饲料中不同维生素 D含量对鲈鱼幼鱼生长性能和钙磷代谢的影响

摘要

本研究旨在探讨饲料中不同维生素D含量对鲈鱼幼鱼生长性能和钙磷代谢的影响。以初始体重为（2．26±0．03） g的鲈鱼幼鱼为试验对象，随机分为6组（每组3个重复，每个重复15尾鱼），饲喂维生素D含量实测值分别为34．2、219．4、393．8、775．9、1534．1和3091．2 IU／kg的等氮等能饲料，进行9周的养殖试验。结果表明：1）当饲料中维生素 D 含量在34．2～393．8 IU／kg时，鲈鱼的增重率随着饲料中维生素D含量的升高显著上升（ P＜0．05），但是当饲料中维生素D含量高于393．8 IU／kg时，鲈鱼的增重率变化不显著并且出现平台期（ P＞0．05）。同样，鲈鱼的特定生长率、饲料效率和蛋白质效率均表现出与增重率相似的变化趋势。2）饲料中维生素D含量显著影响了鱼体粗灰分、钙和磷含量，脊椎骨、鳃盖骨和鳞片粗灰分含量以及脊椎骨钙和磷含量（ P＜0．05），但对鱼体粗蛋白质、粗脂肪和水分含量没有显著影响（ P＞0．05）。3）饲料中维生素D含量对鲈鱼血清碱性磷酸酶活性及羟脯氨酸、钙离子和无机磷含量均有显著影响（ P＜0．05）。4）饲料中维生素D含量显著影响了鲈鱼肝体指数及肝脏脂肪和维生素D含量（ P＜0．05）。随着饲料中维生素D含量的升高，肝脏维生素D含量呈现升高的趋势，并在饲料中维生素D含量达到1534．1 IU／kg时变化趋于平稳。以增重率为评价指标，采用折线模型分析得出鲈鱼幼鱼获得最大生长时对饲料中维生素D的需求量为431．0 IU／kg饲料。以肝脏维生素D含量为评价指标，采用二次曲线模型分析得出鲈鱼幼鱼获得最大肝脏维生素D沉积量时对饲料中维生素D的需求量为2444．4 IU／kg饲料。%A 9⁃week feeding experiment was conducted to evaluate the effects of different dietary vitamin D contents on growth performance, calcium and phosphorus metabolism of juvenile Japanese seabass ( Lateo⁃labrax japonicas). Juvenile Japanese seabass with the initial body weight of (2.26±0.03) g as the experimen⁃tal animal, and were randomly divided into 6 groups with 3 replicates each group and 15 fish per replicate. Fish in the 6 groups were fed six isonitrogenous and isoenergentic diets with the measured contents of vitamin D were 34.2, 219.4, 393.8, 775.9, 1 534.1 and 3 091.2 IU/kg, respectively. The results showed as follows:1) weight gain rare ( WGR) was significantly increased with increasing dietary vitamin D content from 34.2 to 393.8 IU/kg (P<0.05), and when the dietary vitamin D content more than 393.8 IU/kg, the WGR had no significant change and presented a trend of forgetting ( P>0.05) . Special growth rate ( SGR) , feed efficiency ratio (FER) and protein efficiency ratio (PER) showed a similar tendency to WGR. 2) Dietary vitamin D content significantly influenced the contents of ash, calcium and phosphorus in carcass, ash in vertebra, oper⁃culum and scale, and calcium and phosphorus in vertebra of juvenile Japanese seabass ( P<0.05) , but had no significant influences on the contents of crude protein, crude lipid and moisture in carcass ( P>0.05) . 3) Ser⁃um alkaline phosphatase (AKP) activity, and hydroxyproline (HPro), calcium ion (Ca2+) and inorganic phosphorus (Pi) contents were all significantly affected by dietary vitamin D content (P<0.05). 4) Dietary vitamin D content had significant influences on hepatosomatic index, liver lipid and vitamin D contents ( P<0.05) . Liver vitamin D content showed an increased trend with increasing dietary vitamin D content, and it changed to be steady when dietary vitamin D content up to 1 534.1 IU/kg. Broken⁃line model analysis with the WGR as the appraising index shows that juvenile Japanese seabass require 431.0 IU/kg diet vitamin D for max⁃imal growth. Base on the quadratic curve model analysis with the liver vitamin D content as the appraising in⁃dex, juvenile Japanese seabass require 2 444.4 IU/kg diet vitamin D for maximal liver vitamin D deposition.