奶牛乳脂合成及其影响因素

乳脂是一种高质量的天然脂肪,是牛乳的主要营养成分。乳脂率是衡量牛奶品质优劣的关键指标,同时也是制约中国奶业发展的重要因素。近年来,随着中国奶牛业的不断发展,奶牛的产奶量日益提高,但乳脂率却未见增长。通常情况下牛奶的乳脂率为3%~4%,产奶量与乳脂率之间呈相互制约关系,如何提高乳脂率一直是学者们研究的热点。为深入研究并解决这一问题,作者介绍了乳脂组成及合成机理,并从日粮、瘤胃微生物及遗传等方面分析了影响奶牛乳脂合成的因素。同时作者还对影响奶牛乳脂合成的重要功能基因（SREBPs、PPARs、CIDEC基因）及mTOR信号通路的作用进行了综述。乳脂合成是一个动态的、复杂的多网络调控的过程,需要大量的基因参与,研究各信号通路间的相互作用可为人工调控乳脂合成提供理论基础,也为日后泌乳生物学研究奠定理论基础。

Milk Fat Synthesis and Its Influence Factor in Dairy Cow

Milk fat is a kind of natural fat and a main nutritional component of milk. Milk fat percentage is an important index to evaluate milk quality. Lower milk fat percentage could limit dairy industry development.Recently,the milk yield increased,but not milk fat percentage. The milk fat percentage is 3% to 4% in usual,however,milk yield restricts the increase of milk fat percentage and how to increase it become a hot area of lactating research. To further study and solve this problem,we reviewed the research progress on milk fat synthesis and the factors influencing milk fat including diet,rumen microorganism and genetic factor. We also reviewed the genes and signaling pathways related to milk fat synthesis,which includes SREBPs,PPARs,CIDEC,as well as mTOR signaling pathway. Milk fat synthesis is a dynamic process and complex network regulated to a lot of genes,and the researches of the interaction between the various signaling pathways can provide theoretical basis for artificial regulation milk fat synthesis. These information will provide the idea to improve milk fat content,as well as lactation biology.