Crop Sorghum Ensiled With Unsalable Vegetables Increases Silage Microbial Diversity

Abstract

Ensiling vegetables with forage crops is a suggested method of waste diversion and can be directly utilized as a livestock feed. Carrot or pumpkin, ensiled at 0, 20, or 40% dry matter (DM) with crop sorghum, and with or without a second-generation silage inoculant were assessed for nutritive composition, organic acid profiles, aerobic stability and in vitro rumen fermentation characteristics. The study was a completely randomized design, with the fixed effects consisting of vegetable type (carrot vs. pumpkin), level (i.e., the level of vegetables), inoculant (inoculant or non-inoculant) and the interactions, and mini-silos within treatment as the random effect. The experimental unit for sorghum treatments represented by each mini-silo (5 kg capacity). Silage was sampled after 70-days ensiling for nutrient composition, 14-day aerobic stability, organic acid profiles and microbial diversity. After 24 h in vitro incubation, rumen fermentation parameters were assessed, measuring gas and methane (CH4) production, in vitro digestibility and volatile fatty acid concentrations. Sorghum ensiled with carrot or pumpkin at 20% or 40% DM increased crude fat (P ≤ 0.01) and decreased (P ≤ 0.01) silage surface temperature upon aerobic exposure compared to the control. Bacterial communities analyzed through 16S rRNA gene sequencing linearly increased (P ≤ 0.01) in diversity across both vegetables when the vegetable proportion was increased in the silage; dominated by Lactobacillus species. ITS analysis of the fungal microbiota upon silage opening and after 14 days (aerobic stability) identified increased (P ≤ 0.03) fungal diversity with increasing vegetable proportions, predominantly populated by Fusarium denticulatum, Issatchenkia orientalis, Kazachstania humilis, and Monascus purpureus. Upon assessment in vitro, there was an increase (P ≤ 0.04) in in vitro digestibility and some CH4 parameters (% CH4, and mg CH4/g DM), with no effect (P ≥ 0.17) on remaining CH4 parameters (mL CH4/g DM, mg CH4/g digested DM), gas production or pH. However, increasing vegetable amount decreased percentage of acetic acid and increased percentage of propionic acid of the total VFA, decreasing A:P ratio and total VFA concentration as a result (P ≤ 0.01). The results from this study indicate including carrot or pumpkin at 20 or 40% DM in a sorghum silage can produce a highly digestible, microbially diverse and energy-rich livestock feed.

Assessment of inoculating various epiphytic microbiota on fermentative profile and microbial community dynamics in sterile Italian ryegrass

“…However, one of the main challenges during ensiling is the utilization of the wet material with uncontrolled fermentative processes, because several factors influence the synthesis of the fermentation products, such as the predominant micro-organisms in the silage, the fermentable substrates present and the types of fermentation (McDonald et al 1991). Nowadays, many researchers have evaluated the effects of microbial inoculants and mixed silages during ensiling and they showed substantial impacts on fermentation quality and microbial community (Forwood et al 2019;Wang et al 2019a;Wang et al 2019b). Nevertheless, there is a paucity of information regarding the fermentation type of silage.…”

“…Furthermore, microbiota transplantation has become a good way to assess the effects of microbiota in many industries (Panke-Buisse et al 2015;Draper et al 2018). Next generation sequencing technology also provided more possibilities to accurately monitor the microbial succession during ensiling (Forwood et al 2019;Wang et al 2019a). As these research technologies developed, we first proposed to combine the cray irradiation, microbiota transplantation and next generation sequencing methods to elucidate the adaptation process of exogenous microbiota in silage.…”

“…Nowadays, many researchers have evaluated the effects of microbial inoculants and mixed silages during ensiling and they showed substantial impacts on fermentation quality and microbial community (Forwood et al . 2019; Wang et al . 2019a; Wang et al .…”

“…Next generation sequencing technology also provided more possibilities to accurately monitor the microbial succession during ensiling (Forwood et al . 2019; Wang et al . 2019a).…”

Strategies to improve the efficiency of beef cattle production

“…Using food that does not meet the quality grade for human consumption reduces the extent to which components in ruminant diets compete with food for humans. For example, incorporation of unsalable carrot or pumpkin waste at up to 40% of dry matter in ensiled corn or sorghum did not alter silage quality and improved in vitro dry matter digestibility (Forwood et al 2019;Hooker et al 2019). Similarly, grazed forages, hay, silages, and grains are often contaminated by a wide range of mycotoxins, toxic molecules produced by fungi, often as a result of unfavourable ensiling and storage conditions (Gallo et al 2015).…”