Fermentation and aerobic stability of Napier grass silage treated with different levels of citric acid residue

Abstract

AbstractThe experiment was conducted to investigate the effects of different levels of citric acid residue (CAR) on the fermentation quality and aerobic stability of Napier grass. Napier grass was ensiled with no additives control (CON), 1.2% CAR (C1), 3.6% CAR (C2) and 6.0% CAR (C3) on a fresh weight basis in laboratory silos for 3, 6, 9, 15 and 45 days. After opening the silos, the silages were subjected to analyzing the chemical and microbial compositions, and the residual silages ensiled for 45 days were evaluated for aerobic stability. Addition of CAR increased lactic acid/acetic acid, dry matter, lactic acid and water‐soluble carbohydrate contents, and decreased pH, acetic acid, ammonia nitrogen (NH3‐N), neutral detergent fiber, acid detergent fiber and cellulose contents as compared to the control. At the day 45 of ensiling, the C2 and C3 silages showed higher lactic acid contents and lactic acid/acetic acid, and lower NH3‐N and acetic acid contents than these of C1 silages. There was no significant difference in the aerobic stability between CAR‐treated silages and the control. Application of CAR effectively improved the fermentation quality of Napier grass, but had no obvious effects on the improvement of aerobic stability. In conclusion, application of CAR at the level of 3.6% or 6.0% is recommended for Napier grass silage making.