淡水养殖鱼类饲料专题讲座——第二讲 主要淡水养殖鱼类对营养物质的需求

鱼类对营养物质的需求和其它动物一样均需求蛋白质、脂肪、糖(碳水化合物)、维生素和无机盐等五大类营养物质。不同种鱼类和同一种鱼的不同生长阶段,对营养物质的需求量不同。本讲介绍主要淡水养殖鱼类对蛋白质、脂肪、糖、维生素及无机盐的需要量。这些资料对构成配合饲料各营养素的适当含量,编制合理配合饲料的配方提供理论依据。一、蛋白质:蛋白质是鱼类生长和维持生命的物质基础。鱼的生长主要是指蛋白质在体内的积累。鱼类对蛋白质的需要量比较高,一般说来是哺乳动物和     

团头鲂全产业链健康养殖技术研究进展及展望

团头鲂是我国主要的淡水养殖鱼类之一，其具有食性广、养殖成本低、生长快、成活率高、易捕捞、易繁殖等特点，且具有味美、头小、含肉率高、体形好、规格适中等优点，深受消费者欢迎，在增加优质水产动物蛋白供应、提高全民营养健康水平、保障我国食物安全等方面做出了重要贡献。本文综述了团头鲂全产业链技术研究进展，包括新品种培育及育种技术、饲料营养需求调控及投喂技术、养殖应激与病害的生态防控技术、新型养殖模式、营养品质及加工技术等，提出了具有生产性能优、抗病抗逆性强和适于加工的团头鲂种质资源的挖掘，集约化健康养殖模式建立及精准营养供给、生态防控和高品质加工调理技术的研发等产业发展需求和研究方向，以期为团头鲂全产业链的绿色高质量可持续发展提供参考。     

团头鲂"浦江1号"选育技术

团头鲂原产于长江中游的一些大中湖泊中,并逐渐成为我国主要水产养殖对象之一。但自上世纪八十年代中期以来,我国各地团头鲂养殖群体先后出现了较为严重的退化现象,主要表现为生长速度减慢、性成熟提早、体型变长变薄及抗病力下降等,使这一经济鱼类的养殖效益与发展规模受到了一定的限制。为了团头鲂的良种选育和开发利用,上海市松江区水产良种场利用技术依托单位——上海水产大学农业部水产种质资源与养殖生态重点开放实验室的科研成果——团头鲂“浦江1号”于2003年7月28日建立了国家级团头鲂水产良种场。团头鲂“浦江1号”具有生长优势明…     

饲料营养与鱼类的健康

营养状态是决定鱼类抵抗疾病能力的一个重要因子.优质饲料对改善养殖鱼类的健康与提高抗病能力至关重要,这一点已被大量实验所证实.饲料中蛋白质、脂肪、碳水化合物等主要营养成分含量不足,会影响鱼类的正常生长,甚至出现缺乏症;现越来越多的研究发现某些必需营养成分(必需氨基酸、必需脂肪酸、维生素和矿物质)含量不足的饲料会导致鱼类营养不良和抗病力弱,微量营养元素与鱼类抗病力的关系研究日益得到重视.     

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…     

水产动物维生素D3需求、吸收和转运及其与糖脂代谢的关系

维生素D3是水产养殖动物必需的微量营养素,在维持水产动物正常生长、发育和营养代谢等方面具有重要功能。水产动物几乎不能合成维生素D3,主要通过食物获取。为了深入解析维生素D3调控水产动物糖脂代谢的机制,本文综述了近12年来最新的研究进展,包括分水产动物对饲料维生素D3需求量及其影响因素、维生素D3吸收、转运和代谢机理,以及维生素D3调控糖脂代谢的机制。已有的研究主要聚焦于水产动物维生素D3营养生理、代谢和对糖脂代谢的调控,但仍有很多重要的科学问题尚未解决。重点需制定统一的 “水产动物维生素D3需求量”评价标准,加强维生素D3对水产动物糖脂代谢及机制的研究,从而为水产动物维生素D3营养的精准调控奠定基础。     

淡水鱼类肝病的病因与防治

近年来,由于集约化淡水养殖的普及导致鱼类肝病大量暴发,造成严重的经济损失,而淡水鱼类的肝病易被养殖户所忽视,并且耽误治疗。一、淡水鱼类肝病的病因1.营养性因素饲料中蛋白质、脂肪、糖类等营养物质过多或缺乏;饲料中营养指标与养殖对象不适合;饲料蛋白质含量过高;等等。例如:用高营养的鲤鱼饲料投喂团头鲂或草鱼;用鱼苗、鱼种饲料投喂成鱼,且投喂量过多,致使鱼类生长过快,出现肥胖和脂肪肝;饲料中维生素E、胆碱、肌醇、硒等微量元素缺乏,磷缺乏或钙磷比例失调等,都容易诱发肝病。2.毒性物质由多种外来的污染物或内部产生的毒物引起,如…     

大豆凝集素对鱼类的影响

大豆凝集素是大豆中主要的抗营养因子之一。不仅会降低鱼类对饲料的利用率,而且会影响鱼类的生长,甚至引起鱼类大批死亡,对鱼类的健康养殖具有一定的影响。概述了大豆凝集素的定义和结构、抗营养作用的途径、对鱼类的主要抗营养作用、消除方法及未来的研究展望,旨在为合理开发利用植物蛋白源提供依据。     

养殖鱼类营养与配方设计(上)

随着水产养殖业不断进步,要想获得一个较为完善的养殖鱼类饲料配方,不仅要考虑鱼类的营养需求,还应该考虑诸多可能影响到鱼类最终摄取到适量营养物质的因素。不仅要考虑使鱼类能够快速生长,还应该考虑最终渔产品的质量以及养殖对环境的影响。本文就此作一阐述。　　一个好的饲料配方必须是针对性强的配方,因此,配方伊始,必须确定养殖对象。养殖对象确定以后,如果只知道这一种鱼类生物学方面的一些知识,而有关营养需求方面的知识非常缺乏,我们该如何着手制定配方呢?此时,只有充分挖掘该养殖对象生物学知识方面给我们带来的信息,才不至于…     

浅析由于饲料质量引发的鱼病

饲料是发展养鱼生产的物质基础，它是鱼类维持生长所必需的重要物质。因此养鱼工作者必须通晓养殖鱼类的食性和营养需求以及各种饲料的营养作用和加工调制的知识，才能更好地合理利用饲料，以满足鱼类在生长发育过程中所必需的营养，从而达到进一步提高鱼产量的目的。否则...     

养殖鱼类脂肪肝成因及相关思考

养殖鱼类脂肪肝病,是困扰水产养殖业多年的广发性病害,虽经多年研究和防治实践,至今尚不能得到根本遏制。本文回顾了近年来在养殖鱼类脂肪肝研究领域的重要研究成果,从营养和饲料、养殖环境、鱼类生理特性、物种差异和遗传变异等5个方面系统总结了导致养殖鱼类肝脏脂肪过量累积的原因。在综述已有成果的基础上,分析了当前鱼类脂肪肝研究和防治实践中存在的可能误区,并结合自身多年在鱼类、哺乳动物和人类脂肪肝研究中的成果和经验,探讨了养殖鱼类脂肪肝发生的生物学机制,提出了"营养型脂肪肝"与"氧化型脂肪肝"的区分标准,揭示了当前鱼类脂肪肝防治的复杂性和困难性,并对今后鱼类脂肪肝研究和防治实践提出了具体的研究方向和防治策略。     

Estimating Amino Acid Requirement of Brazilian Freshwater Fish from Muscle Amino Acid Profile

Information on nutritional requirement of some Brazilian farmed fish species, especially essential amino acids (EAA) requirements, is scarce. The estimation of amino acids requirements based on amino acid composition of fish is a fast and reliable alternative. Matrinxa, Brycon amazonicus, and curimbata, Prochilodus lineatus, are two important Brazilian fish with potential for aquaculture. The objective of the present study was to estimate amino acid requirements of these species and analyze similarities among amino acid composition of different fish species by cluster analysis. To estimate amino acid requirement, the following formula was used: amino acid requirement = [(amount of an individual amino acid in fish muscle tissue) × (average totalEAA requirement among channel catfish, Ictalurus punctatus, Nile tilapia, Oreochromis niloticus, and common carp, Cyprinus carpio)]/(average fish muscle totalEAA). Most values found lie within the range of requirements determined for other omnivorous fish species, in exception of leucine requirement estimated for both species, and arginine requirement estimated for matrinxa alone. Rather than writing off the need for regular dose–response assays under the ideal protein concept to determine EAA requirements of curimbata and matrinxa, results set solid base for the study of tropical species dietary amino acids requirements.     

Review on European sea bass (Dicentrarchus labrax,Linnaeus, 1758) nutrition and feed management: a practical guide for optimizing feed formulation and farming protocols

As increasing amounts of novel raw materials are used in aquafeed production, it is important to measure their quality against existing ingredients and their effects upon production strategies. A first step to achieving this goal begins with an improved understanding of the underlying growth potential of each farmed species across a range of dietary ingredients and farming practices. Species‐specific physiological limitations and metabolic effects of both single chemicals and complex chemical matrixes are factors to be considered in producing robust fish and a healthy aquaculture sector. The industry must also consider ethical, environmental and economic issues and optimize feed management practices. This review summarizes current knowledge on European sea bass (Dicentrarchus labrax) nutritional requirements, presents current feed management practices for this species, gives insights on a secure framework for using plant ingredients in exchange for traditional marine raw materials and outlines its growth potential through a meta‐analysis of the best‐performance results available in peer‐reviewed scientific publications for this species. As the best‐performing fish were mostly those fed high fish meal fish oil control diets, the summarized results have the potential to be used as a quality control for benchmarking future scientific research in this fish species.     

Nucleotide nutrition in fish: Current knowledge and future applications

The roles of nucleotides and metabolites in fish diets have been sparingly studied for over 25 years. Beside possible involvement in diet palatability, fish feeding behavior and biosynthesis of non-essential amino acids, exogenous nucleotides have shown promise most recently as dietary supplements to enhance immunity and disease resistance of fish produced in aquaculture. Research on dietary nucleotides in fishes has shown they may improve growth in early stages of development, enhance larval quality via broodstock fortification, alter intestinal structure, increase stress tolerance as well as modulate innate and adaptive immune responses. Fishes fed nucleotide-supplemented diets generally have shown enhanced resistance to viral, bacterial and parasitic infection. Despite occasional inconsistency in physiological responses, dietary supplementation of nucleotides has shown rather consistent beneficial influences on various fish species. Although nucleotide nutrition research in fishes is in its infancy and many fundamental questions remain unanswered, observations thus far support the contention that nucleotides are conditionally or semi-essential nutrients for fishes, and further exploration of dietary supplementation of nucleotides for application in fish culture is warranted. Hypothesized reason(s) associated with these beneficial effects include dietary provision of physiologically required levels of nucleotides due to limited synthetic capacity of certain tissues (e.g. lymphoid), inadequate energetic expenditure for de novo synthesis, immunoendocrine interactions and modulation of gene expression patterns. However, currently there are numerous gaps in existing knowledge about exogenous nucleotide application to fish including various aspects of digestion, absorption, metabolism, and influences on various physiological responses especially expression of immunogenes and modulation of immunoglobulin production. Additional information is also needed in regard to age/size-related responses and appropriate doses and timing of administration. Thus further research in these areas should be pursued.     

Fish nutrition research: past,present and future

The systematic, scientific investigation of nutrition dates from the eighteenth century, but for many years, there were few studies on fish. As a result, knowledge about fish nutrition still lags behind that of man and his domesticated terrestrial animals. Initially, there were few incentives to collect information about the nutritional requirements of fish, and it is difficult to carry out experiments on aquatic animals. Fish were being farmed, but the extensive rearing methods used meant that there was no pressing need to gather detailed information that could be used for preparing feeds. Research into fish nutrition started in earnest around the middle of the twentieth century. Since then information has accumulated quite rapidly as research efforts have been spurred on by the expansion of aquaculture and developments within intensive fish farming. Nevertheless, the gaining of more knowledge about the nutrition of fish still needs to be given priority to assist in the continued development and improvement of sustainable practices in aquaculture. In this brief overview, fish nutrition research is placed in a historical perspective by considering some of the major challenges faced by fish nutritionists, how these challenges were addressed, the advances made, and knowledge gaps that need to be filled. The spotlight is focused on nutrient requirements, feed ingredients and their evaluation, and the formulation of diets that promote effective production whilst serving to maintain fish health and well-being.     

Novel methodologies in marine fish larval nutrition

Major gaps in knowledge on fish larval nutritional requirements still remain. Small larval size, and difficulties in acceptance of inert microdiets, makes progress slow and cumbersome. This lack of knowledge in fish larval nutritional requirements is one of the causes of high mortalities and quality problems commonly observed in marine larviculture. In recent years, several novel methodologies have contributed to significant progress in fish larval nutrition. Others are emerging and are likely to bring further insight into larval nutritional physiology and requirements. This paper reviews a range of new tools and some examples of their present use, as well as potential future applications in the study of fish larvae nutrition. Tube-feeding and incorporation into Artemia of ¹⁴C-amino acids and lipids allowed studying Artemia intake, digestion and absorption and utilisation of these nutrients. Diet selection by fish larvae has been studied with diets containing different natural stable isotope signatures or diets where different rare metal oxides were added. Mechanistic modelling has been used as a tool to integrate existing knowledge and reveal gaps, and also to better understand results obtained in tracer studies. Population genomics may assist in assessing genotype effects on nutritional requirements, by using progeny testing in fish reared in the same tanks, and also in identifying QTLs for larval stages. Functional genomics and proteomics enable the study of gene and protein expression under various dietary conditions, and thereby identify the metabolic pathways which are affected by a given nutrient. Promising results were obtained using the metabolic programming concept in early life to facilitate utilisation of certain nutrients at later stages. All together, these methodologies have made decisive contributions, and are expected to do even more in the near future, to build a knowledge basis for development of optimised diets and feeding regimes for different species of larval fish.     

凡纳滨对虾营养生理和高效环保饲料研究进展

凡纳滨对虾(Penaeus vannamei)是我国最主要的海水对虾类养殖品种,2021年海水养殖产量达到119.77万吨,占全国海水虾类养殖总产量的80%以上。目前,国内外对于凡纳滨对虾的营养需求与饲料研究已有较多报道,但是对于不同生长阶段的精准营养需求以及营养素和功能性饲料添加剂的相互关系研究仍不够深入。本文主要就其蛋白质、脂肪、碳水化合物和微量营养素的需求,蛋白源和脂肪源替代鱼粉和鱼油,功能性饲料添加剂应用等方面的研究进展进行综述,以期为凡纳滨对虾的精准营养研究及高效环保饲料的开发提供科学参考,从而推动其养殖业的健康可持续发展。     

脂肪酸对鱼类免疫系统的影响及调控机制研究进展

替代脂肪源的开发和利用是解决鱼油短缺问题的必然选择。然而,随着替代水平的提高,鱼体常常表现免疫水平和抗病能力降低。鱼油替代的本质为脂肪酸替代,深入研究脂肪酸与鱼类免疫的关系显得尤为重要。本实验综述了脂肪酸对鱼类免疫性能的影响及调控机制。饱和脂肪酸会降低鱼类免疫力,而适量添加n-3长链多不饱和脂肪酸(LC-PUFA)、共轭亚油酸(CLA)或提高n-3/n-6多不饱和脂肪酸(PUFA)的比例有利于鱼体免疫力发挥;饲料中脂肪酸主要通过细胞膜结构、信号传导、类花生四烯酸、细胞因子和类固醇激素等途径对鱼类免疫进行调控。脂肪酸与鱼类的免疫性能具有高度相关性,而调控机制的研究尚有较大空间。未来研究应该侧重于以下几个方面:脂肪酸对免疫相关转录因子的调控机制;鱼类肠道脂肪酸组成改变与菌群结构和免疫性能之间的相关性;环境因子对鱼体脂肪代谢和免疫力的影响;非脂肪酸成分(矿物质、维生素)对鱼类脂肪酸代谢和免疫过程的调控机制。     

Effect of dietary high amount of calcium and phosphorous on reducing the prevalence of morphological deformities in GH-transgenic Nile tilapia

To satisfy the world’s growing need for animal protein, it is important to develop or select fish species which are suitable for optimal cultivation in closed recirculating aquaculture systems (CRASs) as an environment-friendly aquaculture technology for providing safe and secure aquaculture food products. We have developed an ‘all fish’ growth-hormone (GH)-transgenic Nile tilapia Oreochromis niloticus (GHTi) which appears to be a predominant candidate for CRAS since it has been found to exhibit two important characteristics, namely, a shorter rearing duration to a market size and lowered N and P discharge load. However, these fish have undergone morphological changes, resulting in a short body which is less acceptable to consumers as an edible fish. One possible solution to reducing the prevalence of such morphological deformities is to determine the association between changes in the nutritional conditions of these fish. To this end, we first calculated the ideal total calcium (Ca) and phosphorous (P) intake (g/kg), ideal daily Ca and P intake and retention (g/kg/day) and ideal daily feeding rate (%) for the fourth filial (F₄) offspring of GHTi. Our hypothesis was that GHTi would achieve the same total retention of Ca (14.6 g/kg) or P (7.69 g/kg) during a 69-day shorter rearing period as their production-matched pedigree common domestic strain (CTi). We estimated that when GHTi were fed conventional commercial diets to satiety, those with a body weight (BW) of more than approximately 230 g could not retain sufficient Ca, while those with a BW of more than approximately 429 g could not retain sufficient P. We then attempted to reduce the prevalence of morphological deformities in GHTi via dietary compound regulation by supplying a high amount of dietary Ca [6.82 % in the diet with Ca supplementation (Ca-S)] or P [4.75 % in the diet with P supplementation (P-S)]. Both the Ca-S and P-S diet improved mineral retention, while those fed on a Ca-S diet showed a lower prevalence of deformities, close to the size-matched CTi. These results suggest that the requirements of dietary Ca and P were significantly higher in GHTi than in CTi and, consequently, that the conventional levels of Ca and P in commercial diets for CTi cannot meet the mineral requirement of GHTi. We therefore propose to develop an optimal feed to meet the altered nutritional requirements of GH-transgenic Nile tilapia for growth-promoting optimization. This may become prerequisite for rearing this GHTi line in CRASs.     

The role of phospholipids in nutrition and metabolism of teleost fish

It has been known for almost 25 years now that inclusion of intact phospholipids in the diet could improve culture performance of various freshwater and marine fish species. The primary beneficial effect was improved growth in both larvae and early juveniles, but also increased survival rates and decreased incidence of malformation in larvae, and perhaps increased stress resistance. Determination of absolute dietary requirements has been hampered by the use, in different dietary trials, of a wide range of phospholipid preparations that can vary greatly both in phospholipid content and class composition. Larval studies have been compromised further by the need on many occasions to supply phospholipid through enrichment of live feeds with subsequent re-modelling of the phospholipid and fatty acid compositions. Generally, the levels of phospholipid requirement are around 2–4% of diet for juvenile fish and probably higher in larval fish. The effects were restricted to young fish, as a requirement for dietary phospholipids has not been established for adult fish, although this has been virtually unstudied. As the majority of studies have used crude mixed phospholipid preparations, particularly soybean lecithin, but also other plant phospholipids and egg yolk lecithin, that are enriched in several phospholipids, it has been difficult to elucidate which specific phospholipid classes impart beneficial effects. Based on the few studies where single pure phospholipid species have been used, the rank order for efficacy appears to be phosphatidylcholine > phosphatidylinositol > phosphatidylethanolamine > phosphatidylserine. The efficacy of other phospholipid classes or sphingolipids is not known. The mechanism underpinning the role of the phospholipids in larval and early juvenile fish must also explain their lack of effect in adult fish. The role of phospholipids appears to be independent of fatty acid requirements although the presence of an unsaturated fatty acid at the sn-2 position may be important. Similarly, the phospholipid requirement is not related to the delivery of other essential dietary components such as the bases choline and inositol. Studies also suggested that the phospholipid effect was not due to generally enhanced emulsification and digestion of lipids. Rather the evidence led to the hypothesis that early developing stages of fish had impaired ability to transport dietary lipids away from the intestine possibly through limitations in lipoprotein synthesis. The current hypothesis is that the enzymic location of the limitation is actually in phospholipid biosynthesis, perhaps the production of the glycerophosphobase backbone and that dietary supplementation with intact phospholipids in larvae and juvenile fish compensated for this. Thus, dietary phospholipids increase the efficiency of transport of dietary fatty acids and lipids from the gut to the rest of the body possibly through enhanced lipoprotein synthesis.