铜缺乏对乳牛自由基代谢的影响

Effect of copper deficiency on the metabolism of free radicals in dairy cattle

为阐明铜缺乏对乳牛体内自由基代谢的影响,本实验选择缺铜地区全血铜低于NRC下限(0.8mg/kg)但无明显摇摆症状的犊牛25头作为亚临床铜缺乏组;并对其中15头进行补铜试验(饲料中添加硫酸铜100mg/kg干重),以15头临床健康乳牛作为对照组,分别于40天及80天采集样并检测全血中自由基的含量及血清中NO(一氧化氮)的含量;同时检测了发病乳牛与对照乳牛(各9头)组织细胞浆中NO的含量。结果表明:发病组及亚临床组乳牛全血自由基含量均显著高于对照组(P〈0.05),各组乳牛血清中NO含量差异均显著(P〈0.05),且发病乳牛大脑、小脑及脊髓NO的含量显著或极显著高于对照组,补铜能够显著降低亚临床缺乏组乳牛全血中的自由基或血清中NO含量。结论:铜缺乏能够影响响乳牛体内的自由基代谢过程。

cows without evidently clinical symptom were selected as subclinical group(the concentration of whole blood copper is below the lower limit ofNRC(0.8mg/kg))and15ones among them were supplemented with copper sulfate(100mg/kg dir matter)to clarify copper deficiency on the metabolism of free radicals in dairy cattle while15clinically healthy cows were uaed as control.The contents of free radicals and NO(nitric oxide)were examined on the day of40and80respectively after the supplementation.The contents of NO in cytoplasm of tissue were also determined in morbid cows with clinical symptom and healthy ones(nine for each).The results show that the contents of free radicals in morbid and sub-clinical group were signficantly higher than that of control group(P<0.05);The differences in contents of NO a-mong all the groups are significant (P<0.05).The contents of NO in cerebrum,cerebellum and spinal cord of morbid group is significantly higher than that of control.Supplementation of copper would decrease significantloy the contents of free radicals in whole blood and that of NO in serum in subclinical group.Conclusion:copper deficiency could affect the metabolic process of free radicals in dairy cattle.