丙酸对多花黑麦草青贮发酵动态变化的影响

The effect of propionic acid addition on the dynamic fermentation changes of Italian ryegrass(Lolium multiflorum) silage

在实验室条件下制备多花黑麦草青贮饲料,评定不同浓度丙酸(0,0.20%,0.25%,0.30%)对其青贮发酵动态变化的影响。结果表明,添加丙酸对多花黑麦草青贮过程中VFAs含量无明显的影响,增加了发酵后期乳酸及WSC的含量及乳酸/乙酸值,在发酵初期降低了乳酸的含量和青贮初期pH值;降低AN/TN值、乙酸含量及生成速度;丙酸在整个发酵过程中呈现很高的趋势。综合考虑,0.25%添加水平,多花黑麦草青贮发酵品质最好。

The ensiling of Italian ryegrass （Lolium multiflorurn） silage was carried out under laboratory conditions and propionic acid was added to give a series of different concentrations （0, 0.20%, 0.25% and 0.30%） to investigate the effect on dynamic changes in the fermentation process. Adding propionic acid to the L. multiflorum silage did not influence the VFAs during ensiling, but increased the lactic acid, WSC and LA/AA at the late stages of ensiling. The propionic acid additive decreased lactic acid and the pH value during the early stages of the fermentation. The AN/TN value and acetic acid content were also decreased in the silage. The propionic acid content was always high during the whole process of ensiling. These results suggest that adding propionic acid to the silage at a rate of 0.25 % is the optimum for fermentation quality of L. multiflorurn.