Department of Fisheries and Wildlife, Faculty of Fisheries and Wildlife, University of Veterinary and Animal Sciences, Lahore, Pakistan.
Department of Zoology, University of Gujrat, Gujrat, Pakistan.
PLoS One. 2022 Sep 16;17(9):e0274734. doi: 10.1371/journal.pone.0274734. eCollection 2022.
The objective of this study was to optimize the organic selenium (Se) requirements of intensively reared silver carp (Hypophthalmichthys molitrix). A total of n = 300 juveniles silver carp 11.40±0.52 cm long, and average weighing 25.28±0.18 grams were randomly assigned to 15 aquaria (20 fish/100L aquaria) and subjected to five different dietary Se levels in a completely randomized design. The diets were pelleted supplemented with exogenous Se methionine @ 0.0, 0.3, 0.6, 0.9 and 1.2 mg/kg of the diet. The fourteen days of aquaria acclimatization was given to fish and then an 84-day feeding trial was conducted. The group supplemented with 0.9 mg/kg Se had greater feed intake, gain in length, body weight %, and specific growth rate with a better feed conversion ratio as compared to those fed on the rest of the dietary levels or control (P<0.05). The deposition of Se was greater in the liver, and kidneys of the fishes fed on diets containing 0.9 and 1.2 mg Se levels than in the rest of the treatments (P<0.05). However, dietary Se levels had no effects on the bioaccumulation of Se in muscle tissues (P>0.05). The proximate analysis showed that dry matter, crude protein, and fat contents of meat were not changed (P>0.05) by dietary treatments. Similarly, values of TBARS, RBCs, Hb, and blood glucose contents were similar (P>0.05) across the treatments. However, the concentration of WBCs, HCT, and MCHC was greater in those groups fed on 0.9 and 1.2 Se levels than in those fed on 0.6, 0.3, and 0.0 Se levels respectively (P<0.05). The activities of ALT, AST, and ALP were lowered in the 0.9 mg Se supplemented fishes compared with the rest of the treatments (P<0.05). The SOD, catalases, and GPx levels for muscle, liver, and whole body were greater (P<0.05) in the Se-supplemented groups than in the control. These outcomes indicated that up to 0.9 mg/kg inclusion of methionine-based Se in the diet of juvenile silver carp improved the growth performance, feed conversion ratio, organs Se enrichment, and antioxidant status without any compromise on meat quality.
本研究旨在优化集约化养殖的草鱼（Hypophthalmichthys molitrix）对有机硒（Se）的需求。将 300 条 11.40±0.52cm 长、平均体重 25.28±0.18 克的草鱼幼鱼随机分配到 15 个水族箱（20 条鱼/100L 水族箱）中，并在完全随机设计中接受五种不同的膳食 Se 水平。饲料用蛋氨酸硒 @ 0.0、0.3、0.6、0.9 和 1.2mg/kg 饲料制成颗粒补充硒。鱼类适应水族箱环境的十四天结束后，进行了 84 天的喂养试验。与其他饮食水平或对照组相比，补充 0.9mg/kg Se 的组具有更高的饲料摄入量、体长增加、体重百分比和特定生长率，以及更好的饲料转化率（P<0.05）。在肝脏和肾脏中沉积的硒在摄食含 0.9 和 1.2mg Se 水平的饮食的鱼类中大于其他处理组（P<0.05）。然而，膳食 Se 水平对肌肉组织中 Se 的生物累积没有影响（P>0.05）。营养成分分析表明，肌肉组织的干物质、粗蛋白和脂肪含量不因饮食处理而改变（P>0.05）。同样，各组的 TBARS、RBCs、Hb 和血糖含量也相似（P>0.05）。然而，与摄食 0.6、0.3 和 0.0mg Se 水平的组相比，摄食 0.9 和 1.2mg Se 水平的组的 WBCs、HCT 和 MCHC 浓度更高（P<0.05）。与其他处理组相比，补充 0.9mg Se 的鱼的 ALT、AST 和 ALP 活性降低（P<0.05）。肌肉、肝脏和全身的 SOD、过氧化氢酶和 GPx 水平在补充 Se 的组中高于对照组（P<0.05）。这些结果表明，在草鱼幼鱼的饲料中添加高达 0.9mg/kg 的蛋氨酸硒可以提高生长性能、饲料转化率、器官 Se 富集和抗氧化状态，而不会对肉质造成任何影响。
