Abstract: 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.

Key words: Alfalfa, Rapeseed straw, Mixed silage, Silage quality, Fermentation quality

摘要： 为探究紫花苜蓿与油菜秸秆按不同比例混贮对其营养品质和发酵品质的影响，本试验以初花期紫花苜蓿和成熟期油菜秸秆为原料，紫花苜蓿和油菜秸秆分别以10∶0（T1），8∶2（T2），7∶3（T3），6∶4（T4），5∶5（T5），4∶6（T6），3∶7（T7），2∶8（T8）和0∶10（T9）进行混贮，分别发酵5，10，20，40和60 d时开袋，采用感官评价，V-Score评分体系对青贮饲料进行综合评价，并分析营养和发酵特性。结果表明：紫花苜蓿单独青贮（T1）发酵较差，添加油菜秸秆可提升乳酸含量，降低pH值、氨态氮/总氮。油菜秸秆单贮（T9）营养价值较低，随紫花苜蓿比例增加，粗蛋白和粗脂肪含量增加，中性洗涤纤维和酸性洗涤纤维降低。随青贮时间延长，各处理组的干物质、粗蛋白、粗脂肪、中性洗涤纤维、酸性洗涤纤维含量呈下降趋势。感官评价和V-Score均显示，青贮40 d时得分较高。青贮40 d时，各处理的pH值较低。青贮发酵40 d，紫花苜蓿∶油菜秸秆为6∶4时，混贮效果最佳，其研究结果为确定紫花苜蓿与油菜秸秆的最佳混贮配比与发酵时间，提供了理论依据。

关键词: 紫花苜蓿, 油菜秸秆, 混合青贮, 营养品质, 发酵品质