Dynamics of Bacterial Community and Fermentation Quality during Ensiling of Wilted and Unwilted <i>Moringa oleifera</i> Leaf Silage with or without Lactic Acid Bacterial Inoculants

Abstract

To investigate the effects of wilting and lactic acid bacterial inoculants on the fermentation quality and bacterial community of <i>Moringa oleifera</i> leaf silage, fresh and wilted <i>M. oleifera</i> leaves were ensiled with or without <i>Lactobacillus farciminis</i> LF or <i>Lactococcus lactis</i> LL for 1, 7, 14, 30, and 60 days. The results showed that wilting, inoculants, and their interaction exerted significant (<i>P < </i>0.05) effects on the fermentation characteristics covering dry matter loss, pH value, lactic acid bacterial number, the ratio of lactic acid to acetic acid, and the relative abundances of bacteria, like for species of <i>Lactobacillus</i>, <i>Lactococcus</i>, <i>Pediococcus</i>, <i>Enterococcus</i>, <i>Leuconostoc</i>, and <i>Enterobacter</i> Both LF and LL improved the fermentation quality of wilted and unwilted <i>M. oleifera</i> leaf silage by accelerating lactic acid production and pH decline, decreasing dry matter loss, and inhibiting yeast and coliform bacterial growth through the whole fermentation process. During ensiling, the abundances of <i>Lactococcus</i>, <i>Enterococcus,</i> and <i>Leuconostoc</i> spp. increased from day 1 to day 7 and then declined sharply from day 7 to day 14. Members of these genera and <i>Enterobacter</i> were inhibited, whereas <i>Lactobacillus</i> spp. were enhanced by these two lactic acid bacterial inoculants. The relative abundances of <i>Enterobacter</i>, <i>Enterococcus,</i> and <i>Pediococcus</i> spp. in inoculated silages were relatively low during the whole ensiling process. A lower abundance of <i>Enterobacter</i> spp. was observed in wilted silages than in unwilted silages. In summary, wilting and lactic acid bacterial inoculants had an influence on bacterial community and the fermentation process; LF and LL improved the fermentation quality of wilted and unwilted <i>M. oleifera</i> leaf silage.<b>IMPORTANCE</b><i>Moringa oleifera</i> leaf is a high-quality feed source for livestock and is increasingly used all over the world. Ensiling might be an effective method for preservation of the leaves. In the practice of silage making, lactic acid bacterial inoculants and wilting are commonly used to improve nutrition preservation. Monitoring the changes in a bacterial community during fermentation gives an insight into understanding and improving the ensiling process. Our results suggest that wilting and lactic acid bacterial inoculants had an influence on the bacterial community and fermentation process of <i>M. oleifera</i> leaf silage. Wilting showed positive effects on silage fermentation by decreasing the abundance of <i>Enterobacter</i> spp., while LF and LL improved the fermentation quality by inhibiting <i>Enterobacter</i> spp. and enhancing <i>Lactobacillus</i> spp. Both LF and LL accelerated the ensiling process from cocci (like <i>Lactococcus</i>, <i>Enterococcus,</i> and <i>Leuconostoc</i> spp.) to lactobacilli.