A Study on Development of Diets for Improvement of Meat Quality of Cultured Fishes

与野生鱼相比，养殖鱼的肉通常更多脂肪，更不可口。本研究的目的是开发添加藻类的饲料，在不降低生长速度的情况下，改善养殖鱼类的肉质。当饲料中添加2%的小球藻提取物时，抑制肌肉中小球藻脂肪的积累，而对鱼类的生长没有明显的影响。当饲料中添加5，10和15%的螺旋藻时，5和10%组的鱼生长优于对照组，而15%组的鱼的增重低于对照组。这些结果表明，在日粮中添加藻类物质的适宜比例不超过10%。在以螺旋藻为饲料的红海鳗中，肌肉中甘油三酯的积累受到抑制，肌肉提取物中的甘氨酸、丙氨酸和三甲胺有增加的趋势。在这方面，通过感官测试证明，肉类的风味和脂肪含量都有所改善。此外，添加5%和10%螺旋藻的饲料与对照组饲料的颗粒化性能和稳定性没有明显差异，说明添加10%的螺旋藻饲料可以有效地改善养殖罗非鱼的肉质，且不会对鱼类的生长产生不良影响。

The meat of cultured fishes is generally more fatty and less palatable than that of wild ones. The purpose of the present study is to develop algae-supplemented diets which enable the improvemnt of meat quality of cultured fishes without decreasing their growth rate.When sweet smelt were fed diets containing 2% of Chlorella-extract, the accumulation of drpot lipids in the muscle was suppressed without appreciable influence upon growth of the fish.When red sea bream were reared with diets containing Spirulina at the levels of 5, 10, and 15%, the fish in the 5 and 10% groups showed superior growth to those in the control group, whereas the weight gain of the fish in the 15% group was lower than that of the control. These results indicate that the proper amount of supplement of algal materials to a diet is less than 10%. In the Spirulina-fed red sea bream the accumulation of triglycerides in the muscle was suppressed, and glycine, alanine, and trimethylamine in the muscle extract showed tendencies to increase. In this connection, the flavor and fattiness of the meat were proved to be improved by the sensory test. Furthermore, no distinct differences were found between Spirulina-supplemented diets at the levels of 5 and 10% and the control diet as to granulatability and stability.Thus it was shown that a diet containing Spirulina up to 10% was effective in the improvement of meat quality of cultured red sea bream without ill effects on growth of the fish.