黄芪茎叶粉对肉牛体外瘤胃发酵参数、产气量及干物质消化率的影响

Effect of Astragalus Membranaceus Straw on Cattle Rumen Digestion In Vitro

[目的]采用人工瘤胃法研究黄芪茎叶粉对肉牛体外瘤胃发酵参数、产气量及干物质消化率的影响,以期为黄芪茎叶粉在反刍动物生产中的应用提供理论参考。[方法]试验分为玉米秸秆对照组(CON组)和黄芪组(AM组)两个处理,每组3个重复,分别于发酵的不同时间点(0、1、2、3、4、5、6、7、8、10、12、14、16、20、24、28、32、36、40、44、48、56、64、72 h)记录两组的产气量,并在发酵72 h后终止发酵,测定发酵液的pH、氨态氮、挥发性脂肪酸和干物质消化率的变化。[结果]1)黄芪茎叶粉极显著降低了瘤胃发酵各时间点的产气量和理论最大产气量,但提高了发酵的产气速率(P<0.01);2)黄芪茎叶粉显著提高了瘤胃挥发性脂肪酸中乙酸的含量和乙酸/丙酸比值(P<0.01),降低了氨态氮、总挥发性脂肪酸、丙酸和丁酸含量(P<0.05);3)黄芪茎叶粉对瘤胃p H和干物质消化率没有显著影响(P>0.05)。[结论]黄芪茎叶粉降低了瘤胃总产气量,对于促进瘤胃乙酸型发酵具有一定调控作用,具有作为反刍动物饲料和饲料添加剂应用的潜力。

【Objective】Effect of Astragalus membranaceus straw on in vitro rumen digestion of cattle was investigated to determine the applicability of Astragalus membranaceus straw in ruminant feed.【Methods】An experiment was divided into two groups of corn stalk meal(CON group)and Astragalus membranaceus straw meal(AM group)with three repeats per group.Gas production in the in vitro fermentation at 0,1,2,3,4,5,6,7,8,10,12,14,16,20,24,28,32,36,40,44,48,56,64,and 72 h were monitored.At 72 h,the terminal pH and contents of ammonia nitrogen,volatile fatty acids,and dry matters digestibility were measured.【Results】(1)In AM group,the amounts of gas production at all sampling points during the fermentation were significantly reduced but the gas production rate was increased(P<0.01).(2)In AM group,the acetic acid content and the acetic acid to propionic acid ratio were significantly higher(P<0.01),but the contents of ammonia nitrogen,total volatile fatty acid,propionic acid and butyric acid were lowered significantly(P<0.05).(3)No significant differences on pH and dry matter digestibility were observed between CON and AM(P>0.05).【Conclusion】Astragalus membranaceus straw decreased the total rumen gas production,and had a certain regulatory effect on rumen acetic acid fermentation,which indicated Astragalus membranaceus straw had the potential to be used as feed and feed additive for ruminants.