Wang Zhengwen, Li Xiongxiong, Zhang Lingyun, Wu Jianping, Zhao Shengguo, Jiao Ting
College of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China.
Key Laboratory of Grassland Ecosystem, Gansu Agricultural University, Lanzhou 730070, China.
Animals (Basel). 2022 Jan 4;12(1):118. doi: 10.3390/ani12010118.
The objective of this experiment was to evaluate the effect of different EOC (0.1425% cobalt lactate + 1.13% oregano essential oil + 98.7275% carrier) levels on in vitro rumen fermentation and microbial changes. Six EOC levels (treatments: 0 mg·L, CON; 50 mg·L, EOC1; 100 mg·L, EOC2; 400 mg·L, EOC3; 800 mg·L, EOC4 and 1500 mg·L, EOC5) were selected to be used to in vitro incubation. The in vitro dry matter digestibility (IVDMD), in vitro neutral detergent fiber digestibility (IVNDFD), in vitro acid detergent fiber digestibility (IVNDFD), pH, ammonia-nitrogen (NH-N) concentration, total volatile fatty acid (TVFA) concentration and microbial protein (MCP) concentration were measured after 48 h incubation, after which the groups with significant nutrient digestibility and fermentation parameters were subjected to 16S rRNA sequencing. The results showed that the total gas production (GP) of the EOC5 group was higher than that of the other groups after 12 h of in vitro incubation. TVFA, NH-N and MCP concentrations were also shown to be higher in group EOC5 than those in other groups ( < 0.05), while NH-N and MCP concentrations in the EOC2 group were lower than those in other groups significantly ( < 0.05). The molar ratio of acetic acid decreased while the molar ratio of propionic acid increased after the addition of EOC. 16S rRNA sequencing revealed that the rumen microbiota was altered in response to adding EOC, especially for the EOC5 treatment, with firmicutes shown to be the most abundant (43.1%). The relative abundance of was significantly lower, while the relative abundance of and was significantly higher in the EOC5 group than those in other groups ( < 0.05). Comprehensive analysis showed that EOC (1500 mg·L) could significantly increase gas production, alter sheep rumen fermentation parameters and microbiota composition.
本试验旨在评估不同水平的EOC（0.1425%乳酸钴+1.13%牛至精油+98.7275%载体）对体外瘤胃发酵和微生物变化的影响。选择6个EOC水平（处理：0 mg·L，CON；50 mg·L，EOC1；100 mg·L，EOC2；400 mg·L，EOC3；800 mg·L，EOC4和1500 mg·L，EOC5）用于体外培养。培养48 h后测定体外干物质消化率（IVDMD）、体外中性洗涤纤维消化率（IVNDFD）、体外酸性洗涤纤维消化率（IVADFD）、pH值、氨氮（NH₃-N）浓度、总挥发性脂肪酸（TVFA）浓度和微生物蛋白（MCP）浓度，之后对营养物质消化率和发酵参数有显著差异的组进行16S rRNA测序。结果表明，体外培养12 h后，EOC5组的总产气量（GP）高于其他组。EOC5组的TVFA、NH₃-N和MCP浓度也高于其他组（P<0.05），而EOC2组的NH₃-N和MCP浓度显著低于其他组（P<0.05）。添加EOC后，乙酸的摩尔比降低，丙酸的摩尔比增加。16S rRNA测序显示，添加EOC后瘤胃微生物群发生了变化，尤其是EOC5处理组，厚壁菌门最为丰富（43.1%）。EOC5组中某菌属的相对丰度显著较低，而另两个菌属的相对丰度显著高于其他组（P<0.05）。综合分析表明EOC（1500 mg·L）可显著提高产气量，改变绵羊瘤胃发酵参数和微生物群组成。
