Seeth Martin tho, Hoedemaker Martina, Krömker Volker
Berl Munch Tierarztl Wochenschr. 2015 Jan-Feb;128(1-2):76-83.
The dry period is essential for the bovine mammary gland to regenerate after the previous lactation. This period is necessary to render an appropriate milk yield during the subsequent lactation. Furthermore, the dry period allows the cure of existing infections of the mammary gland, but also bears an increased risk of new infection. The physiological processes within the bovine mammary gland can be devided in the following way: During the first days of active involution, a change in the cellular architecture is suggested, possibly caused by the high intra-alveolar pressure. Extensive histological changes affecting the capability of synthesis and secretion of milk components are also observed. During the involution, there is a loss of integrity of the mammary epithelial and various substances enter from blood into the mammary lumen. The histological and morphological changes continue during the steady state involution and the period of neolactogenesis. Hence, the composition of the secretion produced by the mammary epithelia changes markedly. Furthermore, the phases of the dry period differ in regard to the susceptibility towards intramammary infections. Therefore, it is necessary to consider the physiological processes during dry cow management. This literature survey describes the essential findings about the changes within the mammary tissue during the dry period.
干奶期对于奶牛乳腺在先前泌乳后进行再生至关重要。这段时期对于在随后的泌乳期实现适当的产奶量是必要的。此外，干奶期有助于治愈乳腺现有的感染，但也会增加新感染的风险。奶牛乳腺内的生理过程可按以下方式划分：在主动退化的最初几天，提示细胞结构发生变化，这可能是由高肺泡内压引起的。还观察到影响乳汁成分合成和分泌能力的广泛组织学变化。在退化过程中，乳腺上皮的完整性丧失，各种物质从血液进入乳腺管腔。在稳定退化期和新泌乳期，组织学和形态学变化仍在继续。因此，乳腺上皮产生的分泌物组成发生显著变化。此外，干奶期的各个阶段在对乳腺内感染的易感性方面有所不同。因此，在干奶牛管理期间考虑生理过程是必要的。这篇文献综述描述了关于干奶期乳腺组织内变化的重要发现。
