本试验旨在研究不同水平无机及有机复合微量元素对蛋鸡血浆抗氧化能力的影响。选取990只22周龄的京红1号蛋鸡，随机分为11组，每组6个重复，每个重复15只鸡。1组为对照组，试验组分别在饲粮中按NRC（1994）推荐需要量的25%、50%、75%、100%、125%添加不同水平的无机（2～6组）或有机复合微量元素（7～11组），其中锰（Mn）、铁（Fe）、锌（Zn）、硒（Se）添加水平参照蛋鸡NRC（1994）标准，铜（Cu）添加水平参照肉鸡NRC（1994）标准。试验期24周。结果表明：1）与对照组相比，添加NRC推荐需要量的75%、100%、125%无机复合微量元素极显著提高了蛋鸡的血浆总超氧化物歧化酶（T-SOD）活性（P<0.01）；添加NRC推荐需要量的100%、125%无机复合微量元素极显著提高了血浆谷胱甘肽过氧化物歧化酶（GSH-Px）活性（P<0.01）；添加NRC推荐需要量的125%无机复合微量元素极显著提高了试验第8周和第24周时血浆总抗氧化能力（T-AOC）（P<0.01）；添加NRC推荐需要量的75%、100%、125%无机复合微量元素极显著降低了试验第16周时血浆丙二醛（MDA）含量（P<0.01）。2）与对照组相比，添加不同水平的有机复合微量元素均极显著提高了试验第8周时蛋鸡的血浆T-AOC，试验第4周、第8周和第16周时血浆T-SOD活性和试验第16周时血浆GSH-Px活性（P<0.01）；添加NRC推荐需要量的50%、75%、100%、125%有机复合微量元素极显著降低了试验第4周和第16周时血浆MDA含量（P<0.01）。3）NRC推荐需要量的75%水平时，试验第8周，有机组血浆T-AOC显著高于无机组（P<0.05）；试验第16周和第24周，有机组血浆GSH-Px活性显著高于无机组（P<0.05）。NRC推荐需要量的125%水平时，试验第16周，有机组血浆T-SOD活性显著高于无机组（P<0.05）。试验表明，蛋鸡饲粮中添加NRC推荐需要量的75%以上无机复合微量元素有利于提高血浆的抗氧化能力；蛋鸡饲粮中添加NRC推荐需要量的25%、50%有机复合微量元素有利于提高血浆的抗氧化能力；在NRC推荐需要量的75%、125%水平时，有机复合微量元素对蛋鸡抗氧化能力的提高效果优于无机复合微量元素。

This experiment was conducted to study the effects of inorganic and organic complex trace elements at different levels on the plasma antioxidant activities of laying hens. Nine hundred and ninety 22-week-old Beijing Red No.1 laying hens were randomly allocated to 11 groups with 6 replicates per group and 15 hens per replicate. Group 1 was control group. Experimental groups=were fed the basal diets supplemented inorganic (groups 2 to 6) and organic complex trace elements (groups 7 to 11) at 25%, 50%, 75%, 100% and 125% of requirements NRC (1994) recommended, respectively. Mn, Fe, Zn, Se were referenced at laying hen requirements of NRC (1994) recommended, while Cu was referenced for broiler. The experiment lasted for 24 weeks. The results showed as follows: 1) compared with control group, inorganic complex trace elements at 75%, 100% and 125% of requirements NRC recommended significantly increased the activity of total superoxide dismutase (T-SOD) in plasma of laying hens (P<0.01), inorganic complex trace elements at 100% and 125% of requirements NRC recommended significantly increased the activity of glutathione peroxidase (GSH-Px) in plasma (P<0.01), inorganic complex trace elements at 125% of requirement NRC recommended significantly increased the total antioxidant capacity (T-AOC) in plasma at weeks 8 and 24 (P<0.01), and inorganic complex trace elements at 75%, 100% and 125% of requirements NRC recommended significantly decreased the content of malonaldehyde (MDA) in plasma at week 16 (P<0.01). 2) Compared with control group,organic complex trace elements at all levels significantly increased the T-AOC in plasma of laying hens at week 8, the activity of T-SOD at weeks 4, 8 and 16 and the activity of GSH-Px at week 16 (P<0.01), and organic complex trace elements at 50%, 75%, 100% and 125% of requirements NRC recommended significantly decreased the content of MDA in plasma at weeks 4 and 16 (P<0.01). 3) At 75% of requirement NRC recommended, the T-AOC at week 8 and the activity of GSH-Px at weeks 16 and 24 in plasma of organic groups were significantly higher than those of inorganic groups (P<0.05). At 125% of requirement NRC recommended, the activity of T-SOD at week 16 in plasma of organic groups was significantly higher than that of inorganic groups (P<0.05). In conclusion, it is benefit to increasing the plasma antioxidant activities that the levels of inorganic and organic complex trace elements supplemented in diet of laying hens are beyond 75% inorganic complex trace element and 25% and 50% organic complex trace elements of requirements NRC recommended. At 75% and 125% of requirements NRC recommended, organic complex trace elements are better than inorganic complex trace elements on antioxidant activities of laying hens.