中文摘要：

摘要：选择产前40d的奶牛40头，每隔5d从尾静脉采集全血1次，测定血液学和血清脂质过氧化指标，探讨奶牛围产期的生理特性。结果表明：白细胞（WBC）在产前5d和分娩当天（0d）明显升高（P〈0．05），产后第5天基本恢复正常，中性粒细胞数（NEU）、淋巴细胞（LYM）与WBC变化趋势一致；分娩当天红细胞（RBC）、血红蛋白（HB）和红细胞比容（HCT）均轻度升高（P〈0．05）；血小板（PI。T）在产前5d开始升高，产后均高于产前（P〈0．05）；血清谷胱甘肽过氧化物酶（GSH-Px）、超氧化物歧化酶（SOD）活性在产前呈逐渐降低的趋势，而血清过氧化氢酶（CAT）活性在产前呈升高的趋势，但分娩时均降低（P〈0．05）；血清丙二醛（MDA）含量在产前呈升高的趋势，而分娩后开始逐渐降低。表明奶牛围产期发生了血液学参数的改变和氧化状态失衡的生理特性。

英文摘要：

ABSTRACT： In order to study the physiological characteristics of the transition cows, forty Holstein dairy cows at 40 d before calving were selected. Whole blood was collected from the tail vein every 5 d to conduct a detection of hematology and serum lipid peroxidation. The results showed that the WBC in 5 d before calving and on the day of calving （0 d） in- creased significantly （P〈0.05）, and returned to normal level basically from 5th d after calving. The contents of NEU and LYM were in line with the variation trend of WBC. The RBC, HB and HCT were moderately elevated （P〈 0.05） on the day of calving. PLT began to rise in 5 d before calving, the level were higher before calving than after calving （P〈 0. 05）. Serum GSH-Px and SOD activities decreased gradually before calving, while the activity of CAT was elevated. But all these decreased after calving（P〈0.05）. The content of MDA in serum was evaluated before calving, and then it started to decrease gradually after calving. In conclusion, the transition cows seem to undergo change of hematological parameters and an imbalance in the oxidative status in the transition period.