Abstract: [Objective] To evaluate the effects of different mixing sowing ratios of Avena sativa and Vicia benghalensis on biomass yield and silage quality. [Methods] The experiment was conducted in Sandaoshui Township, Sinan County, Tongren City, Guizhou Province （27°70′N, 108°09′E） using a single-factor completely randomized design. Six treatments were established with A. sativa:V. benghalensis mixing sowing ratios （by mass） of 3:1 （T1）, 4:1 （T2）, 5:1 （T3）, and 6:1 （T4）, sole A. sativa （C1） and sole V. benghalensis （C2）, each with three replicates. After determining biomass yield at the second cutting stage （A. sativa at milk stage, V. benghalensis at initial flowering stage）, samples were collected, sealed in vacuum bags, and stored at room temperature in a dry indoor environment, and silage quality parameters were assessed after 30 days. [Results] The total fresh and dry forage yields were highest in the C1 treatment, but there was no significant difference （P>0.05） compared with the T4 treatment; the dry forage yields of C1 and T4 treatments were significantly higher （P<0.05） than those of other treatments, and their fresh forage yields were significantly higher （P<0.05） than all treatments except T3. Regarding nutritional composition, dry matter （DM） content showed no significant differences （P>0.05） among T1, T2, T3, T4, and C1 treatments, but was significantly lower （P<0.05） than that of C2 treatment; crude fat （EE） content did not differ significantly （P>0.05） among treatments; acid detergent fiber （ADF） content showed no significant differences （P>0.05） among T1, T2, T3, T4, and C1 treatments; water-soluble carbohydrate （WSC） content in T4 treatment was not significantly different （P>0.05） from C1 treatment, but both were significantly higher （P<0.05） than other treatments. For fermentation parameters, pH and ammonia nitrogen/total nitrogen ratios in T1, T2, T3, and T4 treatments decreased with increasing mixing sowing ratios, while lactic acid and acetic acid contents increased with increasing mixing sowing ratios. Butyric acid was not detected. [Conclusion] Under the experimental conditions, mixing sowing of A. sativa and V. benghalensis enhanced forage nutritional quality and silage fermentation quality, with an optimal mixing sowing ratio of 6:1.

Key words: Avena sativa, Vicia benghalensis, mixing sowing ratio, silage quality