摘要
Twenty ruminally cannulated beef heifers were fed a high corn grain diet in a randomized block design to determine the effect of three direct fed microbial (DFM) strains of Propionibacterium on ruminal fermentation, nutrient digestibility and methane (CH4) emissions. The heifers were blocked in five groups on the basis of BW and used in five 28-day periods. Dietary treatments included (1) Control and three strains of Propionibacterium (2) P169, (3) P5, and (4) P54. Strains were administered directly into the rumen at 5×109 CFU with 10 g of a maltodextrin carrier in a gel capsule; Control heifers received carrier only. All heifers were fed the basal diet (10 : 90 forage to concentrate, dry matter basis). Rumen contents were collected on days 15 and 18, ruminal pH was measured continuously between days 15 and 22, enteric CH4 emissions were measured between days 19 and 22 and diet digestibility was measured from days 25 to 28. Mean ruminal pH was 5.91 and was not affected by treatments. Similarly, duration of time that pH4 production (g/day) was not affected by Propionibacterium strains and averaged 139 g/day. Similarly, mean CH4 yield (g CH4/kg of dry matter intake) was similar for all the treatments. The relative abundance of total Propionibacteria in the rumen increased with administration of DFM and were greater 3 h post-dosing relative to Control, but returned to baseline levels before feeding. Populations of Propionibacterium P169 were higher at 3 and 9 h as compared with the levels at 0 h. In conclusion, moderate persistency of the inoculated strains within the ruminal microbiome and pre-existing high propionate production due to elevated levels of starch fermentation might have reduced the efficacy of Propionibacterium strains to increase molar proportion of propionate and subsequently reduce CH4 emissions.
摘要译文
在随机区组设计中饲喂20个瘤胃插管的牛用小母牛，以确定三种直接饲喂微生物（DFM）丙酸杆菌菌株对瘤胃发酵，营养物质消化率和甲烷（CH4）排放的影响。小母牛在BW的基础上被分成五组，并在五个28天的时间段内使用。膳食处理包括（1）对照和三种丙酸杆菌属菌株（2）P169，（3）P5和（4）P54。将菌株以5×10 9 CFU直接施用于瘤胃中，其中10g麦芽糖糊精载体在凝胶胶囊中;控制小母牛只接受承运人。给所有小母牛喂食基础日粮（10：90饲料以浓缩，干物质为基础）。在第15天和第18天收集瘤胃内容物，在第15天和第22天之间连续测量瘤胃pH，在第19天和第22天之间测量肠道CH4排放，并且从第25天到第28天测量饮食消化率。平均瘤胃pH为5.91并且不是受到治疗的影响。类似地，pH4产生（g /天）不受丙酸杆菌菌株影响并且平均为139g /天的持续时间。类似地，所有处理的平均CH4产量（g CH4 / kg干物质摄入）相似。瘤胃中总丙酸杆菌的相对丰度随着给予DFM而增加，并且相对于对照在给药后3小时更大，但在进食前回到基线水平。与0小时的水平相比，丙酸杆菌P169的群体在3小时和9小时时更高。总之，由于淀粉发酵水平升高，瘤胃微生物组内接种菌株的适度持续性和预先存在的高丙酸盐产生可能降低了丙酸杆菌菌株增加丙酸盐摩尔比例并随后减少CH4排放的功效。
D. Vyas (a1); E. J. McGeough (a1); R. Mohammed (a1); S. M. McGinn (a1); T. A. McAllister (a1);K. A. Beauchemin (a1).... Effects of Propionibacterium strains on ruminal fermentation, nutrient digestibility and methane emissions in beef cattle fed a corn grain finishing diet[J]. animal, 2014,8(11): 1807-1815