Xu Xinxin, Xu Zebang, Yang Bin, Yi Kangle, He Fang, Sun Ao, Li Jianbo, Luo Yang, Wang Jiakun
Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou 310023, China.
Animals (Basel). 2023 Oct 5;13(19):3104. doi: 10.3390/ani13193104.
Cadmium (Cd) is an environmental pollutant, widely existing in soil, and can be absorbed and accumulated by plants. Hunan Province exhibits the worst cadmium contamination of farmland in China. Ruminants possess an abundant microbial population in the rumen, which enables them to tolerate various poisonous plants. To investigate whether the rumen microbiota could respond to Cd and mitigate the toxicity of Cd-accumulated maize to ruminants, 6-month-old cattle were fed with 85.82% (fresh basis) normal whole-plant maize silage diet (CON, = 10) or Cd-accumulated whole-plant maize silage diet (CAM, = 10) for 107 days. When compared to the CON cattle, CAM cattle showed significantly higher gain-to-feed ratio and an increased total bacterial population in the rumen, but a decreased total bacterial population in the colon. CAM cattle had higher relative abundance of and group in the rumen, and group and group in the colon. Notably, microbial correlations were enhanced in all segments of CAM cattle, especially in the jejunum. Transcriptome analysis revealed down-regulation of several immune-related genes in the rumen of CAM cattle, and differentially expressed genes in the rumen were mostly involved in immune regulation. These findings indicated that feeding Cd-accumulated maize diet with a Cd concentration of 6.74 mg/kg dry matter (DM) could stimulate SCFA-related bacteria in the rumen, induce hormesis to promote weight gain, and improve energy utilization of cattle.
镉（Cd）是一种环境污染物，广泛存在于土壤中，可被植物吸收和积累。湖南省是中国农田镉污染最严重的地区。反刍动物瘤胃中存在丰富的微生物种群，这使它们能够耐受各种有毒植物。为了研究瘤胃微生物群是否能对镉作出反应并减轻镉积累玉米对反刍动物的毒性，将6月龄的牛分为两组，分别饲喂85.82%（鲜重）的正常全株玉米青贮饲料（CON组，n = 10）或镉积累全株玉米青贮饲料（CAM组，n = 10），持续107天。与CON组牛相比，CAM组牛的增重与采食量之比显著更高，瘤胃中细菌总数增加，但结肠中细菌总数减少。CAM组牛瘤胃中 和 菌属的相对丰度较高，结肠中 菌属和 菌属的相对丰度较高。值得注意的是，CAM组牛所有肠道段的微生物相关性均增强，尤其是空肠中的 。转录组分析显示，CAM组牛瘤胃中几个免疫相关基因下调，瘤胃中差异表达基因大多参与免疫调节。这些结果表明，饲喂镉含量为6.74 mg/kg干物质（DM）的镉积累玉米日粮可刺激瘤胃中与短链脂肪酸相关的细菌，诱导兴奋效应以促进体重增加，并提高牛的能量利用率。
