体外产气法比较不同活力屎肠球菌对绵羊瘤胃体外发酵的影响

Comparison of Effects of Enterococcus faecium with Different Activities on Rumen in Vitro Fermentation in Sheep Using in Vitro Gas Production Method

本试验旨在研究添加不同活力屎肠球菌对绵羊瘤胃体外发酵参数的影响,探索最适的体内添加水平。本试验采用体外产气法,设置对照组、试验1组、试验2组和试验3组,各组屎肠球菌活力分别为0(对照)、1×10^(12)、1×10^(11)和1×10^(10)CFU/mL,并分别培养3、6、12、24、48 h测定产气量,于24、48 h测定pH、干物质降解率、氨态氮(NH_(3)-N)和挥发性脂肪酸(VFA)浓度。结果表明:各试验组的产气量显著高于对照组(P<0.05);各组pH随着发酵时间增长呈下降趋势;干物质降解率随着发酵时间的增长逐渐增加,试验3组的干物质降解率在发酵24 h时显著高于对照组(P<0.05);各组NH_(3)-N浓度随着屎肠球菌活力的降低而增加,在发酵24 h时试验3组的NH_(3)-N浓度显著高于对照组(P<0.05);添加屎肠球菌显著提高乙酸、丙酸和总VFA浓度(P<0.05)。综上所述,通过各项指标分析比较,建议屎肠球菌在绵羊体内的添加活力为1×10^(10)CFU/mL。

This experiment was aimed to study the effects of adding Enterococcus faecium with different activities on the in vitro fermentation parameters of the rumen of sheep,and explore its optimal addition level in vivo.In this experiment,the control group,test group 1,test group 2 and test group 3 were set up by the in vitro gas production method.The activities of Enterococcus faecium were 0,1×10^(12),1×10^(11)and 1×10^(10)CFU/mL,respectively.They were cultured for 3,6,12,24 and 48 h to measure gas production,and pH,dry matter degradation rate,ammonia nitrogen(NH_(3)-N)and volatile fatty acids(VFA)concentrations were measured at 24 and 48 h.The results showed that the gas production of each group was significantly higher than that of the control group(P<0.05);the pH of each group showed a downward trend with the increase of fermentation time;the dry matter degradation rate gradually increased with fermentation time increase,and the dry matter degradation rate of test group 3 was significantly higher than that of the control group at fermentation 24 h(P<0.05);the NH_(3)-N concentration of each group increased with the decrease of activity;at fermentation 24 h,the NH_(3)-N concentration of test group 3 was significantly higher than that of the control group(P<0.05);adding Enterococcus faecium significantly increased the concentrations of acetic acid,propionic acid and total VFA(P<0.05).To sum up,through the analysis and comparison of various indicators,the optimal added activity of Enterococcus faecium is 1×10^(10)CFU/mL.