DOI:10.1016/j.anifeedsci.2020.114673

Hao Guan, Yang Shuai, Qifan Ran, Yanhong Yan, Xia Wang, Dandan Li, Yimin Cai, Xinquan Zhang

发表期刊：Animal Feed Science and Technology

链接：https://www.sciencedirect.com/science/article/pii/S0377840120305770

Abstract：

A full understanding of changes of the microbiome and metabolome during Napier grass silage in relation to aerobic exposure can improve the nutritional value and extend the aerobic stability of this important feed in tropical and subtropical regions. The round bale silage of Napier grass was prepared with deionized water (control) and screened strains Lactobacillus rhamnosus LR753 (LR753) and L. buchneri 40788 (LB). Silages were stored at ambient temperature (30−40 °C) for 60 days, followed by 2 and 4 days of aerobic exposure. Strains LB and LR753 significantly improved aerobic stability (>84 h vs. 18 h of control) of baled Napier grass silage by inhibiting the growth of Saccharomycetales as for the higher production of acetic acid (P < 0.05). Weissella and Issatchenkia spp. were the dominant bacteria and fungi in 60-day silage, respectively. LC–MS/MS detected a total of 426 metabolites throughout ensiling and aerobic exposure. With the decrease of Weissella spp. and the increase of Acetobacter spp., the metabolites associated with both were mainly odor-related (3-methylbutanoic acid, isoquinoline, and cuminaldehyde) and amines (tryptamine and tyramine) in control silage, while more antimicrobial activity metabolites were found in strains LB and LR753-treated silage (methylbutanoic acid, 1,2-propanediol, and tiglic acid). Screened local strain LR753 showed a promising potential for improving silage fermentation and aerobic stability of Napier grass. The present study indicates that adequately describing the microbiome and metabolome of silages during fermentation and aerobic exposure can improve ensiling practices and the screening of silage inoculants that act synergistically with the natural microbiome of the forage in hot and humid areas.