Hsu J T, Fahey G C
Department of Animal Sciences, University of Illinois, Urbana 61801.
J Dairy Sci. 1990 Jan;73(1):149-52. doi: 10.3168/jds.S0022-0302(90)78658-4.
Triplicate ruminal samples from four rumen-cannulated defaunated sheep (50 kg BW) were used in a completely randomized design experiment with a 2 x 3 factorial arrangement of treatments to test effects of two pretreatments (fresh vs. freezing) and three centrifugation speeds (4640 x g for 30 min; 9820 x g for 20 min; 25,900 x g for 20 min) or quantity of ruminal bacteria harvested and composition of ruminal bacterial samples. There were no differences among centrifugation speeds on quantity of ruminal bacterial harvested, organic matter, total N, RNA, and diaminopimelic acid concentrations (% of DM), or RNA:N, RNA:organic matter, N:organic matter, and diaminopimelic acid:organic matter ratios. However, there were differences between fresh and frozen samples for all measurements except diaminopimelic acid concentration, and the diaminopimelic acid:organic matter ratio, suggesting that freezing ruminal fluid is not appropriate for obtaining truly representative bacterial samples.
来自四只安装有瘤胃瘘管的去原虫绵羊（体重50千克）的三份瘤胃样本，被用于一项完全随机设计实验，该实验采用2×3析因处理安排，以测试两种预处理方式（新鲜与冷冻）和三种离心速度（4640×g离心30分钟；9820×g离心20分钟；25900×g离心20分钟）对收获的瘤胃细菌数量和瘤胃细菌样本组成的影响。在收获的瘤胃细菌数量、有机物质、总氮、RNA和二氨基庚二酸浓度（占干物质的百分比），或RNA:氮、RNA:有机物质、氮:有机物质以及二氨基庚二酸:有机物质比率方面，离心速度之间没有差异。然而，除二氨基庚二酸浓度和二氨基庚二酸:有机物质比率外，新鲜样本和冷冻样本在所有测量指标上均存在差异，这表明冷冻瘤胃液不适用于获取真正具有代表性的细菌样本。
