| The present research was conducted to investigate influence of saponins on variety of rumen microbes and fibre digestibilities. By measuring the ruminal fermentation products and comparing the effects of different saponins (Tea saponins, Yucca schidigera extract and their mixtures), the proper adding amount of saponins was estabilished; By using different concentrate / forage ratios and adding mixtures of Tea saponins and Yucca schidigera extract, the effects of saponins on rumen fermentation, rumen microbes and gas production had been researched in vitro; Furthermore goats fisted with cannulas were used to investigate the effects of Tea saponins, Yucca schidigera extract and their mixtures on rumen fermentation, activities of relative fibrolytic enzymes and digestibilities of fibre in the rumen. The main results showed as follows:1. The effects of different saponins on the protozoa populations and the total protozoa counts with the same ration included 0.6g corn, 0.12g soybean meal and 1.08g Chinese hay had been researched in vitro. Inclusion of different level of saponins inhibited the protozoa growth while the populations of the protozoa had changed, for example Entodinium decreased whereas Diplodinium increased, the group with 0.6% Tea saponins and 0.03% Yucca schidigera extract had significant effect on protozoa populations compare with control group respectively. The groups with the saponin mixtures had the same trend. The combined effect shows that the mixture with 0.3% Tea saponins and 0.03% Yucca schidigera extract was seem to be an optimal amount.2. The experiment was designed to explore the effect of saponins and different concentrate/forage ratios on rumen fermentation and rumen microbes, a 2×4 two factorial design of experiment was adopted: one factor was adding saponins or not(0.3% tea saponin and 0.03% Yucca schidigera extract), the other was four different concentrate/forage ratios (20:80,40:60,50:50,60:40). The results showed that the mixed saponins reduced pH and the group whose concentrate/forage ratio was 20:80 had significant effect (P<0.05). Concentrations of acetate, propionate, butyrate and total VFAs were increased by addition of the mixed saponins, however, from the molar ratio of VFAs it was found that the proportion of propionate and butyrate were decreased while the proportion of propionate was increased, so the acetate/propionate ratio descended. The mixed saponins increased ruminal bacterial protein yield whereas the yield of ruminal protozoal protein was decreased, and the ratio of bacterial protein/ protozoal protein was significantly increased (P<0.05), compare with the control group. The relative amount of Fibrobacter succinogenes was extremely higher by addition of the mixed saponins whose concentrate/forage ratio was not 20:80. And the mixed saponins increased the relative amount of Ruminococcus flavefaciens and Ruminococcus albus except that the concentrate/forage ratio was 40:60.3. The results of gas productin in vitro had showed that the mixture of Tea saponins and Yucca schidigera extract accelerated the rumen fermentation and increased the gas production. The gas productions in saponin groups whose concentrate/forage ratio was not 50:50 were 0.8, 6.3 and 1.7 mL higher than the control group, the effects were not significant (P>0.05), extreme (P<0.01)and significant (P<0.05) respectively.4. The objectives of this study were to investigate effects of adding different saponins on fibre digestibilities and activities of relative fibrolytic enzymes in the rumen. Four Xuhuai goats fitted with rumen cannula were used in a 4×4 Latin square design,and saponins were added into four groups at different levels against the dietary: 0 (C),tea saponin 0.6% (T), Yucca schidigera extract 0.03%(Y) and tea saponin 0.3% + Yucca schidigera extract 0.03% (TY). The result showed that activities of three relative fibrolytic enzymes in groups with spanonins were significantly (P<0.05) or not significantly (P>0.05) higher than the control group, except the activity of cellulase in group Y. The mean digestibilities of DM in group T and Y were lower than the control group but the effect was not significant (P>0.05). While the mean digestibilities of DM in group TY was significantly higher than the control group (P<0.05). The mean digestibilities of NDF in group Y was significantly higher than the control group (P<0.05), in other spanonin groups the mean digestibilities of NDF and ADF had an increasing trend but the effect was not significant (P>0.05).
|
PDF Full Text Request