羔羊腹泻严重影响羔羊的存活、生长和发育，因其病因复杂，发病率高，死亡率高、防控困难，疗效不佳，已成为制约陕北地区养羊业发展的瓶颈问题，严重阻碍了该地区脱贫致富的进程。目前陕北羔羊腹泻的主要病原尚不明确，给该病的防治带来了巨大困难。本研究拟采用微生物宏基因组、高通量测序和生物信息学等技术，通过深度分析健康羔羊和腹泻羔羊肠道微生物群落，以期挖掘出陕北地区羔羊腹泻的疑似病原；然后针对上述疑似病原，通过流行病学调查和相关性分析筛选出引起陕北地区羔羊腹泻的主要病原；最后利用病原分离鉴定、分子流行病学和耐药基因流行病学等技术对这些病原进行遗传进化和耐药水平分析，以揭示这些病原的流行规律和耐药机制，最终明确陕北地区羔羊腹泻防控难、治疗差的根本原因。本项目的顺利开展有利于高效防控陕北地区羔羊腹泻，促进该地区养羊业的提质增效，加快农民脱贫致富，同时也为深入研究羔羊腹泻奠定基础。

Lamb diarrhea seriously affects the survival, growth and development of lambs. Due to its complex etiology, high morbidity and mortality, difficult to prevention and control and poor curative effect, it has become a bottleneck problem that restricting the development of sheep husbandry in northern shaanxi and seriously hinders the process of taking off poor and getting rich in this region. The main pathogens that cause diarrhea in northern shaanxi is still unknown, which brings great difficulties to prevent and control of lamp diarrhea. In this study, we intend to dig out the suspected pathogens which related with lambs diarrhea in northern shaanxi by intestinal microbial communities analysis of healthy and diarrhea lambs using microbial metagenome, high-throughput sequencing and bioinformatics techniques. Then, the main pathogens , which may cause diarrhea, were screened by epidemiological investigation and correlation analysis. Finally, in order to uncover the epidemiology and drug resistance mechanisms of these pathogens, pathogen isolation and identification, genetic evolution, molecular epidemiology and drug resistance epidemiology will be analyzed. We will elucidate the deep reasons for difficulty in prevention and control and poor treatment of lamb diarrhea in northern shaanxi. This project is benefit for efficiently prevent and control of lamb diarrhea in northern shaanxi which will promote the sheep industry development and speed up farmers out of poverty into rich, also, this project will lay a foundation in an in-depth study of lamb diarrhea in the future.