correlation analysis of the flora with significant changes in the gastrointestinal tract and the cytokines that produce significant differences provides data support for the gastrointestinal microbes to regulate the host’s nutritional metabolism,and provides a basis for the production and application of using CK to replace part of the sheep’s roughage.The results show that:1)The concentration of pro-inflammatory factor IL-6 in serum of Tan sheep in CK group increased significantly(P<0.05),while the concentration of IFN-y tended to decrease.2)Compared with the control group,the triglyceride(TRIG)content of the CK group was significantly decreased(P<0.05),the very low-density fatty acid(VLDL)content was extremely significantly decreased(P<0.01),and the low-density fatty acid(LDL)content tended to decrease.Significantly lower(0.05<P<0.1).3)Caragana korshinskii Kom.had a greater impact on the colonic microbiota of Tan sheep,increased the relative abundance of colonic Oscillospira,tended to reduce the relative abundance of pathogenic bacterium Treponema,and improved the structure of colonic microbiota.4)Pseudobutyrivibrio is an important bacterium that affects the content of triglycerides.To sum up,adding CK sticks to the feed can significantly reduce the blood triglyceride,lowdensity lipoprotein and very low-density lipoprotein concentrations of Tan sheep.At the same time,the bacterial community composition in the rumen and colon is optimized,and the body’s fat metabolism may be promoted by changing the bacterial community structure.