The fermentation quality of mixed silage of Medicago sativa and Roegneria turczaninovii

The different proportions of Medicago sativa and Roegneria turczaninovii were ensiled to optimize the proportion of mixed silage by measuring the nutrition constituent, which was used to estimate fermentation quality. The results of this study showed that the silage increased the content of DM and NDF and decreased the CP, ADF, WSC of alfalfa products, and that the silage increased the content of DM, NDF, CP and ADF, and decreased the EE and WSC of R. turczaninovii. The CP and Ca content of mixed silage was significantly higher than R. turczaninovii silage and lower than alfalfa silage, and the content of DM, NDF, ADF was significantly lower than R. turczaninovii silage. As the proportion of R. turczaninovii increased in mixed silage, the pH decreased, and the content of lactic acid accounting for total acid in mixed silage was between two single silages. The content of acetic acid accounting for total acid in the mixed treatment of alfalfa and R. turczaninovii (3∶7) was 33.9%, and was significantly higher than other treatments(P＜0.05), and butyric acid in mixed treatment was little. The content of ammonium nitrogen accounting for total nitrogen in mixed silage was significantly lower than alfalfa silage(P＜0.05)，and was significantly higher than R. turczaninovii silage(P＜0.05). Counts of lactic acid bacteria in all treatments after ensiling reached 106 cfu/g（FM）, and was higher than nonensiling, and counts of lactic acid bacteria and mould in mixed treatments was high than two single silage. The score of fermentation quality of R. turczaninovii silage was 97, and the content of ammonium nitrogen was low; therefore, R. turczaninovii silage was optimal treatment.