An eight‐week feeding trial was conducted to examine the optimal dietary protein and lipid levels for juvenile hybrid sunfish (Lepomis cyanellus ♀ × Lepomis macrochirus ♂). A 5 × 2 factorial layout containing five protein levels (300, 340, 380, 420 and 460 g kg⁻¹) and two lipid levels (30 and 80 g kg⁻¹) was designed. Fish (initial body weight 1.21 ± 0.06 g) were fed the test diets twice daily. The final body weight (FBW) and per cent weight gain (PWG) in fish increased with dietary protein level from 300 to 420 g kg⁻¹, and afterwards decreased with dietary protein level from 420 to 460 g kg⁻¹. Feed intake and feed conversion ratio (FCR) significantly declined with increase dietary protein level. Fish fed at 380 and 420 g kg⁻¹ dietary protein level exhibited higher nitrogen retention efficiency (NRE) and phosphorus retention efficiency (PRE), however, lower nitrogen and phosphorus wastes, than in fish fed at 300 g kg⁻¹ dietary protein level. For different dietary lipid levels, the higher FBW, PWG, NRE and PRE, but the lower feed intake, FCR, nitrogen and phosphorus wastes, were found in fish fed at 80 g kg⁻¹ dietary lipid level than those in fish fed at 30 g kg⁻¹ dietary lipid level. At the end of feeding trail, the contents of body moisture and lipid were significantly influenced by dietary lipid level. According to these results, a diet containing 420 g kg⁻¹ protein and 80 g kg⁻¹ lipid is recommended for efficient growth of juvenile hybrid sunfish.

中文翻译：

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幼年杂交sun鱼的最佳日粮蛋白和脂质水平

进行了为期八周的喂养试验，以检查幼年杂交sun鱼（Lepomis cyanellus♀ × Lepomis macrochirus♂）的最佳饮食蛋白质和脂质水平。设计了一个5×2阶乘布局，其中包含五个蛋白质水平（300、340、380、420和460 g kg ^-1）和两个脂质水平（30和80 g kg ^-1）。每天两次给鱼（初始体重1.21±0.06克）喂食测试饲料。鱼类的最终体重（FBW）和增重百分比（PWG）随着饮食蛋白质水平从300增至420 g kg ^-1而增加，随后随着饮食蛋白质水平从420 g至460 g kg ^-1而降低。饲料摄入和饲料转化率（FCR）随着日粮蛋白质水平的增加而显着下降。以380和420 g kg ^-1的日粮蛋白水平饲喂的鱼比以300 g kg ^-1的日粮蛋白水平饲喂的鱼表现出更高的氮保持效率（NRE）和磷保持率（PRE），但是氮和磷的浪费更低。对于不同的饮食脂质水平，饲喂80 g kg ^-1饮食脂质水平的鱼类要比饲喂30千克的鱼类中更高的FBW，PWG，NRE和PRE，但饲料摄入量，FCR，氮和磷的浪费较低。克千克^-1饮食中的脂质水平。在饲喂结束时，饮食中的脂质水平显着影响了体内水分和脂质的含量。根据这些结果，建议使用含有420 g kg ^-1蛋白质和80 g kg ^-1脂质的饮食来使幼年杂种翻车鱼有效生长。