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

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 (P0.05) 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.