模拟羊瘤胃内环境条件,采用瘤胃液体外发酵技术,在发酵底物中添加不同质量分数的尿素,测定发酵过程pH、甲烷(CH4)、挥发性脂肪酸(VFA)体积分数和产气量.结果表明:瘤胃发酵液pH随饲料添加尿素质量分数的增加而增加；甲烷体积分数随尿素质量分数增加呈降低趋势；尿素质量分数可明显影响瘤胃发酵液的产气量和VFA体积分数；20和30 g/kg的尿素添加水平可提高发酵液的产气量和VFA产量,40和50 g/kg的尿素添加水平抑制产气量和VFA的产量.可见,适宜的尿素添加量可促进瘤胃微生物的发酵过程.%Using rumen fluid fermentation technology in vitro, an experiment was conducted to determine pH, volatile fatty acid (VFA) and Gas-production produced by rumen fermentation fluid after adding different amount of urea as substrate to feed under the similar sheep rumen environment condition. The results showed that: Urea added in feed as substrate could increase pH in the liquid of rumen fermentation. At the same time, pH in rumen fermentation fluid increased constantly as increasing urea concentration. Urea added to feed as substrate could significantly affect gas-production and VFA volume fraction in the liquid of rumen fermentation. The gas-production and VFA volume fraction were improved significantly by adding 20 or 30 g/kg urea to feed in the liquid of rumen fermentation, but that figures were decreased significantly by adding 40 or 50 g/kg urea to feed. These results suggest that a suitable urea addition to feed is beneficial for improving rumen fluid fermentation.
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