Effects of Total Flavonoids from Taraxacum mongolicum Hand.-Mazz. on Fermentation Quality, Antioxidant Status and Microbial Community of Caragana korshinskii Kom. silage

Abstract

The present study aims to investigate effects of total flavonoids from Taraxacum mongolicum Hand.-Mazz. (FT) on fermentation quality, antioxidant status, and microbial community of Caragana korshinskii Kom. (CK) silage. CK was ensiled with no additive (CON), 1% FT, and 2% FT on a fresh weight (FW) basis for 60 days. The results showed that 1% FT and 2% FT groups displayed higher DM content than CON group, and 2% FT group had the best effect on nutrient preservation. Compared with CON and 1% FT groups, 2% FT group exhibited the best silage fermentation quality and the highest antioxidant activity, including increased lactic acid, acetic acid concentrations, and the activities of antioxidant enzymes, as well as decreased pH and the ammonia nitrogen (NH3-N) concentration. Moreover, the addition of 2% FT significantly affected the microbial community, such as increased abundance of Lactobacillus and decreased abundances of Pseudomonas and unidentified Cyanobacteria. The abundances of Lactobacillus parafarraginis and Lactobacillus brevis were negatively correlated to pH, while they were positively correlated with T-AOC, GSH-Px, and CAT activities. In conclusion, 2% FT may be used as additives to promote the fermentation quality and antioxidant activity of CK silage.