The Effects Of Yeast Culture On In Vitro Fermentation Of Rumen Microorganisms And The Metabolism Of Goat Rumen

The effects of Saccharomyces derevisiae yeast culture(Yea-Sacc1026,YC1), autoclaved Yea-Sacc1026(YC2) or Diamond-V XP(YC3) on the in in vitro batch fermentation of mixed rumen microorganisms was examined. In addition, experiments were performed to evaluate the effect of YC3 on the in vitro mixed ruminal microorganism fermentation with different condition. Furthermore, the effect of YC3 on the metabolism of goat rumen were investigated in vivo on the basis of high concentrate diet. This thesis was described in the following five experiments.In the first experiment, the effects of different yeast cultures on the fermentation of rumen microorganisms were investigated. The results showed that neither concentration of YC1 nor YC1 had any effect on final pH, NH3-N, TVFA and the acetate to propionate ratio, there was no effect of treatment and the kind of YC on lactate concentration. 1.5g/L and 2.25g/L of YC3 decreased the final pH or the acetate to propionate ratio and increased TVFA concentrations (P<0.05). Compared with the control, 2.25g/L of YC1 resulted in an increase(P<0.05)in the 12h cumulative gas production, 1.5g/ L and 2.25g/L of YC3 had the same effect. 2.25g/L of YC3 decreased significantly the NH3-N concentration compared with the control (P<0.05).In the second experiment, the thesis investigated mainly the effects of YC3 on the fermentation of mixed rumen microorganisms in vitro with different forages as the substrate. In the presence of all substrates, 2.25g/L of YC3 decreased significantly the final pH and lactate concentration (P<0.05), simultaneity, in vitro dry matter disappearance of all forages was increased (P<0.05). The cumulative gas production and NH3-N concentration were not different with treatment and the kind of substrate (P>0.05), 2.25g/L of YC3 increased acetate concentration (P<0.05) when alfalfa and hay were the substrates, and 1.5g/L and 2.25g/L of YC3 increased significantly propionate concentration for all substrates(P<0.05). 2.25g/L of YC3 decreased significantly the acetate to propionate ratio for all substrates...