嗅觉作为生物感受外界环境中化学物质的基础，为动物生存、觅食、繁殖等提供了保障，具有重要的生命意义。如动物在采食过程中可不接触食物，仅通过嗅觉，根据食物气味作出决策。因此，研究动物对气味的行为响应，揭示其对不同气味刺激的识别机制，作为一个科学问题具有重要的理论及应用价值。本项目通过系统研究小尾寒羊面对不同气味刺激时其行为响应及各阶段关键激素的变化，明确其行为响应的内分泌调控机制。在此基础上，结合小尾寒羊下丘脑及垂体相关基因及miRNA差异表达，从分子水平进一步探讨其对不同气味刺激的分子调控机制。最后综合分析以上研究结果，从行为、内分泌以及分子水平上揭示小尾寒羊对不同气味刺激的响应，确定不同气味对其采食行为的影响，明确其对不同气味识别的根本原因。以上研究不仅充实了家畜行为学研究内容，而且深层次的探讨动物对不同气味刺激的内分泌及分子调控机制，也将进一步丰富我国家畜行为学研究的理论和方法。

Olfactory system has important life meaning as a biological basis for perceiving the chemical substances in the environment, provides an important clue for animal survival, foraging, breeding and so on. In the process of foraging, animal can make decisions based on the smell of food through the olfactory system. Therefore, it is an important scientific question to research animals' response to odor and reveal its recognition mechanism for different odor stimuli. We will detect the behavioral responses of Small Tail Han sheep to different odor stimuli and the changes of key hormones at different stage in this project, and to determine the endocrine regulation mechanism of their behavioral responses. On this basis, combined with related genes and differential expression of miRNA with different parts of hypothalamus and pituitary of Small Tail Han sheep, we will further explore molecular regulation mechanism of different odor stimuli. Finally, we hope that this project can reveal the responses of Small Tail Han sheep to different odor stimuli from behavioral, endocrine and molecular levels based on the above results, determine the effects of different odors on their foraging behavior, and identify their major reasons for different odor recognition. This research will not only replenish the contents of animal behavior study, but also deeply explore the endocrine and molecular mechanism of animal's different odor stimulation, which will further enrich the theory and method of domestic animal behavior research in China.