Addition of Organic Acids and Lactobacillus acidophilus to the Leguminous Forage Chamaecrista rotundifolia Improved the Quality and Decreased Harmful Bacteria of the Silage

Simple SummaryThe leguminous forageChamaecrista rotundifoliacontains a high crude protein content and can be an important feed source for livestock. Forage is preserved mainly as silage, and microbial fermentation is key to high-quality silage. The fermentation quality of silage depends on the microbial community structure and the metabolites produced during silage fermentation. The current study provides evidence that the addition of malic or citric acid and/orLactobacillus acidophilus(L) improves the quality of silage and inhibits the growth of harmful microorganisms.AbstractThis study aimed to investigate the effects of citric acid, malic acid, andLactobacillus acidophilus(L) on fermentation parameters and the microbial community of leguminousChamaecrista rotundifoliasilage. FreshC. rotundifoliawas treated without any additive (CK), or with L (106CFU/g fresh weight), different levels (0.1, 0.3, 0.5, and 1% fresh weight) of organic acid (malic or citric acid), and the combinations of L and the different levels of organic acids for 30, 45, and 60 days of ensiling. The effects of malic acid and citric acid were similar during the ensiling process. Treatment with either citric or malic acid and also when combined with L inhibited crude protein degradation, lowered pH and ammonia nitrogen, and increased lactic acid concentration and dry matter content (p< 0.05). The neutral detergent fiber and acid detergent fiber increased initially and then decreased with fermentation time in all treatments (p< 0.05). Increasing the level of organic acid positively affected the chemical composition ofC. rotundifoliasilage. In addition, the addition of 1% organic acid increased the relative abundance ofLactobacillus, while the relative abundances ofClostridiumandEnterobacterdecreased at 60 days (p< 0.05). Moreover, both organic acids and combined additives increased (p< 0.05) the relative abundance ofCyanobacteriaat 60 days of fermentation. We concluded that adding malic acid, citric acid, and L combined with an organic acid could improve the quality ofC. rotundifoliasilage and increase the relative abundance of beneficial bacteria. The addition of organic acid at a level of 1% was the most effective.Keywords:citric acid;Chamaecrista rotundifoliasilage;Lactobacillus acidophilus;malic acid;microbial diversity