Weimer P J, Waghorn G C, Odt C L, Mertens D R
US Dairy Forage Research Center, USDA-ABS, University of Wisconsin, Madison 53706, USA.
J Dairy Sci. 1999 Jan;82(1):122-34. doi: 10.3168/jds.S0022-0302(99)75216-1.
The effects of four contrasting diets were determined on populations of three species of ruminal cellulolytic bacteria (Ruminococcus albus, Ruminococcus flavefaciens, and Fibrobacter succinogenes) using oligonucleotide probes to rRNA. Diets based on alfalfa silage or corn silage as the primary fiber source were formulated to contain either 24 or 32% neutral detergent fiber measured after alpha-amylase treatment. The diets were fed twice daily to four ruminally fistulated, lactating Holstein cows in a trial using a Latin square design. The cows fed the alfalfa silage diets had higher dry matter intakes and milk production and smaller pH fluctuations than did cows fed the corn silage diets (0.3 vs. 0.8 units). The total populations of the three cellulolytic species at 3 h after feeding ranged from 0.3 to 3.9% of the bacterial domain; R. albus was generally the most abundant of the three species. The data are in general agreement with population assessments obtained by some traditional methods of culture enumeration. Although diet and individual cows had major effects on ruminal pH and volatile fatty acid concentrations and on milk production and composition, differences in cellulolytic populations that were attributable to individual cows were larger than those attributable to diet, suggesting that each cow maintained a unique assemblage of cellulolytic species.
利用针对rRNA的寡核苷酸探针，研究了四种不同日粮对三种瘤胃纤维素分解菌（白色瘤胃球菌、黄色瘤胃球菌和琥珀酸纤维杆菌）数量的影响。以苜蓿青贮或玉米青贮作为主要纤维来源的日粮，经α-淀粉酶处理后，中性洗涤纤维含量分别设定为24%或32%。在一项采用拉丁方设计的试验中，将这些日粮每天分两次喂给四头装有瘤胃瘘管的泌乳荷斯坦奶牛。与饲喂玉米青贮日粮的奶牛相比，饲喂苜蓿青贮日粮的奶牛干物质采食量和产奶量更高，pH波动更小（分别为0.3个单位和0.8个单位）。采食后3小时，三种纤维素分解菌的总数占细菌总数的0.3%至3.9%；白色瘤胃球菌通常是这三种菌中数量最多的。这些数据与一些传统培养计数方法得出的数量评估结果基本一致。尽管日粮和个体奶牛对瘤胃pH值、挥发性脂肪酸浓度以及产奶量和组成有重大影响，但个体奶牛导致的纤维素分解菌数量差异大于日粮导致的差异，这表明每头奶牛都维持着独特的纤维素分解菌组合。
