Sun H, Wu Y M, Wang Y M, Liu J X, Myung K H
Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China ; Qilu University of Technology, Jinan, 250353, China .
Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China.
Asian-Australas J Anim Sci. 2014 Sep;27(9):1285-92. doi: 10.5713/ajas.2013.13742.
An in vitro experiment was conducted to evaluate the effects of Aspergillus oryzae culture (AOC) and 2-hydroxy-4-(methylthio)-butanoic acid (HMB) on rumen fermentation and microbial populations between different roughage sources. Two roughage sources (Chinese wild rye [CWR] vs corn silage [CS]) were assigned in a 2×3 factorial arrangement with HMB (0 or 15 mg) and AOC (0, 3, or 6 mg). Gas production (GP), microbial protein (MCP) and total volatile fatty acid (VFA) were increased in response to addition of HMB and AOC (p<0.01) for the two roughages. The HMB and AOC showed inconsistent effects on ammonia-N with different substrates. For CWR, neither HMB nor AOC had significant effect on molar proportion of individual VFA. For CS, acetate was increased (p = 0.02) and butyrate was decreased (p<0.01) by adding HMB and AOC. Increase of propionate was only occurred with AOC (p<0.01). Populations of protozoa (p≤0.03) and fungi (p≤0.02) of CWR were differently influenced by HMB and AOC. Percentages of F. succinogenes, R. albus, and R. flavefaciens (p<0.01) increased when AOC was added to CWR. For CS, HMB decreased the protozoa population (p = 0.01) and increased the populations of F. succinogenes and R. albus (p≤0.03). Populations of fungi, F. succinogenes (p = 0.02) and R. flavefacien (p = 0.03) were increased by adding AOC. The HMB×AOC interactions were noted in MCP, fungi and R. flavefacien for CWR and GP, ammonia-N, MCP, total VFA, propionate, acetate/propionate (A/P) and R. albus for CS. It is inferred that addition of HMB and AOC could influence rumen fermentation of forages by increasing the number of rumen microbes.
进行了一项体外实验，以评估米曲霉培养物（AOC）和2-羟基-4-（甲硫基）-丁酸（HMB）对不同粗饲料来源之间瘤胃发酵和微生物种群的影响。两种粗饲料来源（中华野麦[CWR]与玉米青贮[CS]）采用2×3析因设计，分别添加HMB（0或15毫克）和AOC（0、3或6毫克）。添加HMB和AOC后，两种粗饲料的产气量（GP）、微生物蛋白（MCP）和总挥发性脂肪酸（VFA）均增加（p<0.01）。HMB和AOC对不同底物的氨氮影响不一致。对于CWR，HMB和AOC对单个VFA的摩尔比例均无显著影响。对于CS，添加HMB和AOC后，乙酸增加（p = 0.02），丁酸减少（p<0.01）。仅添加AOC时丙酸增加（p<0.01）。CWR的原生动物（p≤0.03）和真菌（p≤0.02）种群受HMB和AOC的影响不同。向CWR中添加AOC时，琥珀酸丝状杆菌、白色瘤胃球菌和黄色瘤胃球菌的百分比增加（p<0.01）。对于CS，HMB减少了原生动物种群（p = 0.01），增加了琥珀酸丝状杆菌和白色瘤胃球菌的种群（p≤0.03）。添加AOC增加了真菌、琥珀酸丝状杆菌（p = 0.02）和黄色瘤胃球菌（p = 0.03）的种群。在CWR的MCP、真菌和黄色瘤胃球菌以及CS的GP、氨氮、MCP、总VFA、丙酸、乙酸/丙酸（A/P）和白色瘤胃球菌中发现了HMB×AOC相互作用。据推测，添加HMB和AOC可通过增加瘤胃微生物数量来影响草料的瘤胃发酵。
