草鱼苗种不同投放方式对防控对虾病害的效果比较

选择16个南美白对虾养殖池塘,分5组,前4组池塘为试验组,每组三个池塘,第5组为空白组,各试验组投放不同规格的草鱼苗种,每个试验组各池投放不同密度的草鱼苗种。结果显示:在草鱼苗种密度450~50尾/hm2的情况下,草鱼投放为530g/尾时,养殖利润53 085元/hm2,产出投入比1.94;比规格为760g/尾的池塘利润高13 425元/hm2,产出投入比高0.2;比规格为253g/尾的池塘利润高22 170元/hm2,产出投入比高0.33;比规格为107g/尾的池塘利润高45 540元/hm2,产出投入比高0.78;比空白组的池塘利润高38 940元/hm2,产出投入比高0.66。     

池塘生态养殖草鱼高产试验

采用专用草鱼颗粒饵料,利用生态养殖技术,投放两种主体鱼,充分利用水体空间,通过使用生物制剂、增氧机、微孔增氧等综合措施调控水质,经过158 d的试验,平均单产达到41 700 kg/hm2,其中:草鱼单产20 700 kg/hm2 ;鲤鱼单产18 750 kg/hm2;白鲢单产2 250 kg/hm2;平均饵料系数为1.5,获得纯利润122 250元/hm2.     

U型隔离网在鱼虾混养中的应用分析

选择20个养殖南美白对虾池塘分为四组,每组5个池塘,分别为设U型隔离网混养黄金鲫、鲤鱼,没有隔离网混养黄金鲫、鲤鱼。结果显示:设置U型隔离网混养对虾、黄金鲫池塘,对虾产量为3 672kg/hm2,池塘产值284 019元/hm2,利润105 588元/hm2,产出投入比1.59;比无隔离网组对虾产量高2 197.5kg/hm2,利润高61 510.5元/hm2,产出投入比高0.32。设置U型隔离网混养对虾、鲤鱼池塘,对虾产量为3 519kg/hm2,池塘产值236 440.5元/hm2,利润105 336元/hm2,产出投入比1.80;比无隔离网组对虾产量高2 214kg/hm2,池塘利润高80 227.5元/hm2,产出投入比高0.58。     

黄颡鱼与大宗淡水鱼类池塘混养高产技术

本试验比较分析了2种黄颡鱼高产无公害养殖模式下所取得的产量与经济效益。结果显示,每hm2投放4~5cm黄颡鱼种苗82 500尾,采用主养黄颡鱼、套养主要大宗淡水鱼类(草鱼、鳙鱼、鲢鱼和鲫鱼)的混养池塘生产的总商品鱼每hm2的产量比单养池高出26.1%,其中每hm2比单养池多产出大宗淡水鱼3 105kg,而两种模式中每hm2黄颡鱼产量相当,均在7 500kg/hm2以上;在养殖效益方面,单养池的平均利润为71 550元/hm2,混养池的平均利润为91 770元/hm2,混养池比单养池平均高出20 220元/hm2。因此,主养黄颡鱼、套养主要大宗淡水鱼类(草鱼、鳙鱼、鲢鱼和鲫鱼)的混养模式值得广泛推广。     

湖泊围网蟹鳜混养试验

围网蟹鳜混养面积40 hm2,投放规格200只/kg的人繁长江蟹,放养密度1 500只/hm2,总计6万只;投放5~8cm翘嘴鳜鱼种,放养密度50尾/hm2,总计2 000尾;投放螺蛳2.5万kg,平均放养625 kg/hm2。共捕成蟹3 723 kg、鳜鱼809 kg、青虾1 000 kg、其它经济鱼类1 850 kg,总计重量7 382 kg;渔业总收入223 250元;生产总成本141 300元,总利润81 950元,单位面积利润2 049元/hm2,投入产出比为1∶1.58。     

低温期配合饲料池塘主养草鱼的生产试验

用配合饲料在低温期主养大规格草鱼 ,经过 1 1 0天的试验 ,池塘净产 31 2kg ,饲料系数为 2 1 3 ,饲料成本为 3 83元 /kg ,利润 1 550 5元 /亩 ;结果表明 ,在低温期用配合饲料投喂草鱼可以取得较好的生产效果和经济效益     

山区稻螺共生模式与技术探讨

2019—2020年,利用当地边远、高海拔山区的抛荒农田开展稻螺共生模式试验.投放中华圆田螺养殖种螺750～900 kg/hm2或野生种螺1500～1800 kg/hm2,用基肥+饲料的方式饲养,获得产成螺2280～2580 kg/hm2、稻谷7050～7140 kg/hm2,利润19.41万～20.04万元/hm2的...     

重盐碱地池塘南美白对虾和草鱼种混养模式

为了探讨重盐碱地池塘的渔业养殖模式,进行了南美白对虾和草鱼种混养试验,获得单产鱼虾9 037.5 kg/hm2的结果,其中南美白对虾、草鱼和鲢鱼种分别为4 125 kg、3 600 kg和1 312.5 kg;虾的成活率达59.21%;纯利润达63 900元/hm2,投入产出比1∶1.82.由此可见,南美白对虾和草鱼种...     

投放不同规格鲤鱼苗种防控南美白对虾病害试验

选择12口南美白对虾养殖池塘,分5组,前4组池塘为试验组,每组两个池塘,第5组为空白组,各试验组投放不同规格的鲤鱼苗种。结果显示:在鲤鱼苗种规格80~81g/尾时,池塘利润57 196.2元/hm2,产出投入比为1.49;比规格为52~54g/尾的池塘利润高12 391.5元/hm2,产出投入比高0.09;比规格为32~35g/尾的池塘利润高38 868元/hm2,产出投入比高0.32;比规格为10~11g/尾的池塘利润高48 091.5元/hm2,产出投入比高0.41;比空白组的池塘利润高53 392.5元/hm2,产出投入比高0.41。     

网围套养青虾增效技术初探

在焦岗湖设置的总面积约1 333.3 hm2、主养草食性鱼类的网围中,共放养青虾苗1 600万尾,规格1.5~2.0 cm/尾,平均1.2万尾/hm2。2004年围网套养青虾总产量达4万kg,平均增产30 kg/hm2,增加利润450元/hm2,总利润达60万元。     

池塘主养草鱼种高产试验

在３００５ｍ＾２的池塘里,高密度培养大规格草鱼种,且塔养鲢,鳙,鲤种。采取的技术措施是：草鱼种入池先喂芜萍,２０天后改喂浮萍并驯喂粗蛋白含量较高的小颗粒配饵。草鱼种长到１０ｃｍ后,改喂粗蛋白含量较低的配饵;定期注入新水,增氧,泼洒药物,投喂药饵,高温季节,使池水保持长流水。结果：共产草鱼种５０３２ｋｇ,平均规格８０．１ｇ;鲢鳙鱼种２６６０．６ｋｇ,鲤种５３６．３ｋｇ,纯利４８９２８．６元,投入产出     

Effects of short-term feed restriction on production, processing and body shape traits in market-weight channel catfish, Ictalurus punctatus (Rafinesque)

The effects of feed restriction on channel catfish production, processing yield (carcass and fillet), visceral composition and body shape traits were determined. Channel catfish (initial mean weight =0.77 kg) were stocked into six 0.04‐ha ponds at ～5775 kg ha^?1. Two ponds were assigned to each of three feeding regimes for a 4‐week trial: fed daily to satiation, fed once weekly to satiation and not fed. Fish were measured for weight, processing yield and visceral components after 2 and 4 weeks, and for body shape after 4 weeks. Growth was fastest in fish fed daily, intermediate in fish fed weekly and slowest in unfed fish. There were no differences in survival among feeding regimes. After covariate adjustment for weight differences, fish fed daily had shorter, thicker bodies, and smaller heads than fish from feed‐restricted treatments. Carcass yield was higher for females than males and higher at week 2 than at week 4, but was not affected by feeding regime. Fillet yield was higher for females than males, higher at week 2 than at week 4, and higher for fish fed daily than for feed‐restricted fish (fed once weekly and not fed). Viscerosomatic index (VSI), visceral fat‐somatic index (VFI) and hepatosomatic index were higher at week 2 than at week 4, and highest for fish fed daily, intermediate for fish fed weekly and lowest for unfed fish. Hepatosomatic index and VSI were higher for females than males, but VFI was not different between genders. The female gonadosomatic index increased over time but was not affected by feeding regime. Short‐term feed restriction had negative impacts on growth and fillet yield. Processors could benefit by marketing severely feed‐restricted channel catfish as carcasses rather than fillets since fillet yield declined but carcass yield was unchanged by feed restriction.     

猪草鱼综合养殖试验

１９９３￣１９９４年两年试验证明：猪、草、鱼养殖模式具有节省饲料,肥料,低耗高效等优点。试验表明,用此模式,每百公斤猪粪可产草１２８．８ｋｇ,喂草鱼可产草鱼５ｋｇ,带动滤食鱼３．５ｋｇ,比用猪粪直接养鱼增产２４０％。     

Performance of the amazonian tambaqui, Colossoma macropomum, in pond polyculture

Tambaqui (48%) was reared in polyculture with grass carp (27%) and curimbatá (25%) from 75 g mean weight for a period of 164 days. Ponds of 1200 m² were stocked at a total density of 12720 ha⁻¹. Fish were fed with an experimental diet made from soybean and maize at a daily rate calculated as 3% of the tambaqui biomass. Grass carp received chopped angola grass at a daily rate of 15% of live weight. Ponds were weekly manured with 120 kg of mixed cattle and goat manure. Tambaqui reached a final weight of 492 g. Survival rate was 83%. The experimental polyculture had a mean net yield of 7·5 t ha⁻¹ year⁻¹, with apparent conversion rates of 1·13, 5·5 and 7·7 kg kg⁻¹ of diet, grass and manure, respectively. All three species had a high growth rate (from 1·2 to 2·1 % day⁻¹). Tambaqui's growth was affected by the fall in water temperature in the second part of the experiment. Cost/benefit calculations proved the high profitability of the tested semi-intensive polyculture system.     

草鱼“四联”疫苗在草鱼池塘养殖生产中的应用

利用4口池塘,每公顷放养75～100g/尾的草鱼种31 612尾～36 486尾。其中2口池草鱼种放养时接种草鱼"四联"疫苗,另2口池设为对照。经6个月的饲养试验,结果表明:接种疫苗的试验池草鱼与未接种疫苗的对照池相比,发病率比对照池低10.7%,成活率与平均产量比对照池分别提高12.8%和20.8%。试验初步证明,接种草鱼四联疫苗能有效地增强草鱼对"四病"的抵御能力,提高草鱼养殖成活率,是有效防治草鱼"四病"的有效措施之一。     

Intensive polyculture of common carp (Cyprinus carpio L.) and herbivorous fish [silver carp, Hypophthalmichthys molitrix (Val.), and grass carp, Ctenopharyngodon idella (Val.)]

Intensive polyculture of common carp and herbivorous fish (silver carp and grass carp) at high stocking densities and with intensive feeding with fodder and mineral and organic fertilization was carried out without mechanized aeration and automated feeding.Two stocking patterns were tested. The first, in Pond 1 (with an area of 2.5 ha), had the following stocking rates: one-year carp (C₁), 8000 fish/ha; one-year silver carp (S₁), 1500 fish/ha; and one-year grass carp (G₁), 200 fish/ha. The yield was 6292 kg/ha of standard consumer fish (C₁₊ 743 g, S₁₊ 944 g, and G₁₊ 1000 g) at a relatively low food conversion ratio (2.24) and high survival of all fish. Within the total yield, the two-year carp contributed 76%, the silver carp 21%, and the grass carp 3%. The second stocking pattern, in Pond 2 (0.25 ha), had the following rates: C₁, 8500 fish/ha; S₁, 2000 fish/ha; and G₁, 200 fish/ha, and produced a still higher total yield (6629 kg/ha) at a relatively low food conversion ratio (2.10). The two-year carp in Pond 2 contributed 88% of the total yield, and the herbivorous fish only 12% even though they accounted for 20% of the stock.Our results (Pond 2) are compared with other record yield experiments under similar conditions but including tilapia. At a total stocking rate of 10 700 fish/ha and without participation of tilapia, over a period of 186 days (as against 126 days in the other experiment), our experiments gave a total yield which was 347 kg/ha higher at a food coefficient 15% lower. The growth period was 60 days longer in our experiments but it included April and October when water temperature is much below the optimum and only 4% of the total amount of fodder was assimilated.     

Effects of sodium butyrate stimulation on immune‐related mRNA‐miRNA network in intestine of grass carp

Sodium butyrate is one of the most popular feed additives in animal husbandry. In recent years, sodium butyrate has been increasingly used as supplement in aquaculture. The present study is to investigate the intestinal mRNA and microRNA response to diet with sodium butyrate in grass carp (Ctenopharyngodon idella), an important aquaculture species in China. mRNA and microRNA profiles of intestine of grass carp fed with diet contained 0, 1.0, 2.5, 5.0, 7.5 and 10.0 g/kg sodium butyrate were obtained by RNA‐seq using Illumina Hiseq 2,500 platform. The feeding trial was performed using 18 individuals of 1‐year‐old grass carp (n = 3 for each group) and lasted for 40 days in tanks in laboratory. A total of 349,860,852 sequence reads were generated from six intestinal libraries. Functional analysis of differentially expressed genes showed that genes participated in immune pathways tend to be activated by sodium butyrate supplementation. A total of 700 microRNAs were obtained, including 275 conserved microRNAs and 425 novel microRNAs which are potentially involved in regulating 14,300 genes. Spearman's correlation analysis identified 18 pairs of microRNA‐mRNA associated with immune pathways (p < .01 and R<?0.5). The potential genes targeted by microRNAs include CXCL12, AKT1S1, Cab39 and MHCII which are important genes associated with intestinal immune pathways. To our knowledge, this is the first integrated profiling of both mRNA and microRNA in intestine with supplementation of sodium butyrate in grass carp. The present results suggest that sodium butyrate affects intestinal immune system by regulating microRNA‐mRNA interaction in fish.     

淡水池塘主养鲈试验

报道了首次利用淡水鱼塘,主养鲈兼养鲢,鲤,草鱼等试验,每亩放苗５１５尾,鲈占放养总重的７１．７％;主喂冷冻青鳞鱼,约占７７．７％,辅喂人工配饵;前期只充渗漏水,中后期透明度小于３０ｃｍ时,大量换水。结果：共产商品鱼８８０２ｋｇ,其中鲈３７４０ｋｇ,折合亩产１２４．７ｋｇ,成活率８９％。总产值１２８０４６．８地,纯利７６９６９．８地,平均亩纯利２５６５元,投入产出比１：２．５。     

网箱养鱼高产试验及其技术因子的探讨

本文报导了网箱养殖莫桑比克罗非鱼(Tilapia mossambica)和草鱼(Ctenopharyngodon idellus)高产试验。其中网养莫桑比克罗非鱼获得每平方米净产97公斤，饲料系数为2．16：网养草鱼每平方米净产14．5公斤，饲料系数为2．49。此外，本文论述了网箱结构，饲养环境，养殖方式，饲料配方，投喂技术等技术因子对提高单位产量的关系。作者认为合理选择网箱，敷设饲料台，控制溶氧不低于3mg／L、水温不低于15℃，饲养密度为5—10公斤／米^2，单养，采用蛋白质组分不低于35％的颗粒饲料以及提供10％-2％的日给食率，是网养给食式鱼类获得高产并降低饲料系数的关键。     

饲料中添加谷胱甘肽对草鱼生长、生理指标和抗病力的影响

选用初始体质量约8.50 g的草鱼(Ctenopharyngodon idella),在56 d的饲养期中分别投喂添加5种不同剂量谷胱甘肽(GSH)(添加量分别为0 mg/kg、100 mg/kg、200 mg/kg、300 mg/kg和400 mg/kg)的试验饲料,观察GSH对草鱼生长、生理指标和抗病力的影响。结果表明,饲料中添加GSH能够提高草鱼特定生长率、存活率和饲料效率。其中,300 mg/kg GSH组草鱼的特定生长率和400 mg/kg GSH组草鱼的存活率显著高于对照组;添加GSH各组草鱼的饲料效率均显著高于对照组,当添加量为200 mg/kg时草鱼饲料效率达到最高。与对照组相比,饲料中添加GSH的各组草鱼肝胰指数明显升高,其中200 mg/kg组达到显著水平。饲料中添加GSH能够提高血清IGF-1水平,其中300 mg/kg和400 mg/kg组显著高于对照组。与对照组相比,各实验组草鱼血液白细胞数目有不同程度升高,其中300 mg/kg和400 mg/kg组均达到显著水平。饲料中添加GSH可以提高草鱼对嗜水气单胞菌的抵抗能力,其中200 mg/kg GSH组草鱼攻毒后存活率达到最高。以特定生长率为判定指标,GSH在草鱼饲料中的适宜添加量为350 mg/kg。