长期相对高、低环境温度对肉鸡回肠微生物多样性的影响

Effect of Long-term Relative High and Low Environmental Temperatures on the Microbial Diversity of Ileum in Broilers

【目的】探究长期相对高、低温度环境对肉鸡回肠微生物多样性的影响。【方法】选取300只1日龄艾维茵肉仔鸡,随机均分为3组,分别设为高温组(36.5℃,HI组)、对照组(33.5℃,CI组)和低温组(30.5℃,LI组),温度随日龄平行递减,每天各组间温差均为3℃,其他饲养条件一致,至42 d分别降至22℃、19℃和16℃;每组随机选取12只肉鸡屠宰,采集回肠食糜,进行16S rRNA测序分析。【结果】(1)与CI组相比,HI和LI组Shannon和Simpson指数显著升高(P<0.05)。(2)门水平上,HI组回肠的厚壁菌门、蓝细菌/叶绿体的丰度、厚壁菌门/拟杆菌门(F/B)比值显著高于CI组,拟杆菌门丰度则显著降低(P<0.05);属水平上,HI组回肠的乳酸菌属、曲霉菌属的丰度显著高于CI组,LI组回肠的梭菌属XI、志贺氏大肠杆菌属的丰度显著低于CI组(P<0.05)。(3)转录机制信号通路在CI组显著富集;DNA修复和重组蛋白等18个信号通路在HI组显著富集;乙醛酸和二羧酸代谢等14个信号通路在LI组显著富集。(4) CI组梭菌属ⅩⅧ 与转录机制通路呈正相关,HI组乳酸菌属与磷酸转移酶系统通路呈正相关,LI组潘多拉菌属与乙醛酸和二羧酸代谢通路呈正相关。【结论】长期相对低温环境使肉鸡回肠微生物多样性增加,F/B比值、梭菌属XI、志贺氏大肠杆菌属丰度降低;长期相对高温环境使肉鸡回肠微生物多样性增加,F/B比值降低、乳酸菌属和曲霉菌属的丰度增加,为肉鸡健康养殖提供了理论依据。

[Purpose]To explore the effects of long-term relative high and low environmental temperature on the ileum microbial diversity in broilers.[Method]Three hundred one-day-old Avian broilers were randomly divided into three groups: high temperature group(36.5 ℃, HI), control group(33.5 ℃, CI) and low temperature group(30.5 ℃, LI). The temperature was decreased as a parallel,and the temperature difference among each group was 3 ℃. Other feeding conditions were the same,and 12 broilers in each group were slaughtered at 22 ℃, 19 ℃ and 16 ℃ on the 42 th day. Ileum chyme was collected to 16 S rRNA gene sequencing analysis.[Result](1) Compared with CI group,Shannon and Simpson index in HI and LI groups were significantly higher(P<0.05).(2) At the phylum level, the abundance of Firmicutes, Cyanobacteria/Chloroplast and the ratio of Firmicutes to Bacteroides(F/B) in the ileum of the HI group were significantly higher than those of the CI group,while the abundance of Bacteroides was significantly lower than that of the CI group(P<0.05);At the genus level, the abundance of Lactobacillus and Turicibacter in ileumin HI group was significantly higher than that in CI group, while the abundance of Clostridium XI and Escherichia/Shigella in ileum in LI group was significantly lower than that in CI group(P<0.05).(3) Transcription machinery signal transduction pathway was significantly enriched in CI group. Eighteen signal pathways such as DNA repair and recombination proteins were significantly enriched in HI group. Fourteen signal pathways such as glyoxylate and dicarboxylate metabolism were significantly enriched in LI group.(4) There was a positive correlation between Clostridium ⅩⅧ and transcription machinery pathway in CI group, Lactobacillus and phosphotransferase system pathway in HI group, and Pandoraea and glyoxylate and dicarboxylate metabolism pathway in LI group.[Conclusion]The results showed that the ileum microbial diversity of broilers increased in long-term relatively low temperature environment, while the ratio of F/B, Clostridium XI and Escherichia/Shigella decreased in long-term relatively low temperature environment, while in long-term relatively high temperature environment, the ileum microbial diversity increased, the ratio of F/B decreased, and the abundance of Lactobacillus and Turicibacter increased, which provided a theoretical basis for healthy breeding of broilers.