## 4 Discussion  
### Effect of Moisture Content and Additives on the Fermentation Quality of AWB Mixed Silage  
Raw material MC is one of the key factors affecting the fermentation quality of silage. A raw material MC that is too low results in a dry and rough surface on the raw material, a filling that is difficult to compact, and raw material seams with residual air, causing silage not and deterioration. Excessive MC in raw materials can produce sap that carries nutrients out, while high moisture can promote the growth of harmful microorganisms such as clostridia and molds, causing a decrease in silage quality [23]. A suitable silage material MC is 60-70%, and the pH of good quality silage should be below 4.2 [24]. In this experiment, under the different MC conditions, the pH of each additive treatment group was lower than 4.2, indicating that all AWB mixed silages with L, E, and M were of high quality. In this experiment, the AWB mixed silage in the 60% MC group had the lowest pH and the highest LA content compared to the remaining MC groups. This was explained by the fact that the reduction in raw material MC concentrated the sugars in the cells and raised the sugar concentration. Moreover, wheat bran as an auxiliary improved the nutritional balance of mixed silage materials by increasing the WSC content and promoting the fermentation of lactic acid bacteria, which improved the fermentation quality of silage. [PERSON] et al. [25] found that a low MC group had lower pH and AN/TN, higher LA content, and better fermentation quality of Sudan grass silage compared to a high MC group, which was consistent with the results of this study. [PERSON] et al. [26] found that the AN/TN of _Lolium multiform_ silage gradually decreased with decreasing MC, which is consistent with the results of this study. Under low MC conditions, plant cells were semiarid, resulting in increased osmotic pressure in the plant cytosol of AWB mixed silage, inhibition of the reproductive growth of _Clostridium_, reduced loss of nutrients, and weakened adverse protein breakdown, especially the process of amino acid deamination, resulting in an improvement in the quality of silage [27]. [PERSON] et al. [28] found that the fermentation quality of low-MC pea silage was better than that of high-MC pea silage, with higher LA content and lower protein hydrolysis in the low-MC group. As shown in Table 2, the fermentation quality of AWB mixed silage increased with the decrease in raw material MC, indicating that silage at 60% MC was an effective way to store amaranth. Figure 4: Time required for the temperature of amaranth and wheat bran mixed silage to exceed room temperature by 2 \({}^{\circ}\)C after exposure to air. U, control; L, lactic acid bacteria; E, cellulase; M, mixture of lactic acid bacteria and cellulase. A\({}^{-}\)C Means of moisture contents with different superscripts differ under the same additive treatment (\(p<0.05\)). \({}^{a-c}\) Means of additives treatments with different superscripts differ under the same moisture content (\(p<0.05\)). pH is an important parameter to evaluate the degree of silage fermentation and silage quality. The lower the pH, the lower the activity of harmful microorganisms and plant enzymes in the silage, and the better the quality of silage fermentation. A minimum of 10\({}^{5}\) CFU g\({}^{-1}\) lactic acid bacteria in the silage feedstock was required to produce high-quality silage [29]. In contrast, the general number of lactic acid bacteria attached to fresh plants was 10\({}^{3}\)-10\({}^{4}\) CFU g\({}^{-1}\). Therefore, additional lactic acid bacteria need to be added to the silage raw material to promote fermentation during the silage preparation process. The addition of _L. plantarum_ increased the LA content, decreased the pH and PA content, and improved the fermentation quality of _Lev minus chinensis_ silage compared to the control, in agreement with the results of the trial with L addition at 60% MC [11]. [PERSON] et al. [30] showed that the addition of _L.