水牛唾液对瘤胃消化代谢影响的体外试验研究

从6头装有瘤胃瘘管的公水牛收集瘤胃液和唾液，加干草粉作底物，进行体外厌氧培养。每隔2h采样测pH、挥发性脂肪酸（VFA）、氨氮（NH3－N）、微生物粗蛋白（MCP），并在培养结束后测干物质（DM）和酸性洗涤纤维（ADF）消失率。结果显示，与人工唾液相比，唾液使草粉DM和ADF消失率分别提高17．95％（P＜0．01）和15．30％（P＜0．01）；培养液中MCP、NH3－N、总挥发性脂肪酸（TVFA）分别增加9．16％（P＞0．05），12．24％（P＞0．05）和10．54％（P＜0．05），乙酸和丙酸比例及pH无明显差异。上述结果表明，体外培养条件下，唾液能明显促进瘤胃微生物消化DM和ADF产生VFA，并有促进MCP合成和NH3－N产生的趋势。

Effect of buffalo saliva on rumen digestion and metabolism in vitro

Rumen fluid from six male buffalo with rumen catheter was incubated in anaerobic media to which 20% saliva was added at 39 ℃in vitro with 1.00 g dry hay powders as the substrate.Samples were collected every 2 h to determine the pH,VFA,NH3-N and MCP(microbial crude protein).At the end of culture,substrate was recycled to measure the disappearance rate of general DM and ADF.Compared with artificial saliva,the saliva contained the same protein level and pH,the clearance rate of DM was increased by 17.95%(P＜0.01)and ADF by 15.30%(P＜0.01).MCP,NH3-N and TVFA were enhanced by 9.16%(P＞0.05)，14.24%(P＞0.05)and 10.54%(P＜0.05)，respectively.There were no significant difference both saliva in acetic acid,propionic acid and pH.Results demonstrated that in vitro,saliva promoted significantly digestion of DM and ADF and production of VFA as well as had the potential to increase MCP synthesis and NH3-N release.Saliva played important role in digestion and metabolism of rumen microbes.