中文摘要：

为试验不同程度奶牛乳房炎和抗氧化能力的相关性，检测血液中和乳汁中超氧化物歧化酶（superoxidedismutase，SOD）、谷胱甘肽过氧化物酶（glutathioneperoxidase，GSH—Px）和丙二醛（malonaldehyde，MDA）的活性变化，探讨这些指标是否可以作为判定乳腺损伤的依据。以40头荷斯坦奶牛为试验对象，通过乳汁中体细胞计数法（somaticceltCount，SCC）对其进行分组：C组（SCC〈5×105个／mL）、I组（5×105〈SCC〈1．5×106个／mL）、U组（1．5×106〈SCC〈5×106个／mL）和Ⅲ组（SCC〉5×106个／mL）。结果显示，不同程度乳腺炎血液中和乳汁中MDA的水平均随着乳腺炎的严重程度的增加而呈递增趋势，均高于C组。不同程度乳腺炎血液中和乳汁中SOD、GSH-Px的酶活性均随着乳腺炎的严重程度的增加而呈递减趋势，均低于C组。结果表明，奶牛乳房炎的严重程度和抗氧化能力是呈负相关性，这些指标可以作为判定乳腺损伤的依据。

英文摘要：

Abstract.. The study on the mastitis in cows was designed to detect changes in the activities of super- oxide dismutase （SOD）, glutathione peroxidase （GSH-Px）, and the level of malonaldehyde （MDA） in ser- um, and to investigate the association between different degrees of bovine mastitis and antioxidant activity. We discussed whether the index could be used as the basis for the determination of mammary gland dam- age. The study was performed in 40 Holsteins dairy cows, and all cows were divided into four groups according to somatic cell count （SCC） control （SCC〈5 ×105 cells/mL） ,group Ⅰ （5 ×105〈SCC〈1. 5 ×106 cells/mL）, group Ⅱ （1.5 ×106〈SCC〈5×106 cells/mL）, group Ⅲ （SCC〉5 ×106 cells/mL）. The ac- tivities of SOD, GSH-PX in group Ⅰ , Ⅱ , and Ⅲ decreased along with the degree of mastitis compared to control. These findings provide a better understanding of the relationship between the different degree of bovine mastitis and antioxidant indexes. The indexes in the study could be used as the basis for the deter- mination of mammary gland damage.