维生素C对水生动物免疫和营养作用的研究进展

维生素C是水生动物生长的必需物质．与动物体大部分组织正常执行功能密切相关。本文从维生素C的结构性质、生理功能、水生动物的需要量以及缺乏症等方面综述了维生素C作为饵料添加剂的研究进展。     

维生素C对鱼类营养生理和免疫作用的研究进展

为研究维生素C对大鲵机体生长性能及消化系统各器官结构和功能的影响。实验以鱼粉、鸡肉粉等为蛋白源,鱼油为脂肪源配制大鲵基础饲料,基础饲料中分别添加0、150、300、450、600和750 mg/kg的维生素C (维生素C磷酸酯,35%含量),配制成6种等氮等脂的实验饲料,养殖初始体重为(34.14±0.15) g 的幼鲵。结果显示,大鲵增重率(WGR)随维生素C添加量的升高呈先增大后趋于稳定的变化趋势,在维生素C含量为450 mg/kg 时达到最大,为102.04%。随维生素C添加量的增加,大鲵胃蛋白酶、H⁺-K⁺-ATP酶活性均呈先升后降的趋势。且在维生素含量为300 mg/kg 时均达到最强;肠道糜蛋白酶、脂肪酶及Na⁺-K⁺-ATP酶活性均维生素C含量的升高而呈先升高后平稳的趋势,且均在维生素C含量为450 mg/kg 时达到最强。通过对组织切片观察发现,维生素C添加量为300 mg/kg时更利于大鲵胃及肠道肌层和绒毛的发育。随维生素C含量的增加,大鲵肝脏中CAT、T-SOD、ACP及AKP活性均呈先上升后降低的变化趋势;而MDA、AST和ALT的活性则呈相反的变化趋势。并且,随着维生素C的添加,大鲵肝脏炎性细胞浸润现象明显减少,巨噬细胞数量明显增加。研究表明,适量的维生素C可有效改善大鲵消化道的结构,增强其消化酶活性,提高其生长性能,增强肝脏抗氧化能力,有效地保护肝脏健康。本研究可为探究维生素C对大鲵消化器官发育的影响提供一定的理论依据。

     

鱼类维生素营养研究进展

鱼类维生素营养研究进展沈维华（武汉华中农业大学水产学院，武汉４３００７０）鱼类维生素营养研究可追溯至本世纪三十年代。至五十年代，由于半纯化试验日粮（维生素需要量研究实验日粮），在实验室条件下的成功应用，鱼类维生素营养研究步伐明显加快，至八十年代初期，...     

维生素K对鱼类的营养作用

自然界维生素K主要是叶绿醌PK和甲基萘醌类MK，人工合成的主要是2-甲基-1，4-萘醌，其主要功能除了能促进肝脏合成凝血酶原及凝血因子外。还可影响鱼类的骨生长，鱼体内维生素K的含量和存在形式受食物的影响。     

鱼类的维生素C营养

介绍了Vc的基本性质、功能、鱼类对Vc的缺乏症及10种鱼类对Vc的需要量。     

维生素对鱼类营养作用及需要推存值

水产养殖中鱼类需要多种维生素。适当地使用维生素可以增进鱼体健康,增强抗病能力,提高成活率和促进鱼体生长,反之缺乏维生素则会引起食欲减退、生长缓慢、贫血、脂肪肝、皮肤出血和死亡率增高等不良结果。     

鱼类皮肤出血与维生素营养

随着养殖集约化程度的提高,池养鱼类发生皮肤出血的现象也越来越多。每当发生此类情况,很多渔民往往大剂量使用抗生素治疗,但有时疗效并不显著,引起不小的损失。导致鱼类发生皮肤出血,笔者认为主要有以下几种原因:（１）致病细菌感染,如细菌性出血病、疖疮病、竖鳞病、打印病、弧菌病等;（２）致病病毒感染,如草鱼、青鱼出血病等;（３）寄生虫寄生,如鱼蛭病,锚头鳋病等;（４）机械损伤;（５）维生素缺乏,如ＶＡ、烟酸等缺乏。对于（１）、（２）、（３）、（４）类在相关鱼病学著作中都有详尽阐述,本文只就维生素缺乏而引发的鱼类皮肤出血进…     

冷水性鱼类对维生素的营养需求

本文对维生素的种类及其生理功能、冷水性鱼类对维生素的需求量以及影响饲料中维生素添加剂量的因素、维生素的营养病理进行介绍。     

鱼类糖营养生理的研究进展

蛋白质、脂肪和糖类是鱼类饲料中的三大营养物质,糖类作为重要的能量物质,不仅价格低廉,还具有节约蛋白质、保护环境等作用。饲料中添加适量的糖类可以促进鱼类生长、提高饲料效率。而糖类的过量添加会导致鱼类血糖升高,甚至产生一系列的病理反应,影响其生长和健康。因此,糖类物质在饲料中的正确使用十分重要。近30年来,人们对鱼类糖营养生理领域进行了广泛的研究,特别是近10年来在鱼类对糖的利用能力和特点、影响因素和最适添加水平等方面取得了一系列成果。本文通过对国内外相关研究的回顾和总结,对这一领域的研究成果和研究方法进展进行综述,以期为鱼类的糖营养生理研究提供文献数据。     

苏氨酸的鱼类营养生理研究进展

苏氨酸作为必需氨基酸,在促进鱼类生长、提高免疫力中发挥重要的营养作用.添加苏氨酸可以更好地平衡氨基酸,使饲料中的氨基酸比例更接近理想蛋白质,降低鱼类对饲料中蛋白质含量的要求.饲料中缺乏苏氨酸时,鱼类摄食量降低、生长速率下降、免疫机能抑制等症状.近年来,随着饲料中植物蛋白的广泛使用,苏氨酸逐渐成为限制性氨基酸,进一步研究...     

饲料蛋白质和维生素C含量对黄颡鱼生长和免疫力的影响

将黄颡鱼种放养在网箱中,投喂蛋白质含量30.0%、38.0%或46.0%和维生素C磷酸酯0、500、1000或1500mg·kg-1的半纯饲料。50d的饲养表明:饲料蛋白质含量在38%～40%时,鱼的特殊生长率和蛋白质效率最高,饲料系数最低。饲料维生素C磷酸酯含量为847、850、994和634mg·kg-1时,血清总蛋白、γ球蛋白、溶菌酶活性最高,超氧化物歧化酶活力最低。饲料蛋白质含量从30%上升到38%时,鱼体蛋白含量由60.95%升到69.86%,脂肪由29.27%降至21.69%;达46%时,鱼体蛋白(64.35%)含量下降,而脂肪(26.06%)含量上升。饲料粗蛋白含量为38%时,鱼肌肉中饱和与单不饱和脂肪酸的含量分别极显著地低于和显著高于饲料粗蛋白为30%和46%组。后两组鱼肌肉n-3/n-6值极显著和显著高于饲料蛋白含量为38%时,两个高蛋白饲料组中,鱼肌肉中n-6系列多不饱和脂肪酸和亚麻酸含量极显著和显著高于饲料蛋白30%组。黄颡鱼种饲料中蛋白质和维生素C的最适含量分别为35.58%～40.60%和600～800mg·kg-1。     

维生素C对中华绒螯蟹非特异性免疫的影响

通过在以鱼粉、豆粕、玉米粉和麦麸为主要原料配制而成的每100g基础饲料中分别添加0、250、500、1 000、1 500 mg的VC(以VC多聚磷酸酯为VC源)配制5种试验饲料,对均重为(37.52±2.19)g的中华绒螯蟹进行为期60 d的饲养试验,以酚氧化酶(PO)、抗菌力(Ua)、溶菌酶(UL)、超氧化物歧化酶(SOD)、碱性磷酸酶(AKP)和酸性磷酸酶(ACP)等指标为判据,研究VC对中华绒螯蟹体液免疫因子的影响.结果表明,VC对中华绒螯蟹各组织器官中PO、Ua、UL、SOD、AKP和ACP等活性有显著或极显著的影响(P<0.05或P<0.01),在适宜范围内,随着vc添加量的增加,PO、Ua、UL、AKP和ACP活性显著增强,从而增强中华绒螯蟹的非特异性免疫力,而SOD活性则显著降低(P<0.05),表明VC作为天然抗氧化剂在中华绒螯蟹体内发挥了很大的作用.综上所述,VC作为免疫刺激剂能有效地增强中华绒螯蟹的非特异性免疫力,且VC适宜添加量以500～1 000 mg·(100g)-1饲料为宜.     

Effects of dietary vitamin C on growth,antioxidant activity,and immunity in ricefield eel (Monopterus albus)

A 10-week feeding trial aimed to investigate the effects of dietary vitamin C (l -ascorbic acid) on growth, antioxidant activity, and immunity in ricefield eel, Monopterus albus. Six diets were formulated with different levels of vitamin C supplementation (0.1, 17.5, 34.8, 68.6, 139.7, and 278.5 mg/kg). The results indicated that the weight gain (WG) of the M. albus fed the diets with vitamin C was remarkably higher than that of the M. albus fed the control diet (p < .05), and the quadratic analysis showed an optimal vitamin C level of 80.66 mg/kg. Compared with the control group, serum lysozyme activities, the complement pathway, red blood cell counts, white blood cell counts, immunoglobulin M, and phagocytosis percentage were significantly increased (p < .05) in the treatment groups, and superoxide dismutase activity, serum glucose, and malondialdehyde content were significantly decreased (p < .05) in the treatment groups. The challenge trial with Aeromonas hydrophila showed that the M. albus fed the diets with vitamin C had remarkably reduced cumulative mortality compared with those fed the control diet (p < .05), and mortality in the 68.60 mg/kg diet group was the lowest. Based on WG, the optimal vitamin C supplementation level for M. albus was estimated to be 80.66 mg/kg.     

Dietary vitamin C,immunity and disease resistance in Atlantic salmon (Salmo salar)

Presmolt Atlantic salmon were fed a fish meal based experimental diet supplemented with graded levels of ascorbate-2-monophosphate (AP), equivalent to 40, 400, 2000 and 4000 mg ascorbic acid (AA)/kg for 6 months prior to a bacterial challenge experiment. The liver AA concentration reflected the dietary intake of AP, but not linearly. Growth, hematology and acid phosphatase activity in zymosan stimulated macrophages were not affected by dietary AP. Serum hemolytic complement activity was higher in fish fed the highest AP level, but the variation was not significant. Production of specific antibodies was significantly higher in fish fed the highest AP level 11 and 17 weeks after vaccination. Bacterial challenge with Aeromonas salmonicida showed increased survival in the 4000 AP group. Lysozyme activity in headkidney and serum complement activity and serum iron in fish surviving the challenge were higher in the 4000 AP group, indicating important roles of vitamin C on lysozyme, complement and iron in non-specific disease resistance. The results indicate that high dietary levels of AP favourably affect health in Atlantic salmon. Disease resistance was, however, not correlated with the AA status in the liver.     

Dietary reduction of fish meal,supplementation of vitamin C and fish oil may promote ovary maturation by improving digestibility and immunity in Procambarus clarkii (Crustacea: Decapoda)

Fish meal, vitamin C and fish oil are known to play essential roles in reproduction and immunity in animals. To investigate how the diet affect reproduction under the condition of reducing costs, we designed an experimental diet that decreased the ratio of fish meal with soybean meal from 1:1 to 1:1.5, and supplemented with 0.06% vitamin C and 3.8% fish oil for the crayfish, Procambarus clarkii. After a 100‐day feeding experiment, female crayfish fed the test diet had significantly greater gonadosomatic index (GSI) compared with those fed the basal diet (P < 0.05). At the middle stage of ovarian development, the test diet gave significantly higher trypsin‐specific activity (340.94 ± 57.32 U mg^?1 protein) in hepatopancreas of the crayfish than the basal diet (89.48 ± 10.01 U mg^?1 protein) (P < 0.05). However, hepatosomatic index (HSI) was remarkably decreased for those females fed test diet (P < 0.05). In addition, the experimental diet resulted in markedly lower superoxide dismutase (SOD) activity and malonaldehyde (MDA) levels, especially in the ovaries (P < 0.01). These results suggest that dietary reduction of fish meal, supplementation of appropriate amounts of vitamin C and fish oil may promote ovary development probably by increasing digestibility, as well as by promoting transferring of nutrients from hepatopancreas to ovary and raising immunity of P. clarkii.     

维生素C对大口黑鲈生长与非特异性免疫的影响

以不同维生素C水平(添加量分别为0、500、1000、2000和4000mg·kg-1)的5种饲料喂养初始体重为19g左右的大口黑鲈1个月,每个处理50尾鱼,各处理3个重复,研究维生素C对大口黑鲈生长及非特异性免疫的影响。结果显示:饲料中添加维生素C能显著促进大口黑鲈的生长和脾体指数(P<0·05),然而对大口黑鲈的成活率以及肝体指数等不产生影响(P>0·05);饲料中添加维生素C能显著促进大口黑鲈血清中超氧化物歧化酶活力和溶菌酶活力(P<0·05);随着饲料中维生素C添加水平的提高,大口黑鲈肝脏中维生素C的积累量显著升高(P<0·05)。实验证明,Vc作为免疫刺激剂能有效地提高大口黑鲈的生长与非特异性免疫能力。     

用生长和非特异性免疫力评定异育银鲫维生素C需要量

用维生素 C(Vc)含量为0～1200mg·kg~(-1)的精制饲料,连续投喂异育银鲫8周后,测定异育银鲫生长速度和非特异性免疫指标。结果表明,在饲料Vc含量达150mg·kg~(-1)时日增重率最大,进一步提高饲料Vc含量,日增重率没有显著变化;饲料Vc含量为75mg·kg~(-1)时头肾指数显著提高,而脾指数不受饲料Vc含量的影响;头肾细胞吞噬活性和A花环率均在Vc含量为300mg·kg~(-1)时达最高水平;而血清溶菌酶活性和总补体活性分别在饲料Vc为300mg·kg~(-1)和600mg·kg~(-1)时达最高值。上述结果表明饲料Vc可显著提高异育银鲫免疫力。鉴于Vc的免疫促进作用,建议在疾病多发季节饲料Vc添加量提高到300mg·kg~(-1)。     

Requirements of vitamin C (l-ascorbyl-2-sulphate and l-ascorbyl-2-polyphosphate) and its effects on non-specific immune responses of grouper, Epinephelus malabaricus

An 8‐week feeding trial was conducted to determine two vitamin C derivatives, l ‐ascorbyl‐2‐sulphate (C2S) and l ‐ascorbyl‐2‐polyphosphate (C2PP), to satisfy vitamin C requirement and to test their effects on the non‐specific humoral immune responses of juvenile grouper, Epinephelus malabaricus. C2S and C2PP were each supplemented at 20, 50, 80, 150, 250 and 400 mg kg^?1 diet in the semi‐purified basal diet providing of 7, 16, 28, 55, 86, 142 mg ascorbic acid (AA) equivalent of C2S kg^?1 diet and 4, 9, 15, 31, 49, 75 mg AA equivalent of C2PP kg^?1 diet, respectively. Basal diet without AA supplemented was included as a control. Each diet was fed to triplicate groups of grouper (mean initial weight: 6.69 ± 0.07 g). Fish fed diets with ≥28 mg AA equivalent of C2S or ≥4 mg AA equivalent of C2PP kg^?1 had significantly (P < 0.05) greater weight gain (WG) than fish fed the unsupplemented control diet. Liver AA concentrations were higher in fish fed diets with ≥16 mg AA equivalent of C2S or ≥9 mg AA equivalent of C2PP kg^?1 than fish fed the control diet. Alternative pathway of complement activation (ACP) was higher in fish fed diets with ≥55 mg AA equivalent of C2S or ≥15 mg AA equivalent of C2PP kg^?1 than fish fed the control diet. Lysozyme activity was higher in fish fed ≥86 mg AA equivalent of C2S or ≥15 mg AA equivalent of C2PP kg^?1 than fish fed the control diet. Analysis by broken‐line regression of WG indicated that the adequate dietary vitamin C concentration from each vitamin C derivative in growing grouper is 46.2 mg AA equivalent of C2S kg^?1 diet and 17.8 mg AA equivalent of C2PP kg^?1 diet, and it also indicated that C2S is approximately 39% as effective as C2PP in meeting the vitamin C requirement for grouper. The data suggest that both C2S and C2PP supplementation support non‐specific immune responses of grouper.