Jize Zhang, Zhuoga Deqing, Xiaoqing Zhang, Na Ta, Jiacuo Gesang, Cuicheng Luosang, Bandan Pingcuo
Institute of Grassland Research, Chinese Academy of Agricultural Sciences, Hohhot, China.
Institute of Livestock Research, Tibet Academy of Agriculture and Animal Husbandry Science, Lhasa, China.
Front Microbiol. 2022 Aug 24;13:908326. doi: 10.3389/fmicb.2022.908326. eCollection 2022.
Due to the harsh environment in the Tibetan Plateau, traditional grazing greatly limits the growth potential of local animals and causes severe ecosystem degradation. This is an urgent issue to be solved, which requires alternative strategies for grazing animals in the Tibetan alpine pastoral livestock systems. This study aimed to investigate the effects of different feeding strategies on growth performance and ruminal microbiota-host interactions in the local breed of sheep (Gangba sheep). Thirty 9-month old Gangba sheep ( = 10 per group) were assigned to natural grazing (G), semi-grazing with supplementation (T), and barn feeding (F) groups (supplementation of concentrate and oat hay) based on body weight. At the end of the experiment (75 d), all sheep were weighed, rumen fluid was obtained from six sheep per group, and ruminal epithelium was obtained from 3 sheep per group. The results showed that: (1) Compared with the G and T groups, the F group significantly increased dry matter intake, average daily gain, and feed conversion ratio of animals. Additionally, Gangba sheep in the F group had higher concentrations of ruminal short-chain volatile fatty acids (VFAs), especially propionate and butyrate ( <0.05) than sheep in the G and T groups. (2) The principal coordinates analysis indicated a significant difference in bacterial composition among different feed strategies. More specifically, the relative abundance of propionate (unidentified F082 and ) and butyrate-producing () genera were also observed to be increased in the F group, in which unidentified F082 was identified as a differential biomarker among the three groups according to linear discriminant analysis effect size analysis. (3) The dynamics of the rumen epithelial transcriptome revealed that ECM-receptor interactions, focal adhesion, and PI3K-Akt signaling pathways, which are critical in mediating many aspects of cellular functions such as cell proliferation and motility, were upregulated in the F group. In conclusion, under harsh conditions in the Tibetan alpine meadow, barn feeding increased ruminal VFAs concentrations (especially propionate and butyrate), which stimulated gene expression related to cell proliferation in rumen epithelium, appearing to be superior to natural grazing and semi-grazing in gaining body weight of the local Gangba sheep.
由于青藏高原环境恶劣，传统放牧方式极大地限制了当地动物的生长潜力，并导致严重的生态系统退化。这是一个亟待解决的问题，需要为藏北高寒牧区畜牧系统中的放牧动物找到替代策略。本研究旨在探讨不同饲养策略对当地品种绵羊（岗巴羊）生长性能及瘤胃微生物与宿主相互作用的影响。根据体重将30只9月龄岗巴羊（每组10只）分为自然放牧组（G组）、补饲半放牧组（T组）和舍饲组（F组）（补饲精料和燕麦干草）。实验结束时（75天），对所有绵羊进行称重，每组选取6只绵羊采集瘤胃液，每组选取3只绵羊采集瘤胃上皮组织。结果表明：（1）与G组和T组相比，F组显著提高了动物的干物质采食量、平均日增重和饲料转化率。此外，F组岗巴羊瘤胃短链挥发性脂肪酸（VFAs）浓度，尤其是丙酸和丁酸浓度（P<0.05）高于G组和T组绵羊。（2）主坐标分析表明不同饲养策略下细菌组成存在显著差异。更具体地说，F组中丙酸产生菌（未鉴定的F082和另一种菌）和丁酸产生菌（另一种菌）的相对丰度也有所增加，根据线性判别分析效应大小分析，未鉴定的F082被确定为三组间的差异生物标志物。（3）瘤胃上皮转录组动态变化显示，F组中细胞外基质-受体相互作用、粘着斑和PI3K-Akt信号通路上调，这些通路在介导细胞增殖和运动等细胞功能的多个方面起关键作用。总之，在藏北高寒草甸的恶劣条件下，舍饲提高了瘤胃VFAs浓度（尤其是丙酸和丁酸），刺激了瘤胃上皮细胞增殖相关基因的表达，在增加当地岗巴羊体重方面似乎优于自然放牧和补饲半放牧。
