Effect of storage time on the silage quality and microbial community of mixed maize and faba bean in the Qinghai-Tibet Plateau

Abstract

Tibetan Plateau is facing serious shortage of forage in winter and spring season due to its special geographical location. Utilization of forages is useful to alleviate the forage shortage in winter and spring season. Consequently, the current study was aimed to evaluate the influence of storage time on the silage quality and microbial community of the maize (Zea mays L.) and faba bean (Vicia faba L.) mixed silage at Qinghai-Tibet Plateau. Maize and faba bean were ensiled with a fresh weight ratio of 7:3, followed by 30, 60, 90, and 120 days of ensiling. The results showed the pH value of mixed silage was below 4.2 at all fermentation days. The LA (lactic acid) content slightly fluctuated with the extension of fermentation time, with 33.76 g/kg DM at 90 days of ensiling. The AA (acetic acid) and NH3-N/TN (ammonium nitrogen/total nitrogen) contents increased with the extension of fermentation time and no significantly different between 90 and 120 days. The CP (crude protein) and WSC (water soluble carbohydrate) contents of mixed silage decreased significantly (P < 0.05) with ensiling time, but the WSC content remained stable at 90 days. The Proteobacteria was the predominant phyla in fresh maize and faba bean, and Pseudomonas and Sphingomonas were the predominant genera. After ensiling, Lactobacillus was the prevalent genus at all ensiling days. The relative abundance of Lactococcus increased rapidly at 90 days of ensiling until 120 days of fermentation. Overall, the storage time significant influenced the silage fermentation quality, nutrient content, and microbial environment, and it remained stable for 90 days of ensiling at Qinghai-Tibet Plateau. Therefore, the recommended storage time of forage is 90 days in Qinghai-Tibet Plateau and other cool areas.

Effects of Vachellia mearnsii Tannin Extract as an Additive on Fermentation Quality, Aerobic Stability, and Microbial Modulation of Maize Silage

“…The current study further showed that including tannin extract as a silage additive modulated the microbial composition of the silage, favouring the dominance of phylum Firmicutes. These results agree with other studies that reported the dominancy of phylum Firmicutes on silage produced from different forage materials [41,[50][51][52][53][54]. Phylum Firmicutes constituted from 84% to 97% of the bacterium detected on maize silage in T2, T4, and T5, while in T1 and T3 maize silage, phylum Firmicutes constituted 39% and 42% of the detected bacteria, respectively.…”

“…A low pH in silage indicates well-preserved silage and prevents undesirable bacterial growth [54]; this was observed in the current study, as all treatments recorded a pH below 4.0. However, the microbial characterisation of these silages using genomic technology analysis revealed the presence of undesirable bacteria in T1 (negative control) and T3 (positive control) silages.…”

Effects of the fermentation quality and microbial community of waxy maize mixed with fodder soybean silage

“…Lactococcus, a parthenogenetic anaerobic bacterium, is normally the most abundant in the early stages of silage when the growth and multiplication of Lactococcus are inhibited during the anaerobic process (Zeng et al, 2020). However, Acetobacter may promote the growth of Lactococcus (1.20-2.65%) and cause the proliferation of Sphingomonas, and the correlation between pH and Sphingomonas in the RDA was similar to that reported by Xin et al (2023). However, the abundance of Lactobacillus still significantly increased with the addition of fodder soybeans.…”

“…As the proportion of mixed sowing of fodder soybeans increased, the abundance of Firmicutes gradually increased. The phylum Firmicutes ferments sugar into acid and inhibits Proteobacteria under anaerobic silage conditions, resulting in a decrease in its abundance (Xin et al, 2023). The dominant genera were Lactobacillus, Bradyrhizobium, Lactococcus, Sphingomonas, Klebsiella, and Pseudomonas.…”

Effects of a Delayed Harvest and Additives on the Fermentation Quality of Corn Stalk Silage

“…Ensiling is an effective preservation method that can improve forage palatability, digestibility, and nutrient retention for long-term storage [6]. However, leaving corn stalks in the field, a common practice, leads to nutrient loss [7].…”