| The focus of the article was to introduced the design and manufacture of a novel dual flow continuous culture automation system for simulate rumen. Providing a usefull equipment for the research of rumen fermention.The system was based on Rusitec (Czerkawski, 1977) and CC(Hoover, 1976), we evaluated their ability in order to fit the true rumen environment. The majoy improvement included: (a) moved the overflow port from side wall of fermenter to the buttom, it can excret chyme selectively which had fermented completely; (b) accurately measured the volume of gas procduced in the fermenter by sensors; (c) improved the blade to increase the agitation efficiency; (d) monitor the parameters of fermenter environment in real time; (e) applyed the automatic control technology in the system, operated the equipment by computer, made it easy to operate, saved labour.Designed two experiment to validate the characters of the system: one is system stability test, the other is rumen simulation experiment.Experiment one: system stability test. The purpose was to check out system stability in a long term work, and the parallelism of 4 fermenters. Adding same ration to the 4 fermenters, the rumen fluid donors were three Holstein cows in mid-lactation which installed three sites permanent fistula. In sampling phase, at morning feeding and 4,8,12,16,20h after feeding collected the liquid and solid sample. Collected the datas of pH and temperature in all experiment term by PC, measured the VFA value of samples.The temperature of 4 fermenters was 39.00±0.06℃, 39.03±0.04℃, 39.00±0.04℃, 38.99±0.02℃respectively. It can be find that the temperature of 4 fermenters maintain in the range±0.1℃in all term. The correlation coefficient among 4 fermenters was 1.000, complete correlation. The pH value of 4 fermenters was 6.21±0.11, 6.19±0.15, 6.18±0.10, 6.24±0.11 respectively. The correlation among 4 fermenters'pH value was very significant. The VFA value of 4 fermenters was 107.30±11.81mmol/L, 108.20±12.15 mmol/L, 107.97±11.82 mmol/L, 107.86±11.22 mmol/L. All the correlation coefficient among 4 fermenters was larger than 0.9. These datas show that the effect of 4 fermenters was same, they can keep parallelism in 8 days.Experiment two: rumen simulation experiment. The purpose of the present study was to examine the effect of different concent ration of Bacillus subtilis natto on ruminal microbial fermentation in persistent artificial rumen system. Experimental conditions was same with experiment one. Three groups, including control group, treatment 1 group supplied 1×106mL-1 Bacillus subtilis natto of fermenter capacity and treatment 2 group supplied 1×107mL-1 Bacillus subtilis natto of fermenter capacity were employed. Experiment term was 7 days, first 5days as stationary pHase, last 3 days as sampling pHase. When adding ration at 8:00, supplied solid fermentation product to the wanted level. In sampling pHase, at morning feeding and 2,6,10,16,24h after feeding collected the liquid and solid sample. Measuring the parameters of liquid, include pH value, NH3-N, TVFA and MCP.It was showed from the result that pH value had trend to increase when adding Bacillus subtilis natto. The pH value of control group and 2 treatment group was 6.28±0.18, 6.43±0.10, 6.43±0.09 respectively, but the different between control group and 2 treatment group was not significantly. Bacillus subtilis natto had negative function to rumen microorganism nitrogen metabolism, it lead to increase concentration of NH3-N in rumen. The NH3-N concentration of control group and 2 treatment group was 17.91±6.44mg/L, 18.82±5.85 mg/L, 21.87±4.65 mg/L respectively. MCP value was low, they were 6.13±1.04 mg/L, 4.84±1.45 mg/L, 5.37±1.08 mg/L respectively. It may be the result of reproduction of rumen protozoa. Bacillus subtilis natto increased the content of TVFA to 97.35±19.92 mmol/L, 103.25±21.60 mmol/L, 104.03±21.10 mmol/L respectively. It confirmed the ability of rumen microorganism to digest carbohydrate.
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