Evaluating the fermentation quality and bacterial community of high-moisture whole-plant quinoa silage ensiled with different additives.

Abstract

To explore the potential of whole-plant quinoa (WPQ) as a high-protein source for livestock feed, this study evaluated the effects of additives on the fermentation quality and bacterial community of high-moisture WPQ silage. High-moisture WPQ was ensiled with one of the following additives: untreated control (C), fibrolytic enzyme (E), molasses (M), LAB inoculant (L), a combination of fibrolytic enzyme and LAB inoculant (EL) and a combination of molasses and LAB inoculant (ML). The fermentation quality and bacterial community after 60days of ensiling were analysed. Naturally fermented WPQ exhibited acetic acid-type fermentation dominated by enterobacteria, with low lactic acid content (37.0g/kg DM), and high pH value (5.65), acetic acid (70.8g/kg DM) and NH3 -N production (229g/kg TN). Adding molasses alone or combined with LAB inoculant shifted the fermentation pattern towards increased intensity of lactic acid fermentation, lowering the pH value (<4.56), contents of acetic acid (<46.7g/kg DM) and NH3 -N (<140g/kg TN) and total abundance of enterobacteria (<16.0%), and increasing the lactic acid content (>60.5g/kg DM), lactic/acetic acid ratio (>1.40) and the relative abundance of Lactobacillus (>83.0%). The results suggested that the lack of fermentable sugar could be the main factor of restricting extensive lactic acid fermentation in WPQ silage. Supplementing fermentable sugar or co-ensiling with materials with high WSC content and low moisture content are expected to be beneficial strategies for producing high-quality WPQ silage. High biomass production and high protein content make WPQ to be an ideal forage source for livestock feed. Results of this study revealed the restricting factor for extensive lactic acid fermentation in WPQ silage, which could be helpful in producing high-quality WPQ silage.