豆科牧草的属间、属内、种间与种内均存在着巨大的遗传变异 ,利用这种变异 ,通过育种与选择 ,已培育出可良好地适应广泛的环境与管理条件的品种 ,遗传操作为此提供了更为广阔的空间。在豆科牧草固氮方面 ,对固氮过程、氮向伴生禾草的传送途径及残余氮对后继农作物的价值均有了进一步的理解。对包括施氮、采摘策略和影响混播草地中禾本科 豆科牧草平衡的胁迫等相互作用因素均已给予了阐明。在禾草 /白三叶草草地为基础的家畜生产系统中 ,氮素的损失及其对环境产生的不良作用低于大量施氮的禾草草地系统。与禾草相比 ,豆科牧草无论是用作放牧、青贮或用作干草 ,其物理、化学和解剖学等方面的特性均可增加家畜的嗜食性和自由采食量。由于豆科牧草的营养价值、可利用营养成分和采食特征 ,在单一豆科牧草或豆科牧草比重较大的禾草 豆科牧草混播草地上采食的不同种类、不同类型家畜的个体生产性能均优于在禾草草地上采食者。值得注意的是浓缩单宁在动物营养中的有益作用 ,这类单宁存在于诸如百脉根 (Lotuscorniculatus)、红豆草 (Onobrychisviciifolia)和冠状岩黄芪(Hedyscrumcoroharium)等植物中 ,其防止家畜患膨胀病 ,通过使较多的氨态氮到达小肠而提高氮素的利用 ,并减轻绵羊肠道中线虫的作用。显然 ,培育 Legume forage genus, genus, interspecific and intraspecific genetic variation exists, the use of this mutation, through breeding and selection, has been well developed to adapt to a wide range of environmental and management conditions of the species, genetic Operation provides a broader space for this purpose. In the field of leguminous forages, there is a further understanding of the processes of nitrogen fixation, transmission of nitrogen to associated grasses, and the value of residual nitrogen for subsequent crops. Interaction factors including nitrogen application, picking strategies and stresses affecting the balance of gramineous forage legumes in the mixed-sown grasslands have been elucidated. In the livestock production system based on grass / white clover grassland, the loss of nitrogen and its adverse effect on the environment are lower than those of a large quantity of nitrogen-applied grasses and grassland systems. Compared with grasses, legumes can be used for grazing, silage or hay. Physical, chemical and anatomical characteristics of leguminous grasses increase the diet and free feed intake of livestock. Because of the nutritional value of legumes, the nutrient production and feed characteristics can be exploited to produce individual species of different types and types of livestock on mixed legume forage grasses that have a higher proportion of legumes or leguminous forages The performance is better than in the grazing meadow feed. Of note is the beneficial effect of concentrated tannins in animal nutrition, such tannins found in plants such as Lotuscorniculatus, Onobrychis viciifolia and Hedyscrum coroharium, which prevent the livestock from swelling Diseases, increased nitrogen utilization by allowing more ammonia nitrogen to reach the small intestine, and mitigating the effects of nematodes in the gut of sheep. Obviously, nurture