Understanding the rumen fermentation and methanogenic community in camels fed intensively is critical for optimizing rumen fermentation, improving feed efficiency, and lowering methane emissions. Using Illumina MiSeq sequencing, quantitative real-time PCR, and high-performance liquid chromatography, this study evaluates the influence of different concentrate supplement levels in the diet on rumen fermentation as well as the diversity and structure of the rumen methanogenic community for growing dromedary camels. Twelve growing camels were divided into three groups and given three levels of concentrate supplement, 0.7% (C1), 1% (C2), and 1.3% (C3) based on their body weight. All animals were fed alfalfa hay ad libitum. The levels of total volatile fatty acid, rumen ammonia, and methanogen copy number were unaffected by the supplementation level. Increasing the concentrate supplement level increased the proportion of propionic acid while decreasing the proportion of acetic acid. Increasing the level of concentrate in the diet had no effect on alpha diversity metrics or beta diversity of rumen methanogens. Methanobrevibacter and Methanosphaera predominated the methanogenic community and were declined as concentrate supplement level increased. This study sheds new light on the effect of concentrate supplement level in growing camels’ diet on rumen fermentation and methanogenic community, which could help in the development of a strategy that aimed to reduce methane emissions and enhance feed efficiency.

了解集中饲喂骆驼的瘤胃发酵和产甲烷群落对于优化瘤胃发酵、提高饲料效率和降低甲烷排放至关重要。本研究采用Illumina MiSeq测序、实时定量PCR和高效液相色谱，评估日粮中不同精料添加水平对瘤胃发酵的影响以及生长单峰骆驼瘤胃产甲烷群落的多样性和结构。将 12 头生长中的骆驼分为三组，根据体重分别给予 0.7%（C1）、1%（C2）和 1.3%（C3）三个水平的浓缩物补充剂。所有动物均随意饲喂苜蓿干草。总挥发性脂肪酸、瘤胃氨和产甲烷菌拷贝数的水平不受补充水平的影响。增加浓缩物补充水平会增加丙酸的比例，同时减少乙酸的比例。增加日粮中的浓缩水平对瘤胃产甲烷菌的α多样性指标或β多样性没有影响。甲烷短杆菌属和甲烷球菌属在产甲烷群落中占主导地位，并随着浓缩物补充水平的增加而下降。这项研究为生长骆驼饮食中浓缩物补充水平对瘤胃发酵和产甲烷群落的影响提供了新的线索，这可能有助于制定旨在减少甲烷排放和提高饲料效率的策略。