Department of Animal Sciences, Group Animal Nutrition, Technische Universität München, Freising-Weihenstephan, Germany Physiology Weihenstephan, Technische Universität München, Freising-Weihenstephan, Germany.
J Anim Physiol Anim Nutr (Berl). 2013 Dec;97(6):1104-13. doi: 10.1111/jpn.12020. Epub 2012 Dec 7.
The effects of non-starch-polysaccharide-degrading enzymes, added to a maize silage- and grass silage-based total mixed ration (TMR) at least 14 h before feeding, on the rumen bacterial population were investigated. Six non-lactating Holstein Friesian cows were allocated to three treatment groups using a duplicate 3 × 3 Latin square design with three 31-day periods (29 days of adaptation and 2 days of sampling). Treatments were control TMR [69% forage and 31% concentrates on a dry matter (DM) basis] or TMR with 13.8 or 27.7 ml/kg of feed DM of Roxazyme G2 liquid with activities (U/ml enzyme preparation) of xylanase 260 000, β-glucanase 180 000 and cellulase 8000 (DSM Nutritional Products, Basel, Switzerland). The concentrations of 16S rDNA of Anaerovibrio lipolytica, Fibrobacter succinogenes, Prevotella ruminicola, Ruminococcus flavefaciens, Selenomonas ruminantium and Treponema bryantii, and their relative percentage of total bacteria in rumen samples obtained before feeding and 3 and 7 h after feeding and from two rumen fractions were determined using real-time PCR. Sampling time had only little influence, but bacterial numbers and the composition of the population differed between the transition layer between rumen fluid and the fibre mat (fraction A) and the rumen fluid (fraction B) highlighting the importance to standardize sampling. The 16S rDNA copies of total bacteria and the six bacterial species as well as the population composition were mainly unaffected by the high levels of exogenous enzymes supplemented at all sampling times and in both rumen fractions. Occasionally, the percentages of the non-fibrolytic species P. ruminicola and A. lipolytica changed in response to enzyme supplementation. Some increases in the potential degradability of the diet and decreases in lag time which occurred collaterally indicate that other factors than changes in numbers of non-particle-associated bacteria are mainly responsible for the effects of exogenous enzymes.
在饲喂前至少 14 小时向基于玉米青贮和草青贮的全混合日粮（TMR）中添加非淀粉多糖降解酶，研究其对瘤胃细菌种群的影响。采用三重复 3×3 拉丁方设计，将 6 头非泌乳荷斯坦弗里生奶牛分配到 3 个处理组，共 31 天（29 天适应期和 2 天采样期）。处理组为对照 TMR（干物质基础上 69%饲草和 31%精料）或 TMR 添加 13.8 或 27.7ml/kg 饲料 DM 的 Roxazyme G2 液体，其木聚糖酶活性（U/ml 酶制剂）为 260000、β-葡聚糖酶 180000 和纤维素酶 8000（DSM 营养产品，巴塞尔，瑞士）。使用实时 PCR 测定饲喂前和饲喂后 3 和 7 小时以及两个瘤胃级分中瘤胃液和纤维垫之间的过渡层（级分 A）和瘤胃液（级分 B）中 Anaerovibrio lipolytica、Fibrobacter succinogenes、Prevotella ruminicola、Ruminococcus flavefaciens、Selenomonas ruminantium 和 Treponema bryantii 的 16S rDNA 浓度及其在总细菌中的相对百分比。采样时间的影响很小，但过渡层（级分 A）和瘤胃液（级分 B）之间的细菌数量和种群组成存在差异，突出了标准化采样的重要性。在所有采样时间和两个瘤胃级分中，高水平外源酶补充对总细菌和 6 种细菌的 16S rDNA 拷贝以及种群组成的影响主要不受影响。偶尔，非纤维分解物种 P. ruminicola 和 A. lipolytica 的百分比会因酶补充而发生变化。一些日粮潜在可降解性的增加和滞后时间的减少表明，除了与非颗粒相关细菌数量的变化之外，其他因素主要负责外源酶的作用。
