Oxidative stress occurs during the transition period and causes insulin resistance, which may be reduced by the use of antioxidants in this period. Twenty-four multiparous Holstein dairy cows, at 8 wk before parturition, were divided into 4 equal groups, namely control (Ctrl), vitamin E (VE), selenium (Se), and vitamin E plus selenium (VE + Se) groups. On a daily basis, VE and Se cows received dietary 1.5 IU vitamin E/kg BW and 0.3 mg/kg DM selenium, respectively, from 8 wk before to 3 wk after parturition. Vitamin E plus selenium group received doses similar to VE and Se groups. Insulin sensitivity was evaluated through intravenous glucose tolerance test (ivGTT) at weekly intervals from 3 wk before to 3 wk after parturition. Serum concentrations of total antioxidant status (TAS), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), nonesterified fatty acid (NEFA), and beta-hydroxybutyric acid (BHBA) were assayed weekly before the commencement of ivGTT. Based on the results of ivGTT, the lowest and the highest degrees of insulin sensitivity were detected in Ctrl and VE + Se groups, respectively. The highest and the lowest concentrations of NEFA and BHBA were observed in Ctrl and VE + Se groups, respectively. Total antioxidant status, SOD, and GPx values were significantly lower in Ctrl cows and significantly higher in VE + Se-received cows compared with other groups. However, MDA values in Ctrl and VE + Se cows were significantly higher and lower than the other groups, respectively. Collectively, our results show that dietary administration of vitamin E and selenium ameliorates oxidative stress and lipid mobilization and increases insulin sensitivity in transition cows.

氧化应激发生在过渡期并导致胰岛素抵抗，在此期间使用抗氧化剂可能会降低胰岛素抵抗。24头多产荷斯坦奶牛在分娩前8周被分成4个相等的组，即对照组（Ctrl）、维生素E（VE）、硒（Se）和维生素E加硒（VE+Se）组。从分娩前 8 周到分娩后 3 周，VE 和 Se 奶牛每天分别接受 1.5 IU 维生素 E/kg BW 和 0.3 mg/kg DM 硒。维生素 E 加硒组接受的剂量与 VE 组和硒组相似。从分娩前 3 周到分娩后 3 周，每周通过静脉葡萄糖耐量试验 (ivGTT) 评估胰岛素敏感性。血清总抗氧化状态 (TAS)、丙二醛 (MDA)、超氧化物歧化酶 (SOD)、在 ivGTT 开始前每周检测谷胱甘肽过氧化物酶 (GPx)、非酯化脂肪酸 (NEFA) 和 β-羟基丁酸 (BHBA)。基于 ivGTT 的结果，分别在 Ctrl 和 VE + Se 组中检测到最低和最高程度的胰岛素敏感性。分别在 Ctrl 和 VE + Se 组中观察到最高和最低浓度的 NEFA 和 BHBA。与其他组相比，Ctrl 奶牛的总抗氧化状态、SOD 和 GPx 值显着降低，而接受 VE + Se 的奶牛则显着升高。然而，Ctrl 和 VE + Se 奶牛的 MDA 值分别显着高于和低于其他组。集体，