中文摘要：

引入外来品种改良牲畜被作为干旱半干旱地区发展畜牧业的重要手段,但对其在生产基础差、严重依赖自然资源的小农户生产系统中的适用性却缺乏分析,因而,盲目推广改良可能危及牧民生计,进而导致生态破坏。以位于农牧交错带的内蒙古赤峰市克旗的家畜改良为案例,通过入户访谈,在识别其畜牧业生产系统约束条件的基础上,分析了家畜改良的效果、可行性条件及存在的问题。研究表明：在小农户生产系统中,家畜品种改良并不能提高限制性资源的生产率,而且增加了农户面临的生态风险和市场风险,改良是否可行取决于外部环境能否有效地改善其对限制性资源的利用及平衡风险,尤其是提供稳定的饲料和畜产品市场,以及良好的基础设施、技术及金融保障。

英文摘要：

Importing exotic genes to improve livestock breeds has been an important approach to develop animal husbandry in arid and semi-arid area of China. However,few researches had been done on the appropriateness of such approaches in small household production systems which have poor conditions and greatly rely on natural resources. Importing exotic breeds into such systems without careful analysis may threat the sustainability of the herders＇ livelihoods and destroy the ecosystem. In this article we analyzed the sheep breed improvement case in Keshiketeng Banner which locates in agro-pastoral area of Chifeng,Inner-Mongolia. Through household interviews,characters of production system and limiting factors were identified,based on which the effect,feasibility and potential problems of livestock breeds improvement were analyzed. It was concluded that livestock breeds improvement in small household product system didn＇t improve the productivities of limiting resources,on the contrary,it increased the ecological and market risks facing the households; the feasibility of livestock breeds improvement depended on whether external systems could support the households to improve the efficiency of limiting resources and to balance risks,especially provide steady forage market and animal product market,good infrastructures and financial support.