淀粉诱导奶牛乳脂下降后奶牛瘤胃细菌菌群变化

旨在阐释奶牛日粮添加淀粉对奶牛乳脂及瘤胃细菌菌群变化的影响。选取4头体况相近、健康的泌乳期中国荷斯坦奶牛,试验开始前以基础日粮饲喂并作为对照,饲喂7 d;试验期每头奶牛日粮中添加1.5 kg·d^-1玉米淀粉,饲喂15 d。结果表明,日粮中添加淀粉后,牛奶乳脂率极显著降低(P<0.01)。瘤胃细菌研究表明,在门水平上共检测到28个菌门,玉米淀粉导致瘤胃芽单胞菌门(Gemmatimonadetes)、软壁菌门(Tenericutes)丰度极显著降低(P<0.01),装甲菌门(Armatimonadetes)、酸杆菌门(Acidobacteria)、蓝藻门(Cyanobacteria)丰度显著降低(P<0.05),厚壁菌门(Firmicutes)丰度显著增加(P<0.05)。在属水平上共检测到383个菌属,其中90个菌属发生显著变化。玉米淀粉导致醋酸杆菌属(Acetobacter)、乳酸杆菌属(Lactobacillus)、小球菌属(Pediococcus)、明串珠菌属(Leuconostoc)、毛螺旋菌属-1(Lachnoclostridium-1)、瘤胃球菌属-1(Ruminococcus-1)、普雷沃氏菌属-7(Prevotella-7)等丰度极显著增加(P<0.01),厌氧弧菌属(Anaerovibrio)、肠球菌属(Enterococcus)、栖水菌属(Enhydrobacter)等丰度极显著降低(P<0.01)。本试验结果表明,奶牛日粮中添加一定量的玉米淀粉对瘤胃细菌多样性和种类分布均匀度均无显著影响,但其促进了大部分产酸菌群的增殖。

Changes of rumen bacterial flora after starch induced milk fat depression in dairy cows

This experiment aimed to study the effects of starch supplementation on milk fat and rumen bacterial flora of dairy cows. Four Chinese Holstein cows with similar body conditions and healthy lactation were selected. At the first stage of 7 days, cows were fed by basic diet to be control group. After the second stage of 15 days, cows were fed by basic diet supplemented with an additional 1.5 kg of corn starch per day per head to be experimental group. The results showed that milk fat percentage of dairy cows decreased significantly after starch supplementation (P<0.01). At the phylum level, 28 phyla of rumen bacteria were detected, the richness of Gemmatimonadetes and Tenericutes decreased significantly (P<0.01), Armatimonadetes, Acidobacteria and Cyanobacteria decreased significantly (P<0.05), Firmicutes increased significantly (P<0.05). At the level of genus, 383 genera were detected, 90 of which changed significantly. At the genus level, the abundance of Acetobacter, Lactobacillus, Pediococcus, Leuconostoc, Lachnoclostridium-1, Ruminococcus-1 and Prevotella-7 increased significantly (P<0.01), Anaerovibrio, Enterococcus and Enhydrobacter decreased significantly (P<0.01). In the experiment, flora diversity and distribution uniformity of rumen bacteria in daily cows were not different after adding starch in diet, while proliferation of most acid-producing bacteria was promoted.