To investigate the effects of mixing alfalfa and rapeseed straw in different ratios on the nutritional and fermentation quality of silage， a study was conducted using alfalfa at the early flowering stage and mature rapeseed straw as raw materials. The materials were mixed in the following ratios：10∶0 （T1），8∶2 （T2），7∶3 （T3），6∶4 （T4），5∶5 （T5），4∶6 （T6），3∶7 （T7），2∶8 （T8），and 0∶10 （T9）. The silage bags were opened after 5，10，20，40， and 60 days of fermentation. Silage quality was comprehensively evaluated using sensory evaluation and the V-Score system， and its nutritional and fermentation characteristics were analyzed. The results showed that alfalfa alone （T1） exhibited poor fermentation， while the addition of rapeseed straw increased lactic acid content， and decreased pH and ammonia-nitrogen/total nitrogen （NH₃-N/TN）. Silage made from rapeseed straw alone （T9） had low nutritional value. As the proportion of alfalfa increased， the contents of crude protein and crude fat increased， while the neutral detergent fiber （NDF） and acid detergent fiber （ADF） contents decreased. Prolonging the ensiling time led to decreasing trends in dry matter， crude protein， crude fat， NDF， and ADF contents across all treatments. Both sensory evaluation and V-Score indicated the highest scores at 40 day silage. At this time point， all treatments showed lower pH values. The optimal mixed silage effect was achieved with the alfalfa to rapeseed straw ratio of 6∶4 and the fermentation period of 40 day. These findings provide a theoretical basis for determining the best mixing ratio and fermentation duration for alfalfa and rapeseed straw silage.

Alfalfa  /  Rapeseed straw  /  Mixed silage  /  Silage quality  /  Fermentation quality