Abstract: Forage-livestock balance is the foundation of sustainable development of grassland livestock husbandry and over-grazing is deemed to be the cause of grassland degradation.In this paper,the forage-livestock dynamic balance was estimated by the indices such as dry matter,net energy demand for lactation,digestible crude protein,etc.in Saibei precinct of Zhangjiakou city.The results show: 1.The self-support ratio of fodders was high in 1995-2001,declined gradually in 2002-2005,while increased slightly in 2006;the self-support ratio of coarse fodders was higher than that of fine fodders except some special years.2.The nutrition value of coarse fodders was high with the net energy for milking at 4.66~4.86 MJ/kg DM which neared to standard hay and the digestible crude protein 59.2~68.0 g/kg DM which could meet the protein need of dairy cattle in different growing phases according to the feeding standard of dairy cattle.3.Based on the present forage planting scale,productivity level,exploitation potential of water-soil resources,and utilization of the unformed woodlands,the fitting amount of dairy cattle raised would be 5351 heads at present and 7329 heads in the near future years in Saibei precinct of Zhangjiakou city.

Key words: Agri-pastoral ecotone, Agri-pastoral compound ecosystem, Optimization, Forage-livestock balance

摘要： 草畜平衡是草地畜牧业可持续发展的基础。本文以干物质、产奶净能和可消化粗蛋白等指标,评价1995年以来张家口市塞北管理区的草畜平衡动态。结果表明:1995-2001年管理区的饲草饲料自给率较高,2002-2005年逐年下降,2006年略有反弹,除个别年份外,粗饲料的自给率高于精饲料;当地粗饲料的营养价值较高,其干物质的产奶净能为4.66~4.86 MJ/kg,与标准干草相当,可消化粗蛋白质浓度59.2~68.0 g/kg,按照饲养标准饲喂,能满足奶牛的蛋白质需要;根据目前饲草饲料的种植规模、生产水平以及近期水、土资源开发潜力和未成林地放牧等,管理区当前和近期奶牛适宜规模分别为5351和7329头。

关键词: 农牧交错区, 农牧复合系统, 优化, 草畜平衡