Effect of tannic acids on the fermentation quality and aerobic stability of cassava foliage

The objective of this study was to evaluate the effects of tannic acids on the fermentation quality, aerobic stability, and nutrient content of cassava (Manihot esculenta) foliage silage and to determine the optimal tannic acid addition rate. Experimental treatments included a control (CK) and three treatments of different tannic acid addition ratios (0.5%, 1%, 2% of fresh weight). Silos were opened after 30 days of ensiling and fermentation quality, aerobic stability, and chemical composition were analyzed. Results showed that the addition of tannic acids increased lactic acid content (LA), decreased pH and butyric acid content (P < 0.05), and improved aerobic stability relative to the control. In the 1% addition treatment, pH was lower and LA content and silage scores were higher than in other treatments. Additionally, fiber content decreased (P < 0.05), and crude protein (CP) and relative feed value (RFV) of tannic acid treatments increased. We found that the RFV of the 1% addition treatment was significantly higher than in other treatments. In conclusion, tannic acid addition improves the fermentation quality, aerobic stability, and nutrient value of cassava foliage silage, and results suggest that a 1% tannic acid addition is the most appropriate treatment.