Effects Of Yucca Schidigera On Microbial Nitrogen Recycling Betwen Protozoa And Bacteria Under Diffent Substance In The Rustiec

In this experiment, four goats fitted with rumen cannula were used to determine the effects of concentrate to forage rates on the rumen microbial structure, and ruminal nitrogen recycling in vitro. The substrates for in vitro culture were designed as follows,â… , concentrate-to-forage ratio (corn+bean : straw), A(10:90),B(30:70),C(50:50),D(70:30) respectively;â…¡, concentrate-to-forage ratio (corn+bean : straw): 10:90, 50:50, by adding 0, 0.035g/L and 0.007g/L yucca schidigera extract in culture medium respectively. The results were described bellow.Trial1, as the results showed, the ruminal inner environment was influenced by concentrate to forage ratio. The mean pH decreased conrespendence with concentrate-to-forage ratio increasing, while the NH3-N concentration increased with the increase of the concentrate-to-forage ratio. The NH3-N concentration of A was significantly lower than that of B, C, and D; however no significant difference was detected among B, C, and D. It was also observed that, no significant difference was detected in acetic acid, propanoic acid and TVFA between groups. Furthermore, the grazing rates of rumen protozoa on bacteria were manipulated by the ratio of concentration to forage, and there were, 106.2 cells/(cell h),207 cells/(cell h),184.2 cells/(cell h),210.3 cells/(cell h) for A,B,C,D respectively. When the corresponding values expressed as bacteria-N were: 0.57 pg N/(cell h),1.178 pg N/(cell h),0.99 pg N/(cell h),1.1356 pg N/(cell h). Extrapolating the assimilation quantity of bacterial nitrogen by ciliates per day per capita, there were 27.53 mg N/(d capita);53.654 mg N/(d capita);47.74 mg N/(d capita);54.00 mg N/(d capita), or the bacterial protein were 0.172 g Pr/(d capita),0.3353 g Pr/(d capita),0.298g Pr/(d capita),0.341 g Pr/(d capita) respectively, with group D recording the highest bacterial protein recycling and turnover rates.In trial 2, the objectives of this part were to study the effect of yucca schidigera extract (YSE) on rumen fermentation parameters and ruminal nitrogen recycling under partial concentrate (forage) substrates. Under the same concentrate-to-forage-ratio substrates, the pH and NH3-N concentration decreased conrespendence with the concentration of yucca schidigera extract in the culture, whereas the propanoic acid increased with the concentration of yucca schidigera extract. Additionally, yucca schidigera extract led to an increase of bacterial density, and a decrease of protozoal density. It was further observed that, the grazing rates of rumen protozoa on bacteria were altered by yucca schidigera extract, and there were, 339.9cells/(cell h),314.7cells/(cell h),339.9cells/(cell h),233.4cells/(cell h),167.1 cells/ (cell h),199.8 cells/(cell h) for A,B,C,D,E,F, respectively. The results revealed yucca schidigera extract could decrease the grazing rates of rumen protozoa and the MCP recycling, either in the partial concentrate substrates, or the partial forage substrates, and the concentration of 0.035g/L was more effective than the concentration of 0.007g/L.