The Effect And Mechanism Of Hericium Erinaceus Polysaccharides Mitigating SARA In Goat

In this experiment,SARA model was established in vivo,and fermentation for 24 hours in vitro.According to the changes of pH,lactic acid,VFA,HIS,LPS and other indicators,we could evaluate the effect of HEP on alleviating SARA of goat.We could also analysis effects on the number of lactic acid metabolic related microbial flora,metabolic products and enzyme activity during acid-producing,so to evaluate the effect of HEP on mitigating SARA and to explore its mechanism.Experiment 1:Establishment of rumen SARA model and evaluation of the effect on SARA by adding HEP for fermentation in vitro.We constructed SARA model in vivo,8 goats was divided into 4 experimental periods according to the ratio of crude and coarse feeding,and self-control was adopted;the rumen fluid was collected from every experimental period,and the ? experimental period was initially determined SARA according to the range of pH value(The ratio of grain to raw was 8:2),The rumen fluid collected from the experimental period was used for fermentation in vitro,and the changes of lactic acid,VFA,HIS and LPS in each experimental period were determined to comfirm that the SARA model was successfully established.The experiment of fermentation in vitro was designed with single factor.The amount of HEP was 0,0.2%,0.4%,and0.8%(of the substrate quality),and each group was repeated 4 times.The results showed that the pH in group of HEP was higher than that in control group at each sampling point,and there was significant difference from control group at 9 h,12 h,18 h and 24h(P<0.05),which slowed down the dropping speed of pH.The group of0.4% added was higher than other experimental groups;the addition of0.4%,0.8% significantly reduced HIS content(P<0.01),and significantly reduced LPS content(P<0.05);HEP has good effect on SARA of goat,especially with 0.4% added.Experiment 2: The effect of adding HEP on lactic acid-related flora with SARA rumen fluid fermentating in vitro.We study the effect on SARA with rumen fluid added HEP fermentating for 24 h in vitro.Exceptfor 6 h,the numbers of S.bovis and L.f in 0.4% and 0.8% experimental groups were significantly lower than those in the control group(P<0.05).The concentration of M.e in the experimental group was higher than that in control group.There was no significant change on the number of the S.r;0.4%,0.8% experimental group inhibited the main lactic acid-producing bacteria at 24 h and promoted the reproduction of M.e.Experiment 3: The effect of HEP on acidogenic metabolites and enzyme activities of SARA with rumen fluid fermentating in vitro.The results showed that concentration of lactic acid,acetic acid,propionic acid,butyric acid and total VFA in experimental groups were lower than those in the control group,and difference in above indexes were significant at 0.4% experimental group(P<0.05),and its ratio value of acetic acid and propionic acid was significantly higher than that in the control group at 18 h and 24 h(P<0.05).The activities of enzyme in experimental groups were lower than those in control group,and differences were significant at 18 h and 24 h(P<0.05);The concentration of pyruvic acid was lower in experimental groups and the difference was significant at 12 h and 18 h(P<0.05);PFK activity in 0.4%,0.8% experimental groups was significantly improved than that in control group(P<0.05),and FDP was significantly higher at 6 h and 12 h(P<0.05,);the activity of LDH in experimental groups was significantly lower than that in control group at 18 h and 24 h(P<0.05).The mechanism of HEP alleviating SARA on goats: When SARA occurs,HEP can slow down the speed of acid-producing metabolic by controlling activities of AMS,HK,PFK,PK,LDH and concentrations of FDP and pyruvic acid;while inhibiting the growth of lactic acid-producing bacteria,It can also promote the growth of M.e,and finally reduce lactic acid accumulation,slow down the change of pH,improve the mode of rumen fermentation,reduce the accumulation of harmful metabolites on LPS and HIS,and balance the number of microbial flora related to lactic acid metabolism.