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罗氏沼虾健康养殖是指依据罗氏沼虾的生长、繁殖、活动规律和和态要求，选择科学的养殖模式，采用系统的规范管理技术和营造良好的生态环境使其健康快速生长。其养殖技术主要应抓好以下几个方面。 1把好种苗培育关 健康无病的苗种是罗氏沼虾健康养殖的首要条件。罗氏沼虾苗种培育要注意以下几点。 1.1选用规格 7～ 10厘米健康的罗氏沼虾作亲本，冬季培育注意操作，不要碰伤虾体。 1.2育苗时间控制 26～ 28天，水温 28℃左右，淡化时间 2～ 3天，出苗前逐步降低水温至 22～ 25℃。 1.3增加苗种中间培育过程，将 0.7厘米左右的淡化苗进行专池… 相似文献
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罗氏沼虾是目前养殖的淡水虾中体型较大的品种。我国自1976年由日本引进后，目前已在全国各地广泛养殖，并形成一套较为完整的技术。现将近年国内外有关罗氏沼虾营养需要、饲料技术的研究情况总结如下。1营养需要1.1对蛋白质和氨基酸的需要罗氏沼虾对饲料中蛋白质适宜含量，王吉桥（1994）认为，是依发育阶段、环境条件和饲养方式等不同而变化在14％－38％之间，在天然饵料较丰富的土池塘中，饲料中蛋白质含量14％就可以；在天然饵料不足或密度过大时，饲料中蛋白质以22％－38％为宜。我国上海、江苏、浙江等地，饲料中蛋白质含量多为30％－… 相似文献
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随着罗氏沼虾养殖水平的提高,放苗密度不断加大,给养殖水体带来很重的压力,特别是高温季节,罗氏沼虾生长快,饵料投喂多,代谢量大,常常伴有雷阵雨天气,从而给养殖管理增加了难度,再加上成 相似文献
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在罗氏沼虾养殖过程中，普遍存在性早熟问题，很多体长在5～6cm的雌虾抱卵腔内已充满了卵。关于罗氏沼虾性早熟问题，一般认为是由以下两个原因造成的：(1)有效积温过高：在现行的池塘养殖过程中，由于水体较小，水位较低，水温的回升比河道、水库要快得多，而且罗氏沼虾的养殖一般都在高温季节，水温长时间过高，加速了罗氏沼虾的性腺发育，从而产生了性早熟现象；(2)营养过剩：营养过剩主要是指蛋白质过剩。在罗氏沼虾养殖过程中，所投喂的饵料几乎全部是高品质的商品饲料。投喂过多过精的商品饲料，一方面加速了罗氏沼虾的生长，另一方面… 相似文献
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近期，作者走访了珠江三角洲的养虾区，发现在罗氏沼虾养殖过程中存在不少误区，现对较为普遍的问题总结如下。 1水质管理的误区 1.1投苗早期水质不肥 清塘后，水质还没有培肥，就急于投苗。由于池塘水体偏瘦，可供幼虾摄食的生物饵料缺乏，影响幼虾的生长和成活率。 1.2换水不科学 养殖的中后期，池水过肥，虾农常常一次性大量换水 (特别是换水方便的地方 )，引起池塘的水温波动太大，影响虾的摄食和生长。 1.3 盲目加深水位 罗氏沼虾养殖的最适水深为 1.5～ 1.8 m，水体过浅，则水温波动较大，溶氧量减小，易影响虾的的生长；水体过深… 相似文献
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近些年来,国内外在对虾养殖技术中,试用一种“规则性停食投饲法”(也叫“规则性绝食”或“周期性停食”——Periodic starvation),即改变原来每日连续投饲的传统习惯,采用有规律的间断性安排,以日为单位,试行几日投饲、几日停投的办法,使养殖的对虾既满足营养需要和增加体重,又节省饲料和劳力,对于成本经济核算来讲颇有益处。一般来说,对于养殖小、中虾阶段是适宜的。由于停投饲料期间,对虾并不排除摄食剩余饲料和其它有机物质,并非真正的“绝食”或“停食”。所以更确切地讲,采用这种投饲方法,称为“间断性投饲”比提为 相似文献
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在罗氏沼虾育苗过程中，本人试验了以投喂鱼肉、蛋黄来培育幼体，以减少丰年虫的用量，达到降低饲料成本的目的，现将试验情况总结如下。 相似文献
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斜带石斑鱼仔鱼的摄食节律及日摄食量 总被引：18，自引：1，他引：18
鱼类的日摄食节律分为白天摄食、晚上摄食、晨昏摄食和无明显节律四种类型。为了解斜带石斑鱼早期发育阶段的日摄食量及昼夜摄食规律,对孵化15天的仔鱼(全长4.86±0.38mm)在不同昼夜节律下的日摄食量和摄食节律进行了研究。结果如下:实验包括自然昼夜组(对照组)、持续光照组和持续黑暗组,各组对轮虫的日摄食量分别为142个/尾、156个/尾和47个/尾;白天摄食量比例分别为总摄食量的91.3%,80.5%和71.7%。对照组在正午(14:00)出现一个明显的摄食高峰;持续光照组在下午(16:00～18:00)出现明显的摄食小高峰;黑暗组则未出现明显的摄食峰。持续光照组在夜间的群摄食率明显高于对照组;黑暗组在白天的群摄食率明显低于对照组。持续光照组摄食强度小幅度增加,日摄食量为对照组的109.9%;而黑暗组摄食强度则明显下降,日摄食量为对照组的33.1%。综上所述,斜带石斑仔鱼摄食节律明显,属于典型的白天摄食类型;仔鱼的摄食与光照有着紧密的关系。 相似文献
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鲻鱼仔,稚鱼轮虫日摄食量的研究 总被引：2，自引：0，他引：2
为了解鲻鱼不同发育阶段对轮虫摄食量和昼夜摄食规律，我们对第１０，２０日龄的仔鱼和第３０日龄的稚鱼进行轮虫日摄食量的试验。结果表明；第１０日龄的鲻仔鱼，平均全长３．６０９毫米，轮虫日摄食量为４１９－５１０个／尾，昼夜的摄食比例为７５．６％和２４．４％。第２０日龄的后期仔鱼，平均全长６．１５毫米，轮虫日摄食量为６８９－１１１２个／尾，昼夜摄食比例为７１．２％和２８．８％。 相似文献
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The effects of feeding level on growth, retention efficiency, faeces production and energy partitioning of redlip mullet were studied. A practical diet was used and fed at six levels from starvation, 1%, 2%, 3%, 4% of body weight (BW) to satiation for 3 weeks. The temperature was kept at 24±1°C. Reducing the feeding amount resulted in significantly lower weight gain, and retention efficiency was significantly affected by feeding levels and attained the maximum at maximum feeding intake. Feeding 2% BW was the minimum required for fish to maintain growth. Fish carcass composition under different feeding levels could be divided into three groups: (1) starvation and FL1; (2) FL2 and FL3 and (3) FL4 and satiation, with significant differences among the groups but no differences in the groups except that ash content remained at constant value. Body composition of fish of group 2 was close to initial fish. The thermal‐unit coefficient was 0.0381 at satiation, and significantly increased with increasing feeding levels. In order to accurately estimate basal metabolism (HeE), another trial on the relationship between HeE (kJ) and BW (g) was carried out. An exponential curve as HeE=0.1255BW0.8386 explained this relationship. Intake energy (IE) increased from 11.30 to 63.08 kJ per fish, matching with different feeding levels. Energy allocated to growth of IE decreased with reducing feeding amount. There was a linear relationship between metabolism energy and retention energy in percentage. 相似文献
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J. D. Celada J. M. Carral R. Rodríguez M. Sáez-Royuela A. Aguilera P. Melendre J. Martín 《Aquaculture International》2007,15(6):489-495
After artificial reproduction of tench, larvae must be maintained indoors, and studies on rearing conditions are needed, focussing
on the reduction of labour and costs. Three experiments on larvae (5th day post-hatch) were conducted for 25 days using Artemia nauplii as the sole food in order to determine basic feeding and density conditions during the first rearing period. Tench
were maintained in 25 l fibreglass tanks, supplied with an artesian water flow throughout of 0.2 l min−1. Water temperature was 22.5 ± 1°C, and the photoperiod was natural. Larvae fed on a restricted amount of nauplii reached
high survival rates, even with the minimum of 50 nauplii larva−1 day−1. This amount of food may be sufficient at least for the first 25 days of exogenous feeding if fast growth is not the priority,
and high densities can be maintained with good survival rates (over 90% up to 160 larvae l−1 and 77% with 320 larvae l−1). When food was supplied in excess once a day, high survival rates were achieved (91–97%), without differences among the
densities tested. Animals at a density of 100 l−1 reached the highest length (15.57 mm) and individual weight (46.8 mg). This growth is greater than those reported in studies
feeding several times a day. It could be deduced that, while live food remains available for tench, it is not necessary to
feed so frequently. Considering the relationship among the initial number of animals, final survival and growth and ration
supplied, the new data reported here are useful to establish suitable stocking densities under both culture and experimental
conditions. 相似文献
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投喂频率对鳡幼鱼摄食及生长的影响 总被引：1，自引：2，他引：1
研究了不同投喂频率(1次/d,2次/d,3次/d,4次/d)对鳡(Elopichthys bambusa)幼鱼摄食及生长的影响,试验持续30 d。结果显示:投喂频率从1次/d增加到4次/d,鳡幼鱼的摄食率逐步提高,1次/d组的摄食率显著低于其他组(P<0.05);体重增加率、特定生长率有不同程度增高,在3次/d时达到最高;饲料转化率逐次下降,1次/d组显著高于其他组(P<0.05)。随着投喂频率增加,实验各组组内个体体重差异显著下降,鳡的规格趋于整齐,组间每日摄食表现也各不相同。试验表明:鳡的生长受投喂频率的影响,每天投喂3次是鳡养殖的最佳投喂频率。 相似文献
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对河蟹育苗期的苗种病因,症状及预防措施进行了综合报道,提出了对弧菌病,丝状菌病,真菌病,固着类纤毛虫病等的诊治方法,预防措施是切断水源和饵料等带入病原体的途径,控制饵料投量,提高投饵技术,从蚤状幼体到大眼幼体各期饵料的适宜投饵喂量,以其日最大摄食量的７０％为宜,并提出亲蟹最好在１１月交配,采取抱卵蟹越冬方式。 相似文献
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Two cottonseed cake feeding strategies were tested in pond culture of hand-sexed male Nile tilapia, Oreochromis niloticus (L.). (W0 > 80 g), with the objective of making better use of the algal blooms which develop when cottonseed cake is applied to a pond. In the conventional ‘progressive feeding strategy’, the daily amount of cottonseed cake was adjusted monthly for the total tilapia bioweight estimated from sampling, assuming that cottonseed cake primarily acted as a tilapia feed. In the ‘linear feeding strategy’, ponds received a fixed daily amount of cottonseed cake throughout the trial, based on the hypothesis that tilapia would cover their nutritional requirements mostly by grazing the algae. Each feeding strategy was tested at two feeding levels. Mean daily feeding rate R in the progressive feeding strategy averaged 48.6 (low feeding level) and 102.5 kg ha?1 day?1 (high feeding level), and 49.8 and 82.9 kg ha?1 day?1 in the linear feeding strategy. Significantly better growth rates and feed conversion rates were obtained in the progressive feeding strategy. Average extrapolated net pond production was highest at Rpr=6% body weight day?1 (10.61 ha?1, year?1). It was concluded that cottonseed cake contributed to tilapia growth mainly directly as a tilapia feed rather than indirectly as a pond fertilizer via algal production. Finally, the appropriateness of the metabolic feeding rate Rmb(BW0.8 day?1) was discussed, compared with the progressive feeding rate Rpr (%BW day?1). (BW denotes body weight). A practical, two-step linear feeding method was proposed for cottonseed cake as a ‘rule of thumb’ that is workable in the field. 相似文献
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Studies on the effects of feeding frequency on the growth of young estuary groupers (Epinephelus tauvina) with initial size ranging from 16.2 to 16.9 cm in total length were conducted in floating net-cages. Seven feeding frequencies in the order of one feeding in 5 days, 4 days, 3 days, 2 days, 1 day, two feedings daily and three feedings daily were studied. Optimal growth and good food conversion ratio as well as higher survival rate were obtained in groups fed to satiation with one feeding in 2 days. Weight gains were substantially reduced in groups fed to satiation with one feeding in 5, 4 or 3 days and were not enhanced when the feeding frequencies were increased to two or three feedings daily. The fact that food conversion ratios were similar in fish fed to satiation with one feeding in 5, 4, 3 and 2 days suggests food intake to be important as a growth limiting factor. Total food intake per feeding was appreciably higher in fish fed once in 2 days. The intake of food was found to be closely related to the amount of food remaining in the stomach, intake being maximal when the stomach was empty. The food deprivation time in estuary groupers was found to be about 36 hours at which over 95% of the food was digested and less than 0.5% body weight of food remained in the stomach. Hence, feeding the fish at 48-hour intervals, i.e. once in 2 days, greatly enhanced maximum intake and efficient utilization of the food. 相似文献
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近年来,中国水产养殖业高速发展,水产动物投喂策略逐渐受到重视。列举与分析了一系列国内外水产动物饲料投喂策略的相关研究内容,并进行了较为系统的整理与总结。投喂策略是现代集约化水产养殖生产过程中重要的生产管理要素,其技术内涵可简要概括为投喂频率、投喂率和投喂作业方式等,不同的水产动物种类以及不同的生长阶段所需的适宜养殖投喂策略亦不相同。叙述了投喂策略对养殖动物生长性能、消化代谢能力、应激免疫水平、行为响应以及存活率等影响,为水产动物饲料投喂策略的选择和相关技术理论的研究提供参考。 相似文献