Abstract:

[Objective] To assess the effects of different wilting time and ensiling time on fermentation quality of whole plant corn silage. [Method] The silage corn Zea mays L. var. Quchen 9 was used as raw material of ensiling experiment. At late milky ripeness stage, the whole plant silage corn was harvested and crushed, and was subsequently wilted in the shade for 0 （CK）, 1, 2, 3 and 4 days respectively before being ensiled in separate plastic barrel with volume of 5 L. The fermentation quality was evaluated after 60, 90 and 120 days of ensiling. [Result] The moisture content of corn silage decreased with the extension of wiling time, and the corn silage prepared with raw material wilted for 2, 3 and 4 days had significantly （P<0.05） lower moisture content than CK. The pH value of corn silage prepared with raw material wilted for 2, 3 and 4 days was significantly （P<0.05） higher than that of CK, with the exception of wilted for 2 days and ensiled for 120 days. Wilting time exhibited significant （P<0.05) effects on the contents of lactic acid, butyric acid, neutral detergent fiber （NDF） and acid detergent fiber （ADF）, whereas ensiling time only significantly （P<0.05） affected the contents of lactic acid and butyric acid. In addition, lactic acid content increased with the prolongation of ensiling time, and butyric acid content increased after the raw material being wilted. In CK, corn silage ensiled for 90 and 120 days had significantly （P<0.05） higher NDF concentrations in comparision to that ensiled for 60 days. The fermentation quality of corn silage was diminished as a result of wilting in V-Score analysis using ammoniacal nitrogen, acetic acid, propionic acid, and butyric acid as evaluative indicators. The corn silage prepared with crushed raw material without being wilted （CK） had better fermentation quality. [Conclusion] Corn silage has better performance in comprehensive fermentation quality when the raw material is ensiled for 60 days without wilting. It is not recommended to reduce the moisture content by wilting after crushing and then ensiles when the moisture content of raw material is 74%.

Key words: corn silage, wilting time, organic acid, ensiling time, fermentation quality