摘要:
用分别含20%（低）、40%（高）葡萄糖和糊精的4种等氮（粗蛋白为35.5%）、等能(16.8 kJ·g-1)饲料饲养平均尾重为3.7±0.3 g彭泽鲫16周，投饲率为4%左右，研究投喂频率分别为每天2次和每天6次时鲫鱼对糖利用性的差异.结果显示，鲫鱼的增重率、饲料效率和蛋白质效率都随投喂频率增加而显著提高 (〖WTBX〗P〖WTBZ〗0.001).投喂频率为每天2次时，增重率表现为高糖组显著低于低糖组 (〖WTBX〗P〖WTBZ〗=0.003)，葡萄糖组显著低于糊精组(〖WTBX〗P〖WTBZ〗=0.003)，蛋白质沉积率表现为糊精组显著高于葡萄糖组(〖WTBX〗P〖WTBZ〗0.05)；投喂频率为每天6次时，增重率无显著差异，糖源和糖水平对蛋白质沉积率的影响均无显著差异.脂肪和能量沉积率也有相似的趋势，且高糖组脂肪沉积率接近或大于100%，提示有大量糖类转化为体脂.投喂频率增加，体脂含量显著增加 (〖WTBX〗P〖WTBZ〗0.001).投喂频率为每天6次时，高葡萄糖组体脂含量显著低于其它各组.鱼体粗蛋白、粗灰分及水分含量受饲料糖种类、水平及投喂频率的影响不明显.高糖组糖化血红蛋白含量显著高于低糖组(〖WTBX〗P〖WTBZ〗0.001)，血浆甘油三酯及胆固醇各组无显著差异.上述结果提示增加投喂频率显著改善鲫鱼对饲料糖的利用，其原因可能与削弱或消除代谢通量迁移有关.
Abstract:
Four isonitrogenous (35.5% dry matter) and isocaloric (16.8 kJ·g-1 dry matter) diets with two types (dextrin and glucose) and two levels (20% and 40% respectively) of carbohydrates were fed carps (〖WTBX〗Carassius auratus〖WTBZ〗 〖WTBX〗pengzesis〖WTBZ〗) at 2 times a day and 6 times a day respectively for 16 weeks to determine the effect of feeding frequency on the carbohydrate utilization. The initial fish weight was 3.7±0.3 g and three replicates were conducted. The weight gain rate, feed efficiency and protein efficiency ratio were improved when the feeding frequency increased from 2 times a day to 6 times a day. When the feeding frequency was 2 times a day, the fish fed the dextrin diet gained significantly more body weight than fish fed the glucose diet (〖WTBX〗P〖WTBZ〗=0.003), regardless of carbohydrate levels. Besides, the fish fed the low carbohydrate diet growth better than fish fed high carbohydrate (〖WTBX〗P〖WTBZ〗=0.003), regardless of carbohydrate types. When the feeding frequency was 6 times a day, however, there were no significant difference in body weight gain. When the feeding frequency was 2 times a day, fish fed the dextrin diet gained significantly more protein retention efficiencies than fish fed the glucose diet(〖WTBX〗P〖WTBZ〗0.05), while no significant difference was observed when feeding frequency was 6 times a day. The retentions of lipid and energy at different frequencies followed the same general pattern as protein retention. Moreover, lipid retention in fish fed high carbohydrate were close to or more than 100%, indicating a part of dietary carbohydrate was transformed to body lipid. The body lipid increased significantly when the feeding frequency increased from 2 times a day to 6 times a day, and when the feeding frequency was 6 times a day, the body lipid of fish fed diet HG lower than that of fish fed other diets. The body protein, ash and moisture weren’t affected by dietary carbohydrate types or levels, nor feeding frequencies. The glycated hemoglobin was higher in fish fed high carbohydrate diet than fish fed low carbohydrate diet(〖WTBX〗P〖WTBZ〗0.001), however, no significant difference was observed in plasma triglycerides and total cholesterols. These results indicated that high feeding frequency improved the carbohydrate utilization by 〖WTBX〗Carassius auratus〖WTBZ〗 〖WTBX〗pengzesis〖WTBZ〗. The reason might be related with weakened or eliminated the shift in metabolic flux induced by high blood glucose.
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