Zhang Jiawei, Liu Yichao, Wang Zhijun, Bao Jian, Zhao Muqier, Si Qiang, Sun Pengbo, Ge Gentu, Jia Yushan
Key Laboratory of Forage Cultivation, Processing and High Efficient Utilization of Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010019, China.
Key Laboratory of Grassland Resources, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010019, China.
Microorganisms. 2023 Feb 17;11(2):513. doi: 10.3390/microorganisms11020513.
Silage of native grasses can alleviate seasonal forage supply imbalance in pastures and provide additional sources to meet forage demand. The study aimed to investigate the effects of (LP), (LB), and in combination with (PB) on the nutritional quality, fermentation quality, and microbial community of native grass silage at 2, 7, 15, and 60 days after ensiling and at 4 and 8 days after aerobic exposure. The results showed that dry matter content, crude protein content, the number of lactic acid bacteria, and lactic acid and acetic acid content increased and pH and ammonia nitrogen content decreased after lactic acid bacteria (LAB) inoculation compared with the control group (CK). LP had the lowest pH and highest lactic acid content but did not have greater aerobic stability. LB maintained a lower pH level and acetic acid remained at a higher level after aerobic exposure; aerobic bacteria, coliform bacteria, yeast, and molds all decreased in number, which effectively improved aerobic stability. The effect of the compound addition of LAB was in between the two other treatments, having higher crude protein content, lactic acid and acetic acid content, lower pH, and ammonia nitrogen content. At the phylum level, the dominant phylum changed from Proteobacteria to Firmicutes after ensiling, and at the genus level, and were the dominant genera in both LAB added groups, while was the dominant genus in the CK treatment. In conclusion, the addition of LAB can improve native grass silage quality by changing bacterial community structure. LP is beneficial to improve the fermentation quality in the ensiling stage, LB is beneficial to inhibit silage deterioration in the aerobic exposure stage, and compound LAB addition is more beneficial to be applied in native grass silage.
天然牧草青贮料可以缓解牧场季节性草料供应不平衡的问题，并提供额外的草料来源以满足草料需求。本研究旨在调查乳酸杆菌（LP）、芽孢杆菌（LB）以及乳酸杆菌与芽孢杆菌联合添加（PB）对天然牧草青贮料在青贮后2天、7天、15天和60天以及有氧暴露后4天和8天的营养品质、发酵品质和微生物群落的影响。结果表明，与对照组（CK）相比，接种乳酸菌（LAB）后，青贮料的干物质含量、粗蛋白含量、乳酸菌数量以及乳酸和乙酸含量增加，pH值和氨氮含量降低。LP的pH值最低，乳酸含量最高，但有氧稳定性不强。LB在有氧暴露后保持较低的pH值水平，乙酸含量较高；需氧菌、大肠菌群、酵母菌和霉菌数量均减少，有效提高了有氧稳定性。复合添加LAB的效果介于其他两种处理之间，粗蛋白含量、乳酸和乙酸含量较高，pH值和氨氮含量较低。在门水平上，青贮后优势门从变形菌门变为厚壁菌门；在属水平上，添加LAB的两个组中，乳杆菌属和芽孢杆菌属是优势属，而CK处理中肠杆菌属是优势属。综上所述，添加LAB可通过改变细菌群落结构来提高天然牧草青贮料品质。LP有利于提高青贮阶段的发酵品质，LB有利于抑制有氧暴露阶段青贮料的变质，复合添加LAB更有利于应用于天然牧草青贮料。
