不同饲养密度对笼养蛋鸡十二指肠肠道菌群的影响

本试验采用聚合酶链式反应(PCR)-变性梯度凝胶电泳(DGGE)方法探究不同饲养密度对笼养海兰灰蛋鸡十二指肠肠道菌群的影响。随机选取1 250只11周龄海兰灰蛋鸡,按照不同饲养密度随机分为5个组:A组900 cm2/只、B组675 cm2/只、C组540 cm2/只、D组450 cm2/只、E组380 cm2/只,每个组内50个重复。5个组均在相同的环境和饲养管理模式下进行饲养。分别于16、26、50周龄时,在每个组中随机选取5只鸡,取十二指肠内容物,用PCR-DGGE法进行肠道菌群分析。结果表明,在同一个饲养密度内,随着饲养周龄的增加笼养蛋鸡十二指肠肠道菌群结构相似系数逐渐减小;16周龄时高密度组与低密度组之间十二指肠肠道菌群结构相似性很高,即肠道菌群结构差异较小;26和50周龄时高密度组与低密度组之间十二指肠肠道菌群结构相似性很低,即肠道菌群结构差异很大。由此可见,随着饲养周龄的增加笼养蛋鸡十二指肠肠道菌群结构差异增大;2种有益菌(Lactobacillus gastricus和Lactobacillus alvi)在高饲养密度组(D组和E组)中消失,饲养密度高于450 cm2/只对笼养蛋鸡十二指肠肠道菌群结构具有不利的影响。

Effects of Different Stocking Density on Microbial Flora of Duodenum for Caged Layer

The test used the polymerase chain reaction ( PCR )-denaturing gradient gel electrophoresis ( DGGE) methods to explore the effects of different stocking density on the microbial flora of duodenum for caged Hy-line Gray laying hens.A total of 1 150 eleven-week-old Hy-line Gray laying hens were randomly al-located into 5 groups with 50 replications with the stocking density of 900, 675, 540, 450 and 380 cm2 per layer, respectively.All the hens were reared under the same environment condition and with the same manage-ment model.Five hens were selected randomly from every group at the age of 16, 26 and 50 weeks, the intes-tinal samples of duodenum were taken to analyze the micro by PCR-DGGE.The results showed that in the same stocking density, the similarity coefficient of duodenum microbial flora of caged layers was decreased with the increasing of breeding weeks;at the 16 week of age, the microbial flora of duodenum was highly sim-ilar between high density group and low density group, there was no obvious difference for structure of intesti-nal flora;at the 26 and 50 week of age, the microbial flora of duodenum was lowly similar between high den-sity group and low density group, there was significant differences for structure of intestinal flora.In conclu-sion, with the increasing of feeding week age, the structure of the microbial flora of duodenum is changed sig-nificantly; two kinds of beneficial bacteria ( Lactobacillus gastricus and Lactobacillus alvi) disappear in high stocking density ( group D and group E); the feeding density higher than 450 cm2/per layer have adverse effects on the structure of the microbial flora of duodenum of cage laying hens.