Lentilactobacillus hilgardii Inoculum, Dry Matter Contents at Harvest and Length of Conservation Affect Fermentation Characteristics and Aerobic Stability of Corn Silage.

Francesco Ferrero,Ernesto Tabacco,Giorgio Borreani

doi:10.3389/fmicb.2021.675563

Francesco Ferrero, Ernesto Tabacco + Show 1 more

Open Access

https://doi.org/10.3389/fmicb.2021.675563

Copy DOI

Journal: Frontiers in Microbiology	Publication Date: Jun 2, 2021
Citations: 10	License type: CC BY 4.0

Affiliation: University of Turin

Abstract

Heterofermentative Lentilactobacillus hilgardii isolated from sugarcane silage, has recently been proposed as a silage inoculant to increase aerobic stability. Various conditions can influence the activity of LAB and their ability to alter silage quality (e.g., DM content and length of conservation). The aim of this study has been to evaluate the effect of L. hilgardii on the fermentation quality and aerobic stability of whole crop corn silage with different DM contents (from 26 to 45%), conserved for various conservation lengths (13–272 days). The silages were analyzed for their DM content, pH, fermentative profile, microbial count, and aerobic stability. L. hilgardii showed a positive effect on improving the aerobic stability of silages, due its ability to produce acetic acid, and reduced the yeast count. The acetic acid content increased as the conservation period increased and decreased as the DM content increased. The yeast count was reduced during conservation in a DM dependent manner and the inoculation with LH determined a reduction in the count of 0.48 log cfu/g. The aerobic stability increased as the conservation period increased, and the treatment with LH on average increased the aerobic stability by 19 h. The results of this experiment suggest that higher aerobic stability could be achieved in corn silages by ensiling at medium or low DM contents, or by increasing the length of conservation if a higher DM content at ensiling is needed. The inoculation with LH helps to improve the aerobic stability of corn silages by reducing the yeast count.

Highlights

The presence of spoiled silages on a farm is a challenge, and it results in a reduction of the nutritive value of the silage and an increase in the risks to animals and humans (Driehuis et al, 2018)
It was negatively correlated with the microbial counts and fiber component of the silages (NDF, Acid detergent fiber (ADF), and hemicellulose)
The present study indicated that the aerobic stability of silage is closely related to the yeast count and, albeit indirectly, to the antifungal activity of acetic acid, and that several interacting factors can influence its magnitude

Summary

Introduction

The presence of spoiled silages on a farm is a challenge, and it results in a reduction of the nutritive value of the silage and an increase in the risks to animals and humans (Driehuis et al, 2018). Aerobic deterioration is common in many silages that are opened and exposed to air, with the rate of spoilage being highly dependent on the numbers and activity of the spoilage organisms in the silage and on the fermentative profile of the silo at opening (Muck et al, 2018). Acetic acid has been reported to be an effective compound that improves aerobic stability by reducing yeasts during conservation and by limiting their growth after silage is exposed to air (Kleinschmidt and Kung, 2006; Comino et al, 2014; Ferrero et al, 2019). Subsequent studies were conducted to evaluate the impact of L. hilgardii on ensiling fermentation and on the aerobic stability of corn silages, and they reported higher concentrations of acetic acid, lower yeast populations, and a higher aerobic stability than uninoculated silages (Reis et al, 2018; Ferrero et al, 2019; Costa et al, 2021)

Methods

Results

Conclusion