AUTHOR=Forwood Daniel L. , Holman Devin B. , Chaves Alex V. , Meale Sarah J. 

TITLE=Unsalable Vegetables Ensiled With Sorghum Promote Heterofermentative Lactic Acid Bacteria and Improve in vitro Rumen Fermentation

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.835913

DOI=10.3389/fmicb.2022.835913

ISSN=1664-302X

ABSTRACT=<p>This study characterized the nutritive and microbial profiles and the fermentation characteristics of silage with the following compositions on a dry matter (DM) basis: (1) 100% sorghum, (2) 70% sorghum + 30% carrot or pumpkin, and (3) 40% sorghum + 60% carrot or pumpkin. The treatments were further divided based on the addition or no addition of a probiotic inoculant. After 70 days of ensiling, the silage was incubated for 48 h using the <italic>in vitro</italic> batch culture technique. Crude protein and non-fiber carbohydrates in the silage increased (<italic>P</italic> ≤ 0.01) by 5.7 percent point (pp) and 9.6 pp, respectively, with pumpkin at 60% DM. The V4 region of the 16S rRNA gene was sequenced to profile pre-ensiled and ensiled archeal and bacterial communities. Silages containing carrot or pumpkin strongly influenced the microbial structure (PERMANOVA: <italic>R</italic><sup>2</sup> = 0.75; <italic>P</italic> &lt; 0.001), despite the ensiled treatments being dominated by <italic>Lactobacillus</italic> spp., except for the control, which was dominated by <italic>Weissella</italic> and <italic>Pediococcus</italic> spp. (<italic>P</italic> &lt; 0.01). Linear discriminant analysis indicated that carrot and pumpkin silages were responsible for the increased relative abundance of <italic>Lactobacillus</italic> and <italic>Acinetobacter</italic> spp. (log LDA score ≥ 2), respectively. After 48 h of incubation, carrot and pumpkin inclusion increased (<italic>P</italic> &lt; 0.01) the <italic>in vitro</italic> DM digestibility by 22.5 and 31.3%, increased the total volatile fatty acids (VFAs) by 16 and 20.6% (<italic>P</italic> &lt; 0.01), respectively, and showed a tendency (<italic>P</italic> = 0.07) to increase the gas production. Therefore, this study supports the use of carrot or pumpkin in sorghum silages to maximize feed digestibility and total VFA concentrations.</p>