Huang Dongyu, Jahazi Joshua Daniel, Ren Mingchun, Zhang Lu, Liang Hualiang
Key Laboratory of Integrated Rice-Fish Farming Ecology, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China.
Vet Sci. 2024 Nov 18;11(11):576. doi: 10.3390/vetsci11110576.
A 9-week experiment investigated the effects of dietary cobalt levels on the growth performance, antioxidant capacity, and immunity of largemouth bass. Six feed groups were designed and each group received different cobalt levels, including 0.129 mg/kg (control group), 0.192 mg/kg, 0.201 mg/kg, 0.233 mg/kg, 0.277 mg/kg, and 0.316 mg/kg. The results show that the control group (0.129 mg/kg diet) had the lowest final body weight (FBW), weight gain rate (WGR), and specific growth rate (SGR), and the highest feed conversion ratio (FCR), when compared to the cobalt supplementation groups. Dietary cobalt levels of 0.192 mg/kg increased the body protein content and decreased the body moisture content. Regarding antioxidant capacity, the highest catalase (CAT) activity was found in the 0.277 mg/kg dietary cobalt group, while the malondialdehyde (MDA) content was significantly diminished; the total antioxidant capacity (T-AOC) content and glutathione peroxidase (GSH-Px) activity exhibited the highest values in the 0.192 mg/kg and 0.233 mg/kg dietary cobalt groups, respectively. Regarding gene expression, compared with the control group, the mRNA expression of was upregulated in the 0.192 mg/kg, 0.233 mg/kg, and 0.277 mg/kg dietary cobalt groups, while the mRNA expression of was diminished when dietary cobalt levels were below 0.233 mg/kg. In addition, the highest and mRNA expression levels were observed in the 0.201 mg/kg and 0.233 mg/kg dietary cobalt groups, respectively. According to the quadratic regression analysis based on the SGR and FCR, the optimal requirement was 0.24 and 0.26 mg/kg of dietary cobalt, respectively.
一项为期9周的实验研究了饲料中钴水平对大口黑鲈生长性能、抗氧化能力和免疫力的影响。设计了六个饲料组，每组接受不同的钴水平，包括0.129毫克/千克（对照组）、0.192毫克/千克、0.201毫克/千克、0.233毫克/千克、0.277毫克/千克和0.316毫克/千克。结果表明，与补充钴的组相比，对照组（饲料中钴含量为0.129毫克/千克）的终末体重（FBW）、增重率（WGR）和特定生长率（SGR）最低，饲料转化率（FCR）最高。饲料中钴水平为0.192毫克/千克时，鱼体蛋白质含量增加，水分含量降低。在抗氧化能力方面，饲料中钴含量为0.277毫克/千克的组过氧化氢酶（CAT）活性最高，丙二醛（MDA）含量显著降低；总抗氧化能力（T-AOC）含量和谷胱甘肽过氧化物酶（GSH-Px）活性分别在饲料中钴含量为0.192毫克/千克和0.233毫克/千克的组中表现出最高值。在基因表达方面，与对照组相比，饲料中钴含量为0.192毫克/千克、0.233毫克/千克和0.277毫克/千克的组中 的mRNA表达上调，而当饲料中钴水平低于0.233毫克/千克时， 的mRNA表达降低。此外，分别在饲料中钴含量为0.201毫克/千克和0.233毫克/千克的组中观察到 和 的mRNA表达水平最高。根据基于SGR和FCR的二次回归分析，饲料中钴的最佳需求量分别为0.24和0.26毫克/千克。
