Li Yuyu, Du Shuai, Sun Lin, Cheng Qiming, Hao Junfeng, Lu Qiang, Ge Gentu, Wang ZhiJun, Jia Yushan
Key Laboratory of Forage Cultivation, Processing and High Efficient Utilization of Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot, China.
Key Laboratory of Grassland Resources of Ministry of Education, Inner Mongolia Agricultural University, Hohhot, China.
Front Microbiol. 2022 Mar 16;13:830121. doi: 10.3389/fmicb.2022.830121. eCollection 2022.
Ensiling native grass is an effective method to protect the nutritional quality of forage and alleviate feed shortages in the cold winter of the Inner Mongolian Plateau. To improve the usability of native grass resources as feed in China, the effects of lactic acid bacteria and molasses additions on the microbial population, fermentation quality, and nutritional quality of native grass during silage were investigated. Treatments were a control treatment with no additive (CK), lactic acid bacteria (L), molasses (M), and lactic acid bacteria in combination with molasses (L+M), all of which were stored at ambient temperature (17-28°C) for 7, 14, 30, and 60 days. The results showed that all additives improved nutritional value and fermentation quality with low pH and ammonia nitrogen (NH-N) and high crude protein (CP) and water soluble carbohydrate (WSC) than control silage over the ensiling period. Compared with L or M silage, the L+M silage combination improved fermentability, as evidenced by higher LA content and a faster pH drop during the first 7 days of ensiling. With prolonged ensiling time, the combined addition of L and M could increase the count of desirable , decrease microbial diversity, and inhibit the growth of undesirable microorganism, such as Clostridia, , and abundance compared with silage treated with CK, L. or M. Application of L together with M could further improve the silage quality of native grass by altering bacterial community structure. In summary, the addition of lactic acid bacteria and molasses increased the relative abundance of of native grass silage and improved fermentation quality.
青贮天然牧草是保护内蒙古高原寒冷冬季牧草营养品质、缓解饲料短缺的有效方法。为提高我国天然牧草资源作为饲料的可用性，研究了添加乳酸菌和糖蜜对天然牧草青贮过程中微生物种群、发酵品质和营养品质的影响。处理方式包括不添加任何添加剂的对照处理（CK）、乳酸菌（L）、糖蜜（M）以及乳酸菌与糖蜜组合（L+M），所有处理均在环境温度（17-28°C）下储存7、14、30和60天。结果表明，在青贮期内，与对照青贮相比，所有添加剂均能改善营养价值和发酵品质，具有较低的pH值和氨态氮（NH-N），以及较高的粗蛋白（CP）和水溶性碳水化合物（WSC）。与L或M青贮相比，L+M青贮组合提高了发酵能力，青贮前7天乳酸含量更高，pH值下降更快就是证明。随着青贮时间延长，与CK、L或M处理的青贮相比，L和M的联合添加可增加有益菌数量，降低微生物多样性，并抑制梭菌等有害微生物的生长。L与M一起使用可通过改变细菌群落结构进一步提高天然牧草的青贮品质。总之，添加乳酸菌和糖蜜增加了天然牧草青贮中有益菌的相对丰度，提高了发酵品质。
