| Background:Greenhouse effect has been the focus of global attention in recent years. Oneof primary causes is the excessive emission of methane. Beef cattle farms are one of the important sources of methane production. Previous study showed that plant polyphenol could increase the undegradable protein and decrease methane production in the meantime. However, plant polyphenol withdifferent structures has different biological functions.Objective:To study the effects of polyphenolic extract from involucres of Castanea mollissima Blume (PICB) on rumen fermentation, methane production and microorganisms in beef cattle, in vitro artificial rumen culture experiment and cannula experiment were carried out to illuminate the mechanism of PICB in regulating rumen fermentation and inhibiting methane production, which could proviide theoretical foundation for PICB as the feed supplement to decrease the rumen methane emission by ruminants.Methods:1. The effects of PICB with different concentrations (concentration of 0%,0.1%,0.2%, 0.3%,0.4% and 0.5%, on dry matter basis) were studied using in vitro rumen fermentation. Gas production, methane production and dry matter degradation rate and the optimal concentration was determined.2. The effects of PICB on the number of rumen microorganisms were studied through real-time PCR technique (0% and 0.2% PICBas control group and the trial group, respectively).Results:1. PICB had no obvious influence on the pH value of in vitro rumen fermentation fluid. Compared with the control group, addition of 0.3%PICB significantly reduced (P<0.05) the NH3-N concentration of in vitro fermentation fluid. Addition of PICB had no significant effect on the content of the total volatile fatty acid (VFA) of in vitro rumen fermentation fluid. Addition of 0.2% and 0.3% of PICB outstandingly reduced (P<0.05) the proportion of acetic acid. Addition of 0.2%PICB remarkably raised (P<0.05) the proportion of propionic acid. While addition of 0.2% and 0.3%PICB significantly decreased (P<0.05) the ratio of acetic acid to propionic acid, when compared with the control group. Adding 0.3%PICB to 0.1%PICB could significantly reduce the content of rumen butyrate (P< 0.05). Addition of PICB had no obvious effect (P>0.05) on the contents of isobutyric acid, isovaleric acid and valeric acid in the in vitro rumen fermentation fluid. Compared with the control group, addition of 0.2% of PICB notably boosted (P<0.05) the 12h gas production of in vitro fermentation, and meanwhile significantly decreased (P<0.05) the content of CH412h after in vitro fermentation. Addition of PICB had no significant influence on the contents of H2, oxygen-nitrogen, and CO2 12h after in vitro rumen fermentation as well as the 48h dry matter degradation rate.2. PICB had no significant influence on the 96h gas production, theoretical maximum gas production and gas production rate of in vitro rumen fermentation. The theoretical maximum gas productionin the high dose group was significantly lower than lower dose group.the rate of gas production was significantly higher in low dose group than that in other groups.3. Addition of PICB had no significant influence on the number total bacteria, protozoa, as well as the relative quantity of butyrivibrio fibrisolvens in rumen fluid Compared with the control group, the PICB experiment group notably reduced (P<0.05) the relative quantity of methanogens in rumen fluid on 4h and 6h after morning feeding.Conclusion:PICB could reduce the quantity of rumen methane, regulate rumen fermentation, remarkably reduce the production of beef cattle rumen methane, and decrease the greenhouse effect induced by beef rearing. |
PDF Full Text Request