不同糖源对达氏鲟幼鱼生长、体成分及生理生化指标的影响

分别以糊精、小麦淀粉、玉米淀粉、α-淀粉(预糊化玉米淀粉)、蔗糖、葡萄糖为糖源,配制6种等氮等能的半纯化饲料,喂养达氏鲟(Acipenser dabryanus)幼鱼(68.05 g±1.63 g)8周,研究饲料中糖源对达氏鲟幼鱼生长性能、体成分及生理生化指标的影响。结果发现糊精、小麦淀粉、玉米淀粉、α-淀粉组实验鱼饲料效率和蛋白质效率显著高于蔗糖和葡萄糖组(P0.05),玉米淀粉组实验鱼增重率、特定生长率和饲料效率最高。不同糖源对达氏鲟肥满度影响不显著(P0.05),而对肝体比和脏体比均影响显著(P0.05)。肝体比和脏体比最高的为葡萄糖组,最低的为小麦淀粉组。小麦淀粉组全鱼、肌肉和肝中粗蛋白含量最高,葡萄糖组全鱼和肌肉的粗蛋白含量最低且均显著低于其他各组(P0.05)。糊精、蔗糖和葡萄糖组全鱼和肌肉粗脂肪显著高于其他各组(P0.05)。α-淀粉组肝糖原显著高于其他各组(P0.05),α-淀粉组和葡萄糖组肌糖原显著高于其他各组(P0.05)。肝和血液中甘油三酯和总胆固醇含量和肌体和血液中糖水平呈正相关。不同糖源对达氏鲟消化道消化酶和肝丙酮酸激酶、磷酸烯醇式丙酮酸激酶活性影响显著(P0.05),对肝己糖激酶、磷酸烯醇式丙酮酸羧化酶活性影响不显著(P0.05)。研究结果表明,在饲料中添加玉米淀粉作为糖源更有利于达氏鲟幼鱼生长。

Effects of different carbohydrate sources on growth performance, body composition, and physiological and biochemical parameters of juvenile Dabry's sturgeon (Acipenser dabryanus)

An 8-week feeding trial was conducted to determine the effects of different carbohydrate sources on growth performance, body composition, and physiological and biochemical parameters of juvenile Dabry's stur-geon (Acipenser dabryanus). Six isonitrogenous and isoenergetic semi-purified diets were prepared with dextrin, wheat starch, corn starch,α-starch, saccharose, and glucose as carbohydrate sources. Mean initial body weight of the study fish was (68.05±1.63) g.The results indicated that feed efficiency and the protein efficiency ratio values of the dextrin, wheat, starch, corn starch, andα-starch groups were significantly higher than those in the saccha-rose and glucose groups (P<0.05). Fish fed the diet containing corn starch had the highest weight gain ratio, spe-cific growth rate, and feed efficiency. No effect of the different carbohydrate sources on condition factor was ob-served (P>0.05). However, the hepatopancreas somatic index (HSI) and visceral somatic index (VSI) were sig-nificantly affected by the different carbohydrate sources (P<0.05). The highest HIS and VSI were seen in the glu-cose group, whereas the lowest HIS and VSI were observed in the wheat starch group. The wheat starch group had the highest crude protein content in whole body, muscle, and liver. The glucose group had significantly lower whole-body and muscle crude protein contents than those in the other groups (P<0.05). Whole-body, muscle, and crude lipid contents in the dextrin, saccharose, and glucose groups were significantly higher than those in the other groups (P<0.05). Hepatic glycogen content was significantly higher in theα-starch group than that in the other groups (P<0.05). Muscle glycogen contents in theα-starch and glucose groups were significantly higher than those in the other groups (P<0.05). Triglyceride and total cholesterol levels in the liver and serum were positively cor-related with whole-body and serum glucose contents. The different carbohydrate sources had significant effects on enzyme activities in the digestive tract and those of pyruvatekinase and phosphoenolpyruvate carboxy kinase in the liver (P<0.05). However, hexokinase and phosphoenolpyruvate carboxylase activities in the liver were not significantly affected by the different dietary carbohydrate sources (P>0.05). These results indicate that corn starch was the optimal carbohydrate source for juvenile Dabry's sturgeon.