Effect of different moisture contents on fermentation quality of baling silage of monoculture oat and oat and common vetch mixture

In order to study the effects of different moisture contents and single silage and mixed silage on the quality of baling silage, oat (Avena sativa) silage alone, oat and common vetch (Vicia sativa) mixed silage (6:4) were wilted to target moisture contents (45%~50% (A1) and 65%~70% (A2) for baling silage. These bales were sampled on 40, 80 and 120 days after ensiling, with 3 replicates for each treatment. The results showed that moisture contents, silage alone and mixed silage had significant effects on silage quality. Treatments at 65%~70% moisture content had more stable contents of crude protein (CP)、lactic acid (LA) and water soluble carbohydrate (WSC), lower pH value and ammonia nitrogen (NH3-N) counts, showing a better ensiling effectiveness. Treatment A1 had much larger decreasing amount than A2 on CP content. A2H significantly reduced pH value, and its LA content remained the highest at 40, 80 and 120 d, still up to 0.82% on 120 d, 64.00% higher than the lowest A1CK (0.50%). Treatments at mixed seeded oat and vetch can significantly improve the quality of silage fermentation. After 40 d of ensiling, A2H had the highest calcium and phosphorus contents (1.34% and 0.24%), and A1H was in the second (1.16% and 0.23%), which were significantly (P<0.01) higher than control. In addition, the CP content of A1 and A2H was 31.94% and 14.70% higher than that of control after 80 d of ensiling, respectively. In conclusion, in alpine pastoral area of Qinghai-Tibet Plateau, mixed seeding oat and vetch harvested at grain filling and flowering stage respectively, with 65%~70% moisture content could significantly improve the quality of baling silage.