Tight junctions are almost impermeable structures located near the apical border of epithelial cells; increase in the permeability of mammary gland cells’ tight junctions may alter milk composition and its suitability for industrialization. Sixteen Holstein dairy cows were studied to evaluate mammary gland cells’ tight junction permeability (indicated by plasma lactose levels) from cows producing stable or unstable milk to ethanol at 72 °GL concentration. Rectal temperature, respiratory rate and milk parameters were also compared and weather conditions (temperature–humidity index) monitored. Temperature–humidity index did not vary for cows producing stable or unstable milk, so there were no differences in physiological traits. Cows producing unstable milk presented elevated tight junctions’ permeability, probably due to higher days in milk. The odds of cows producing unstable milk (clots formation when mixed with ethanol below or equal 72 °GL) increases according to elevations in days in milk and tight junction permeability.

中文翻译：

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在乙醇测试中生产稳定或不稳定牛奶的奶牛乳腺细胞的紧密连接渗透性

紧密连接是位于上皮细胞顶端边缘附近的几乎不可渗透的结构；乳腺细胞紧密连接的通透性增加可能会改变牛奶成分及其工业化的适用性。研究了 16 头荷斯坦奶牛，以评估从生产稳定或不稳定牛奶的奶牛到 72 °GL 浓度的乙醇的乳腺细胞的紧密连接渗透性（由血浆乳糖水平表示）。还比较了直肠温度、呼吸频率和牛奶参数，并监测了天气条件（温度-湿度指数）。产奶稳定或不稳定的奶牛的温湿度指数没有变化，因此生理性状没有差异。奶牛产奶不稳定，紧密连接的渗透性升高，可能是由于牛奶中的天数较高。