一、奶牛泌乳生理与营养调控

重点开展奶牛氨基酸需要与平衡研究，为完善我国奶牛代谢蛋白质体系提供素材；利用相关组学技术开展泌乳生理的机制研究；开发南方地区非常规饲料资源，提出科学的加工调制技术；提出奶牛主要营养代谢病的营养预防技术。（国家奶牛产业技术体系岗位科学家项目）

Lactation physiology and nutritional manipulation in dairy cows. This work is to study the effects of amino acid supply and balance on lactation performance to contribute to the establishment of metabolizable protein system for dairy cows in China The omics technologies will be employed in the study of lactation physiology. Dietary strategies and processing technologies will be developed to exploit the unconventional feed resources in southern China. Nutritional strategies will be worked out to prevent the dairy cows from the main metabolic diseases. (Funded by China Agriculture Research System)

二、高产奶牛乳腺低氧应激成因的代谢与分子机制

通过在体奶牛和乳腺细胞试验，建立奶牛乳腺低氧应激模型；分析高产、热应激下奶牛泌乳性能、乳腺细胞形态与功能、关键代谢产物，揭示高产下奶牛低氧应激的诱发机制；施加抗应激制剂，研究其对奶牛血气参数、乳腺功能和低氧应激关键基因及核心分子网络的影响。揭示高产奶牛乳腺低氧应激成因的代谢与分子机制，为建立缓解高温高湿和高产下奶牛乳腺低氧应激、保障奶牛乳腺代谢稳态提供新的知见，丰富和发展高产奶牛健康养殖的理论与实践。（国家自然科学基金重点项目）

Metabolic molecular mechanism involved in cause of hypoxia stress in mammary gland of lactating dairy cows. The individuals with hypoxia and normal status are screened from a large cohort of high-yielding lactating cows to investigate lactation performance, morphology and function of the mammary epithelial cells, and key metabolites, to verify the core molecular networks, and to reveal the mechanism with which hypoxia stress is induced by high production. Meanwhile, similar studies will be conducted in the high-yielding dairy cows under heat stress. Finally, anti-stress agents with different function modes are selected and used in high-yielding dairy cows and/or under heat stress to study their effects on blood gas parameters, mammary function, and key genes and core molecular network related to hypoxia stress. Based on the above results, we are to reveal the metabolic and molecular mechanism of hypoxia stress in mammary gland of high-yield dairy cows, which will provide new insights in relieving hypoxia stress in high-yielding dairy cows under heat stress, and ensuring the mammary metabolic homeostasis in dairy cows. (Funded by the National Natural Science Foundation of China)

三、围产期和泌乳前期奶牛氧化应激发生机制及其营养调控策略研究

开展围产期和泌乳前期奶牛饲养试验，通过瘤胃液、血液、牛奶、乳腺组织等样品分析，运用基因组、代谢组、蛋白质等多组学分析手段，解析抗氧化作用网络和代谢通路；在此基础上，通过体外奶牛乳腺细胞培养，筛选靶向性调控氧化应激的抗氧化制剂；最后通过奶牛试验，验证这些抗氧化制剂的效果，为缓解围产期和泌乳前期奶牛氧化应激、保障奶牛健康提供营养策略。（科技部重点研发计划国际科技合作项目）

Mechanism of oxidative stress in perinatal and early-lactation cows and their nutritional regulation strategies. In this study, feeding experiments in perinatal and early-lactation dairy cows will be carried out to obtain the samples of rumen fluid, blood, milk, mammary gland, etc.,and multi-omics methods such as metagenome, metabolome and proteome are employed to analyze the antioxidant network and metabolic pathways. Based on the above results, in vitro mammary gland cells are cultured to screen antioxidants that target oxidative stress. Finally, dairy cow experiments are conducted to verify the effects of these antioxidants in order to provide nutritional strategies for alleviation of the oxidative stress of dairy cows in the perinatal and early-lactation period to ensure the health of dairy cows. (Funded by Intergovernmental Collaborative Project in S&T Innovation under the National Key Technologies R&D Program, China)

四、基于系统生物学方法鉴定调节奶牛氮利用效率和牛奶品质的分子和代谢表征物

本项目拟利用系统生物学技术，对日粮相同但乳蛋白产量不同的大群奶牛开展基因测序、表观遗传修饰和转录后调控系统研究，全面分析高或低乳蛋白产量奶牛的瘤胃微生物宏基因组、瘤胃液代谢组、血液转录组和代谢组，旨在验证影响乳蛋白产量的分子与代谢表征物，解析影响乳蛋白产呈的生物学系统调节机制，为改善奶牛饲料效率和选育优质奶牛提供科学知识。（国家自然科学基金海外与港澳学者合作基金）

System biology based approaches to identify molecular and metabolic markers for improvement of nitrogen utilization efficiency and milk quality in dairy cows, funded by The National natural Science Foundation of China. The project is aimed to validate the identified molecular and metabolic biomarkers related to milk protein production from previous study in the commercial herd, and to characterize the biological systematic mechanism and regulation on the cows' milk protein production. It will provide implication to improve feed efficiency and contribute to scientific knowledge in the cow's breeding in China dairy industry. (Funded by The National Nature Science Foundation of China)

五、幼龄反刍动物消化道微生物演替与肠道发育调控

课题拟采用宏基因组学、宏转录组学、代谢组学、数字基因表达谱分析等技术，研究舍饲条件下，不同营养源对幼龄反刍动物微生物定植、演变与消化道发育与功能的影响。以微生物多样性和功能的时空演变为轴，通过微生物及其代谢产物与上皮增殖和分化、吸收和屏障功能、免疫和信号调节的关联分析，探讨幼龄反刍动物消化道微生物的定植规律；幼龄反刍动物消化道微生物及其代谢产物调控幼龄反刍动物消化道上皮发育与功能的信号转导机制，探索缓解断奶应激的主要营养学措施并明确相关机制。（国家重点研发项目课题）

Microbial succession in the gastrointestinal tract of young ruminants and their regulation of gastrointestinal development. To explore the signal transduction mechanism of gastrointestinal epithelial development and function in young ruminants, to alleviate weaning stress and clarify the related mechanism, metagenomics, metatranscriptomics, metabolomics and digital gene expression profiling were used to study the effects of different nutrient sources on microbial colonization and gastrointestinal tract development in young ruminants. Based on the spatial and temporal evolution of microbial diversity and function, the colonization regularity of microorganisms in the gastrointestinal tract of young ruminants, and the regulation of microorganisms and their metabolites in the gastrointestinal tract of young ruminants were studied by the correlation analysis of microorganisms and their metabolites with epithelial proliferation and differentiation, absorption and barrier function, immunity and signal regulation. (Funded by Key Technologies R&D Program)

六、Nrf2-ARE通路介导的奶牛乳腺上皮细胞抗氧化应激作用机制及其营养调控研究

以Nrf2-ARE信号通路为切入点和分子靶标，利用奶牛乳腺上皮细胞体外培养模型，结合奶牛生产实验和活体取样技术，在细胞、组织和个体多水平系统研究奶牛乳腺细胞氧化应激中细胞反应及Nrf2-ARE信号通路的作用机制探讨Nrf2-ARE信号通路作为抗氧化剂分子靶点的可能性。该研究有利千揭示奶牛乳腺氧化应激的分子机制，阐明Nrf2-ARE信号通路与乳腺健康的关系为奶牛乳腺健膜高效泌乳提供理论基础并为反刍动物天然抗氧化添加剂的开发应用提供参考。（国家自然科学基金项目）

Mechanisms of Nrf2-ARE-mediated antioxidation in bovine mammary epithelial cells and its nutritional manipulation strategies. Nrf2 is a transcription factor which regulates the expression of several antioxidant/detoxifying enzymes through its interaction with the antioxidant responsive element (ARE) in gene promoters and plays a central role in protection of the cells against cytotoxicity caused by oxidative stress. However, the effects of oxidative stress and antioxidants have not been well studied in bovine mammary epithelial cells (bMECs). Therefore, the objectives of this project are to investigate the molecular and cellular mechanisms of Nrf2-ARE-mediated antioxidation and evaluate the antioxidative effects of several natural antioxidants targeting Nrf2-ARE signaling in bMECs. Knowledge generated from this study will provide new insights into oxidative stress of dairy cows and provide scientific basis for the application of antioxidant in dairy production. (Funded by the National Science Foundation of China)

七、ChREBP通路调节奶山羊乳腺糖酵解的机制研究

代谢葡萄糖供给量较高时，乳腺糖酵解增强并产生大量乳酸，从而损害乳腺健康并降低乳腺合成能力，目前，泌乳乳腺糖酵解研究逐渐受到关注，但其调控机制方面的研究较少。碳水化合物反应元件结合蛋白(ChREBP)是营养素调控动物乳腺糖酵解的重要靶基因，因此明确ChREBP通路调控乳腺糖酵解的机制对改善乳腺健康和泌乳效率具有重要意义。本研究拟结合课题组前期基础，利用奶山羊乳腺上皮细胞培养为模型，在细胞水平上揭示ChREBP调节奶山羊乳腺糖酵解的机制，为通过营养手段调控反刍动物乳腺糖酵解提供基础数据。（国家自然科学基金项目）

Mechanism of ChREBP in regulating mammary glycolysis of lactating dairy goat. When large quantity of glucose was supplied to lactating mammary gland, glycolysis processing of the mammary gland was improved and lactic acid was over-secreted, which finally reduced health status and efficiency of mammary gland. Recently, glycolysis of lactating mammary gland drew great interest although knowledge on the regulatory mechanisms was largely required. The ChREBP is an important target for the glycolysis regulation of mammary gland. Thus, to clarify how ChREBP regulated glycolysis of the mammary gland glycolysis is important for the health and efficiency of mammary gland. Our study attempts to reveal the role and mechanism of ChREBP in regulating mammary gland glycolysis, which will contribute to the mammary gland glycolysis regulation basing on nutritional method. (Funded by the National Science Foundation of China)