呋喃唑酮对饲养水及草鱼体表粘液中菌群的影响

对饲养水中泼洒不同浓度（０．２ｍｇ／Ｌ、０．５ｍｇ／Ｌ和１．０ｍｇ／Ｌ）的呋喃唑酮后，研究了饲养水及草鱼体表粘液中好氧与兼性厌氧细菌的数量及组成变化。结果表明：用药前，饲养水及粘液中的菌群主要有Ａｅｒｏｍｏｎａｓ、Ｅｎｔｅｒｏｂａｃｔｅｒｉａｃｅａｅ、Ｖｉｂｒｉｏ、Ｆｌａｖｏｂａｃｔｅｒｉｕｍ、Ａｃｉｎｅｔｏｂａｃｔｅｒ、Ｐｓｅｕｄｏｍｏｎａｓ、Ｃｏｒｙｎｅｂａｃｔｅｒｉｕｍ、Ｓｔａｐｈｙｌｏｃｏｃｕｓ和Ｂａｃｉｌｕｓ，此外，水体中还检测到Ｍｉｃｒｏｃｏｃｕｓ和Ａｌｃａｌｉｇｅｎｅｓ。水体及粘液中的细菌数量在用药后１２ｈ或２４ｈ时降至最低，在４８ｈ或９６ｈ时恢复到原来的水平。用药后，水体及粘液中的优势菌群未发生改变，但Ｆｌａｖｏｂａｃｔｅｒｉｕｍ的比例显著增加，Ａｅｒｏｍｏｎａｓ、Ｖｉｂｒｉｏ和Ｅｎｔｅｒｏｂａｃｔｅｒｉａｃｅａｅ明显减少，Ｐｓｅｕｄｏｍｏｎａｓ和Ａｃｉｎｅｔｏｂａｃｔｅｒ则未能检测到，其他各类群的比例也有一定的变化。菌群的变化速度与用药浓度有关。

与ADV有关的饲养水貂非化脓性脑膜炎

美国研究人员在成龄饲养水貂观察到与水貂阿留申病细小病毒(ADV)有关的严重非化脓性脑膜炎。脑的病变包括严重的局部弥漫到连片淋巴浆细胞脑脑膜炎,伴有神经胶质细胞增生、卫星现象以及炎症轻度扩散到软膜蛛网膜中。用PCR在被侵袭水貂的肠系膜淋巴结、脾、脑和肝中鉴定出ADV。

青年蛋鸡的饲养管理要点

主要探讨青年蛋鸡的饲养管理要点,青年期蛋鸡要根据其日龄,合理选择饲料的营养配比,提供科学的饲养管理方式,做好疾病防治,以期提高蛋鸡的健康状态,保证产蛋期蛋鸡的产量、蛋的大小和蛋的营养含量,为养殖户带来更好的经济效益。

抑制鱼病的有效措施——测水饲养法

池塘实行测水饲养法养鱼，是降低鱼类发病率的有效措施，其具体方法是：

测水投饲养鱼法

为降低成本,我公司总结了“测水投饲养法”。(一)测水温定投饵量。鱼类属变温动物,其消化摄食强度与水温有关。一般说,在适温范围内(7—32℃),水温越高,鱼的摄食量越大(尤其是不坚持“四定”投饵的塘),发病率(主要指草鱼)也越高。要使鱼长得快又少发病,必须根据全年水温升降规律确定日投饲量。具体方法:早春时节。

利用温泉水和工厂余热水养鳖

利用温泉水和工厂余热水养鳖是比较经济和理想的。温泉水和工厂余热水的温度一般都高于30℃。在供养殖使用时,要把河水、井水、泉水等水温降到最适温度30℃才可使用。可将温泉水和河水等分别引进,同时用阀门调节,注入饲养池。

访明州以饲养业为主的三户农家

在明尼苏达州,农民中多数是专门种植作物或兼养猪、牛的农户,也有一部分专门饲养家畜或动物或以饲养家畜、动物为主的农户。经美中友协的介绍,我特地定访了三户以饲养家畜及小动物为主的农户,他们的饲养业都干得十分出色。

测水投饲 养鱼见效

为提高饲料利用率,降低饲料成本,我们在养鱼生产中总结出"测水投饲养鱼法",对于北方地区养鱼非常适合.

栾城县召开多种经营科技交流会

最近,栾城基地县召开了多种经营科技交流会,其盛况赛过了商品物资交易会,充分显示了当前农村大好形势的一个新特点:责任制的建立和社员家庭多种经营的开展,带来了可喜可贵的“科学热”。这次会的开法和以往不一样,通知典型队、户和全县社、队代表参加,欢迎群众自愿参加,连着三天,县大礼堂挤满了人。许多老年人拄着拐杖,妇女抱着小孩赶来参加会。会上,有经营养殖业、种植业好的17个队和户介绍经验。冶河大队焦锁子介绍了对小鸡四个周龄期的饲养搭配、管理;对蛋鸡的饲料、供水、温度怎样掌握的方法。他喂的鸡闹病少,成长快,产蛋多。去年,

ARTIFICIAL PROPAGATION AND BREEDING OF MARINE FISH IN CHINA

Since the 1990s, artificial propagation and breeding technique of marine fish in China have developed by way of increasing species and fry numbers, with special stress laid on valuable species. Large quantities of artificial fry can meet the needs of both marine cage culture and pond culture for most species. Experimental results obtained by scientists have been put into use in actual production. Fish fry production has entered a period of sustainable development. So far, at least 44 species (21 families) of marine fish have been successfully bred in China. The artificial fry number of large yellow croaker (Pseudosciaena crocea) exceeded 300 million in 1999. The species whose artificial fry numbers have each surpassed 10 million annually are red drum (Sciaenops ocellatus), Japanese seabass (Lateolabrax japonicus), cuneate drum (Nibea miichthioides), spring spawning red seabream (Pagrosomus major) and threebanded sweetlip (Plectorhynchus cinctus). Millions of artificial fry are bred annually in the species of black porgy (Sparus macrocephalus), Russell’s snapper (Lutjanus russelli), javelin grunt (Pomadasys hasta), miiuy croaker (Miichthys miiuy) and skewband grunt (Hapalogenys nitens). The fish in the family Sciaenidae are the main species in artificial propagation and breeding. Some problems and prospects on marine fish culture and stock enhancement are also discussed and some proposals for sustainable development are put forward in this article.

微囊藻毒素在鲤鱼体内生物富集作用的初步研究

为了解微囊藻毒素在鲤鱼体内生物富集作用 ,用ELISA法对饲养不同时间的鲤鱼肝脏和肌肉以及饲养用水中的微囊藻毒素进行测定。结果显示 ,鲤鱼肝脏和肌肉的微囊藻毒素含量在试验第七天达到峰值 ,分别为 1 4 3ng g和 2 5 3ng g。饲养用水微囊藻毒素在第四天达到 11 36ng g ,是整个试验期间的最高值。不同时间鲤鱼肝脏对微囊藻毒素的生物富集能力均明显高于肌肉 ,鲤鱼肝脏的生物富集系数在实验第三十五天达到 396 1 6 ,为整个试验的最高值 ,肌肉的生物富集系数在试验开始后 2 8d内平缓上升 ,维持在 80 0左右 ,整个试验期间肝脏的生物富集系数基本是肌肉的 3 9倍。本研究为囊藻毒素对水产品的污染和制定其在水产品中的限量标准提供了依据。

Factors that Affect Pellet Quality： A Review

Pelleting is the most popular thermal processing technique in poultry industry. Birds fed pelleted diets have greater feed intake and weight gain, and better feed conversion ratio. However, this better performance can only be achieved, if the pellets remain intact until they are ingested by the birds. Many factors may affect pellet physical quality, such as feed nutritional composition, ingredient particle size, conditioning temperature and time, feed moisture, etc.. Despite their importance, sometimes these factors are not managed properly, therefore, pelleted feed may not contain a high amount of intact pellets. In addition, the possible interactions among these variables may yield different responses in comparison with those expected when individual factors are considered. Very few experiments have been conducted to evaluate the impact of combined factors on pellet quality. This may be explained by the presence of many qualitative and quantitative factors in the manufacturing process. Research indicates that heat processing and feed formulation, especially fat inclusion level, are the factors which have the biggest influence on pellet quality. Strategies, such as the expansion process and fat inclusion restriction or post pellet liquid fat application could be implemented to produce high physical quality pellets. More research is needed to identify which factors have a positive or negative effect on pelleting process and to find new strategies to improve pellet physical quality.

Removal of Nitrogen and Phosphorus from Animal and Municipal Wastewaters as Dittmarite

Phosphorus and nitrogen are known causes of eutrophication in rivers, lakes streams and estuaries. The sources of these nutrients are diverse and they include chemical fertilizers, CAFOs （Confmed Animal Feeding Operations）, land application of animal and municipal as well as industrial wastewaters. Application of manure slurries to crop land beyond allowable limits could result in high levels of phosphorus and nitrogen in runoff that negatively impact aquatic animals. Municipal wastewater treatment plants are setup to remove these nutrients from domestic and industrial wastewater through a network of treatment processes. Controlling the discharge of phosphorus and nitrogen in wastewater is a key factor in preventing eutrophication. This paper presents work done to enhance a chemical precipitation process that removes over 90% of dissolved phosphorus and nearly 20% of dissolved nitrogen from both synthetic and municipal wastewaters. The objective of the study is to remove nitrogen and phosphorus from wastewater as dittmarite, a value-added mineral fertilizer found in nature. A laboratory procedure was developed that generated significant quantities of dittmarite from various wastewaters. Pure dittrnarite contains nitrogen, phosphorus and magnesium in approximate molar ratios of 1：1.2：1.2 that can support plant growth. It is produced as a wet precipitate from chemical reactions that occur in the wastewater treatment process; it can be dried for proper handling and utilization. Municipal wastewater treatment plants, high volume fish producers, CAFOs and individual rural homeowners could all benefit from this technology for on-site removal of nitrogen and phosphorus from produced wastewaters.

Layered farming for Marsupenaeus japonicus Bate

Marsupenaeusjaponicus Bate is one of the most valuable cultured shrimp species in China and outdoor earthen pond farming is the most common method of culturing this organism. The need to increase soil usage efficiency in aquaculture has been recognized and a great deal of research effort has been directed toward development of super-intensive farming systems. However, current research and development in this field is largely devoted to Litopenaeus vannamei Boone, while to M.japonicus Bate it has been neglected. In this study, a layered fanning system was designed and a 66-day study was conducted in M.japonicus Bate culture. The system comprised bracket and sand layers that divided a shrimp tank filled to a depth of 1.2 m into four water layers. Conventional tank culture （unlayered） was used as a control. The results show that survival rate, feed conversion efficiency and production of M.japonicus Bate in the layered farming system were 68%, 18%, and 0.59 kg/m^2, respectively, all of which are significantly higher than in the unlayered fanning system （P〈0.01）. These findings confirmed the possibility of using a layered system to culture M. japonicus Bate.

Protein-sparing effect of carbohydrate in diets for juvenile turbot Scophthalmus maximus reared at different salinities

The aim of the present study was to investigate the protein-sparing effect of carbohydrate in diets for juvenile turbot(Scophthalmus maximus) reared at five salinities(12,18,24,30,and 36).The fish were fed three isocaloric and isolipidic diets for 60 days.The results show that specific growth rate(SGR)and feed conversion efficiency(FCE) were higher in fish reared at salinities of 18 and 36,but lower at 12.Fish fed with diet C25P40(25%carbohydrate and 40%protein) had lower SGR and FCE values compared with those fed with the C5P52(5%carbohydrate and 52%protein) and C15P46(15%carbohydrate and 46%protein) diets;however,there was no statistical difference between diet C5P52 and C15P46.SGR and FCE values were unaffected by diet composition in fish reared at salinity 36.Hepatic lipogenic enzyme activities were higher in fish reared at 18 and 36,but lower at 12,while glucokinase(GK) activity was higher in fish reared at 12,and lower at 18 and 36.Dietary starch enhanced GK activity while depressing lipogenic enzyme activity.However,lipogenic enzyme activity increased with increasing dietary starch in fish reared at 36.It is recommended that salinity should be maintained > 12 in the farming of juvenile turbot.In addition,an increase in gelatinized starch from 5%to 15%could spare 6%dietary protein in fish reared at salinities of 18-30,while higher salinity(36) could improve dietary carbohydrate use and enhance the protein-sparing effect,which is linked with the induction of lipogenic capacities.

Pond culture of seaweed Sargassum hemiphyllum in southern China

The seaweed Sargassum hemiphyllum is widely distributed throughout the coastal waters of Asia and has high commercial value. In recent years, its natural biomass has declined due to over-exploitation and environmental pollution. To seek for a feasible way to culture this seaweed efficiently, we designed a simple long-line system in a shrimp pond for the culture during winter, and the growth and nutritional composition of the seaweed were examined. Results show that the cul^re system was durable and flexible allowing S. hemiphyllum to grow vertically offthe muddy bottom of the pond. Although the length of pond- cultured S. hemiphyllum was inhibited by water depth, the weight-specific growth rate （（1.65±0.17）%/d） was nearly three times higher than that of wild plants （（0.62±0.19）%/d）. The crude protein （6.92%±0.88%） and ash content （21.52%±0.07%） of the pond-cultured seaweed were significantly lower than those of the wild plants （9.38%±-0.43% and 26.93%±0.07%, respectively）; however, crude fat （1.01%±0.04%） was significantly higher than that of the wild plants （0.87%±0.02%）. In addition, the nutritional composition of both pond-cultured and wild S. hemiphyllum was comparable to or even higher than those of other common seaweeds being used as food and/or aquaculture fodder. Future studies shall be focused on the impact of environmental parameters on its growth and nutritional composition.

Compensatory growth in hybrid tilapia (Oreochromis mossambicus×O. niloticus) reared in seawater, following restricted feeding

Hybrid tilapia weighing 7.71 g were reared in seawater at 24.0-29.0℃ for 8 weeks. The controls were fed to satiation twice a day throughout the experiment, whereas treatment groups were fed at 0.5%, 1.5% or 3.0% body weight per day for 4 weeks, and then to satiation for the remainder of the experiment. During the first 4-week period, there was a curvilinear relationship between growth rate and ration size. Fish fed 0.5% and 1.5% rations displayed compensatory growth response of 2 weeks duration during realimentation. The weight-adjusted growth rate of fish fed at 3% ration was not significantly different from that of the controls by the end of the experiment, when none of the treatment groups had caught up in body weight with the controls. Hyperphagia was observed for the first 2 weeks of realimenatation in fish previously fed at 3% ration, but persisted for the whole realimentation period in groups previously fed at 0.5% and 1.5% rations. None of the feed restricted groups showed improved digestibility, feed efficiency, or protein and energy retention efficiency.

Phosphorus budget of redeye mullet (Liza haematocheila T. & S.) under graded feeding levels

Experiment on phosphorus budget of redeye mullet (Liza haematocheila T. & S.) was con- ducted at water temperature 21℃ and salinity 33. The results showed that the growth phosphorus (phosphorus that allocated into growth, GP) increased from –30.84% to 15.83% by feeding on graded amount of diets (starvation, 1%, 2%, 3%, 4% body weight and satiation). The GP linearly increased with feeding levels (FL) as GP (mg) =–0.785 + 0.604 FL, and at satiation the relationship between GP and body weight (BW) was GP (mg) = 1.5991 BW 0.768 5. In the budget, IP (intake phosphorus) = GP + FP (faecal phosphorus) + EP (excretion phosphorus). FP showed an irregular tendency with different feeding levels, and EP decreased with increasing feeding levels but rebound at satiation. The P budget at satiation was 100IP = 15.84 GP + 64.62 FP + 19.55 EP.

Breeding and mass scale rearing of clownfish Amphiprion percula: feeding and rearing in brackishwater

Breeding and mass scale larval rearing of clownfish Amphiprion percula is very limited in brackishwater. We designed an indoor program of A. percula culture in brackishwater with a salinity of 24±1, during which the impacts of feed type, water temperature, and light intensity, on the efficiency of its reproduction, were revealed. The fish were accommodated along with sea anemones in fibre glass tanks to determine the influence of brooder diet on breeding efficiency. Higher reproductive efficiency [number of eggs laid （276±22.3 eggs）] was observed when fish were fed live Acetes sp. rather than clam （204±16.4 eggs）, trash fish （155±12 eggs） and formulated feed （110±10 eggs）. The spawning rate was increased during September and October （water temperature, 28.74±0.55℃） on average of 2.4 spawning per month; and low spawning rate was in January （water temperature, 24.55±0.45℃） on average of I spawning per month. Among three light intensities （100, 500, and 900 1x） set to evaluate larval survival rate, larvae showed the highest survival rate （65.5%） at 900 lx. The breeding method specifically in brackishwater developed in the present study is a new approach, will help the people from the regions of estuary and backwater to enhance their livelihood and it will lead to reduce the exploitation from the wild habitat.

Influence of dietary n-3 LC-PUFA on growth, nutritional composition and immune function in marine fish Sebastiscus marmoratus

Abstract A 60-day feeding experiment was conducted to investigate the influence of dietary omega-3 long-chain polyunsaturated fatty acids （n-3 LC-PUFA） on growth, nutritional composition and immune function of marine fish Sebastiscus marmoratus. Five diets containing 3.6, 10.2, 18.2, 26.5, or 37.0 g/kg n-3 LC-PUFA were prepared. The results reveal significant influences of dietary n-3 LC-PUFA on the final weight, weight gain, specific growth rate, feed conversion ratio, and condition factor. As dietary n-3 LC- PUFA increased, weight gain and specific growth rate increased and were significantly higher in groups fed 18.2, 26.5 and 37.0 g/kgthan in groups fed 3.6 and 10.2 g/kg （P〈0.05）; there was no significant difference between groups fed 18.2, 26.5, or 37.0 g/kg （P〉0.05）. With increasing dietary n-3 LC-PUFA, eicosapentaenoic acid and docosahexenoic acid content in muscle and liver increased significantly, immunoglobulin class M content gradually increased from 9.1 to 14.8 Ixg/L, and lysozyme activity content increased from 1 355 to 2 268 U/mL. Broken line model analysis according to weight gain indicated that a dietary n-3 LC-PUFA level of 18.2 g/kg is essential for normal growth at a fat level of 125 g/kg. Therefore, appropriate dietary n-3 LC-PUFA not only promote growth and improve the n-3 LC-PUFA content, but also enhance immune function in S. marmoratus.