A 14-week feeding trial was conducted to determine the effects of dietary L-ascorbyl-2-polyphosphate on the growth performance, haematological parameters, biochemical characteristics, and skeletal features of juvenile hybrid grouper (♀Epinephelus fuscoguttatus × ♂E. lanceolatus). Eight experimental diets containing graded vitamin C (VC) levels (0, 18, 45, 78, 144, 245, 386, and 762 mg/kg) were prepared and fed to triplicate groups of fish (initial body weight: 10.41 ± 0.06 g). The final body weight, weight gain rate, specific growth rates, and fish survival increased when fed with diets supplemented with VC regardless of the supplementation level. Total feed intake reduction was observed in fish fed non-VC diet. Whereas no significant differences were detected in the feed conversion ratios and protein efficiency ratios among fish treatments. The hepatic VC concentration was positively correlated with dietary VC supplementation and reached a plateau when supplemented with more than 386 mg/kg diet. Higher total protein and alkaline phosphatase levels in blood serum and incidence of skeletal deformities were recorded in the fish fed with a control diet compared to other treatments. The results indicate that adding 18 mg/kg of VC is optimum and further increase does not provide any significant benefit to fish growth and health.

中文翻译：

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日粮L-抗坏血酸2-聚磷酸盐对杂种石斑鱼（♀Epinephelus fuscoguttatus × ♂E. lanceolatus）生长性能、血液学参数、生化特性和骨骼特征的影响

进行了为期 14 周的饲养试验，以确定日粮 L-抗坏血酸-2-多磷酸盐对杂种石斑鱼（♀ Epinephelus fuscoguttatus  × ♂ E . lanceolatus）生长性能、血液学参数、生化特征和骨骼特征的影响）。制备了含有分级维生素 C (VC) 水平（0、18、45、78、144、245、386 和 762 毫克/千克）的八种实验饮食，并将其喂给三组鱼（初始体重：10.41 ± 0.06 克） ）。无论补充水平如何，当饲喂补充有 VC 的饮食时，最终体重、体重增加率、特定生长率和鱼的存活率都会增加。在喂食非 VC 饮食的鱼中观察到总采食量减少。而鱼类处理之间的饲料转化率和蛋白质效率比没有检测到显着差异。肝脏 VC 浓度与膳食 VC 补充呈正相关，当补充超过 386 mg/kg 饮食时达到平台期。与其他处理相比，用对照饮食喂养的鱼的血清中总蛋白和碱性磷酸酶水平更高，骨骼畸形的发生率更高。结果表明，添加 18 mg/kg 的 VC 是最佳的，进一步增加对鱼的生长和健康没有任何显着的好处。