Abstract Although selenium (Se) supplementation is a common practice in poultry, the best source and level has not been established yet. Thus, a 42-day experiment involving diets with three levels (0.1, 0.2 and 0.5 mg/kg) of supplemental Se from sodium selenite (SS), selenised yeast (SY) and nanoelemental Se (SN) was conducted to evaluate the possible differential responses of broiler chickens to inorganic, organic and nano Se sources relative to a control diet. Throughout the experiment, broilers receiving Se supplements had higher feed intake, body weight gain (BWG) and survival rate than the control. Broilers fed dietary SY or SN had improved BWG compared with those fed the SS-supplemented diets. Broilers treated with Se supplementation had increased serum glutathione peroxidase (GPx) and thioredoxin reductase (TrxR) activities and produced higher antibody responses to avian influenza virus (AIV) and sheep red blood cell (SRBC) versus the control. These effects were enhanced with increasing Se addition, except for GPx that responded equally to all supplemental Se levels. Also, broilers receiving supplementary SY or SN exhibited higher anti-AIV and anti-SRBC titres along with more elevated serum Se, TrxR activity and total antioxidant capacity compared with those receiving SS. At the same time, SN had the most increasing effect on anti-SRBC titre. To conclude, diet supplementation with 0.5 mg/kg of Se in the form of SY or SN was capable of meeting the Se demands of broiler chickens for optimum growth and antioxidant capability, while SN seemed to be the most effective Se source in enhancing immunity. Highlights Diet supplementation with SN and SY, especially at 0.5 mg/kg diet, improved broiler performance and carcase quality of chickens compared with SS. SY and SN showed more favourable effects on oxidative status and immunocompetence. The best anti-SRBC titre was observed with SN.

中文翻译：

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亚硒酸钠、硒化酵母和纳米元素硒对肉鸡性能反应、免疫和抗氧化功能的比较评价

摘要 虽然硒 (Se) 补充是家禽的常见做法，但尚未确定最佳来源和水平。因此，进行了一项为期 42 天的实验，涉及三种水平（0.1、0.2 和 0.5 毫克/千克）来自亚硒酸钠 (SS)、硒化酵母 (SY) 和纳米元素硒 (SN) 的补充硒的饮食，以评估可能的差异肉鸡对无机、有机和纳米硒源相对于对照日粮的反应。在整个实验过程中，接受硒补充剂的肉鸡比对照组具有更高的采食量、体重增加 (BWG) 和存活率。与饲喂 SS 补充日粮的肉鸡相比，饲喂 SY 或 SN 日粮的肉鸡的 BWG 有所改善。与对照组相比，补充硒的肉鸡血清谷胱甘肽过氧化物酶 (GPx) 和硫氧还蛋白还原酶 (TrxR) 活性增加，对禽流感病毒 (AIV) 和绵羊红细胞 (SRBC) 产生更高的抗体反应。这些效果随着硒添加量的增加而增强，除了 GPx 对所有补充硒水平的反应相同。此外，与接受 SS 的肉鸡相比，接受补充 SY 或 SN 的肉鸡表现出更高的抗 AIV 和抗 SRBC 滴度以及更高的血清硒、TrxR 活性和总抗氧化能力。同时，SN对抗SRBC滴度的增加作用最大。总而言之，在日粮中添加 0.5 mg/kg SY 或 SN 形式的硒能够满足肉鸡对最佳生长和抗氧化能力的硒需求，而SN似乎是增强免疫力最有效的硒来源。亮点 日粮中添加 SN 和 SY，尤其是 0.5 mg/kg 日粮，与 SS 相比，改善了肉鸡性能和鸡的胴体质量。SY和SN对氧化状态和免疫能力显示出更有利的影响。用 SN 观察到最好的抗 SRBC 滴度。