Study On Rumen Fermentation By Dual-flow Continuous Culture System And The Application Of Artificial Rumen

The study was conducted to investigate the effects of different quantities and frequencies of feeding and dilution rates on the artificial ruminal fermentation by dual-flow continuous culture system (DFCCS) to discuss its feasible working conditions. RPMet was made with different proportion of grease and DL-Met, and its releasing rate was studied by DFCCS and rumen nylon-bag method. From this way, the releasing rates of RPMet in vitro can be educed. In another way, the correlation degrees of ruminal fermentation between DFCCS and animals can be made by discussing the effect of ruminal fermentation with feeding different methionine.With the increasing of feeding quantities, the pH was significantly decreased (P < 0.05) and NH3-N has evident improved (P < 0.05). With the decreasing of feeding frequencies, the pH of rumen fluid was obviously decreased (P < 0.05).When improving the dilution rates of DFCCS, the pH,NH3-N and the molar percentage of propionic acid should be increased (P < 0.05) obviously. But the ratio of PA/AA and the disappearance rates of nutrients were significantly decreased (P < 0.05).At this diet condition the feasible feeding quantities was 48g/d,and it should be fed every one hour a time. The appropriate LDR was 12%/h,and the appropriate SDR was 4%/h.The releasing rates of RPMet were significantly lower than that of DL-Met (P < 0.05) ;the proportions of the appended grease had significant affection (P < 0.05) on the stability of RPMet. Different RPMet had similar degradable trend when in the DFCCS and in the rumen and it was sample and stable when the releasing rates were determined with DFCCS. A regression equations for the releasing rates of incubation times of RPMet between using DFCCS and rumen nylon-bag method were established. So DFCCS is a feasible method to assess the stability of RPAA.There was a close correlation of ruminal fermentation indexs between DFCCS and animals. The disappearance rates of nutrients in vitro were lowerthan in vivo. Discussed the changes of the AA profiles between diets and artificial rumen chyme appended DL-Met, Glu and Ala had higher AA concentration (P< 0.05) in the artificial rumen chyme. On the contrary, Lys, His, Asp and Pro had lower AA concentration (P < 0.05) .Compared with artificial rumen chyme appended RPMet, Val, Glu and Ala had higher AA concentration (P < 0.05) in the disposals of appended RPMet. In the other way, His and Asp had lower AA concentration (/)<0.05) .