不同饲料蛋白水平下点带石斑鱼对鸡肉粉、羽毛粉和血粉混合物的利用能力

通过10周网箱养殖实验,评价了不同饲料蛋白水平下点带石斑鱼对1种鸡肉粉、羽毛粉和血粉混合物的利用能力。采用2×4实验设计,设2个饲料蛋白水平(490 g/kg和530 g/kg粗蛋白),每个饲料蛋白水平下设4个鱼粉水平,其中1组饲料中加入500 g/kg鱼粉(对照),另外3组饲料中分别加入139、278、416 g/kg的鸡肉粉、羽毛粉和血粉混合物(鸡肉粉∶羽毛粉∶血粉=65∶20∶15)替代对照饲料中30%、60%、90%的鱼粉。实验鱼初始体重为(33.4±0.1) g。实验期间,除恶劣天气外,每天分两次按饱食量投喂实验鱼。实验结果表明,饲料蛋白水平对摄食量、增重,饲料系数、氮储积效率、能量储积效率和鱼体组成无显著影响;饲料鱼粉含量显著影响增重,饲料系数、氮储积效率和能量储积效率,但对摄食量和鱼体组成无显著影响。在相同饲料蛋白水平下,特定生长率(SGR)随鱼粉含量降低而下降;当鱼粉含量相同时,摄食高蛋白饲料的鱼SGR略高于摄食低蛋白饲料的鱼。本实验结果显示,通过添加鸡肉粉、羽毛粉和血粉混合物可将点带石斑鱼饲料鱼粉含量降低到200 g/kg,在490~530 g/kg范围内提高饲料蛋白水平无助于降低点带石斑鱼饲料鱼粉含量。

The capacity of malabar grouper in utilizing a blend of poultry by-product meal, feather meal and blood meal as fish meal substitutes at different dietary protein levels

A 10 week net pen experiment was carried out to examine the capacity of malabar grouper(Epinephelus malabaricus)in utilizing a blend of poultry by product meal,feather meal and blood meal at different dietary protein levels.A 2×4 experimental design,including two dietary protein levels(490 and 530 g/kg crude protein)and four fish meal level(500,350,200,50 g/kg),was established.At each dietary protein level,one feed was formulated to contain 500 g/kg herring meal as control,and in the remaining three feeds,the blend that was formulated to contain 65% poultry by product meal,20% feather meal and 15% blood meal was incorporated at 139,278 or 416 g/kg to replace 30%,60% or 90% of the fish meal.Initial body weight of the experimental fish was(33.4±0.1)g per fish.During the experiment,fish were fed to satiation twice daily except the days during which extremely high temperature or heavy waves occurred.The results of the experiment indicated that dietary protein level did not significantly affect feed intake(FI),weight gain(WG),feed conversion ratio(FCR),nitrogen retention efficiency(NRE),energy retention efficiency(ERE)and whole body composition,while dietary fish meal content had significant effect on WG,FCR,NRE and ERE.At the same dietary protein level,specific growth rate(SGR)decreased with the decrease of fish meal level.At the same dietary fish meal level,fish fed the feeds containing 530 g/kg crude protein had slightly high SGR relative to fish fed the feeds containing 490 g/kg crude protein.Results of the present study reveal fish meal level in diets for malabar grouper can be reduced to 200 g/kg by incorporating the blend of poultry by-product meal,feather meal and blood meal,and no benefit was found in reducing dietary fish meal level for malabar grouper by elevating dietary protein level from 490 to 530 g/kg crude protein.