饲料糖种类和水平对青鱼、鲫生长和体成分的影响

用分别含20%（低）、40%（高）葡萄糖和糊精的等氮（粗蛋白为35%干物质）,等能（16.4 kJ/g）饲料分别饲养青鱼（Mylopharyngodn piceus）和鲫鱼（Carassius auratus）8周,研究饲料糖种类和水平对青鱼和鲫的生长、体成分的影响.青鱼和鲫鱼平均体质量分别为2.14 g和6.75 g.结果表明,两种鱼都是糊精组增重率、饲料效率、蛋白质效率显著高于葡萄糖组,提示两种鱼对糊精利用效率比葡萄糖高.饲料糖含量低时增重率、饲料效率、蛋白质效率相对高,提示两种鱼对脂肪作为能源的利用效率高于糖.两种鱼糊精组脂肪蓄积率显著高于葡萄糖组,体脂、肝脂、肌脂含量也高于葡萄糖组,提示糊精比葡萄糖更容易以脂肪形式积累在体内.青鱼对实验饲料的利用效率高于鲫鱼,推测这与能量代谢有关.[中国水产科学,2006,13（3）：452-459]

Effects of level and seurce of dietary carbohydrate on growth and body composition of Mylopharyngodon piceus and Carassius auratus

A study was conducted to determine the ability of Mylopharyngodon piceus and Carassius auratus to utilize different seurces of carbohydrate(dextrin and glucose) and the effects of their levels(20% and 40%) in diets.The diets were isonitrogenous(35% crude protein) and isocaloric(16.4?kJ/g).Triplicate groups,each with 30 Mylopharyngodon piceus and 15 Carassius auratus,and average initial body weights about 2.14?g and 6.75?g respectively,were fed with one of the test diets for 8 weeks in indoor circular aquarium system. Weight gain ratio,feed efficiency ratio,protein efficiency ratio,protein and lipid retention efficiency,body composition were measured at the end of the experiment period. The weight gain ratio of M.piceus fed with diets of 40% glucose,40% dextrin,20% glucose and 20% dextrin were 205.06%,224.24%,205.53% and 244.82% respectively.The weight gain ratio of C.auratus fed the corresponding diets were 98.35%,110.77%,107.22% and 119.04% respectively.Both of M.piceus and C.auratus had significant increases of weight gain,feed efficiency ratio and protein efficiency ratio when fed the diets containing dextrin than those fed the diets containing the same level of glucose.Fishes fed 20% carbohydrate diets had significant(P<0.05) increase of weight gain,feed efficiency ratio and protein efficiency ratio compared to those fed 40% carbohydrate diets.These results suggested both fishes utilize dextrin better than glucose,and utilize lipid better than carbohydrate.Fishes fed diets containing dextrin obtained not only higher lipid content in body,hepatic and muscle,but also higher lipid retention efficiency than those fed the diets containing the same level of glucose,which indicated that dextrin was more potent to synthesize lipid than glucose.Lipid renention efficiency and glycogen content increased as the dietary carbohydrate increasing,indicating that a part of dietary carbohydrate was converted into glycogen and lipid by fishes.M.piceus obtained higher weight gain and feed efficiency ratio than C.auratus even when fed with the same diets,that maybe related to energy metabolism.