Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
Anaerobe. 2013 Apr;20:65-73. doi: 10.1016/j.anaerobe.2013.02.005. Epub 2013 Mar 5.
High grain feeding has been associated with ruminal pH depression and microbial dysbiosis in cattle. Yet, the impact of high grain feeding on the caprine rumen and hindgut microbial community and lipopolysaccharide (LPS) release is largely unknown. Therefore, the objective was to investigate the effect of increasing dietary levels of barley grain on the microbial composition and LPS concentrations in the rumen and colon of goats. Effects were compared with respect to the responses of ruminal and colonic pH and short-chain fatty acid (SCFA) generation. Growing goats (n = 5-6) were fed diets containing 0, 30, or 60% coarsely ground barley grain for 6 weeks. Ruminal ciliate protozoa were counted with Bürker counting chamber, and quantitative PCR was used to compare bacterial populations. Increasing dietary grain level linearly increased (P < 0.05) ruminal numbers of entodiniomorphids. With the 60% grain diet, there was a reduction in ruminal abundance of the genus Prevotella and Fibrobacter succinogenes, whereas the ruminal abundance of Lactobacillus spp. increased compared to the 0 and 30% grain diets (P < 0.05). In the colon, abundance of the genus Prevotella and F. succinogenes increased (P < 0.05) in goats fed the 60% grain diet compared to those fed the other diets. Colonic abundance of Clostridium cluster I was related to the presence of grain in the diet. Ruminal LPS concentration decreased (P < 0.05) in response to the 60% grain diet, whereas its colonic concentration increased in response to the same diet (P < 0.05). Present results provide first insight on the adaptive response of rumen protozoa and rumen and colonic bacterial populations to increasing dietary levels of grain in goats. Although luminal pH largely affects microbial populations, fermentable substrate flow to the caprine hindgut may have played a greater role for colonic bacterial populations in the present study.
高谷物喂养与牛的瘤胃酸度降低和微生物失调有关。然而，高谷物喂养对山羊瘤胃和后肠微生物群落和脂多糖（LPS）释放的影响在很大程度上尚不清楚。因此，本研究旨在研究增加大麦谷物日粮水平对山羊瘤胃和结肠微生物组成和 LPS 浓度的影响，并比较其对瘤胃和结肠 pH 值和短链脂肪酸（SCFA）生成的响应。生长山羊（n = 5-6）饲喂含 0、30 或 60%粗磨大麦谷物的日粮 6 周。使用 Bürker 计数室计数瘤胃纤毛虫原虫，并用定量 PCR 比较细菌种群。随着日粮中谷物水平的增加，内毛目原虫的数量呈线性增加（P < 0.05）。在 60%的谷物日粮中，普雷沃氏菌属和纤维丁酸弧菌的瘤胃丰度减少，而乳酸杆菌属的瘤胃丰度与 0 和 30%的谷物日粮相比增加（P < 0.05）。在结肠中，与其他日粮相比，饲喂 60%谷物日粮的山羊中普雷沃氏菌属和 F. succinogenes 的丰度增加（P < 0.05）。Clostridium cluster I 的结肠丰度与日粮中谷物的存在有关。瘤胃 LPS 浓度随 60%谷物日粮而降低（P < 0.05），而结肠 LPS 浓度则随同一日粮而增加（P < 0.05）。本研究结果首次提供了关于山羊瘤胃原虫以及瘤胃和结肠细菌种群对日粮中谷物水平增加的适应性反应的见解。尽管腔内容物 pH 值在很大程度上影响微生物种群，但在本研究中，可发酵底物向山羊后肠的流动可能对结肠细菌种群的影响更大。
