乳中的脂肪主要以脂滴的形式悬浮于乳中，称为乳脂肪球。母乳中脂肪球成分、结构和粒径大小对子代的生长和健康具有重要作用，但关于母猪乳脂肪球结构、影响因素和调控机理方面还知之甚少。本项目拟首先系统测定母猪乳中脂肪球颗粒大小变异的生理因素（如母猪泌乳阶段、品种、胎次、乳头位置、母猪和乳猪健康状况等），通过母猪血液和乳中脂类代谢相关因子水平分析脂肪球颗粒大小变异的生理机制；进一步从母猪乳中分离出不同大小等级的乳脂肪球颗粒，检测和比较不同粒径的乳脂肪球在脂肪酸组成、极性脂质含量和超分子结构上的差异；最后探测哺乳母猪饲粮中脂肪含量、卵磷脂水平或不同碳链长度脂肪酸（C18、C16和C14）对母猪乳中脂肪球颗粒大小、成分和结构及子代生长健康的影响及机制。研究成果为深入了解母猪乳的活性成分和功能，揭示母猪乳中脂肪球粒径大小变异的生理及营养调控机制，提高母猪乳质量，开发新型的代乳料等方面提供新的思路和试验数据。

Fat is present in milk in the form of spherical droplets of micronic size: the milk fat globules (MFG). The compositions, structure and size of MFG have been shown to play a central role in the health and growth of piglets, However, little attention has been paid to the structure，function，effect factor and regulation mechanism of MFG in sows. In a preliminary experiment，we plan to explore the effects of physiological factors such as phase, breed, parity, nipples, and the healthy status of sows and piglets on MFG size, and analyze the mechanism through the related factors of lipid metabolism in sow milk and blood. Next, we shall separated milk and obtain different levels of MFG，and compare their fatty acid composition, polar lipid content and supermolecular structure. We study the effects and mechanism of feeding diets with and without adding fat, lecithin levels or different length of carbon chain fatty acid （C18、C16 and C14） on size, composition and structure of MFG in sows and growth and health of piglets . Our results will provide a new idea and test data to further understand the composition and function of sow milk, reveal the physiological and nutritional regulation mechanism of MFG size in sows, improve the quality of milk in sow and develop a new of milk replacer for piglets.