Abstract
We investigated the variation in microbial community and fermentation characteristics of whole-plant corn silage after treatment with lactic acid bacteria (LAB) and organic acids. The fresh corn forages were treated with a combination of L. acidophilus and L. plantarum (106 CFU/g fresh material) or a 7:1:2 ratio of formic acid, acetic acid, and propionic acid (6 mL/g fresh material) followed by 45 or 90 days of ensiling. Silages treated with LAB showed increased lactic acid content and decreased pH after 45 days. Although treatment with LAB or organic acids decreased the common and unique operational taxonomic units, indicating a reduction in microbial diversity, the relative abundance of Lactobacillus was elevated after 45 and 90 days compared with control, which was more distinct in the organic acid groups. Moreover, we found higher levels of acetic acid and increased abundance of Acetobacter in silages treated with organic acids whereas undesirable microorganisms such as Klebsiella, Paenibacillus, and Enterobacter were reduced. In summary, the quality of corn silages was improved by LAB or organic acid treatment in which LAB more effectively enhanced lactic acid content and reduced pH while organic acid inhibited the growth of undesirable microorganisms.
Highlights
Corn silage is a highly nutritious forage for livestock and has a higher yield and energy density as well as lower cost compared with other forage sources (Armstrong et al, 2008)
The dry matter (DM) and water-soluble carbohydrates (WSC) content decreased after ensiling, which is mainly due to oxygen consumption by plant cells in silages at the early stage of ensiling followed by fermentation of WSC by microorganisms into lactic acid (Dunièrea et al, 2013)
The WSC content in Lactic acid bacteria (LAB) and organic acids groups was lower than CON group in this study, which is mainly due to the WSC content changed dynamically during the ensiling, the WSC was released by acid hydrolysis of fiber fraction, was used by LAB for the production of organic acids
Summary
Corn silage is a highly nutritious forage for livestock and has a higher yield and energy density as well as lower cost compared with other forage sources (Armstrong et al, 2008). A meta-analysis of 130 articles revealed that LAB inoculants improved the fermentation of grass and legume silages, but did not affect the fermentation of corn, sorghum, and sugar cane silages (Oliveira et al, 2017). Inoculated silage with LAB enhanced milk production based on a meta-analysis of 31 lactating dairy cow studies and the increased effects were not affected by forage type and LAB species (Oliveira et al, 2017; Muck et al, 2018). The insignificant effect on corn silage fermentation may be caused by the presence of higher levels of WSC and epiphytic bacteria as well as its low buffering capacities (Weinberg and Muck, 1996). Profiling of the silage microbial community may improve our understanding of silage formation and preservation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
