| 摘要: |
| 采用单因素实验设计方法，进行了饲料中添加维生素C对点带石斑鱼生长和组织中维生素C积累量影响的研究，设计了6个不同维生素C水平(0、35、70、140、280、700mg/kg)的等氮等能饲料，对石斑鱼幼鱼进行为期 8周的生长实验，每个水平三个重复，每个养殖单元放养初始体重为10g左右的点带石斑鱼幼鱼20尾。饲养实验在海水网箱(1.5m×1m×2.0m)中进行。结果表明，饲料中未添加维生素C组的增重率、特定生长率以及存活率显著低于维生素C添加组，饲料中添加维生素C的浓度为 70mg/kg组的增重率和特定生长率最高。对鱼体生物学指标的分析表明，饲料中添加维生素C并不影响鱼体的肥满度和内脏比指数，却显著影响肝体比指数。鱼体水分、蛋白质和灰分含量不受饲料中维生素C添加水平的影响，然而对鱼体脂肪含量的影响显著。随着饲料中维生素C添加水平的提高，石斑鱼肌肉和肝脏中维生素C的积累量显著升高。以增重率和特定生长率为指标，点带石斑鱼维生素C的适宜需要量为70mg/kg。 |
| 关键词: 维生素C 石斑鱼 生长 组织中维生素C积累量 |
| DOI： |
| 分类号: |
| 基金项目:国家“十五”重大科技计划项目 ,2001DA505/06号 |
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| EFFECT OF THE DIFFERENT LEVELS OF DIETARY VITAMIN C ON GROWTH AND TISSUE ASCORBIC ACID CONCENTRATIONS IN JUVENILE GROUPER EPINEPHELUS COIOIDES |
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ZHOU Qi-Cun1,2, LIU Yong-Jian1, MAI Kang-Sen1,3, TIAN Li-Xia1
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1.School of Life Science, Zhongshan University, Guangzhou, 510275;2.Fisheries College, Ocean University of Zhanjiang, Zhanjiang, 524025;3.Fisheries College, Ocean University of China, Qingdao, 266003
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| Abstract: |
| A single-factor experiment was conducted to study the effects of dietary vitamin C (L-ascorby-l-2-monophosphate) on growth of juvenile grouper (Epinephelus coioides), body distribution of ascorbic acid concentrations, histopathological changes and main body composition of whole body. Six iso-nitrogenous and iso-energetic diets in the levels of 0, 35, 70, 140, 280 and 700mg/ kg L-ascorby-l-2-monophosphate were fed twice daily (09:00, 17:00). Triplicated groups of 20 with initial weight of about 10g were fed with the diets in the levels for 8 weeks. The experiment was done in floating net cages (1.5m×1.0m×2.0m). Results indicated that after 8 weeks of the feeding trial, weight gain (WG), specific growth ratio (SGR) and survival rate (SR) of the fish fed with the control diet (L-ascorby-l-2-monophosphate un-supplemented diet) were significantly lower than those with vitamin C enriched diets.WG, SGR and SR were the highest in the fish fed in 70 mg/kg level. However, with increase of dietary vitamin C supplemented levels from 0 to 70 mg/kg, the WG and SGR increased significantly; but with increase of dietary vitamin C from 70 to 700 mg/kg, the WG and SGR decreased slightly. No significant change in SR was found in the vitamin C enriched groups but the SR were higher than the un-supplemented vitamin C group. In addition, no significant differences for viserosomatic index and condition factor were shown between different groups. But it is clear that the hepatosomatic index was affected by enriched vitamin C diets, for example, the un-supplemented vitamin C group and the group in 700 mg/kg level were significantly lower than other groups. Moisture, protein and ash concentration in whole body of juvenile grouper were not affected by the supplemental levels of dietary vitamin C; but the lipid concentration in the juvenile grouper increased significantly while vitamin C food enrichment from 0 to 35 mg/kg, while with the increase of vitamin C supplemented level in diet was upper to 70 mg/kg, the lipid concentration decreased significantly. For changes in ascorbic acid concentrations in the grouper muscle and liver, clear increases were found with the vitamin C enrichment. For instance, the ascorbic acid concentrations with no vitamin C enriched were the lowest among all, with the increase of vitamin C supplemented level in diet, the ascorbic acid concentrations increased significantly. Meanwhile, the ascorbic acid concentrations in liver were higher than in muscle’s levels which were in a same supplemented level. Based on the WG and SGR of juvenile grouper, it is proposed that the optimal vitamin C enrichment in the form of L-ascorby-l-2-monophosphate for juvenile grouper growth is about 70 mg/kg. |
| Key words: Vitamin C (L-ascorby-l-2-monophosphate), Grouper(Epinephelus coioides), Growth, Tissue ascorbic acid concentrations |
