饲料中添加维生素C对鱼类生长、免疫及抗应激能力影响的研究进展

维生素C作为水生动物所必需的营养要素之一,在促进鱼类生长、抵御疾病侵袭、提高鱼类免疫力及抗应激等方面具有重要作用。文章概述了影响鱼类对维生素C需求量的几个因素以及维生素C对鱼类生长、免疫力和抗应激能力的作用,可以为维生素C对鱼类影响的相关研究提供理论依据。     

团头鲂营养需求与健康研究进展

团头鲂是我国主要的大宗淡水养殖品种之一,其养殖规模在近10年不断扩大。团头鲂的营养物质需求主要以生长和营养缺乏症为评价指标。而营养物质对鱼类健康,如免疫反应和抗病力等影响的研究尚不充分。一般认为,饲料中营养物质搭配合理、品质优良有利于维持鱼类生理健康,并能保护养殖水环境。此外,一些营养物质如维生素,在鱼类的免疫机制中发挥重要作用。未来水产饲料应具有促进水产动物生长和维持健康的双重作用,通过营养调控预防鱼类疾病是保证水产养殖可持续发展的重要策略之一。本研究综述了团头鲂对蛋白质、脂肪、碳水化合物、维生素和矿物质营养需求的研究进展,以及饲料营养元素对团头鲂免疫力及抗病力影响的最新报道,以期为团头鲂高效配合饲料的开发提供科学参考。     

水中添加V_c对氨氮致死浓度下鲤鱼幼鱼的影响

正维生素C又称为抗坏血酸,是一种水溶性维生素,是鱼体生长和维持正常生理机能所必需的营养素。多数鱼类体内缺乏合成维生素C的L-古洛糖酸内酯氧化酶(L-gulonolactone oxidase,GLO),必须从食物中获取Vc。Vc作为一种重要的生理和免疫调节因子,在提高鱼体免疫力、抗病力和缓解应激方面具有重要作用。     

佳纬越冬鱼用系列产品

鱼类越冬期间,由于不摄食或在越冬前营养不良,体质较弱,抗应激能力差,易在外界环境突变或疾病侵袭下死亡。因此,作好越冬鱼的管理工作以及越冬前期培育工作是非常重要的。下面是佳纬公司为鱼类越冬准备的一些产品,可供参考。一、越冬安：“越冬安”是在鱼类越冬前一个月添加于饲料中,以提高鱼体免疫力和抗应激能力,从而最终提高鱼类越冬成活率的一种添加剂。越冬安是在预混料的基础上对一些增加免疫力和执应激的维生素,如VC、VE、VA……等进行强化添加,同时添加免疫增强剂而配制而成的。在满足鱼类生长的前提下,以提高鱼类体…     

养殖鱼类营养与配方设计（下）

了解抗营养因子对饲料质量的影响非常重要，只有了解了抗营养因子对饲料质量的影响，才能确定一些原料在饲料中添加的上限，以免过多添加造成营养的破坏或对鱼类的生长造成危害。常见的天然抗营养因子包括：蛋白酶抑制因子、红血球凝集素、植酸、棉酚、环丙烯脂肪酸、硫葡萄糖苷、芥子酸、硫胺素酶和单宁(鞣酸)等，表8(见文末)是它们对鱼类的影响以及消除的措施。     

国外简讯

鱼类抗应激和防病的营养物质　　加拿大水产科研人员对鱼类患病与应激的关系进行了研究。发现鱼类的应激系由环境条件引起 ,患病因应激所致 ,且与体内微量营养物质密切相关。饲料中营养物质的推荐剂量以生长、饲料效率以及生殖指数为标准。鱼类正常生长需要 4 5种营养物质。除维生素 B6、叶酸、胆碱外 ,大多数维生素直接影响体液反应。维生素 B6、叶酸和胆碱与维生素 B12一起参与核酸代谢 ,直接影响免疫反应和蛋白质合成。营养物质对免疫产生非常重要的相互作用、协同作用和对抗作用 ,显著影响鱼类的生殖。营养物质除影响鱼的免疫能力和抗…     

饲料维生素营养对鱼苗骨骼发育的影响

在人工繁殖鱼类幼苗时,常出现大量骨骼畸形的个体。这些鱼不仅生长速度慢,而且免疫力低,死亡率高,严重影响了水产养殖业的经济效益。综述了饲料维生素营养（A、D、E、K和C）对鱼类骨骼发育和病理学影响的研究进展,从而为幼鱼配合饲料生产性开发和水产养殖业的健康发展提供参考。     

酵母多糖可预防鱼病

美国太平洋水生物研究所经过十年的应用表明，酵母多糖可提高鱼类的免疫力而预防鱼病的发生。应用中，科研人员先后对大西洋鲑、斑点叉尾鲴、虎头虾、虹鳟、比目鱼等种群的鱼类进行注射，随饵料口服、浸泡等不同的给药方式，均发现鱼体对鳗弧菌、抑麦克菌及附生菌的抵抗力大幅增加，具有确定的提高鱼体免疫力和抗病菌能力的生物学特征，因此可以作为鱼类抗群体病发生的预防性生物制剂。     

鱼类对维生素的利用及研究进展

维生素是维护鱼类健康、促进生长发育和调节生理功能所必需的一类低分子有机化合物。维生素的生理功能主要是调节体内的物质和能量代谢，参与氧化还原反应。下面主要介绍一些对鱼类健康生长有重要作用的维生素。 　　1. VA 　　VA对表皮和粘液层的完整性以及粘液的分泌很重要，可降低鱼体对一些传染性疾病的易感性，强化巨噬细胞的功能。以 2倍于生长需求量的 VA饲喂鲑鱼和斑点叉尾，可显著减少因白点虫寄生引起的死亡。 VA缺乏时，主要损害鱼类的眼和骨骼发育，例如鲤缺 VA时，体色苍白，生长缓慢，鳃和皮肤出血，鳃盖边缘皮膜反曲、…     

脂类和维生素对鱼类生殖的影响

营养素作为影响鱼类生殖全过程的一种外部因素，对亲鱼的生殖力和卵子质量等具有重要作用。综述了近年来国内外有关营养素与鱼类生殖的研究概况，详细阐述了脂类和维生素对鱼类生殖的影响。     

Effect of dietary vitamin C on growth performance,body composition and biochemical parameters of juvenile Chu's croaker (Nibea coibor)

Vitamin C is an essential micronutrient for normal physiological and immune functions of fish. However, its requirements and effects in Chu's croaker (Nibea coibor) are currently unknown. A 56‐day feeding trial was conducted to evaluate the optimal dietary vitamin C requirements based on its effects on growth performance, body composition and biochemical parameters in juvenile Chu's croaker (14.17 ± 0.1 g). Six isoproteic (450 g/kg crude protein) and isolipidic (100 g/kg crude lipid) diets were formulated to contain 2.24 (basal diet), 39.03, 85.01, 171.16, 356.49 and 715.46 mg/kg of vitamin C. The results showed that fish fed on 171.16 mg/kg vitamin C diet had the highest growth performance and feed utilization. Fish fed on the basal diet had higher malondialdehyde (MDA) content and lower activities of antioxidant enzymes in the serum and liver as compared with those fed on vitamin C diets. Polynomial analysis indicated that the optimal dietary vitamin C requirements of juvenile Chu's croaker were 102.28, 98.21, 150.26, 165.38, 71.46, 176.19, 84.84 and 103.78 mg/kg based on weight gain, specific growth rate, liver storage, muscle storage, liver MDA content, liver alanine aminotransferase activity, liver alkaline phosphatase activity and liver superoxide dismutase activity, respectively. We recommend an inclusion level in the range of 71.46–150.26 mg/kg vitamin C in the diets of juvenile Chu's croaker for optimum growth performance, liver function, antioxidant capacity and innate immunity functions.     

Effect of Dietary Vitamin C on Weight Gain,Tissue Ascorbate Concentration,Stress Response,and Disease Resistance of Channel Catfish Ictalurus punctatus1

Juvenile channel catfish Ictalurus punctatus (average initial weight, 6.5 g/fish) were fed twice daily to apparent satiation with practical-type diets containing 0, 50, 150, or 250 mg supplemental vitamin C/kg from L-ascorbyl-2-polyphosphate for 10 wk under laboratory conditions. At the end of the feeding period, one half of the fish were stressed for 2 h by confinement and both stressed and nonstressed fish were exposed to a virulent strain of Edwardsiella ictaluri. Weight gain and feed conversion efficiency were lower for fish fed the basal diet than those fed diets containing supplemental vitamin C. No differences were observed in weight gain and feed conversion among fish fed diets containing supplemental vitamin C. There were no differences in feed consumption and survival (prior to experimental infection) among treatments. No vitamin C deficiency signs except reduced weight gain were observed in fish fed the basal diet. Serum cortisol concentrations were higher in stressed fish than in non-stressed fish. Dietary vitamin C level had no effect on serum cortisol concentration. As dietary vitamin C increased, ascorbate concentration in serum and liver increased. Confinement stress had no effect on serum and liver ascorbate concentrations. Cumulative mortality of channel catfish 21 d subsequent to experimental infection with E. ictaluri was higher for stressed fish than for nonstressed fish. Regardless of stress or nonstress, overall mortality for fish fed the basal diet was lower than the fish fed diets containing supplemental vitamin C. There were no differences in post-infection antibody levels among treatments or between stressed and nonstressed fish. Results from this study indicate that channel catfish require no more than 50 mg/kg dietary vitamin C for normal growth, stress response, and disease resistance.     

Long-term effects and interactions of dietary vitamins C and E on growth and reproduction of yellow perch, Perca flavescens

This study was conducted to examine the effects of dietary vitamin C and/or E and their interaction on growth and reproductive performance in yellow perch. Yellow perch juveniles were divided into four treatments with triplicate groups and fed with one of four semi-purified diets for 32 weeks. The experimental diets were formulated to contain no or high vitamin E levels (160 mg/kg) without or with vitamin C supplementation (250 mg/kg) designated as diets −C−E, −C+E, +C−E, or +C+E, respectively. The growth rates and survival of yellow perch fed with +C−E and +C+E diets were significantly higher than the fish fed with −C−E diet. Total- and dehydro-ascorbate concentrations in liver and testis increased in response to its dietary supplementation. The -tocopherol concentration in sperm was significantly affected by dietary supplementation of vitamin C. Gonadosomatic index of males was lower in the fish fed with −C−E diet compared to that of fish fed with other diets. Hatching rates of embryos obtained from testing sperm viability was significantly improved in fish fed with the diets sufficient in vitamin C (82±7%) compared to the fish fed with the −C−E diet (59±7). This study indicates that supplementation of dietary vitamin C and E increase growth rate, and semen quality can be improved by dietary vitamin C supplementation within one maturation cycle, and vitamin C may spare sperm vitamin E depending on vitamin E stores in tissues.     

维生素C对泥鳅幼鱼生长和免疫的影响

水温21~26℃下,分别在基础饲料中添加不同含量的维生素C(以抗坏血酸多聚磷酸酯为维生素C源,添加量分别为0、50、120、240、360、500mg/kg),研究维生素C对(1.996±0.176)g泥鳅幼鱼的影响。试验结果表明,随着维生素C添加量的增加,泥鳅幼鱼的特定生长率呈现先升后降趋势,并在添加量为132.2mg/kg时达到最高值,显著高于其他几个试验组(P0.05)。组织和肌肉中的维生素C积累量随着饲料中维生素C添加量的增加呈先升后降趋势,在132.2mg/kg时和248.8mg/kg时分别达到最高。随着饲料中维生素C含量的增加,溶菌酶活性也呈现出先升后降趋势,在362.6mg/kg时达到最高,显著高于其他组(P0.05);血清总抗氧化能力呈上升趋势,以特定生长率和血清溶菌酶含量为指标,做折线模型回归分析最终求得泥鳅幼鱼饲料中维生素C的最适添加量分别为95mg/kg和423.3mg/kg。     

Effect of Dietary Vitamin C on Tissue Vitamin C Concentration in Channel Catfish,Ictalurus punctatus,and Clearance Rate at Two Temperatures-A Preliminary Investigation

Four trials were conducted with channel catfish, Ictalurus punctatus, under controlled laboratory conditions or in earthen ponds, to evaluate effects of dietary vitamin C concentration and feeding period on liver and anterior kidney vitamin C concentration. Clearance rate of vitamin C in liver and anterior kidney was also evaluated in unfed fish or fish fed a vitamin C-free diet. Results indicated that tissue vitamin C concentration is generally proportional to deitary vitamin C concentration, and that it may reach a maximum concentration within 2 weeks in fish fed diets containing vitamin C. Tissue vitamin C may be reduced to a minimum concentration within 2 weeks when fish were not fed or fed with a vitamin C-free diet at a high temprerature (31°). As temperature was reduced from 31 to 10°C there was a 44% and 13.6% drop in liver and anterior kidney vitamin C concentrations, respectively. At 10°C tissue vitamin C remained relatively constant (100 to 120 mg/g for liver, and 200 to 250 mg/g for anterior kidney) for at least 12 weeks if tissue vitamin C was saturated prior to reducing water temperature. Liver vitamin C appeared to be affected more dramatically by dietary vitamin C concentration and cleared more rapidly than anterior kidney during times of vitamin C deficiency.     

The effects of dietary vitamin C on mucosal immune responses and growth performance in Caspian roach (Rutilus rutilus caspicus) fry

This study was conducted to investigate the effects of different levels of dietary vitamin C on some skin mucus immune parameters, mucus antimicrobial activity and growth performance of Caspian roach (Rutilus rutilus caspicus) fry. Six hundred sixty Caspian roach (1.4 ± 0.02 g) fry were allocated to 12 tanks (55 fish per tank), and triplicate groups were fed diets containing 0, 1,000, 1,500 and 2,000 mg kg^?1 vitamin C for 60 days. At the end of the trial, the epidermal mucus protein level, alkaline phosphatase and antimicrobial activity against two gram-positive bacteria (Streptococcus faecium and Micrococcus luteus) and gram-negative bacteria (Escherichia coli and Serratia marcescens) as well as growth performance were measured. The results demonstrated that feeding on vitamin C significantly elevated skin mucus alkaline phosphatase and protein levels compared to the control group (P < 0.05). However, lysozyme activity was undetectable in both the vitamin C-fed roach fry and the control group. Skin mucus antimicrobial activity was increased following vitamin C administration, and the bacterial growth inhibition zones were significantly elevated in vitamin C-fed roach (P < 0.05). Similar results were obtained in case of the minimum inhibitory concentration of skin mucus. Also fish fed the control diet had a significantly lower weight gain, specific growth rate and condition factor compared to the other treatments (P < 0.05). These results revealed that dietary vitamin C beneficially affects the skin mucus immune parameters and growth performance of Caspian roach fry.     

The effects of dietary vitamin C on growth performance,serum enzymes activities and resistance to Vibrio alginolyticus challenge of yellow drum Nibea albiflora

A 9‐week feeding trial was conducted to determine the optimal dietary vitamin C requirement and its effects on serum enzymes activities and bacterial resistance in the juvenile yellow drum Nibea albiflora (initial weight 33.2 ± 0.10 g). Six practical diets were formulated containing vitamin C 2.1, 45.3, 89.6, 132.4, 178.6 and 547.1 mg kg^?1 diet supplied as l ‐ascorbyl‐2‐monophosphate. The fish fed 547.1 mg kg^?1 diet showed a significantly higher survival than that fed 2.1 mg kg^?1 diet. The weight gains and specific growth rate of the fish fed 2.1 mg kg^?1 diet were significantly lower than those of the fish fed 89.6–547.1 mg kg^?1 diets. The liver vitamin C concentration firstly increased with increasing dietary vitamin C supply from 2.1 to 178.6 mg kg^?1 diet and then stabilized. The serum superoxide dismutase activities of the fish fed 547.1 mg kg^?1 diet were significantly lower than those of the fish fed 2.1–89.6 mg kg^?1 diet. The fish fed 2.1 mg kg^?1 diet had a significantly higher alkaline phosphatase activity than those in the other groups except the 45.3 mg kg^?1 group. Fish that received diets containing vitamin C at 547.1 mg kg^?1 had significantly higher nitro blue tetrazolium and lysozyme activity, and fish that received diets containing vitamin C at 45.3–547.1 mg kg^?1 exhibited resistance against Vibrio alginolyticus infection. The dietary vitamin C requirement of the juvenile yellow drum was established based on broken‐line model of weight gain to be 142.2 mg l ‐ascorbyl‐2‐monophosphate kg^?1 diet.     

褐牙鲆亲鱼野生群体与养殖群体维生素A、C、E含量的比较

为探讨养殖褐牙鲆(Paralichthys olivaceus)亲鱼后代较野生亲鱼后代质量下降这一问题,本实验分析了野生与人工养殖(包括营养强化处理)褐牙鲆亲鱼肌肉、肝脏及卵中维生素A、维生素C、维生素E含量的差异,并进行了养殖褐牙鲆维生素营养强化的探索实验.结果显示,野生与养殖亲鱼肌肉和肝脏中维生素A含量无显著差异,野生亲鱼卵中维生索A含最显著高于养殖亲鱼(P<0.05);野生亲鱼肝脏和卵中维生素C含量显著高于养殖亲鱼(P<0.05),肌肉中两者无显著差异(P>0.05);维生素E含量在野生和养殖亲鱼各组织内均有显著差异(P<0.05),仅肝脏中养殖亲鱼显著低于野生亲鱼(P<0.05),其余组织均为养殖亲鱼较高.在本实验中,营养强化显著增加了养殖亲鱼肌肉和肝脏维生素A、维生素C及卵和肝脏中维生素E的含量,但对卵中维生素A和C的含量均无显著影响(p>0.05),而肌肉中维生素E含量则显著降低(P<0.05).上述结果表明,养殖与野生褐牙鲆亲鱼卵中维生素A、C、E含量存在一定的差异,可能与养殖褐牙鲆亲鱼后代质量下降有关,本实验所采用的营养强化方法仅增加了养殖亲鱼卵中维生素E的含量,而对卵中维生素A和维生素C的含量无显著影响,更为有效的强化方式有待进一步研究.     

Dietary vitamin E could improve growth performance,lipid peroxidation and non‐specific immune responses for juvenile cobia (Rachycentron canadum)

An 8‐week feeding trial was conducted to establish the dietary vitamin E requirement of juvenile cobia. The basal diet was supplemented with 10, 20, 30, 40, 60, 120 mg vitamin E kg^?1 as all‐rac‐α‐tocopheryl acetate. The results indicated that fish fed the diets supplemented vitamin E had significantly higher specific growth rate, protein efficiency ratio, feed efficiency and survival rate than those fed the basal diet. It was further observed that vitamin E concentrations in liver increased significantly when the dietary vitamin E level increased from 13.2 to 124 mg kg^?1. Fish fed the basal diet had significantly higher thiobarbituric acid‐reactive substances concentrations in liver than those fed the diets supplemented vitamin E. Fish fed the diets supplemented with 45.7 and 61.2 mg kg^?1 vitamin E had significantly higher red blood cell and haemoglobin than those fed the basal diet, while fish fed the diets supplemented with 61.2 and 124 mg kg^?1 vitamin E had higher immunoglobulin concentration than those fish fed the basal diet. Lysozyme and superoxide dismutase were significantly influenced by the dietary vitamin E level. The dietary vitamin E requirement of juvenile cobia was established based on second‐order polynomial regression of weight gain and lysozyme to be 78 or 111 mg all‐rac‐α‐tocopheryl acetate kg^?1 diet, respectively.     

Dietary vitamin C requirement of juvenile Chinese sucker (Myxocyprinus asiaticus)

An 8‐week growth experiment was conducted to quantify the appropriate dietary vitamin C requirement of juvenile Chinese sucker (Myxocyprinus asiaticus). Triplicate groups of 30 experimental fish [initial body weight: (7.1 ± 0.3) g] were cultured in 500 L aquaria and fed with semi‐purified diets containing six levels [10.1 (unsupplemented diet), 37.4, 64.9, 125.2, 244.2 and 482.0 mg kg^?1 diet, respectively] of vitamin C (supplied as L‐ascorbyl‐2‐polyphosphate). Results showed that weight gain of Chinese sucker was significantly increased with increasing dietary vitamin C levels, but there was no significant difference of weight gain among fish fed the diets containing more than 125.2 mg kg^?1 vitamin C. As dietary vitamin C increased, the liver vitamin C content of fish showed the increasing trend firstly and then stabled, while the muscle vitamin C content significantly increased without reaching a constant level. Lower liver malondialdehyde content was observed in 125.2, 244.2 and 482.0 mg kg^?1 vitamin C groups, and higher antioxidant capacity and superoxide dismutase activities were observed in supplemented groups when compared to the unsupplemented group. Liver aspartate aminotransferase and alkaline phosphatase activities were also significant affected by dietary vitamin C. Ash content of fish fed the diet with 244.2 or 482.0 mg kg^?1 vitamin C was significantly higher than that of fish fed the other diets. However, dietary vitamin C had no significant effects on whole‐body crude protein, lipid and moisture contents. The vitamin C requirement of juvenile Chinese sucker was estimated to be 84.6 and 126.1 mg kg^?1 based on weight gain and liver vitamin C concentration respectively.