PDF(Pubmed)
Abstract：
The objective of this experiment was to investigate the effects of Lactobacillus plantarum and molasses on the nutrient composition, fermentation quality, bacterial count, aerobic stability, and microflora of alfalfa silage in sandy grasslands. The experimental treatments included control (CK), 106 CFU/g Lactobacillus plantarum (L), 5% molasses (M), and 106 CFU/g Lactobacillus plantarum + 5% molasses (LM). The nutrient composition, fermentation quality, bacterial count, aerobic stability, and microflora were determined after 14 days and 56 days of ensiling, respectively. The results showed that the addition of L, M, and LM reduced dry matter loss (DM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) content, and increased water-soluble carbohydrates (WSC) and ether extract (EE) content, compared to the CK group. Meanwhile, more lactic acid (LA) and accelerated fermentation were observed, causing the pH value to drop below 4.5 in the L, M, and LM groups after 56 days of ensiling. The addition of L, M, and LM promoted lactic acid bacteria (LAB), and inhibited yeast. The addition of L significantly increased the content of acetic acid (AA). In terms of microflora, the addition of L, M, and LM made Firmicutes become the dominant bacterial phylum earlier, while Lactobacillus, Weissella, and Pediococcus had a higher abundance. According to the result of Pearson\'s correlation, there is a very significant negative correlation between pH value and Lactobacillus (P < 0.01) and a very significant positive correlation between pH value and Lactococcus, Enterobacter, Enterococcus, and Leuconostoc (P < 0.01), which may be inhibited by Lactobacillus under the decreased pH value. The results of the prediction of microbial genes indicated that the addition of M could enhance the carbohydrate metabolism and membrane transport metabolism, which may contribute to LA production by LAB metabolism. In general, L, M and LM all improved the fermentation quality and reduced the loss of nutrients to varying degrees, but considering the fermentation quality, the overall effects of M and LM were better than L. M and LM are recommended to be used as silage additives in the process of alfalfa silage in sandy grasslands to improve the quality.
摘要：
本实验的目的是研究植物乳杆菌和糖蜜对营养成分的影响。发酵质量，细菌计数,有氧稳定性，沙质草地苜蓿青贮和微生物区系。实验处理包括对照（CK），106CFU/g植物乳杆菌（L），5%糖蜜（M），和106CFU/g植物乳杆菌+5%糖蜜(LM)。营养成分，发酵质量，细菌计数,有氧稳定性，在青贮14天和56天后测定微生物区系，分别。结果表明,添加L,M,和LM减少干物质损失（DM），中性洗涤剂纤维（NDF），和酸性洗涤剂纤维(ADF)含量，增加水溶性碳水化合物（WSC）和乙醚提取物（EE）的含量，与CK组相比。同时,观察到更多的乳酸（LA）和加速发酵，导致L中的pH值降至4.5以下，M,和LM组在青贮56天后。L的加入,M,和LM促进乳酸菌（LAB），并抑制酵母。L的添加显著增长了乙酸(AA)的含量。就微生物而言，L的加法,M,LM使Firmicutes更早成为主要的细菌门，而乳酸菌，Weissella,片球菌的丰度较高。根据皮尔逊相关性的结果，pH值与乳杆菌呈极显著负相关(P<0.01),pH值与乳球菌呈极显著正相关,肠杆菌,肠球菌,和明串珠菌（P<0.01），在pH值降低的情况下，乳酸菌可能会对其产生抑制作用。微生物基因的预测结果表明，添加M可以增强碳水化合物代谢和膜运输代谢，这可能有助于通过LAB代谢产生LA。总的来说,L,M和LM均不同程度地提高了发酵质量，减少了营养物质的损失，但是考虑到发酵质量，M和LM的总体效果优于L。建议在沙地苜蓿青贮过程中使用M和LM作为青贮添加剂，以提高青贮质量。
