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

• Published in: Frontiers in microbiology 2022-05, Vol.13, p.835913-835913
• Main Authors: Forwood, Daniel L, Holman, Devin B, Chaves, Alex V, Meale, Sarah J
• Format: Article
• Language: English
• Subjects: 16S rRNA sequencing; in vitro rumen fermentation; microbial profiling; Microbiology; sorghum; unsalable vegetable silage
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2022.835913

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 batch culture technique. Crude protein and non-fiber carbohydrates in the silage increased ( ≤ 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: = 0.75; < 0.001), despite the ensiled treatments being dominated by spp., except for the control, which was dominated by and spp. ( < 0.01). Linear discriminant analysis indicated that carrot and pumpkin silages were responsible for the increased relative abundance of and spp. (log LDA score ≥ 2), respectively. After 48 h of incubation, carrot and pumpkin inclusion increased ( < 0.01) the DM digestibility by 22.5 and 31.3%, increased the total volatile fatty acids (VFAs) by 16 and 20.6% ( < 0.01), respectively, and showed a tendency ( = 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.