奶牛乳腺退化及其营养调控研究进展

Research Progress of Dairy Cow Mammary Gland Involution and Its Nutrition Regulation

乳腺退化是奶牛干奶过程中的关键阶段。在乳腺退化过程中,乳腺上皮细胞内的囊泡和脂滴逐渐增多,细胞器萎缩,细胞紧密连接通透性增加,乳成分合成能力下降,细胞凋亡增加。近年来,越来越多的研究开始关注干奶期奶牛乳腺退化发生机理及其调控手段,主要原因是加速奶牛干奶初期乳腺退化一方面可以降低干奶期乳腺内感染发生的风险,另一方面有提高短干奶期(30 d左右)奶牛下一泌乳周期产奶量的潜在可能。目前研究表明,转化生长因子-β1(TGF⁃β1)/Smad和酪氨酸激酶(JAK)/信号传导与转录激活因子3(STAT3)2条信号通路在乳腺退化中扮演着重要角色,且通过营养手段可以调控奶牛的乳腺退化过程。本文旨在对奶牛乳腺退化的相关机制和乳腺退化营养调控最新研究进展进行综述,以期为现代高产奶牛健康养殖提供新的思路,为未来进一步研究奶牛乳腺退化提供参考。

Mammary gland involution is one of the most important stages of the dry period.In the process of mammary gland involution,the number of vesicles and lipid droplets in mammary epithelial cells gradually in⁃creased,organelle atrophied,cell tight junction permeability increased,milk composition synthesis decreased,cell apoptosis increased.In recent years,more and more studies have paid attention to the mechanism and con⁃trol measures of mammary gland involution in dry cows.The main reason is that accelerating the early stage of dry period may reduce the risk of intramammary infections in the dry period,and may increase the milk pro⁃duction of short dry dairy cows in the subsequent lactation.Recent studies demonstrated that transforming growth factor⁃β1(TGF⁃β1)/Smad and Janus kinase(JAK)/signal transducer and activator of transcription 3(STAT3)signal pathways play important role in the mammary gland involution,and several nutritional strate⁃gies could regulate this process.In this review,the latest research progress of related mechanisms and nutrition⁃al regulation of dairy cow mammary gland involution were summarized,which could provide new insights for healthy dairy cow production and for the further mammary gland involution research.