鲻配合饲料适宜蛋白含量及蛋白能量比的初步研究

配制粗蛋白含量分别为２４％，２８％和３２％的三种试验饲料投喂鲻共８周，结果表明蛋白含量为２８％的饲料组的平均增重（克／尾）和特定生长率（％ｄ）均为最大值，饲料蛋白质含量对鲻肌肉成份没有影响，配制四种蛋白能量比（Ｐ：Ｅ）分别为８６．２，９０．３，９４．９和１００．０ｍｇ／ｋＣａｌ的饲料投喂鲻，养殖时间为６周，平均增重分别为３２．５，３４．２，３１．３和２３．８特定生长率分别为０．７０，０．７９，０．

A PRELIMINARY STUDY ON THE OPTIMUM PROTEIN LEVEL AND PROTEIN TO ENERGY RATIO OF THE DIET FOR MUGIL CEPHALUS

The protein requirement of young grey mullet, Mugil cephalus, was studied by using three diets containing 24%, 28% and 32% protein for eight weeks. The results showed that average weight gain and special growth rates(SGR) of the diet of 28% protein were both the highest. The protein content of the diets had no effects on the muscle composition of the fish. Four diets with protein to energy (P:E) ratios of 86. 2, 90. 3, 94.9 and 100. 0 mg protein/kCal energy were fed to groups of grey mullet for a period of six weeks.Average weight gains were 32. 5, 34. 2, 31. 3 and 23.8 g/ind respectively, and the SGR were 0. 70, 0. 79, 0. 74 and 0. 60 respectively. Composition of muscle was no significance affected by dietary P to E ratio. However, protein content of whole body decreased and lipid content increased at low P to E ratios. The optimum P to E ratio for grey mullet was determined to be 91mg/kCal, based on high weight gain and low lipid deposition in the abdominal cavity.