Abstract: To solve the problem of unbalanced nutrition of Alfalfa (Medicago sativa) and Gramineous grass silage alone,Alfalfa was intercropped with Triticale (Triticosecale Wittmack),Oats (Avena sativa),Maize (Zea mays) and Sweet Sorghum (Sorghum bicolor) and then silaged. The microstructure,nutritional quality,sensory quality,fermentation quality and in vitro digestion effect of four kinds of Gramineous grasses before and after silage were studied. The results showed that a large number of folds were appeared on the surface of forage leaves after silage,the epidermal cells of the leaves were arranged messily,and the cell boundaries were not clear. Compared with fresh grass,in vitro digestion of silage produced a large number of fragmented structures,which made it be more degraded by rumen microorganisms. The crude protein content and relative forage value of the four mixed silage treatments increased by 23.79%~50.07% and 9.44%~15.97%,respectively,compared with the single silage of Gramineous grasses. The contents of water soluble carbohydrat and lactic acid increased by 5.38%~84.41% and 38.14%~93.95%,respectively,compared with Alfalfa single silage. Among the four mixed silage treatments,the fermentation quality and sensory quality scores of Alfalfa + Sweet Sorghum mixed silage were the highest. In summary,the intercropping of Alfalfa and Sweet Sorghum and then mixed silage could not only balance and retain nutrients but also improve fermentation quality.

Key words: Bean/grass intercropping, Mixed ensiling, Microstructure, Silage quality, In vitro digestion

摘要： 为解决紫花苜蓿（Medicago sativa）和禾本科牧草单独青贮营养不均衡的难题，本研究将紫花苜蓿分别和小黑麦（Triticosecale Wittmack）、燕麦（Avena sativa）、玉米（Zea mays）及甜高粱（Sorghum bicolor）进行间作种植并青贮，对青贮前后4种禾本科牧草叶显微结构、营养品质、感官品质、发酵品质及体外消化效果进行研究。结果表明：青贮后牧草叶片表面出现大量褶皱，叶片表皮细胞排列凌乱，细胞边界不清晰；与鲜草相比，青贮处理经体外消化会产生大量破碎结构，从而使其被瘤胃微生物降解的程度更高。4种混贮处理的粗蛋白含量与相对饲用价值比禾本科牧草单贮增加了23.79%~50.07%和9.44%~15.97%；而可溶性碳水化合物和乳酸含量比紫花苜蓿单贮增加了5.38%~84.41%和38.14%~93.95%。4种混贮处理中，紫花苜蓿+甜高粱混贮的发酵品质和感官品质评分均为最高。综上，紫花苜蓿和甜高粱间作种植后进行混合青贮，既能均衡并保留营养成分，还可改善发酵品质。

关键词: 豆/禾牧草间作, 混合青贮, 显微结构, 青贮品质, 体外消化