关键词: 农牧交错区, 农牧复合系统, 优化, 草畜平衡

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