摘要
The objective of this study was to evaluate the effect of heat stress on meta-taxonomic and metabolic profiles of prokaryotes in beef cattle rumen. Six pure-breed Nellore heifers with ruminal cannulas were used in the study. Six treatments were tested in a 6 × 6 Latin Square with six periods of 21days. The treatments were evaluated in a 2 × 2 + 2 factorial arrangement, consisting of 4 combinations: two temperatures conditions (thermoneutral, TN: 24 °C; and heat stress, HS: 34 °C) and two dietary energy concentration [low-energy (37% non-fibrous carbohydrates – NFC, 12 Mcal of metabolizable energy per kg of dry matter) or high-energy concentration (50.5% NFC, 18.49 Mcal of metabolizable energy per kg of dry matter)] plus two additional treatments with animals maintained in TN conditions but with your intake restricted (TN-RI) to the same of the heifers in HS with the two dietary energy concentration. The meta-genome was sequenced by MiSeq Sequencing System platform, and the DNA sequences were analysed using Geneious 10.2.3 software. The metabolic profile was evaluated by liquid and gas chromatography. Animals under HS presented lower (P = 0.04) prokaryote richness than animals under TN conditions. The genera Flavonifractor (1.4%), Treponema (0.6%) and Ruminococcus (0.9%) showed the lowest (P < 0.04) and Carnobacterium (7.7%) the highest (P = 0.02) relative abundance when the animals were submitted to HS, in relation to animals in TN. A total of 49 different metabolites were identified in the ruminal samples. The concentration of isobutyric acid (4.32 mM) was highest in bovine rumen under HS conditions. Heat stress influenced the microbiota and concentration of some organic acids in beef cattle rumen. There was a reduction in the richness of rumen in cattle under heat stress, but the diversity of prokaryotes was not affected.
摘要译文
本研究的目的是评估热应激对肉牛瘤胃中原基和代谢谱的影响。在研究中使用了六种纯净的纯净的小嘴母牛，用于瘤胃外套。在6×6拉丁广场中测试了六个治疗方法，其中六个月为21天。在2×2 + 2因子排列中评估治疗，由4种组合组成：两个温度条件（ThermOnetral，TN：24°C;和热应激，HS：34℃）和两种膳食能量浓度[低能量（37％非纤维状碳水化合物 - NFC，每千克代谢能量12个MCAL）或高能浓度（50.5％NFC， 18.49 MCAL每千克干物质的可代谢能量）加上两种额外的动物在TN条件下保持，但随着两种饮食能量浓度的摄入量限制（TN-RI）与HS中的继返者相同。 Meta-基因组被MiSeq测序系统平台对测序，使用毒性10.2.3软件分析DNA序列。通过液相和气相色谱评估代谢型材。在HS下的动物呈下（p = 0.04）原核性富含TN条件下的动物。 Genera FlavOnifractor（1.4％），串粒细胞（0.6％）和喇叭杆菌（0.9％）显示最低（P <0.04）和肉毒杆菌（7.7％）最高（P = 0.02）相对丰度，当动物提交到HS时，关于TN中的动物。在谣言样品中鉴定了共49种不同的代谢物。在HS条件下，牛瘤中的异丁酸（4.32mm）的浓度最高。热应力影响了牛肉瘤中一些有机酸的微生物群和浓度。在热胁迫下，牛中瘤胃的丰富性降低，但原核生物的多样性不受影响。
Gustavo FelipeCorreia Sales[a];Beatriz FerreiraCarvalho[a];Rosane FreitasSchwan[a];Leonardode Figueiredo Vilela[a];Javier AndrésMoreno Meneses[b];Mateus PiesGionbelli[b];CarlaLuiza da Silva ávila[b];. Heat stress influence the microbiota and organic acids concentration in beef cattle rumen - ScienceDirect[J]. Journal of Thermal Biology, 2021,97