BACKGROUND Cage-rearing in laying ducks, as a novel rearing system, not only fundamentally solves the pollution problem of the duck industry and improve bio-safety and product quality but also exhibits more benefits by implementing standardized production compared with the floor-rearing. Of course, this system also brings some welfare problems and stress injuries to layers due to lack of water environment and limited activities in the cages. However, the effects on the factors of antioxidant defense and inflammatory injury in the early cage stage are not well-understood. RESULTS In this study, eighty Shaoxing layers were reared on floor and in cages from 12 weeks of age. The ducks were caged 1, 2, 4, 7, and 10 days, the factors of antioxidant defense and inflammatory injury were investigated. The results showed that the caged ducks suffered liver injury to a certain extent when the ducks were just put into the cages. Analysis of antioxidant enzyme activities indicated that the different rearing system could not affect the change of antioxidant capacities, while the liver malondialdehyde (MDA) level was significant higher in the 2-d, 7-d, and 10-d ducks compared with the 1-d ducks during the change of days, while catalase (CAT) activity showed the opposite results. Additionally, quantitative real-time PCR (qRT-RCR) revealed that the relative mRNA levels of endoplasmic reticulum (ER) stress-related gene (CHOP and GRP78) were significantly upregulated in cage rearing ducks compared to that of the floor rearing ducks. Moreover, the mRNA levels of inflammatory cytokines including cycloxygenase-2 (COX-2), nitric oxide synthase (iNOS), Interleukin 1 beta (IL-1β), Interleukin 2 (IL-2) and Interleukin 6 (IL-6), were also increased significantly in caged layers. CONCLUSIONS Taken together, although antioxidant defense has no obvious effect on cage stress, the stress levels of laying ducks vary greatly in the early cage stage, which not only caused liver tissue damage to some extent, but also resulted in increases in the expression of the factors of inflammatory injury. Therefore, we recommend that anti-stress agents should be added in the feed to alleviate the stress in the early cage stage.

中文翻译：

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网箱和地板饲养系统对蛋鸭抗氧化防御和炎症损伤因子的影响。

背景技术作为一种新颖的饲养系统，在鸭蛋中饲养笼子不仅从根本上解决了鸭业的污染问题，提高了生物安全性和产品质量，而且与地板饲养相比，通过实施标准化生产具有更多的益处。当然，由于缺乏水环境和网箱活动受限，该系统还会带来一些福利问题，并给蛋鸡造成压力伤害。然而，笼子早期对抗氧化剂防御和炎症损伤因子的影响尚不清楚。结果在这项研究中，从12周龄开始，在地面和网箱中饲养了80个绍兴层。将鸭子圈养1、2、4、7和10天，研究其抗氧化防御和炎性损伤的因素。结果表明，将鸭直接放入笼中会造成一定程度的肝损伤。对抗氧化酶活性的分析表明，不同的饲养系统不会影响抗氧化能力的变化，而2-d，7-d和10-d鸭的肝脏丙二醛（MDA）水平明显高于1。 -d鸭在日间变化中，而过氧化氢酶（CAT）活性则显示相反的结果。此外，定量实时PCR（qRT-RCR）显示与笼养鸭相比，笼养鸭中内质网（ER）应激相关基因（CHOP和GRP78）的相对mRNA水平显着上调。此外，炎症细胞因子的mRNA水平包括环氧化酶2（COX-2），一氧化氮合酶（iNOS），在网箱中，白细胞介素1β（IL-1β），白细胞介素2（IL-2）和白细胞介素6（IL-6）也显着增加。结论综上所述，尽管抗氧化防御对笼压力没有明显影响，但在笼早期，产蛋鸭的应激水平变化很大，不仅在一定程度上引起了肝组织损伤，而且导致了其表达的增加。炎症损伤的因素。因此，我们建议在饲料中添加抗应激剂以减轻笼养初期的应激。不仅在一定程度上引起肝组织损伤，而且导致炎症损伤因子表达的增加。因此，我们建议在饲料中添加抗应激剂，以减轻笼养初期的应激。不仅在一定程度上引起肝组织损伤，而且导致炎症损伤因子表达的增加。因此，我们建议在饲料中添加抗应激剂，以减轻笼养初期的应激。