Abstract: [Objective] This study aimed to clarify the effects of mixed ensiling of fresh corn stover and vegetable soybean straw on feed quality and in vitro digestibility, and to screen for the optimal mixing ratio. [Methods] Using ′Zhengyuan Nuo 432′ fresh corn stover and ′Zhexian 86′ vegetable soybean straw as raw materials, seven treatments were designed based on the fresh weight ratio of fresh corn stover∶vegetable soybean straw as 0∶1 （A1）, 1∶3 （A2）, 2∶3 （A3）, 1∶1 （A4）, 3∶2 （A5）, 3∶1 （A6）, and 1∶0 （A7）. A 60-day ensiling trial was conducted an experiment. The effects of different mixing ratios on silage feed quality were comprehensively evaluated using sensory evaluation, nutritional component analysis, fermentation quality analysis, in vitro digestibility determination, and correlation analysis of the indicators, along with the Entropy Weight-TOPSIS method. [Results] In the sensory evaluation, treatments A3, A4, A5, and A6 were rated as excellent, exhibiting an aromatic odor, intact structure, and good color retention, while A1, A2, and A7 were rated as good. Regarding nutritional components, the crude protein （CP） content significantly increased as the proportion of vegetable soybean straw increased （P<0.05）, while the water soluble carbohydrate （WSC） and neutral detergent fiber （NDF） contents significantly increased as the proportion of fresh corn stover increased （P<0.05）; no significant differences were observed in dry matter （DM） and acid detergent fiber （ADF） contents among all treatments （P>0.05）. In terms of fermentation quality, lactic acid （LA） content significantly increased with the elevation in fresh corn stover proportion （P<0.05）; acetic acid （AA）, butyric acid （BA）, and ammoniacal nitrogen （NH₃-N） contents first decreased and then increased with the increase in fresh corn stover proportion; treatments A5 and A6 exhibited higher LA content and lower BA and NH₃-N contents; the pH values did not significantly differ among treatments （P>0.05）. Regarding in vitro digestibility, the in vitro neutral detergent fiber digestibility （IVNDFD） significantly decreased with the increase in fresh corn stover proportion （P<0.05）; the in vitro dry matter digestibility （IVDMD） of the mixed silage groups was significantly higher than that of the single fresh corn stover silage group （A7） （P<0.05）. Correlation analysis showed that CP was highly significantly positively correlated with IVNDFD and IVDMD （P<0.01）, and highly significantly negatively correlated with WSC （P<0.01）. ADF was highly significantly positively correlated with AA, BA, NH₃-N, and pH （P<0.01） and highly significantly negatively correlated with WSC, LA and IVDMD （P<0.01）, and highly significantly negatively correlated with IVNDFD （P<0.01）. WSC was highly significantly positively correlated with LA and IVDMD （P<0.01）, and highly significantly negatively correlated with AA, BA, NH₃-N, and pH （P<0.01）. IVNDFD was highly significantly positively correlated with IVDMD （P<0.01）. The comprehensive evaluation using the Entropy Weight-TOPSIS method indicated that the A5 treatment group （fresh corn stover∶vegetable soybean straw=3∶2） achieved the highest comprehensive score （0.45） and ranked first. [Conclusion] When fresh corn stover and vegetable soybean straw were mixed and ensiled at a fresh weight ratio of 3∶2, the feed quality was optimal, and the in vitro digestibility was relatively high. The observed correlations between indicators revealed the intrinsic links among raw material nutritional characteristics, fermentation process, and digestion utilization efficiency, providing a scientific basis for the feed utilization of these straw resources.

Key words: fresh corn stover, vegetable soybean straw, mixed silage, feed quality, in vitro digestibility, Entropy Weight-TOPSIS method