白花草木樨与玉米秸秆混合青贮的发酵品质及有毒成分分析

Effects of different mixed ratio and fermenting period on efficiency of mixed silage of Melilotus albus and corn straw

本试验设置白花草木樨（Melilotus albus）与玉米（Zea mays）秸秆的比例为10∶0, 8∶2, 6∶4, 4∶6, 2∶8, 0∶10共6个青贮比例处理, 30、45和60 d 3个青贮时间处理, 测定发酵品质、化学成分和香豆素、双香豆素含量, 由此确定白花草木樨和玉米秸秆混合青贮的最佳比例和时间。结果表明, 随着白花草木樨比例增大, 各混贮中pH值、氨态氮/总氮和粗蛋白含量呈升高趋势, 乳酸、中性洗涤纤维和酸性洗涤纤维含量呈降低趋势, 各处理青贮饲料较青贮原料中香豆素和双香豆素含量显著降低（P〈0.05）。白花草木樨与玉米比例为2∶8的青贮品质及降毒效果最佳, 不同青贮时间, 混贮料pH值下降了3.87～4.03, 粗蛋白含量比玉米单贮增加了38.34%～46.47%, 香豆素含量降低了80.99%～81.82%, 双香豆素含量降低了90.52%～91.00%。青贮30 d后, 随时间延长, 青贮品质、香豆素及双香豆素含量无明显变化。

Melilotus albus and corn straw were mixed and silaged at ratio of 10∶0, 8∶2, 6∶4, 4∶6, 2∶8 and 0∶10, respectively. The nutrition composition, fermentation quality, coumarin and dicoumarol content were measured after 30, 45 and 60 d ensilage. The aims of this study were to seek optimal mixed silage radio and ensiling days of M.albus and corn straw, improve the fermentation quality and nutrition composition, and reduce the content of coumarin and dicoumarol. The result showed that, with the increase of the proportion of M.albus, pH, ammonia/total nitrogen, crude protein and lactic acid increased while the neutral detergent fiber and acid detergent fiber decreased. The coumarin and dicoumarol contents of all mixed silage were significantly lower （P〈0.05） than raw material of M.albus. The mixed silage with M.albus and corn straw at ratio of 2∶8 was best as the pH value reduced to 3.87-4.03, the content of crude protein increased by 38.34%-46.47% compared with single corn straw silage and the coumarin and dicoumarol content decreased by 80.99%-81.82% and 90.52%-91.00% compared to raw material of M.albus. Ensiling days had no significant effect on the fermentation quality and content of coumarin and dicoumarol.