卵形鲳鲹幼鱼饲料中适宜蛋白能量比的研究

Optimum Dietary Protein to Energy Ratio in Juvenile Pompano,Trachinotus ovatus

以鱼粉、豆粕为蛋白源,豆油、鱼油为脂肪源,配制9种不同蛋白能量水平的饲料,蛋白质3个水平(38%、43%、49%),每个蛋白水平设3个脂肪梯度(6%、10%、14%),其蛋白能量比为19.3～27.4mg/kJ。卵形鲳鲹初始质量为(25.02±0.16)g,每个处理设3个重复,每个网箱(1.5 m×1.0 m×2.0m)放养卵形鲳鲹苗20尾,养殖试验持续8周。结果显示,卵形鲳鲹特定生长率随饲料蛋白水平的升高而显著升高(P<0.05)。投喂含43%或49%蛋白质、6%脂肪饲料的卵形鲳鲹表现出较好的特定生长率。饲料中不同的脂肪水平未表现出蛋白质节约效应,较高的脂肪水平反而抑制了卵形鲳鲹的特定生长率、饲料效率和蛋白质效率。卵形鲳鲹鱼体蛋白和脂肪含量分别随饲料蛋白质和脂肪水平的上升而显著升高(P<0.05)。在该试验条件下,卵形鲳鲹幼鱼饲料中最适蛋白质、脂肪水平和蛋白能量比分别为43%、6%和24.4 mg/kJ。

A growth experiment was conducted to determine the optimal dietary protein-energy（P/E）ratio in juvenile pompano,Trachinotus ovatus [initial body weight（25.02±0.16） g].The juveniles were stocked into in sea floating cages（1.5 m×1.0 m×2.0 m）at a rate of 20 individuals per cage and randomly fed nine practical diets containing three protein levels（38%,43% and 49%）and three lipid levels（6%,10% and 14%）,P/E ratios ranging from 19.30 mg/kJ to 27.40 mg/kJ twice daily（9：00 and 16：00）to apparent satiation with triplication for 8 weeks.The specific growth rate（SGR） was found to significantly increase with increasing dietary protein from 38% to 43% irrespective of dietary lipid（P 0.05）.The fish fed the diet containing 43% or 49% protein and 6% lipid showed the maximal SGR.However,the fish fed the diet with 43% protein and 6% lipid had significantly higher feed efficiency ratio（FER）,protein efficiency ratio（PER）and energy retention（ER）than other groups did（P0.05）.Carcass protein and lipid content was significantly increased with the increase in dietary protein and lipid levels whereas body moisture was constant regardless of the dietary treatment,indicating that the diet containing 43% protein and 6% lipid with P/E of 24.4 mg protein/kJ was optimal for the pompano juveniles.