三倍体虹鳟饲料虾青素添加策略探讨

选择17万余尾平均体重约1 kg的三倍体虹鳟(Oncorhynchus mykiss)进行饲料虾青素水平对三倍体虹鳟生长性能、出成率和肌肉着色影响的中试试验。试验设计3种饲料配方,分别在同一商业饲料配方基础上添加20、30 mg/L和40 mg/L的虾青素。在周长100 m的圆形商业网箱中进行为期10个月的养殖投喂,每种饲料投喂3个网箱。结果表明：添加40 mg/L虾青素饲料组三倍体虹鳟增重率和饲料系数方面均表现出优势;添加40 mg/L虾青素饲料组三倍体虹鳟肝脏小,肝色好,肥满度高;添加40 mg/L和30 mg/L虾青素饲料分别在商品鱼上市前七个月和九个月进行投喂,肉色即可达到标准(SalmoFanTM值>28)。     

虾青素酯皂化工艺研究

以NaOH-甲醇溶液为皂化液,采用正交试验方法,对虾青素酯皂化工艺中NaOH浓度、皂化温度和皂化时间3个因素进行最优水平的筛选。经试验确定虾青素酯最佳皂化工艺条件为2.0g/L的NaOH-甲醇溶液,在15℃条件下皂化5h,虾青素酯达到最佳的皂化效率,样品中游离虾青素含量从皂化前的25.765μg/mL提高到88.175μg/mL。     

虾青素和角黄素对虹鳟肌肉着色和肝脏总抗氧化能力的影响

分别在基础饲料(对照组)中添加100 mg/kg的虾青素、角黄素,混合色素(50 mg/kg虾青素+50 mg/kg角黄素)饲喂初始体重为(56.60±0.63) g的虹鳟60 d,考察虾青素和角黄素对虹鳟肌肉着色和肝脏总抗氧化能力的影响。结果显示,饲料中添加了虾青素、角黄素和混合色素后对虹鳟增重率、饲料系数及肌肉常规成分、肌肉失水率、含肉率均无显著影响(P> 0.05)。虾青素组、角黄素组和混合色素组虹鳟肌肉的比色卡得分、红度、虾青素含量和血清总类胡萝卜素含量均比对照组有显著提高(P< 0.05);虾青素组虹鳟肌肉比色卡得分(26.25)和红度值(18.40)显著高于角黄素组(22.38, 14.13)和混合色素组(24.00, 15.70)(P< 0.05);虾青素组虹鳟肌肉虾青素含量为4.75 mg/kg (30 d)和6.45 mg/kg (60 d),均显著高于混合色素组的3.87 mg/kg (30 d)和5.48 mg/kg (60 d)(P< 0.05);在虹鳟血清总类胡萝卜素含量方面,虾青素组 > 混合色素组 > 角黄素组;虾青素组、角黄素组、混合色素组虹鳟肝脏的总抗氧化能力之间无显著差异(P> 0.05),分别为2.39 U/mg,2.25 U/mg,2.39 U/mg,均较对照组(2.03 U/mg)显著提高(P< 0.05)。上述结果表明：饲料中添加100 mg/kg虾青素、角黄素及虾青素+角黄素混合(1∶1)均能有效改善虹鳟肌肉颜色,提高肝脏总抗氧化能力,虾青素、虾青素+角黄素混合(1∶1)对虹鳟肌肉的着色效果优于角黄素。     

虾青素在鱼类饵料中的应用研究进展

虾青素是一种具有多种生理功能的类胡萝卜素,在水产动物养殖中具有重要作用。本文就虾青素的理化性质和来源,对虾青素在水产动物养殖中的着色作用、抗氧化、抗应激和提高水产动物生长、繁殖和发育性能等方面进行了综述。     

虾青素应用前景广阔

虾青素是一种极具潜力的色素和抗氧化剂,具有许多重要的生理功能.本文对虾青素的生物来源及其生理功用等方面进行了叙述.     

虾青素生物学来源和功能的研究进展

虾青素(Astaxanthin)即3,3’—二羟基-4,4’二酮基-β,β’胡萝卜素,又称虾黄质、虾黄素、龙虾壳色素、还原型虾红素。虾青素的分子式为C40H52O4,是一种萜烯类非维生素A源胡萝卜素,呈艳丽的红色,易溶于二硫化碳、丙酮、苯和氯仿,因其具有着色功能和极强的抗氧化性,提高免疫力;近年来越来越受到国内外食品、医药、化妆品、养殖、饲料等领域研究人员的重视。1虾青素的生物学来源虾青素在动物体内和羽毛中,尤其是水生动物体内(如虾、蟹)普遍存在。早在20世纪30年代虾青素就已从虾、蟹中分离出来。除了从水产品加工的废弃物中提取虾青素外,从…     

虾青素的开发及其在水产养殖上的应用

虾青素是一种极具潜力的色素和抗氧化剂 ,具有许多重要的生理功能。本文对虾青素的生物来源及其生理功用等方面进行了叙述 ,最后着重介绍了虾青素在水产养殖中的增加养殖对象着色 ,提高存活率 ,促进生长、繁殖、发育等方面功用 ,并对这些方面的应用研究进展作出较详细的叙述     

虾青素在鱼类饲粮中应用研究进展

虾青素是一种具有多种生理功能的类胡萝卜素,在水产动物养殖中具有重要作用。本文就虾青素的理化性质和来源,对虾青素在水产动物养殖中的着色作用、抗氧化、抗应激和提高水产动物生长、繁殖和发育性能等方面进行了综述。     

投喂虾青素对哲罗鲑虾青素含量和抗氧化力的影响

水温12～18℃,将体质量(435.63±21.32)g的哲罗鲑饲养在6.0 m×2.5 m×1.2 m的流水水泥池中,投喂含100 mg/kg人工合成虾青素(对照组)和10、20、40、60 mg/kg天然虾青素(雨生红球藻)饲料,每两周检测试验鱼肌肉中的虾青素含量和鳃、肝脏、前肠、后肠、幽门垂、肌肉、血清、血细胞的...     

虾青素对日本沼虾血细胞密度及吞噬活力的影响

从雨生红球藻粉中提取虾青素,以60mg/kg的浓度添加到日本沼虾（Macrobrachium nipponemis）的配合饵料中,在实验室条件下饲养三周,研究虾青素对日本沼虾血淋巴密度及吞噬活力（吞噬百分比和吞噬指教）的影响。结果显示添加虾青素组的日本沼虾不论是血细胞密度还是吞噬活力都显著高于对照组,表明虾膏素可显著提高日本沼虾的免疫力。     

Apparent amino acid availability from feedstuffs in extruded diets for rainbow trout Oncorhynchus mykiss

Apparent amino acid availability coefficients of several typical and novel feed ingredients were determined in rainbow trout using extruded diets and the faecal stripping technique. The ingredients were tested included five fish meals, three terrestrial animal by‐products, five plant protein concentrates, four plant meals, and seven low‐protein plant ingredients. Amino acid availability from the fish meals was relatively high ranging from 90 to 101%. Lower coefficients overall were observed for Menhaden fish meal FAQ when compared to the other fish meals. No differences in apparent amino acid availability were detected among the animal by‐products. Within the plant concentrate group, rice protein concentrate and barley protein concentrate exhibited generally lower amino acid availabilities compared to other concentrates tested. Among the plant meals, only the availabilities of histidine, valine, isoleucine and lysine in flaxseed meal were lower than those of soybean meal. Apparent amino acid availabilities among the low‐protein plant products were variable and significantly different.     

虹鳟鱼核型及DNA含量分析

采用植物血球凝素（ＰＨＡ）体内注射、肾组织细胞短期培养、常规空气干燥法制备了虹鳟的染色体，并进行了核型分析。虹鳟二倍体的染色体为６０条，其核型为２２ｍ＋１ｓｔ＋７ｔ，ＮＦ＝１０４。以外周血红血球为样本，鸡红血细胞为对照，用美国产的ＦＡＣＳｔａｒｐｌｕｓ流式细胞仪测定了虹鳟的二倍体细胞核的ＤＮＡ含量，其ＤＮＡ含量为鸡血对照的１．５１倍，绝对含量为３．４７±０．２１ｐｇ／Ｎ。     

The degree of carotenoid esterification influences the absorption of astaxanthin in rainbow trout, Oncorhynchus mykiss (Walbaum)

The absorption of astaxanthin from diets (30 mg kg^?1 inclusion) supplemented with either unesterified astaxanthin; isolated astaxanthin monoesters, diesters or a cell‐free carotenoid extract from Haematococcus pluvialis were studied in rainbow trout (>200 g). No significant differences (P > 0.05) were recorded in the apparent digestibility coefficients (ADC) (≈60–65%) between astaxanthin sources. However, following consumption of a single meal, peak serum astaxanthin levels at 32 h (≈1.0–1.6 μg mL^?1) were significantly higher (P < 0.05) in fish fed unesterified astaxanthin and astaxanthin monoester, compared to fish fed astaxanthin diester and the cell free extract. However, no significant differences (P > 0.05) were recorded in serum astaxanthin uptake rates between sources of astaxanthin. Results suggest that the extent of carotenoid esterification negatively influences the peak serum levels of astaxanthin in rainbow trout.     

Effects of dietary chromium picolinate supplementation on serum glucose, cholesterol and minerals of rainbow trout (Oncorhynchus mykiss)

The effect of chromium (chromium picolinate, CrPic) supplementation at various levels (0, 400, 800 or 1600 μg Cr/kg diet) on serum concentrations of glucose and cholesterol and on serum and liver concentrations of Cr, Zn, Cu and Fe of rainbow trout (Oncorhynchus mykiss) was evaluated. One-year-old rainbow trout (n=120) were randomly assigned to four treatment groups, each with two replicates of 15 fish. The fish were fed either a control diet or the control diet supplemented with either 400, 800 or 1600 μg Cr/kg diet. Serum glucose and cholesterol concentrations decreased (p=0.001) with higher dietary chromium supplementation. Increasing dietary chromium supplementation linearly increased serum chromium and zinc concentrations (p=0.001). Serum copper and iron concentrations did not change (p>0.10) as dietary chromium supplementation increased. Liver chromium and zinc concentrations linearly increased (p=0.001). Also, liver Cu and Fe concentrations did not change (p>0.10) as dietary chromium supplementation increased. The results of present study conclude that supplemental chromium to the diet of rainbow trout influences serum and liver Cr and Zn concentrations, thus most probably functions of the organs as well as the welfare of raibow trout.     

Effect of dietary bile extracts on serum response of astaxanthin in rainbow trout (Oncorhynchus mykiss): a preliminary study

Effects of porcine bile extracts added at three different dietary concentrations 0, 10 and 20 g kg^?1 were studied on astaxanthin serum concentration in rainbow trout (mean weight 200 ± 7 g). Astaxanthin from micro‐algae Haematococcus pluvialis and synthetic astaxanthin (CAROPHYLL® pink) were incorporated in diets of rainbow trout at a rate of 100 mg astaxanthin kg^?1 of feed. Fish were hand fed twice a day. After 5 days of feeding there was a significant effect of the pigment source on the ratio (total blood astaxanthin per unit body weight to cumulative astaxanthin intake per unit body weight). Trout receiving synthetic astaxanthin showed a significantly (P < 0.05) higher ratio than trout fed algal astaxanthin. Increasing dietary bile extract did not lead to produce any effect on this ratio. The power of the statistical analysis is discussed. Therefore, the interaction (pigment source × dietary bile concentration) showed no more effect.     

Effects of dietary keto-carotenoids (canthaxanthin and astaxanthin) on the reproductive performance of female rainbow trout Oncorhynchus mykiss (Walbaum)

The aim of this study was to clarify further the relationship between dietary keto-carotenoids (canthaxanthin and astaxanthin) and reproductive performance in female rainbow trout. Three experiments were undertaken in three successive breeding seasons. In addition to a control diet, fish were fed a canthaxanthin-supplemented diet (200 mg canthaxanthin kg⁻¹ feed, designated as 6mC200) for 6 months prior to spawning (experiment A); the same diet as in A but for either 3 months (3mC200) or 6 months (6mC200) before spawning (experiment B); diets with one of two levels of astaxanthin supplementation, 50 mg (6mA50) or 100 mg (6mA100) kg⁻¹ feed, or a diet with 100 mg canthaxanthin kg⁻¹ feed (6mC100) fed for 6 months (experiment C).
There was no significant influence of carotenoid supplementation on either the frequency of maturing females or the date of maturation. The number of ova per kg of female body weight averaged 2700 and did not vary significantly among fish fed the different diets. Across experiments A, B and C there was no significant difference in egg and larval survival among fish fed carotenoid-supplemented and control diets. In experiment A, 6mC200 females produced smaller eggs than controls but this result was not confirmed in experiments B and C. In general, eyed egg yield appeared partly dependent upon egg size. Alevin weight was also correlated with egg weight. The growth test conducted on fingerlings from experiment B failed to provide any evidence of an effect of feeding carotenoid supplemented diets to the female parent. Pigment analyses conducted on alevins revealed that canthaxanthin fed to the female parent was transferred into the eggs and therefore to the larvae, although canthaxanthin was metabolized within a few weeks after hatching.     

Protective effects of a synbiotic against experimental Saprolegnia parasitica infection in rainbow trout (Oncorhynchus mykiss)

A combination of probiotics and prebiotics as synbiotics allows assessing their synergistic effects. This study evaluated the effects of a synbiotic supplement on growth performance, haematological parameters and resistance to Saprolegnia parasitica in rainbow trout, Oncorhynchus mykiss (Walbaum) fingerlings. Fish fed a dietary synbiotic in three levels of 0.5, 1.0 and 1.5 g kg^?1 thrice a day. The fingerlings were challenged with Saprolegnia parasitica after 60 days post feeding and their mortalities recorded up to 15 days. The fingerlings at all three experimental treatments showed significant (P < 0.05) increases in final mean weights and specific growth rates (SGR). The best feed conversion ratio (FCR), feed conversion efficiency (FCE) and maximum survival rate were also obtained by the fish fed 1.0 g synbiotic kg^?1 diet. Furthermore, supplementation with synbiotic significantly increased blood factors at all treatments. After challenges with Saprolegnia parasitica, the synbiotic‐fed groups showed significantly higher survival rates compared with the control group. These results reveal that a dietary synbiotic of 1.0 g kg^?1 fed for 60 days leads to increased growth performance and survival rate as well as improved feeding efficiency in rainbow trout fingerling, rendering them more resistant against infection by Saprolegnia parasitica.     

虹鳟pmela基因的克隆及其在不同发育阶段和组织中的表达分析

前黑素小体蛋白a (premelanosome protein,pmela)基因是黑色素合成通路中的关键基因之一,对动物的体色有着重要影响。为探讨pmela基因在虹鳟(Oncorhynchus mykiss)体色变异中的作用,本研究利用cDNA末端快速扩增(rapid amplification of cDNA ends,RACE)技术对pmela基因cDNA全长进行克隆并运用生物信息学方法分析该基因的序列特征,同时采用qRT-PCR比较pmela在野生型虹鳟(虹鳟)、黄色突变型虹鳟(金鳟)和杂交F₁代受精期至孵化后3个月不同发育时期及成鱼不同组织中的相对表达量。研究获得pmela基因cDNA全长序列3 476 bp,包含2 532 bp开放阅读框,编码843个氨基酸。序列分析发现,Pmela为疏水性蛋白且存在PKD功能结构域。同源性比对发现,虹鳟Pemla氨基酸序列与红鲑(Oncorhynchus nerka)的同源性高达97.75%;进化分析结果显示,虹鳟与红鲑的亲缘关系最近,与人类(Homo sapiens)和小鼠(Mus musculus)的亲缘关系最远。...     

Metabolism of exogenous histamine in rainbow trout (Oncorhynchus mykiss)

Information on the metabolism of exogenous histamine in fish is of much concern regarding the effect of dietary histamine on fish. Histamine catabolic enzymes, diamine oxidase and histamine N-methyl transferase were measured in the tissues of rainbow trout. Diamine oxidase was detected in the stomach, pylorus caeca and intestine. Histamine N-methyl transferase was detected only in the liver.A change in the contents of histamine and its metabolites was observed in the tissues of rainbow trout after oral administration of histamine. A large amount of imidazole acetic acid was observed in the serum, kidney, liver and muscle. On the other hand, 1-methyl histamine was detected only in the liver. Histamine and its metabolites, imidazole acetic acid and 1-methyl histamine were metabolized and diminished within 48 hr in all tissues.These results showed that histamine was metabolized by two metabolic routes in rainbow trout. One is the main pathway producing imidazole acetic acid by intestinal diamine oxidase and the other is the complementary pathway producing 1-methyl histamine by liver N-methyl-transferase.     

Effects of dietary nucleotides on the antioxidant status and serum lipids of rainbow trout (Oncorhynchus mykiss)

An 8‐week feeding experiment was conducted to evaluate the effects of dietary nucleotides (0, 0.5, 1, 1.5 and 2 g kg^?1) on serum antioxidative biomarkers and lipid contents of rainbow trout fingerlings. The serum triglycerides and low‐density lipoprotein (LDL)‐C levels were significantly decreased in fish fed diets containing 1.5 and 2 g kg^?1, whereas serum high‐density lipoprotein (HDL)‐C was higher in trout receiving diets with those levels of nucleotides. A significant decrease in thiobarbituric acid reactive substances concentration was observed in groups receiving 1.5 or 2 g kg^?1 of dietary nucleotides in comparison with control group (?32% and ?27%, respectively). A significant decrease was observed in catalase and serum glutathione peroxidase activity in trout fed 1.5 and 2 g kg^?1 dietary nucleotides compare with other groups. There were no significant changes in serum superoxide dismutase activity among the experimental groups. In conclusion, these results suggest that dietary nucleotides may reduce lipid peroxidation by increasing the levels of antioxidant lipoprotein, HDL‐C, and decreasing the LDL‐C, the main substrate of lipid peroxidation.