Department of Animal Science, Federal University of Viçosa, Viçosa, 36570900, Brazil.
Production Systems, Natural Resources Institute Finland (Luke), 31600, Jokioinen, Finland.
BMC Vet Res. 2021 Apr 9;17(1):151. doi: 10.1186/s12917-021-02855-4.
Selenium (Se) has been recognized as an essential micronutrient for nearly all forms of life. In recent decades, broiler responses to dietary Se supplemental levels and sources have received considerable attention. On environmental grounds, organic trace mineral utilization in practical broiler feeds has been defended due to its higher bioavailability. In such feeds, trace minerals are provided simultaneously in the same supplement as inorganic salts or organic chelates, a fact commonly ignored in assays conducted to validate organic trace mineral sources. The current assay aimed to investigate growth and biochemical responses, as well as Se retention of growing chicks fed diets supplemented with organic and inorganic Se levels and where the trace minerals (zinc, copper, manganese, and iron) were provided as organic chelates or inorganic salts according to Se source assessed. In so doing, a 2 × 5 factorial arrangement was used to investigate the effects of sodium selenite (SS) and selenium-yeast (SY) supplemented in feeds to provide the levels of 0, 0.08, 0.16, 0.24, and 0.32 mg Se/kg.
Chicks fed selenium-yeast diets had body weight (BW), and average daily gain (ADG) maximized at 0.133 and 0.130 mg Se/kg, respectively. Both Se sources linearly increased (P < 0.05) the glutathione peroxidase (GSH-Px) activity in chick blood but higher values were observed in sodium selenite fed chicks (P < 0.05). Both Se sources influenced thyroid hormone serum concentrations (P < 0.05). Chicks fed SY exhibited greater retention of Se in the feathers (P < 0.05). Relative bioavailability of selenium yeast compared with SS for the Se content in carcass, feathers, total and Se retention were, 126, 116, 125 and 125%, respectively. SY supplementation resulted in lower liver Se concentration as Se supplementation increased (P < 0.05).
Based on performance traits, the supplemental level of organic Se as SY in organic trace minerals supplement to support the maximal growth of broiler chicks is 0.133 mg Se/kg.
硒（Se）已被认为是几乎所有生命形式的必需微量元素。近几十年来，肉鸡对日粮硒补充水平和来源的反应受到了相当多的关注。出于环境原因，由于其生物利用率更高，实用肉鸡饲料中的有机微量矿物质的利用得到了辩护。在这种饲料中，痕量矿物质同时以无机盐或有机螯合物的形式提供在同一补充物中，这是在进行验证有机痕量矿物质来源的测定时经常被忽视的事实。本试验旨在研究生长和生化反应以及生长雏鸡的硒保留率，这些雏鸡饲喂补充有机和无机硒水平的日粮，其中痕量矿物质（锌、铜、锰和铁）根据评估的硒源提供有机螯合物或无机盐。为此，使用 2×5 因子安排来研究亚硒酸钠（SS）和硒酵母（SY）在饲料中的补充对提供 0、0.08、0.16、0.24 和 0.32mg Se/kg 的影响。
饲喂硒酵母日粮的雏鸡体重（BW）和平均日增重（ADG）分别在 0.133 和 0.130mg Se/kg 时达到最大值。两种硒源均呈线性增加（P<0.05）雏鸡血液中的谷胱甘肽过氧化物酶（GSH-Px）活性，但 SS 组的活性更高（P<0.05）。两种硒源均影响血清甲状腺激素浓度（P<0.05）。饲喂 SY 的雏鸡羽毛中硒的保留量更高（P<0.05）。与 SS 相比，SY 对硒在胴体、羽毛、总硒和硒保留中的相对生物利用率分别为 126%、116%、125%和 125%。随着硒补充量的增加，SY 组肝脏中的硒浓度降低（P<0.05）。
根据生长性能，在有机微量矿物质补充剂中作为 SY 添加的有机硒的补充水平为 0.133mg Se/kg，可支持肉鸡雏鸡的最大生长。
