Improved fermentation efficiency, fiber degradation and nutrient preservation in whole-plant corn silage via co-inoculation of cellulose-decomposing bacteria and lactic acid bacteria

Context Due to the prolonged dry periods during the transition from winter to spring, there is a seasonal imbalance in forage supply, making silage one of the key substitutes for fresh grass during arid seasons. However, the high fiber content remains a major constraint on nutrient utilization and digestibility. The use of microbial additives offers a safe approach to alleviate this issue, with the combination of cellulose-decomposing bacteria (CDB) and lactic acid bacteria (LAB) representing an emerging strategy. Aims The purpose of this study was to investigate the impact of co-inoculating with a selected efficient CDB strain and LAB on the fermentation quality and fiber degradation of whole-plant corn silage. Methods A candidate strain of CDB was selected based on its enzyme production and tolerance, and was subsequently mixed with LAB at varying ratios (2:1, 1:1, 1:2). Cellulase, CDB, LAB and different proportions of CDB-LAB were added to whole-plant corn silage, and their effects were observed on Days 3, 7 and 60. Key results A cellulolytic bacterium, Bacillus paralicheniformis NS25, with high enzyme production was screened. LS-21 showed the best overall performance after Day 60 by reducing dry matter loss, decreasing fiber content, and increasing the concentrations of organic acids, crude protein and water-soluble carbohydrates. Co-inoculation reduced the content of structural carbohydrates, increased the content of non-structural carbohydrates and improved the aerobic stability of whole-plant corn silage. Conclusions The co-inoculation of LAB and CDB in a 2:1 ratio showed superior performance throughout the fermentation process. Implications The different effects of compound microbial additives provide theoretical basis for improving the quality of whole-plant corn silage, and rational development and utilization, so as to be better applied to practical production.