State Key Laboratory of Seed Innovation and Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, PR China; Engineering Research Center of Grassland Industry, Ministry of Education, Lanzhou University, Lanzhou 730020, PR China; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Lanzhou University, Lanzhou 730020, PR China.
State Key Laboratory of Seed Innovation and Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, PR China; Engineering Research Center of Grassland Industry, Ministry of Education, Lanzhou University, Lanzhou 730020, PR China; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Lanzhou University, Lanzhou 730020, PR China.
Animal. 2023 Aug;17(8):100906. doi: 10.1016/j.animal.2023.100906. Epub 2023 Jul 6.
Sweet sorghum silage (SS; Sorghum dochna 'Dochna') has been extensively studied in recent years as a supplementary forage-to-corn silage (CS; Zea mays L.), but there are still relatively few studies on its effects on the rumen environment of sheep. Determining the short-term impact of converting roughage from corn straws to SS compared to CS on rumen fermentation and bacterial population dynamics was the main goal of the current study. Twelve female thin-tailed Han sheep (29.8 ± 1.34 kg) were randomly divided into one of two treatments: concentrate supplemented with SS or CS, respectively. During the 15-day pretest period, concentrate was fed in two separate feedings at 0800 h and 1800 h, and ensure that the animals were all consumed within an hour of being fed. Thereafter, the animals had free access to corn straw. The feeding procedures during the pretest period were the same as during the measurement period. Rumen fluid was collected via sheep esophageal tube on the last day of adaptation phase (1-7 days) and stabilisation phase (8-30 days), respectively. The results showed that there was a similarity in the total concentration of VFA (volatile fatty acid) and the proportions of acetate, propionate, butyrate, and branched-chain VFA (P > 0.05) and microbial diversity indices (P > 0.05) between the two silage groups throughout the experimental period. The concentration of Ammonia nitrogen (P = 0.001) and proportion of valerate (P = 0.028) decreased in the CS and SS groups, respectively. The abundance and predicted function of rumen bacteria in the SS group did not differ significantly (P > 0.05) between the two measurement phases. However, the abundance of Prevotella_1 (P = 0.038) was higher in the CS group than in the SS group at 7 d. The abundances of Firmicutes (P = 0.005) and Ruminococcaceae_NK4A214_group (P = 0.002) increased, while the abundances of Bacteroidetes (P = 0.044), Proteobacteria (P = 0.046), and Prevotella_1 (P = 0.009) decreased in the CS group at 30 d. Genes related to pyruvate metabolism (P = 0.020) were significantly higher at 30 d than at 7 d, whereas purine metabolism (P = 0.007), pyrimidine metabolism (P = 0.007), and metabolic pathways (P = 0.010) were lower at 30 d in the CS group. In conclusion, this study indicated that SS maintained a steady rumen environment, while CS caused high fluctuations in bacterial abundance and predicted function for sheep.
近年来，甜高粱青贮（SS； Sorghum dochna 'Dochna'）作为玉米青贮（CS； Zea mays L.）的补充饲料得到了广泛研究，但关于其对绵羊瘤胃环境影响的研究仍然相对较少。本研究的主要目的是确定将粗饲料从玉米秸秆转换为 SS 与 CS 相比对瘤胃发酵和细菌种群动态的短期影响。12 只雌性细尾寒羊（29.8±1.34kg）被随机分为两组：分别补充 SS 或 CS 的浓缩饲料。在 15 天的预测试期间，浓缩饲料在 0800 h 和 1800 h 分两次喂食，并确保动物在喂食后一个小时内全部消耗。此后，动物可以自由采食玉米秸秆。在预测试期间的喂养程序与测量期间相同。在适应阶段（1-7 天）和稳定阶段（8-30 天）的最后一天，通过羊食管管分别收集瘤胃液。结果表明，在整个实验期间，两组青贮饲料的总挥发性脂肪酸（VFA）浓度和乙酸盐、丙酸盐、丁酸盐和支链 VFA 的比例（P>0.05）以及微生物多样性指数（P>0.05）相似。CS 和 SS 组的氨氮（P=0.001）浓度和戊酸盐（P=0.028）比例均下降。在 SS 组中，瘤胃细菌的丰度和预测功能在两个测量阶段均无显著差异（P>0.05）。然而，在第 7 天，CS 组的 Prevotella_1 的丰度高于 SS 组（P=0.038）。Firmicutes（P=0.005）和 Ruminococcaceae_NK4A214_group（P=0.002）的丰度增加，而 Bacteroidetes（P=0.044）、Proteobacteria（P=0.046）和 Prevotella_1（P=0.009）的丰度下降CS 组在第 30 天。丙酮酸代谢相关基因（P=0.020）在第 30 天显著高于第 7 天，而嘌呤代谢（P=0.007）、嘧啶代谢（P=0.007）和代谢途径（P=0.010）在 CS 组中较低第 30 天。综上所述，本研究表明 SS 保持了稳定的瘤胃环境，而 CS 导致绵羊的细菌丰度和预测功能发生了剧烈波动。
