江苏大丰池塘草鱼、鲫鱼混养高产与疾病防控关键技术分析(上)

正池塘养殖鱼类疾病防控是养殖鱼类获得好的养殖效益和经济效益的基础,通过池塘生态链控制实现对病原生物的生物学控制、通过饲料途径对养殖鱼类的健康维护,可获得很好的养殖鱼类成活率和生长效果,且在维护养殖鱼类健康的条件下,保障养殖鱼类获得最佳的生长速度、养殖鱼产品的食用安全质量,实现池塘养殖过程的非药物病害控制、养殖过程的数据化分析和控制,这是池塘养殖质量提升的主要发展方向。     

利用浮游动物评价不同类型养殖水体营养状况

2008年8月对湖南省常德市6种不同养殖类型水体(三角帆蚌养殖水体、外河、粗放式养殖水体、滤食性鱼类养殖水体、草食性鱼类养殖水体、肉食性鱼类养殖水体)的浮游动物进行了调查.结果显示:三角帆蚌养殖水体和滤食性养殖水体中优势种为砂壳虫(Difflugia),草食性鱼类养殖水体和肉食性鱼类养殖水体中优势种为萼花臂尾轮虫(Br...     

如何正确识别养殖鱼类的饥饱

正确识别养殖鱼类的饥饱,不仅关系到养殖鱼类的生长状况、病害的发生,而且还对养殖饲料成本的高低起着至关重要的作用。笔者经过多年对池塘养鱼的试验、观察和研究,特别是对鱼类吃食情况进行了多年的细致观察、记录和总结,对如何正确识别养殖鱼类的饥饱总结出了以下几点意见,希望能给广大从事鱼类养殖的朋友一点帮助。     

世界养殖鱼类的改良及其动向

养殖技术的提高及日臻完善,和选育生长快、产量高、抗病强的养殖鱼类,是养殖业发展的两大标志。现就当今世界养殖鱼类的改良及其动向,择要介绍如下。 (一) 引种移殖对优良鱼类的引种移植,是养殖鱼类改良的重要内容。鱼类繁殖、养殖和运输技术的提高,为这项工作创造了条件。引种移植包括开发本国的鱼类资源,变     

鳢科鱼类养殖技术的现状

鳢鱼类是亚洲、非洲热带性淡水经济鱼类,据文献记载,鳢科鱼类有30种。目前国内外养殖的种类主要有:乌鳢、纹鳢、斑鳢、点鳢、细斑鳢以及缘鳢等6种。我国和东南亚一些国家和地区养殖鳢科鱼类有悠久的历史,但养殖技术仅停留于传统的养殖方法。迄今为止,尚未形成一整套完整的科学养殖体系。近几年来,许多国家和地区对肉食性鳢科鱼类养殖发生了兴趣。现将一些国家和地区养殖鳢科鱼类的方法作扼要地介绍:     

养殖水体变化对鱼的生长影响

<正>养殖水体的优劣对鱼类生存、生长起着关键性作用。掌握和了解养殖水体水质变化的特点以及水质与鱼类生长的关系,就能很好地控制水质变化,保持优良的水质,为鱼类生长创造一个舒适的生存水体环境。做到健康养殖,减少病害,提高生产效益,提升产品质量。1养殖水体环境主要构成鱼类养殖水体不仅有适宜鱼类生活的生物和非生物因子,还有对鱼类生活有害的生化物质。判断养殖水体优劣的主要几项指标包括:水温、溶     

鲑科鱼类及其养殖状况

本文介绍鲑科鱼类及其主要生物学特点、鲑科鱼类在世界渔业经济中的重要地位和养殖产业技术发展现况。鲑科鱼类属典型的冷水性鱼类,高蛋白、富含不饱和脂肪酸、营养丰富、可食部分大、无肌间刺、易加工,是欧美人民的传统水产食品和重要养殖鱼类。鲑鱼是世界三大养殖鱼类之一,其养殖产量仅在鲤鱼和罗非鱼之后,海水鱼类养殖中,半数以上(54.3%)来自鲑鱼产量。2005年,世界鲑鱼产量280万吨,其中195万吨(69.6%)来自人工养殖。本文也简要叙述了我国鲑鱼养殖的历史和现状,以及在鲑鳟鱼类遗传育种、养殖新品种开发、营养与饲料、病害防治、繁殖期调控等方面的研究进展,并针对我国鲑鳟鱼产业发展存在的问题提出了建议。     

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。     

利用强效免疫多糖预防鱼类疾病(上)

正在水产养殖场很容易观察到一种现象,无论是什么种类的传染性疾病在养殖鱼类中发生时,均不大可能导致全池的所有养殖鱼类在同一时间发病,而总是有一部分养殖鱼类先发病,另一部分养殖鱼类在稍后的时间内发病,还有一部分养殖鱼类自始至终也可能不发病。在同一个池塘中养殖的鱼类,受到池塘中某种病原感染的机会应该是均等的,为什么同池的养殖鱼类发生疾病的时间和状态会出现这样的差别呢?即     

常规养殖鱼类的健康养殖技术

常规养殖鱼类主要包括：草鱼、青鱼、鲢、鳙、鲤、罗非鱼、鲮、鲈鱼等鱼类。常规养殖鱼类的养殖仍成为内陆地区水产养殖的主流，成熟的养殖技术是渔民增收的重要保证。本人经过多年的养殖实践，现将常规养殖鱼类的健康养殖技术要点总结以下，以供参考。     

The effects of dietary inulin on growth performances,survival and digestive enzyme activities of common carp (Cyprinus carpio) fry

This study was conducted to investigate the effects of dietary inulin on growth performance, diet utilization, survival rate, carcass composition and digestive enzymes activities (amylase, lipase and protease) of carp (Cyprinus carpio) fry (0.55 ± 0.02 g). After acclimation, fish were allocated into 9 tanks (40 fish per tank) and triplicate fish groups were fed, control diet (0 g) or diets containing 5 g and 10 g inulin kg^?1 for 7 weeks. No significant effect on growth performance and diet utilization of fish fed inulin compared with the control group was observed. However, supplementation of inulin significantly increased survival rate and carcass lipid content, while carcass protein content significantly decreased. Dietary inulin had no significant effects on digestive lipase, protease and amylase activities.     

Postprandial kinetics of gene expression of proteins involved in the digestive process in rainbow trout (<Emphasis Type="Italic">O. mykiss</Emphasis>) and impact of diet composition

The impact of increased incorporation of plant ingredients on diets for rainbow trout was evaluated in terms of gene expression of gastric (gastric lipase, pepsinogen) and intestinal (prolidase, maltase, phospholipase A2) digestive enzymes and nutrient transporters (peptide and glucose transporters), as well as of postprandial levels of plasma glucose, triglycerides and total free amino acids. For that purpose, trout alevins were fed from the start of exogenous feeding one of three different experimental diets: a diet rich in fish meal and fish oil (FM–FO), a plant-based diet (noFM–noFO) totally free from fish meal and fish oil, but containing plant ingredients and a Mixed diet (Mixed) intermediate between the FM–FO and noFM–noFO diets. After 16 months of rearing, all fish were left unfed for 72 h and then given a single meal to satiation. Blood, stomach and anterior intestine were sampled before the meal and at 2, 6 and 12 h after this meal. The postprandial kinetics of gene expression of gastric and intestinal digestive enzymes and nutrient transporters were then followed in trout fed the FM–FO diet. The postprandial profiles showed that the expression of almost all genes studied was stimulated by the presence of nutrients in the digestive tract of trout, but the timing (appearance of peaks) varied between genes. Based on these data, we have focused on the molecular response to dietary factors in the stomach and the intestine at 6 and 12 h after feeding, respectively. The reduction in FM and FO levels of dietary incorporation induced a significant decrease in the gene expression of gastric lipase, GLUT2 and PEPT1. The plasma glucose and triglycerides levels were also reduced in trout fed the noFM–noFO diet. Consequently, the present study suggests a decrease in digestive capacities in trout fed a diet rich in plant ingredients.     

复合益生菌对眼斑双锯鱼(Amphiprion ocellaris)肠道消化酶、菌群结构以及形态的影响

为探讨饲料中添加复合益生菌对眼斑双锯鱼(Amphiprion ocellaris)肠道消化酶、菌群结构及形态的影响,将135尾初始体重(0.79±0.01)g的眼斑双锯鱼随机分为3组,每组3个重复,分别投喂复合益生菌有效活菌添加量为0%(对照组)、3%(L3组)和6%(L6组)的饲料,进行为期28 d的养殖试验。结果显示,复合益生菌能提升试验鱼肠道蛋白酶的活性,其中L3组肠道蛋白酶显著提升(P<0.05);能显著降低试验鱼肠道淀粉酶活性(P<0.05);能降低脂肪酶活性(P>0.05)。随着饲料中益生菌添加量的增加,试验鱼肠道中变形菌门丰度开始增多,拟杆菌门丰度降低。饲料中益生菌添加量的增加显著降低试验鱼肠道肌层厚度并显著增加试验鱼肠道绒毛高度(P<0.05)。可见,饲料中添加3%复合益生菌可改善眼斑双锯鱼肠道消化酶活性,提高肠道微生物群落多样性,改善肠道组织形态和功能。     

Effect of enzyme supplementation to dehulled lupin-based diets on growth, feed efficiency, nutrient digestibility and carcass composition of rainbow trout, Oncorhynchus mykiss (Walbaum)

High inclusion levels of dehulled lupin (Lupinus angustifolius) in salmonid diets significantly decrease growth rates. This may be caused by the high concentrations of non‐starch polysaccharides including oligosaccharide (OS) in lupin. The antinutritive effects of OS have not yet been fully investigated in fish. The objective of this study was to determine the effect of enzyme supplementation of dehulled lupin‐based diets on the fish performance. There were two control diets: a fish meal‐based diet with no plant protein (FM) and a diet that contained 50% dehulled lupin (L). Four experimental diets based on diet L and containing four different exogenous enzyme supplements were used: diet L(E) (Energex^™); diet L(B) (Bio‐Feed^™ Pro); diet L(α) (Alpha galactosidase^™); and diet L(Mix), which contained all the enzymes. Fish were randomly stocked into tanks in duplicate groups of 38 fish, 16.58±0.169 (SE) g, and were fed twice a day for 6 weeks. The supplemented enzymes did not improve weight gain in fish fed lupin‐based diets. However, mixed enzyme significantly improved Protein Efficiency Ratio (PER). Apparent digestibility of DM, CP and GE significantly improved in fish‐fed L(E) diet. None of the supplemented enzymes affected digestive tract indices or carcass composition. Surprisingly, weight gain was significantly higher in fish‐fed L(α), L(E) and L(Mix) diets as compared with FM diet. Feed intake was significantly higher in fish‐fed L, L(α) and L(E) diets compared with the FM diet. It is concluded that storing of lupin kernel under a suitable condition may have partially hidden the positive effects of exogenous enzymes through activating the endogenous enzymes.     

Digestive Enzyme Activity during Initial Ontogeny and after Feeding Diets with Different Protein Sources in Zebra Cichlid,Archocentrus nigrofasciatus

This study aims to describe changes in the activity of digestive enzymes of the zebra cichlid, Archocentrus nigrofasciatus, from hatching until 30 d after hatch (d.a.h.), and to evaluate the effects of feeding diets with different levels of fishmeal (FM) substitution with alternative nonanimal protein sources from 30 d.a.h. up to the age of 60 d.a.h. Results indicated that the developmental patterns of digestive enzymes from the exocrine pancreas and intestine are similar to those of other phylogenetically close cichlids, although they seemed to develop faster than other species as indicated by the peaks in enzyme activity, which were detected at younger stages of development. The 100% FM replacement with different alternative nonanimal protein sources had a negative impact on the growth performance of A. nigrofasciatus juveniles, whereas fish fed the diet with a 50% FM replacement showed similar results to those fed the 100% FM diet. Fish showing the lowest growth rate had also the lowest enzyme activity, especially in relation to the intestinal brush border enzymes. This study assesses the digestive capabilities and nutritional condition of the zebra cichlid fish and provides knowledge on the potential for FM substitution in their feeds.     

海洋仔鱼消化酶变化及饵料的影响

近年来海洋仔鱼消化系统,包括胃、肠道以及胰脏发育的研究进展进行了综述,描述了其消化系统在发育过程中形态和功能的变化,对仔鱼发育过程中包括胃蛋白酶、胰酶、肠酶及其他消化酶的变化以及饵料组分的影响进行了总结。     

草鱼和青鱼消化酶的分布特性

选择草鱼(C tenopharyngodon idellus)和青鱼(Mylopharyngodon piceus)作试验鱼,对它们消化道的酸性蛋白酶、碱性蛋白酶、淀粉酶以及三酰基甘油脂酶沿消化道及肝脏和胰腺中的活性分布进行了比较研究。研究表明:这些酶在消化道中呈现不同的分布规律,在肝脏和胰腺中酶的活性高于在消化道中相应酶的活性;同种鱼不同消化酶的分布有所差别;两种鱼消化组织中的各种酶活性分布规律也有差别;青鱼和草鱼的主要消化酶在不同消化器官中的分布有较大差别。     

酸化剂对草鱼生长和非特异性免疫能力的影响

为考察不同类型酸化剂对草鱼生长及生理机能的影响,在基础饲料(对照组)中分别添加0.21％磷酸、柠檬酸、乳酸和复合酸,饲养初始体重为(10.33±0.03)g草鱼(Ctenopharyngodon idellus)8周.结果表明:(1)与对照组相比,饲料中添加0.21％柠檬酸、乳酸和复合酸均显著提高草鱼的增重率、特定生长...     

Growth, digestive enzyme activities and hepatic glycogen levels in juvenile Colossoma macropomum Cuvier from South America during feeding, starvation and refeeding

Abstract. Feeding trials with juvenile Colossoma macropomum Cuvier (approximately 40g) were carried out to study their protein requirements and their efficiency in metabolizing vegetable protein. Two groups of diets were used. In one group, the crude protein consisted exclusively of fish protein concentrate. In the second group the protein consisted of a mixture (55:45) of vegetable and animal protein without fish meal. In each group 30 and 50% protein levels were used. The highest weight increase (1·64%/day) and the lowest feeding rate were obtained with the 50% protein fish meal free diet. During the trial all fish accumulated visceral fat while body protein content decreased and dry matter increased. There was a high correlation between liver weight and liver glycogen. The highest amounts of liver glycogen were induced by diets containing fish meal and/or low protein content. In contrast lo visceral fat deposits, accumulated liver glycogen was of less significance for surviving starvation periods. The activity of digestive enzymes depends on both stomach and gut fullness. Trypsin activity, contrary to pepsin, was correlated with diet protein content, a-amylase activity was not correlated with diet composition.     

Effect of dietary administration of Psychrobacter sp. on the growth,feed utilization,digestive enzymes and immune responses of grouper Epinephelus coioides

A 60‐day feeding trial was conducted to assess the effect of incorporating dietary Psychrobacter sp., one predominant bacterium with antagonistic activity in the gut of fast‐growing grouper Epinephelus coioides, on the growth, feed utilization, digestive enzymes and immune responses of E. coioides at regular monthly intervals. The fish were fed with control diet (without probiont) or probiotic diet supplemented with 1.0 × 10⁸ CFU g^?1Psychrobacter sp. No significant improvement in weight gain (WG) and specific growth ratio (SGR) were observed in the probiotic group, but a significant improvement in feed conversion ratio (FCR) was observed in fish fed the probiotic diet for 60 days. Although not statistically significant, enhanced hepatopancreatic protease and lipase activities and intestinal amylase activity were observed in probiotic group at day 60. A slightly increase in phagocytic activity and phagocytic index was observed in fish fed probiotic diet for 60 days. Serum lysozyme activity showed no significant differences between the probiotic group and the control group during the whole experiment period, while an increasing trend of superoxide dismutase (SOD) activity in the probiotic group was observed. Serum complement component 3 (C3) level of the probiotic group was higher than that of control in the whole feeding period, while complement component 4 (C4) level of the probiotic group was significantly higher than that of the control at day 60. The results of the current study firstly demonstrated potential for Psychrobacter sp. as a novel probiont to improve feed utilization, digestive enzymes and innate immunity in E. coioides.