贝壳矿物质在饲料添加剂中的应用

据分析,软体动物贝壳中含有钙、鳃、钴、镁等矿物活性元素约30种,氨基酸10余种,以及多肽、胶原等。这些物质绝大多数是动物生长发育、提高免疫力、增强体质所必需的,如钙、硒、锶、镁、钴等为鱼、虾、蟹的磷、甲壳及骨骼所必要的元素;锌、镍、磷等为神经系统和生殖系统的重要组     

贝壳矿物质在饲料添加剂中的应用

据分析,软体动物贝壳中含有钙、锶、钴、镁等矿物活性元素约30种,氨基酸10余种,以及多肽、胶原等。这些物质绝大多数是动物生长发育、提高免疫力、增强体质所必需的,如钙、硒、锶、镁、钴等为鱼、虾、蟹的鳞、甲壳及骨骼所必要的元素;锌、镍、磷等为神经系统和生殖系统的重要组分;钾、钠则为循环系统中的电介质。不少养殖经营者深知在饲料配方中添加矿物元素的重要性,但却盲目地加入一些如硫酸锌、硫酸铜、硫酸镁、氯化铁、氯化钴及磷酸钙等无机矿化物作为添加剂,结果带来了不少副作用。     

酸化骨粉作饲料添加剂养鱼效果好

近年来，由于配合饲料工业的发展，使长期用作饲料添加剂的骨粉在市场上日趋紧张，据调查骨粉由1983年的每公斤0．20元，到1985年4月上升到每公斤0．32元。而且还在不断上涨。如果以磷酸氢钙来代替骨粉，则售价较高也不可取，因此我们本着提高骨粉利用率的原则，经过反复试验，用了酸化骨粉作饲料添加剂。方法是在100克骨粉中加入25毫升冰醋酸(浓度大于99％)，这样处理后的骨粉作饲料喂鱼，取得了较好的养鱼效果。     

新型渔用饲料添加剂

由北京市农业科学院土肥所主持、河北石家庄地区水产良种场协作进行的新型渔用饲料添加剂饲养鲤鱼种试验取得良好效果，于1989年10月7日验收。为了降低成本，扩大添加剂来源，土肥所科研人员开发了两种新型添加剂，     

渔用绿色饲料添加剂及其科学应用

一、渔用绿色饲料添加剂的概念及特点渔用绿色饲料添加剂是由绿色生产系统生产出来的无污染、无残留、抗疾病、促生长、应用于渔用饲料或养殖生产的各种添加物,是生产无公害渔用饲料,进而生产绿色水产品的关键环节。渔用绿色饲料添加剂有以下主要特点:①具有稳定的理化性质和生     

渔用饲料添加维C稀土的初步研究

为了探索维C稀土对养鱼效果的影响，我们于1987年在室内进行了该添加剂对饲养效果影响的梯度试验，现将试验结果总结如下。     

如何提高渔用饲料养殖效果

随着水产科学技术的发展,配合饲料的营养成分全面而合理、适口性好、散失浪费少、投喂方便、饲料报酬高等优点,已逐渐被广大养殖者所接受。笔者在基层调查时发现,使用配合饲料养殖水产动物,其效果相差甚大。究其原因,是在选择和使用饲料过程中,忽视了一些重要的问题,现浅析如下,供养殖者参考。     

渔用复合肥养鱼经济效果评价

针对水产养殖而研制的渔用复合肥对于提高肥料利用率、弥补阶段性的肥源短缺、促进“肥水鱼”的生产和提高总体效益具有积极的现实意义。 1.渔用复合肥的经济特性一般水产养殖的肥料投入多以有机肥为     

网箱养鲤饲料添加剂的试验

<正> 一、材料与方法 1.筛选规格为50g/尾的建鲤2400尾,随机分为两组,每组1200尾。各置规格为2×2×2米网箱中,悬于同一框架上饲养。试验地点是贵阳市百花湖网箱养鱼场,时间在1991年5月4日至10月10日共157天。水温是第一月平均16℃,第二月平均18℃,后三月平均23℃。试验期中最高水温26℃,最低12℃试验方法见表1。     

深水网箱需求式自动投饵装置的初步研究

深水网箱的自动化控制是我国网箱事业发展的趋势。本文对现有投饵装置进行了分析，在此基础上，设计了一种需求式自动投饵装置，旨在提高投饵效果。网箱养殖鱼群经过驯化，有求食需求时自动触动水下金属管，并通过传感器启动下料机构。该装置通过可编程控制器(PLC)实现投饵过程控制，其优点是能根据养殖鱼类需求，实时投饵，饵料利用率高，水体污染少，满足当前深水网箱自动化发展的需求。     

Water quality fluctuations under floating net cages for fish culture in Lake Cirata and its impact on fish survival

ABSTRACT:   Vertical profiles of water quality were surveyed before and after mass mortality of fish cultured in cages in Lake Cirata, a man made lake in Indonesia. The first survey was performed 4 months before the mass mortality and the second survey was carried out 4 days after the mass mortality. In the first survey, the conditions below 8 m depth were reductive and anoxic, although at 8 and 10 m depth, the water became oxidative in spite of low oxygen concentration in the second survey. These changes were probably caused by strong mixing of surface water with deeper water. Eight months after the mass mortality, when the redox potential at 8 m became reductive again, exposure tests of fish were performed in different layers in the water column around the cage. During the exposure tests the redox potential of the water was less than −100 mV and 93% of carp died within 6 h of exposure at 8 m depth. These results indicated that the mass mortality was caused by the strong mixing of surface water with reductive water in deeper layers.     

Selection of marine species and meals for cephalopod feeding based on their essential mineral composition

A quantitative analysis of the essential mineral content (mg kg^?1 dry weight) was carried out in 31 samples, including molluscs, crustaceans, fish and meals in an attempt to identify those most suitable for formulating cephalopod diets. The mineral ratios (MR: content in the test sample/content in whole Octopus vulgaris) were used as index of nutritional quality. Both crustaceans and oysters presented an optimal profile that covered the macro‐ and microelements composition of O. vulgaris. These samples differed from the rest by their higher Ca, Mg, B, Cu and Zn contents based on a principal component analysis. Fish were deficient in macroelements, such as Na (MR: 70–420 g kg^?1) and Mg (MR: 220–690 g kg^?1), but would be good source of K, Ca and P. Most fish were also deficient in Fe, Zn and Cu, although the copper content would be the most affected (MR: 3–130 g kg^?1). Fish and krill meals showed a high content of Ca and P, although both would be deficient in Na (MR: 440–470 g kg^?1) and Cu (130–540 g kg^?1), along with K, Fe and Zn in krill and Mg and B in fish. Among the plant meals, sunflower and soybean were the most appropriate, presenting higher total content of minerals and MRs above 1000 g kg^?1 for all minerals, except Na, Cu and Zn.     

海水网箱单养及混养褐篮子鱼试验效果初探

为探讨褐篮子鱼（Siganus fuscescens）的养殖模式和网衣清洁作用,在4只传统网箱中进行了不同养殖模式的试验。试验采用单养与混养模式（与日本黄姑鱼Nibea japonica、大黄鱼Pseudosciaena crocea混养）,设置空白对照组、单养组、混养组Ⅰ和Ⅱ。5个多月的养殖试验结果表明,混养组中褐篮子鱼的日增重率高于单养组,养殖成活率均在95％左右,无显著差异。与对照组相比,通过2个月的养殖,单养组和混养组网箱附着的裂片石莼（Ulvafasciata Delile）均被褐篮子鱼摄食干净。由此表明,褐篮子鱼喜欢摄食网衣附着藻类,因此可以减少网箱清洗工作量,并在混养时可提高单位水体的鱼产量。     

Effect of algal species and concentration on development and fatty acid composition of two harpacticoid copepods,Tisbe sp. and Tachidius discipes,and a discussion about their suitability for marine fish larvae

We compared the development and fatty acid content of the harpacticoid copepods Tachidius discipes and Tisbe sp. fed with different microalgal species (Dunaliella tertiolecta, Rhodomonas sp., Phaeodactylum tricornutum, Isochrysis galbana and a concentrate of Pavlova sp.), which differed in cell size and fatty acid composition. Tisbe could develop in 11 days with every alga to the same average stage, whereas Tachidius developed poorly when fed with Isochrysis and Dunaliella. Feeding with Phaeodactylum resulted in a fast development of both copepods at low algal concentrations. However, reproduction was higher with Rhodomonas as food than with the other algae. Fatty acid compositions of copepods were influenced by their food source, but both were able to convert docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) from precursors. Tachidius fed with Rhodomonas or Phaeodactylum was closest to the DHA/EPA/arachidonic acid (ARA) ratio of 10 : 5 : 1 considered optimal for some marine fish larvae. Tachidius showed similar development and reproduction capacity as Tisbe, but requested higher absolute fatty acid contents in the diet. Tisbe was superior in the utilization of bacteria as additional food source and the bioconversion of precursor fatty acids. Phaeodactylum and Rhodomonas are recommendable food sources for both copepod species, but Phaeodactylum is more easily cultured.