## 4 Discussion
### Effect of Different Additives on the Quality of Whole-Plant Millet Silage  
At silo open, the pH levels in the LP, S, and MIX additive treatment groups were significantly lower than in the CK group, indicating that the additives positively influenced the preservation of the silage, leading to enhanced fermentation quality [26]. Moreover, the MIX group exhibited superior characteristics, with a pH value of 3.96, an LA content of 6.59% DM and a better LAB count and LA/AA ratio compared to the other two additive groups. In the LP group, homolactic fermentation LAB rapidly produced a significant amount of LA using the WSCs available in the raw materials at the beginning of fermentation, thereby lowering the pH in the silage environment. Adding sucrose provided a fermentation substrate beneficial for LAB proliferation, facilitating further acid production and pH reduction [35]. The S group had the highest DM content (38.5%), which was significantly higher than the CK group, which aligns with similar findings reported by [PERSON] [36]. The addition of sucrose enhanced the early production of LA during ensiling, rapidly reducing the silage pH and thereby inhibiting harmful microbial activity and minimizing nutrient losses [37]. Furthermore, sucrose itself contributes to a high DM content [38]; the MIX group had a lower DM content compared to the S group, likely due to the additional use of LP which consumes nutrients, thus reducing its DM content. The additive groups also showed lower NDF and ADF contents than the CK group, similar to the findings by [PERSON] [39], potentially due to the presence of fibrolytic enzyme-producing microbes that reduce fiber content [40]. _Lentilactobacillus buchneri_ has been shown to produce ferulic acid esterase--a part of the hemicellulose-degrading enzyme system that breaks ester bonds between hemicelluloses and lignin--enhancing cellulose utilization [41]. Research by [PERSON] [42] and others indicates that LAB can produce a significant amount of cellulase during fermentation, reducing the fiber content in silage and enhancing the quality. Moreover, the organic acids produced during ensiling can hydrolyze digestible parts of the cell walls, further reducing fiber content [43]. Additionally, [PERSON] et al. found that _Lactiplantibacillus plantarum_ also has the ability to degrade cellulose [44]. Effect of Different Additives on the VFA Contents and Aerobic Stability of Whole-Plant Millet Silage  
During the 7-day (168 h) monitoring of aerobic stability, it was observed that the temperature of all groups did not exceed room temperature by more than 2 \({}^{\circ}\)C. However, the contents of LA and AA in all treatment groups (except for group S) decreased after the aerobic stability test and the pH levels increased, though they remained significantly lower than those in the CK group. Upon aerobic exposure, air penetrates the silage, promoting the rapid growth and reproduction of yeasts and general bacteria, which utilize the remaining sugars and LA as fermentation substrates [45; 46]. The AA produced by heterofermatative LAB metabolism in the silage has antifungal activity, which can enhance the aerobic stability of the silage [47; 48]. Additionally, the experiment was conducted in winter, when the indoor temperature was relatively low (around 20 \({}^{\circ}\)C), which may have influenced the aerobic stability results. Studies have found that the LA content in Experiment 2 is lower than in Experiment 1. This may be due to Experiment 2 being conducted in the second year based on the results of Experiment 1. Owing to differences in the climate and other environmental factors, the millet grown in different years may have varying growth conditions and durations, leading to differences in the composition and quality of silage materials. In Experiment 1, the WSC content of the dough stage raw material was 92.7 \(\pm\) 10.4 g/kg DM, while in Experiment 2, it was 21.3 \(\pm\) 3.96 g/kg DM.