Abstract It was hypothesized that dietary copper (Cu) nanoparticles, as a substitute for the commonly used copper sulfate, could contribute to lowering the dietary inclusion levels of Cu without compromising growth performance or reducing Cu digestibility and utilization in turkeys. An experiment was carried out on 648 one-day-old Hybrid Converter turkeys divided into 6 groups with 6 replicates per group in a two-factorial design with 3 dietary inclusion levels of Cu (20, 10 and 2 mg kg−1) and 2 dietary sources of Cu, copper sulfate and Cu nanoparticles (Cu-SUL and Cu-NPs, respectively). The apparent digestibility coefficients of minerals were determined after 6 weeks, and tissue samples were collected after 14 weeks of experimental feeding. A decrease in the dietary inclusion levels of Cu from 20 to 10 and 2 mg kg−1 did not reduce the body weights of turkeys at 42 and 98 days of age. In comparison with the remaining treatments, the lowest dietary inclusion level of Cu significantly decreased MDA concentrations in small intestinal tissue (P=0.002) and in the bursa of Fabricius (P=0.001). The replacement of Cu-SUL with Cu-NPs differentially modulated the redox status of selected tissues, i.e., enhanced SOD activity in small intestinal tissue (P=0.001) and decreased total glutathione levels in the bursa of Fabricius (P=0.005). In general, neither the different levels nor sources of additional dietary Cu (main factors) exerted negative effects on the histological structure of the duodenum and jejunum in turkeys. The intestinal digestibility of Cu increased with decreasing dietary Cu levels, and as a consequence, the highest apparent digestibility coefficient of Cu (and zinc) was noted in turkeys fed diets with the addition of 2 mg kg−1 Cu-NPs. Therefore, the environmental burden of excreted Cu was substantially reduced along with decreasing dietary Cu levels but it did not depend on the Cu source.

中文翻译：

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不同水平的铜纳米颗粒和硫酸铜对火鸡小肠形态测量指标、抗氧化状态和矿物质消化率的影响

摘要 据推测，日粮铜 (Cu) 纳米颗粒作为常用硫酸铜的替代品，有助于降低日粮中铜的含量，同时不会影响火鸡的生长性能或降低铜的消化率和利用率。对 648 只一日龄杂交转化火鸡进行了一项试验，分为 6 组，每组 6 个重复，采用双因素设计，具有 3 个日粮添加水平的 Cu（20、10 和 2 mg kg-1）和 2 Cu、硫酸铜和 Cu 纳米颗粒（分别为 Cu-SUL 和 Cu-NPs）的膳食来源。6 周后测定矿物质的表观消化率系数，实验饲喂 14 周后收集组织样本。日粮中铜的含量从 20 降至 10 和 2 mg kg-1 并没有降低 42 和 98 日龄火鸡的体重。与其余处理相比，Cu 的最低膳食添加水平显着降低了小肠组织 (P=0.002) 和法氏囊 (P=0.001) 中的 MDA 浓度。用 Cu-NPs 替代 Cu-SUL 可差异调节所选组织的氧化还原状态，即增强小肠组织中的 SOD 活性（P=0.001）并降低法氏囊中的总谷胱甘肽水平（P=0.005）。一般来说，不同水平或来源的额外膳食铜（主要因素）都不会对火鸡十二指肠和空肠的组织结构产生负面影响。Cu 的肠道消化率随着日粮铜水平的降低而增加，因此，在添加 2 mg kg-1 Cu-NPs 的日粮中饲喂的火鸡中，铜（和锌）的表观消化率最高。因此，排泄铜的环境负担随着日粮铜水平的降低而显着降低，但这并不取决于铜的来源。