Garling D L, Wilson R P
J Nutr. 1976 Sep;106(9):1368-75. doi: 10.1093/jn/106.9.1368.
Twenty-one semipurified diets were formulated to determine the optimum protein:energy ratio (P/E) for channel catfish fingerlings. Seven crude protein levels and three energy levels at each protein level were utilized. The protein, lipid, and digestible carbohydrate sources were hexane-extracted whole egg powder, salmon-corn oil mixture, and white dextrin, respectively. After an initial 2 week conditioning period, the experimental diets were fed in triplicate to groups of 30 +/- 3 channel catfish fingerlings weighing 205 +/- 10 g and kept in 110 liter flow-through aquaria at 26.7 +/- 1.1 degrees. The diets were fed at a rate equalling 3% of the total wet body weight/day divided into three equal feedings and adjusted weekly for 9 weeks. An approximate fivefold increase in body weight was observed. These data indicate that the concept of P/E ratios must be restricted to diets containing adequate levels of protein and total energy. Based on average daily gain, diets containing energy levels between 275 and 341 kcal/100 g had an optimum P/E ratio of approximately 88 (24-36% crude protein). Diets containing 24% crude protein and 275 kcal/100 g diet appeared to be utilized more efficiently in terms of percent protein deposited than diets containing higher crude protein levels.
配制了21种半纯化日粮，以确定斑点叉尾鮰鱼种的最佳蛋白质：能量比（P/E）。使用了7种粗蛋白水平，每种蛋白水平下有3种能量水平。蛋白质、脂质和可消化碳水化合物来源分别为己烷萃取全蛋粉、鲑鱼-玉米油混合物和白色糊精。在最初2周的适应期后，将实验日粮一式三份投喂给每组30±3尾、体重205±10克的斑点叉尾鮰鱼种，并饲养在110升的流水水族箱中，水温为26.7±1.1摄氏度。日粮投喂量为相当于鱼体总湿重的3%/天，分三次等量投喂，并每周调整一次，持续9周。观察到鱼体重增加了约五倍。这些数据表明，P/E比的概念必须局限于含有足够蛋白质和总能量水平的日粮。基于平均日增重，能量水平在275至341千卡/100克之间的日粮，其最佳P/E比约为88（粗蛋白含量为24-36%）。就蛋白质沉积百分比而言，含24%粗蛋白和275千卡/100克日粮的日粮似乎比含较高粗蛋白水平的日粮利用效率更高。
