Hogan J S, Weiss W P, Smith K L, Sordillo L M, Williams S N
Department of Dairy Science, Ohio State University, Wooster 44691, USA.
J Dairy Sci. 1996 Jan;79(1):71-5. doi: 10.3168/jds.S0022-0302(96)76335-X.
Eighteen cows were challenged by intramammary infusion with Escherichia coli 727 to determine the effects of acute clinical mastitis on alpha-tocopherol concentrations in plasma and milk. Cows were fed diets supplemented with 1000 IU of vitamin E/d from calving through the experimental period. At challenge, geometric mean DIM was 33 d. Each mammary quarter was diagnosed with an IMI and clinical mastitis at 24 and 48 h after challenge. The alpha-tocopherol concentrations in milk from challenged quarters were approximately 60% greater by 24 and 48 h after challenge than concentrations at prechallenge and 168 h postchallenge. Plasma alpha-tocopherol concentrations did not change after intramammary challenge. The alpha-tocopherol in plasma and milk was correlated at 48 and 168 h postchallenge but not at prechallenge or 24 h postchallenge. Milk alpha-tocopherol and SCC were correlated positively across all sample periods. Milk fat and milk alpha-tocopherol concentrations were correlated at each sample period except 24 h postchallenge. Increases in milk alpha-tocopherol during clinical mastitis were not correlated to milk production, DMI, or BSA concentration in milk. Changes in milk alpha-tocopherol concentration during clinical mastitis were similar to the dynamics of milk SCC.
通过乳腺内注入大肠杆菌727对18头奶牛进行攻毒，以确定急性临床型乳腺炎对血浆和牛奶中α-生育酚浓度的影响。从产犊到实验期结束，给奶牛饲喂每日补充1000 IU维生素E的日粮。攻毒时，平均胎次间隔（DIM）为33天。攻毒后24小时和48小时，每个乳腺象限均被诊断为患有亚临床型乳房炎（IMI）和临床型乳腺炎。攻毒后24小时和48小时，受攻毒乳腺象限的牛奶中α-生育酚浓度比攻毒前和攻毒后168小时的浓度高出约60%。乳腺内攻毒后，血浆α-生育酚浓度没有变化。攻毒后48小时和168小时，血浆和牛奶中的α-生育酚存在相关性，但攻毒前或攻毒后24小时不存在相关性。在所有采样期，牛奶α-生育酚和体细胞计数（SCC）呈正相关。除攻毒后24小时外，在每个采样期，乳脂肪和牛奶α-生育酚浓度均呈相关。临床型乳腺炎期间牛奶α-生育酚的增加与牛奶产量、干物质采食量（DMI）或牛奶中的牛血清白蛋白（BSA）浓度无关。临床型乳腺炎期间牛奶α-生育酚浓度的变化与牛奶SCC的动态变化相似。
