Development Of A Novel Dual-flow Rumen Simulate System And Research Of Operation Parameters

A novel dual-flow continuous culture rumen simulating system by auto controlled was designed in present study. A series of experiments were conducted to test the instrutment performance, analyze the change of fermentation parameters with different dilution rate, and compare the feed digestion between continuous culture rumen simulating stystem and nylon bag.First, the working principle and structure of novel continuous culture rumen simulating system was researched on the bases of structure and performance for all the continuous culture system all over the world. The novel dual-flow continuous culture rumen simulating system combined with the performance of rumen in ruminant contains fermenter, mixing device, and liquid, solid and gas discharge device. The first component is the fermenter which is the key point of design. The other four components includ stirring shaft, liqiud over-flowing apparatus, solid chyme discharging and gas exhausting apparatus. Furthermore these five components were organized in the final design. The typic characteristics of the system are exhausting gas with differential pressure switch, discharging solid chyme with sieving and over-flowing liquid in closed condition.Second, based on the stability of embeded system, the expansibility of DCS and the flexibility in use and operation of upper management computer, the auto control model was conducted. A set of auto control system of the continuous culture system based on DCS and embeded system was designed. The hardware of the direct and supervisory control layer was produced. Furthermore the software of the upper management computer, the dirrect and supervisory control layer was programed.Third, a comprehensive test for this novel dual-flow continuous culture system was conducted in present study. The results demonstrated there was4days adaptation and the system would be stabled from the5th days incubation to the last day. The results during the experiment period shown that there were parallelism among four fermenters, and most parameters for four fermenters were similar to the animal, so the system is a effective equipment to simulate the rumen fermentation. Compared with the currently continuous culture system, it was effective to solve problem for the solid chyme accumulation in fermenter, and it was a combination with the batch culture (in vitro gas production) and continuous culture system.Fourth, the effect of dilution rate on the rumen fermentation was conducted in order to evaluate the stable of present system.The results shown that:the fluctuation of the fermenter during adapation and sampling period were very small no matter how dilution rate it was; the pH and NH3-N concentration in rumen fluid were significant increasing following by the increase of dilution rate from8%/h to12%/h, but the VFA were decreased. There were no differ for the ratio of acetate and propionate; The digestibility of DM, OM, CP, and NDF shown a little decrease, but there were no difference for the treatment of dilution rate.The digestibility of EE, protozoal number, enzyme for cellulose and strarch degradation, and microbial protein were not affected by the dilution rate.Fifth, the technology of nylon bag was used to evaluate the nutrition of same feed which was also used in present system. The digestibilty of feed in continuous cultures sytem were coincided with the value of feed in nylon bag, and there were no differfor both way.