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采用降温、防感染处理和加强营养等方法对野生暗纹东方亲鱼进行产后护理,使野生亲鱼产后的成活率达到75%,人工养殖亲鱼产后成活率达到100%。暗纹东方亲鱼产后死亡的一般原因多为鱼体受伤、催产不当、忽视产后亲鱼护理所致。对产后亲鱼采取适当的护理措施,可提高亲鱼利用率。 相似文献
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哺乳仔猪死亡是养猪生产中的重要损失,正常情况下断奶前死亡率在10%以下,良好的猪场管理可使断奶前死亡率降至1%～2%以下.如何提高哺乳仔猪的成活率,争取哺乳阶段的仔猪全活全壮是每个养猪业主共同关心的问题,哺乳期仔猪成活率的提高可为保育阶段提供更多数量的生长育成猪,进而生产出较多的育肥猪.因此哺乳仔猪饲养的好坏,对养猪业的经济效益有着十分重要的影响. 相似文献
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《畜禽业》2014,(5)
猪增生性肠炎,又称为猪增生性肠病,是由胞内劳森菌感染引起的一种以保育猪或生长育肥猪出血性、顽固性或间歇性下痢,以回肠和结肠段黏膜呈腺瘤样增生为主要特征的肠道综合症。620周龄的生长育成猪较易感,虽然被感染猪死亡率仅有5%20周龄的生长育成猪较易感,虽然被感染猪死亡率仅有5%10%,但患猪饲料利用率比正常猪下降17%10%,但患猪饲料利用率比正常猪下降17%40%,被迫淘汰率升高,养殖损失较大。主要有急性型、慢性型、亚临床型,通过流行病学、病原检查、血清检查、临床症状可以将其与一般下痢区分开。提高管理措施,严格引种,加强免疫,消毒,药物预防治疗等可以有效控制此病。早诊断早治疗至关重要。 相似文献
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<正>在目前养猪生产中,仔猪死亡率高,育成率低对养猪业危害很大,特别是在广大农村,有的养猪场仔猪的成活率甚至低于50%以下,严重影响猪场的经济效益,有的猪场甚至因此而破产倒闭。所以,科学养育仔猪提高其成活率是目前应该重视的问题,笔者认为应采取综合措施才能达到预期效果。 相似文献
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通过对1000尾史氏鲟驯化全人工饲料开口试验,观察其摄食、生长与形态发育状况。生长曲线表明:不论是体长还是体重,50日龄前增长缓慢,50￣100日龄则以较快速度增长。经100天饲养,平均体长达28.3cm,平均体重达69.7g,并获得了的86.7%开口成活率和73.4%的成活率,从而达到提高开食率和成活率的目的。 相似文献
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<正>在生猪饲养过程中,每年因各种疾病而死亡的生猪约占养猪总数的10%,死亡猪中约80%以上为未成年猪。仔猪刚出生,身体各个器官发育不健全,尤其免疫系统识别和抵御病原微生物的功能很弱,在母源抗体降低到一定水平时,正是仔猪死亡最高危险期。引起仔猪死亡的原因十分复杂,除了营养因素、环境变化外,感染疾病是导致仔猪死亡的主要原因。因此,如何采取有效措施、预防和控制仔猪死亡,提高仔猪成活率,已成为畜牧兽医工作者主要解决的课题。 相似文献
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J A Beardmore 《Aquaculture Research》2005,36(10):1035-1036
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根据2012—2013年龙江入海口水域的水质调查数据,对该水域氮、磷营养盐分布状况、结构特征及富营养评价进行了研究。结果表明,2012年和2013年DIN含量范围分别为0.808~5.285、0.610~5.383 mg/L,PO4-P含量范围分别为0.028~0.324、0.096~0.643mg/L,呈不同程度的超标状态并有上升趋势。受海水稀释作用,营养盐浓度由河口向外逐渐降低;受枯水期地表径流减少导致营养盐浓缩的影响,营养盐含量呈现冬、春季高,夏、秋季低的季节性变化;NH4-N在DIN中的占比在51.15%~63.25%和43.88%~69.39%之间,DIN的污染程度主要受NH4-N控制。营养盐结构上N/P比值范围为10.83~13.12,接近适合浮游植物生长繁殖的Redfield比值(16∶1),潜在性富营养化程度评价分析表明该水域处于富营养化状态,N、P营养盐绝对浓度高,可能有赤潮等严重海洋生态问题发生的潜在风险。 相似文献
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《Journal Of Applied Aquaculture》2013,25(1):95-101
Paddlefish, "Polydon spathula," overwintered in monoculture and in polyculture with fingerling channel catfish, "Ictalurus punctatus," or with rainbow trout, "Oncorhynchus mykiss," were examined for growth and compatibility in nine 0.04-ha ponds. Paddlefish in polyculture had significantly greater (P ≤ 0.05) individual weight gains than those in monoculture. Feed in polyculture treatments probably served as a fertilizer, promoting zooplankton production for paddlefish consumption and growth. Paddlefish in polyculture with fingerling channel catfish had significantly greater (P < 0.05) individual weight gains than paddlefish polycultured with rainbow trout, although there was less feed input with channel catfish than with rainbow trout. Bloody and frayed fins on paddlefish stocked with rainbow trout suggested fin nipping by rainbow trout which may have interfered with paddlefish feeding and growth. Paddlefish overwintered in polyculture with fingerling channel catfish demonstrated increased weight gains and good species compatibility. 相似文献
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黄海北部春季和夏季浮游动物生态特性与时空分布 总被引：2，自引：0，他引：2
根据2015年3月(春季)和6月(夏季)对黄海北部辽宁近岸海域的浮游动物调查结果,分析了两个季节的浮游动物种类、生物量、丰度等群落结构特征。此次调查共鉴定出浮游动物47种,其中春季42种,夏季34种。浮游动物以浮游幼虫和小型桡足类为主。桡足类幼虫、棘皮动物幼体、桡足类幼体、洪氏纺锤水蚤、短角长腹剑水蚤、小拟哲水蚤、拟长腹剑水蚤和腹针胸刺水蚤为春季优势种;夏季浮游动物优势种依次为桡足类幼体、洪氏纺锤水蚤,拟长腹剑水蚤、短角长腹剑水蚤、桡足类幼虫、小拟哲水蚤和腹针胸刺水蚤。春季浮游动物平均生物量为512.09mg/m~3,平均丰度为15 522.18个/m~3;夏季浮游动物平均生物量为218.84mg/m~3,平均丰度为7582.39个/m~3;浮游动物生物量和丰度均为春季较高。黄海北部辽宁沿岸海域的浮游动物生物量、丰度较高。水温是影响浮游动物群落结构的重要环境因子。 相似文献
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随着中国改革开放的深入,海洋渔业捕捞的发展正走上正规化,从而使得沿海地区水上安全通信在保障海上生产安全、促进海洋渔业经济稳定发展中的作用越来越重要,特别是近两年来,由政府资助为渔民统一购置安装单边带电台,使渔业无线电通信真正成为"信息交流的桥梁"、"安全生产的耳目"、"科技服务的窗口",是海洋渔业不可替代的通信方式.但随之而来的的问题和矛盾也逐渐显露并严重制约着渔业无线电通信管理事业的健康发展.作为渔业通信管理工作者,如何加强渔业通信网络建设,不断提高为渔民生产服务的质量,确保渔民生命财产安全,成为当前义不容辞的责任.下面结合当前渔业通信管理工作的现状,谈一谈渔业通信管理工作中存在的问题及解决措施. 相似文献
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D Barutzki 《Tier?rztliche Praxis》1990,18(3):245-250
A review is presented on the species spectrum, biology and epidemiology of endo- and ectoparasites of sheep and goats in Germany. Current therapeutic, prophylactic and metaphylactic measures are given and discussed. 相似文献
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M. W. APRAHAMIAN P. HICKLEY B. A. SHIELDS G. W. MAWLE 《Fisheries Management and Ecology》2010,17(2):93-105
Abstract Inland fisheries in England and Wales have high economic and social values. Managing participation to maximise fishery performance is key to maintaining this status. The capital value of fishing rights for migratory salmonid fisheries is €165 million. Coarse fisheries contribute €1030 million to the economy. The central tenet to increasing participation in recreational salmonid fisheries is that an increase in stock size will result in more anglers accessing the fishery. This was examined for salmon on the rivers Usk and Lune where exploitation restrictions increased the number of salmon available to anglers. On the River Lune, the number of salmon available post‐intervention increased by 66%. There was no significant increase in catch while the number of anglers decreased by 16.3%. On the River Usk, the closure of the net fishery potentially resulted in an additional ～1200 salmon being available. Following closure, there was no significant change in rod catch or in the number of anglers. Increased participation is dependent less upon stock manipulation for coarse fisheries and more upon facilitating the activity. In recent years, urban fishery development programmes have provided improved access to local fishing opportunity. Also, new anglers have been targeted through campaigns such as Get Hooked on Fishing and the Scout Angler Badge. 相似文献
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Miriam Fernández Montserrat Rodríguez-Ruiz Stefan Gelcich Luciano Hiriart-Bertrand Juan Carlos Castilla 《水产资源保护:海洋与淡水生态系统》2021,31(7):1760-1771
- Despite significant progress made in Chile, and globally, in establishing marine protected areas (MPAs), the actual contribution to marine biodiversity conservation needs to be revised, to focus on representativeness and the diversity of tools alongside effective implementation, management, and enforcement.
- This study makes progress in this direction, describing the most recent advances in marine conservation in Chile and analysing the contribution of the different conservation instruments as well as the distribution of designated areas across ecoregions. Furthermore, it examines the potential contribution of alternative area-based instruments to balance ocean protection. The advances observed in Chile were compared among four South American countries and five leading countries in ocean conservation, analysing protection levels in coastal areas, continental exclusive economic zones, and overseas territories.
- Data on MPA boundaries and attributes were sourced from the World Database on Protected Areas and complemented the official information on MPAs and territorial user rights for fisheries and for indigenous people in South America.
- The current level of protection in Chile is among the highest in the world in area coverage and in the proportion of the continental exclusive economic zone assigned to fully protected areas. However, it exhibits the strongest imbalances in the distribution of designated MPAs between coastal and oceanic waters, in comparison with the leading countries and also within South America (Perú, Chile, Argentina, and Uruguay), and among ecoregions.
- The patterns observed suggest that Chile has advanced, but concentrated, conservation efforts in low-threat, remote ecoregions. There is an urgent need to progress towards high-threat ecoregions, which implies balancing the needs of nature and people. The distribution of ancillary conservation instruments can help double the level of protection in threatened coastal areas, filling gaps in marine conservation and creating an opportunity to progress and diversify conservation strategies.