The present experiment containing two dietary cadmium (Cd) levels (0 and 5 mg/kg) and two lipoic acid (LA) levels (0 and 600 mg/kg) was carried out to investigate the effects of dietary Cd on the growth, antioxidant capacity, immunity and intestine morphology of Macrobrachium nipponense and the alleviation effects of LA. We found that dietary Cd and LA had no significant effects on the growth of prawns. Dietary Cd significantly decreased the activity of antioxidant enzymes, resulting in a higher MDA level in the hepatopancreas. LA was added to diets that increased these antioxidant enzyme activities. Similarly, dietary Cd decreased the activity of lysozyme and content of NO in the serum, whereas dietary LA ameliorated these negative effects. Dietary Cd significantly increased the activities of GOT and GPT in the serum, and LA supplementation decreased the activities of these enzymes in the serum. The intestinal villus of prawns fed the diet containing Cd was partly detached from the basement membrane, and LA protected the integrity of the gut. In conclusion, dietary Cd depressed the antioxidant capacity and immunity, destroyed the intestine morphology of prawns and LA supplementation alleviated these negative effects caused by Cd.

中文翻译：

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日粮镉对日本沼虾抗氧化能力、免疫和肠道形态的负面影响及硫辛酸的缓解作用

本实验包含两种膳食镉 (Cd) 水平（0 和 5 毫克/千克）和两种硫辛酸 (LA) 水平（0 和 600 毫克/千克），旨在研究膳食 Cd 对生长、抗氧化剂的影响日本沼虾的能力、免疫和肠道形态以及 LA 的缓解作用。我们发现日粮 Cd 和 LA 对虾的生长没有显着影响。膳食镉显着降低抗氧化酶的活性，导致肝胰腺中更高的 MDA 水平。LA 被添加到增加这些抗氧化酶活性的饮食中。类似地，膳食镉降低了溶菌酶的活性和血清中 NO 的含量，而膳食 LA 改善了这些负面影响。膳食镉显着增加血清中 GOT 和 GPT 的活性，而补充 LA 则降低了血清中这些酶的活性。喂食含有镉的饲料的虾的肠绒毛部分从基底膜上分离，而 LA 保护了肠道的完整性。总之，膳食镉降低了抗氧化能力和免疫力，