不同投喂率和投喂频率对大杂交鲟幼鱼生长、体成分和生化指标的影响

为探讨大杂交鲟(Huso dauricus♀×Acipenser schrenckii♂)适宜投喂率和投喂频率,本实验分别设计了5个投喂率(0.4%、0.8%、1.2%、1.6%和2.0%)和5个投喂频率(1次/d、2次/d、3次/d、4次/d和5次/d),研究不同投喂率和投喂频率对大杂交鲟生长、体成分和生化指标的影响。投喂率实验中鱼初重(335.87±0.82)g,投喂频率实验中鱼初重(334.77±1.06)g,养殖周期为10周。结果表明,随着投喂率升高,实验鱼增重率、特定生长率、肝体比、脏体比、肥满度,肌肉粗蛋白、粗脂肪和肝粗脂肪含量显著升高(P0.05),血清谷丙转氨酶、谷草转氨酶和胃蛋白酶活性均显著升高(P0.05);饲料效率、全鱼和肌肉水分含量均显著降低(P0.05);全鱼粗脂肪含量,血清总蛋白、白蛋白和高密度脂蛋白胆固醇含量,肠脂肪酶活性呈先升高后降低趋势(P0.05)。随着投喂频率增加,实验鱼增重率、特定生长率和饲料效率无显著差异(P0.05);1次/d投喂频率组脏体比、肥满度和全鱼粗脂肪含量显著低于其他各组(P0.05),2次/d投喂频率组全鱼粗蛋白含量显著高于其他各组(P0.05)。不同投喂频率对实验鱼除血清葡萄糖含量以外的其他血清生化指标和胃肠消化酶活性或含量均无显著影响(P0.05)。综合以上结果认为,在300～600g大杂交鲟的养殖过程中日投喂率在1.2%～1.6%,投喂频率为2次/d比较适宜。

Effects of different feeding rates and frequencies on the growth performance, body composition, and biochemical parameters of juvenile hybrid sturgeon

China has become the largest producer of sturgeon in the world. Hybrid sturgeon)] is one of the dominant aquacultures organisms in China. However, the feeding strategy for hybrid sturgeon has not been clearly outlined. To determine the optimum feeding rate and frequency for juvenile hybrid sturgeon, an experiment was conducted to study the effects of different feeding rates and frequencies on the growth performance, body composition, and biochemical parameters of juvenile hybrid sturgeon. The fish were randomly assigned into 10 groups with 3 replicates per group, including 5 groups (initial body weight:335.87±0.82 g) treated with different feeding rates (0.4%, 0.8%, 1.2%, 1.6%, and 2.0%) and another 5 groups (initial body weight:334.77±1.06 g) treated with different feeding frequencies (once, twice, three times, four times, and five times a day). After the 10-week feeding trail, the increased feeding rate significantly improved the weight gain rate (WGR), specific growth rate (SGR), hepatosomatic index (HSI), viscerosomatic index (VSI), and condition factor (CF) of hybrid sturgeon (<0.05). In addition, the crude protein and lipid content in muscle, crude lipids in the liver, pepsin activities, serum alanine aminotransferase (ALT), and aspartate aminotransferase (AST) also increased significantly with the increasing feeding rate (<0.05). However, the feed efficiency (FE), whole body moisture, and muscle moisture decreased significantly with the increasing feeding rate (<0.05). Meanwhile, the whole body crude lipids, total protein (TP), albumin (ALB), and high density lipoprotein cholesterol (HDL-C) in the serum firstly increased with the increasing feeding rate, but then decreased (<0.05). On the other hand, the feeding frequency had no significant effects on the WGR, SGR, or FE of hybrid sturgeon after the 10-week feeding trail (>0.05). The VSI, CF, and content of whole body crude lipids of the fish fed once a day were significantly lower than that of the other groups (<0.05). In addition, a significantly higher content of the whole body crude protein was observed in the fish fed twice a day compared with that of the other groups (<0.05). No significant effects of the feeding frequency were found on the digestive enzyme activities in the stomach and intestine or the serum biochemical parameters, except for the glucose level (>0.05). Overall, according to the results of this study, the optimum feeding strategy with regards to the feeding rate and feeding frequency for juvenile hybrid sturgeon (300-600 g) was suggested to be 1.2%-1.6% of the body weight with meals twice per day.