饲料镁不影响鲈鱼(Lateolabrax japonicas)幼鱼的生长及鱼体镁含量

Dietary Magnesium did not Affect Growth Performance and Fish Body Magnesium Content in Juvenile Japanese Seabass, Lateolabrax japonicas

中文关键词: 鲈鱼  镁  生长性能  鱼体成分

英文关键词: Lateolabrax japonicus  Magnesium  Growth performance  Body composition

中文摘要:

      以鱼粉和豆粕为主要蛋白源，以鱼油和豆油为脂肪源，向基础饲料中分别添加0、1.53、3.57、5.61、7.65、9.69 g/kg MgSO4·7H2O，配制镁含量分别为186、350、542、735、950、1220 mg/kg的6种实验饲料，用于饲养初始体重为(28.0±2.5) g的鲈鱼(Lateolabrax japonicas)为56 d，每组设3个重复，实验在流水系统中进行，水体镁的含量为1220 mg/L。结果显示，不同水平的饲料镁对鲈鱼幼鱼成活率、特定生长率、饲料效率无显著影响(P>0.05)；不同水平的饲料镁对鲈鱼幼鱼肝体比(HSI)、脏体比(VSI)及肥满度(CF)无显著影响(P>0.05)；饲料镁对鲈鱼幼鱼肌肉粗蛋白、粗脂肪及灰分无显著影响(P>0.05)；饲料镁对鲈鱼幼鱼肌肉、脊椎骨及血清镁含量无显著影响(P>0.05)。研究表明，鲈鱼幼鱼可以从海水或基础饲料原料中吸收的镁足够满足自身对镁的需求，因此，不需要在饲料中额外补充镁。

英文摘要:

      Most of magnesium (Mg) in fish is contained in the bone. Dietary magnesium has been reported to affect growth in several species, but the effect of dietary Mg on growth of seabass (Lateolabrax japonicus) is unknown. This study was conducted to investigate the effect of dietary Mg supplement on growth, feed efficiency, morphometry index, and Mg concentration in vertebrae, muscle and serum of seabass. Six experimental diets were formulated to contain graded levels of Mg by supplementing the basal diet with 186, 350, 542, 735, 950, and 1220 mg/kg Mg in the form of Mg sulphate (MgSO4·7H2O). Triplicate groups of juvenile seabass with an initial body weight of (28.0±2.5) g were fed to apparent satiation twice daily for 56 d with the waterborne Mg concentration of 1115 mg/L. The experiment was carried out in flowing-water tanks. Dietary Mg supplement did not improve the specific growth rate, survival rate and feed efficiency of seabass (P>0.05). The hepatosomatic index, viscerosomatic index, condition factor, Mg concentration in vertebrae, muscle and serum were not affected by dietary Mg supplementation(P>0.05). Also crude protein, crude lipid, moisture and ash contents in muscle were no significantly different (P>0.05). These indicates the Mg requirement of sea bass was met by fish fed the basal diet and waterborne Mg concentration. Therefore, it is no need to additional magnesium supplementation in feed