## 4 Discussion
### Effect of Moisture Content and Additives on the Aerobic Stability of AWB Mixed Silage  
The multiplication and growth of yeasts and molds will cause silage to spoil during aerobic exposure. When silage was exposed to air, the anaerobic environment became aerobic. Due to the lack of oxygen, yeasts and molds start to proliferate and decompose LA and CP, which leads to silage spoilage, as evidenced by increased temperature and pH [53]. In this study, the aerobic stability of AWB mixed silage gradually decreased with increasing MC. Compared with 60% MC, the aerobic stability was reduced by 57 h, 57 h, and 72 h in the L, E, and M groups, respectively, under 70% MC conditions. This was explained by the fact that a high MC in raw materials can promote the growth of harmful microorganisms such as clostridia and molds, which are more likely to cause aerobic spoilage. [PERSON] et al. [54] found that an appropriate reduction in MC could improve the aerobic stability of alfalfa silage, which was consistent with the results of this study. The aerobic stability of silage is very important, and if silage can sustain a high aerobic stability, it can greatly preserve the nutrient content in silage and reduce the accumulation of mycotoxins [53]. At 60% MC, the aerobic stability of the control, L, E, and M groups was 96 h, 129 h, 138 h, and 153 h, respectively. The control group had the highest DM content, which limited the degree of fermentation of the silage, resulting in higher concentrations of residual WSC in the silage and promoting the growth of undesirable microorganisms such as yeasts and molds that were exposed to air to multiply [55]. This may explain the worst aerobic stability of the AWB mixed silage in the control group. AA and PA are highly active antifungals and can effectively inhibit the activity of aerobic microorganisms [56]. According to Table 2, the higher content of AA and PA in L-, E-, and M-inoculated silages at 60% MC may be one of the reasons for their improved aerobic stability. Silage of mulberry (_Morus alba_ L.) leaves with lactic acid bacteria can improve aerobic stability up to 128 h [55], which was consistent with the results of this study. In this study, the aerobic stability of the L-inoculated silage was improved. However, it was reduced by 7% and 19% compared to the E and M groups, respectively. Lactic acid bacteria fermentation increased the LA content in the silage, which showed poor antifungal activity compared to AA and PA [57]. _Lactobacillus plantarum_ belongs to homofermattative lactic acid bacteria, whose fermentation mainly produces lactic acid, while the amount of short-chain fatty acids produced that can inhibit the growth and reproduction of yeasts and molds is very small. The exposure of silage to air and the gradual oxidation of LA by lactic acid-assimilating yeasts leads to an increase in silage pH, which provides the necessary conditions for the growth and reproduction of undesirable microorganisms [58]. Homofermattative lactic acid bacteria promote the growth of yeast and reduce aerobic stability. Heterofermattative lactic acid bacteria such as _Lactobacillus brucei_ fermentation produce AA that better inhibits the activity of undesirable microorganisms, such as yeasts and molds, and prolongs the aerobic stability of silage [59]. Thus, the L-inoculated silage showed lower aerobic stability than the E and M groups. Cellulase can degrade the lignocellulosic components in the cell wall of silage to WSC, provide sugar for many fungi, and make silage corrupt. This was inconsistent with the results of AWB mixed silage inoculated with E in this experiment. [PERSON] et al. [60] showed that there was no clear link between WSC content and silage stability in an aerobic environment and that the aerobic stability of silage was prolonged at higher WSC content, in agreement with the results of E-inoculated AWB mixed silage in this study.