This experiment aimed to investigate rumen fermentation characteristics, microbial protein concen-tration and gas production parameters of sheep under the different levels of metabolic glucose through the in vitro artificial rumen fermentation. A single factor experiment design with 4 metabolic glucose levels [ 125 ( A) , 138 ( B) , 153 ( C) and 168 g/kg( D) ] was adopted. Culture medium of 2 mL was collected for analysis at 0, 2, 4, 6, 8, 12 and 24 hours, respectively. The results showed as follows:1) with the increas-ing of metabolic glucose level, the pH of culture medium was significantly decreased at 8 to 24 h ( P<0.05 or P<0.01); at 2 h, the ammonia nitrogen concentration of group D was significantly higher than that of group A ( P<0.05) , while at 6 h, the concentration of group A was significantly higher than that of the other three groups ( P<0.05) . 2) The bacterial protein concentration at 6 h of group D was significantly higher than that of group A ( P<0.05); with the increasing of metabolic glucose level, the concentrations of propionic acid, bu-tyric acid and total volatile fatty acids were increased in general, while acetate/propionate was decreased. 3) With the increasing of metabolic glucose level, the theological maximum gas production and reaching time of 1/2 of the theological maximum gas production were significantly reduced ( P<0.01); the potential gas pro-duction has no significant change ( P>0.05); the 24 h gas production and the constant of gas production rate were significantly decreased and increased ( P<0.05 or P<0.01) , respectively. The results indicate that the in-creasing of metabolic glucose level can improve the concentrations of propionic acid and total volatile fatty acids, meanwhile, can provide more sugar precursors for the sheep.%本试验旨在通过人工瘤胃体外培养,研究不同代谢葡萄糖水平下的绵羊瘤胃发酵特性、微生物蛋白质浓度和产气参数。采用单因子试验设计,共设计4个代谢葡萄糖水平[125( A)、138( B)、153( C)、168 g/kg( D)]。体外试验所用瘤胃液采自4只安装有永久性瘤胃瘘管的绵羊。分别于培养0、2、4、6、8、12、24 h采集2 mL培养液用于分析。结果表明：1)8~24 h培养液pH随着代谢葡萄糖水平的提高而出现显著或极显著下降( P<0.05或P<0.01)；氨氮浓度在2 h时D组显著高于A组( P<0.05),而在6 h时A组显著高于其他3组( P<0.05)。2) D组6 h培养液细菌蛋白浓度显著高于A组( P<0.05)；随着代谢葡萄糖水平的提高,培养液丙酸、丁酸、总挥发性脂肪酸的浓度总体呈升高趋势,乙酸/丙酸呈下降趋势。3)随着代谢葡萄糖水平的提高,理论最大产气量极显著降低(P<0.01),达1/2理论最大产气量的时间极显著缩短(P<0.01)；潜在产气量无显著变化(P>0.05),24 h产气量和产气速率常数分别显著或极显著下降和上升( P<0.05或P<0.01)。结果提示,提高代谢葡萄糖水平,可以提高丙酸、总挥发性脂肪酸的浓度,同时可为绵羊提供较多的生糖前体物质。
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