瘤胃持续模拟技术的研究

本研究包括瘤胃持续模拟装置(RSI)的设计和RSI稳定性与模拟效果的研究两部分。RSI由发酵系统、温度控制系统、搅拌系统和样品收集系统组成,核心是6个发酵罐。以6头瘘管牛为对照,用精粗比为1:1的日粮研究了RSI的稳定性和模拟效果。结果表明,RSI的NH_3-N浓度、TVFA浓度、pH和每天产气量的变异系数都小于7％;当外流速度和固体颗粒控制孔径增加时NH_3-N浓度和TVFA浓度下降,pH值上升;而喂料量增加则有相反的结果。当RSI的外流速度为1.36ml/min、控制孔径1.5mm和喂料量30g/d时,发酵罐内的NH_2-N浓度、TVFA浓度和pH值与牛瘤胃液的测定值最接近(P>0.05),各种挥发性脂肪酸的比例也没有显著差异(P>0.05)。

STUDY ON RUMEN SIMULATION TECHNIQUE

In the present study,a rumen simulation instrument (RSI) with six fermentation vessels was designed.The RSI consists of fermentation,temperature contol,stirring and sampling systems.The stability and effect of simulation of the RSI were studied with six bulls with rumen cannulea as control.The results showed that all coefficients of variation(C.V.%) were less than 7% for values of NH3-N,TVFA and pH in the fermentation vessels.With increases of outflow rates and particle control sizes,the concentrations of NH3 - N and TVFA decreased,pH values rose,but with increase of feed input,the concentrations of NH3 - N and TVFA increased,pH values decreased.Under outflow rate 1.36ml/min,particle control size 1.5mm and feed input 30g/d,the concentrations of NH3-N,TVFA and pH value obtained from RSI.were closest to the in vivo values were(10.91 vs 11.10 mg/100ml,10.23 vs 10.46mmol/100ml and 6.93 vs 6.88,respectively),and there were no significant differences in proprotions of various VFAs between the RSI anc! in vivo values(P >0.05).Fermentation gas in the vessels in RSI can be exactly collected ana measured.