生产对虾科饲应注意的要点

近年来，随着国家对水产养殖业的重视，以及受国外水产养殖技术的影响，我国的水产养殖业发展迅猛。尤其是斑节对虾(草虾)、日本对虾(花虾)、墨吉对虾(白虾)的养殖，越来越引起养殖业主的重视。养殖业主对虾料的要求也越来越高。由于对虾的消化系统短而且细，消化吸收能力差，所以对虾饲料加工要求远比普通畜禽饲料的加工要求高。下面，着重探讨一下生产对虾饲料应注意的几个要点。     

湛江对虾养殖业现状调查

湛江拥有大面积适合鱼、虾养殖的水域，水产养殖业在华南地区乃至全国占有举足轻重的地位。当前，湛江水产养殖业依然方兴未艾，水产饲料业大有可为。为了深入观察现状，思考产业未来趋势，本刊以对虾养殖业为切入点，着重调查了种苗繁育、养殖模式、疾病防控、加工出口等产业环节的运营现状。调研中，广东恒兴集团、广东粤海饲料集团提供了大力的协助……     

湛江对虾养殖业现状调查

湛江拥有大面积适合鱼、虾养殖的水域,水产养殖业在华南地区乃至全国占有举足轻重的地位。当前,湛江水产养殖业依然方兴未艾,水产饲料业大有可为．为了深入观察现状,思考产业未来趋势,本刊以对虾养殖业为切入点,着重调查了种苗繁育、养殖模式、疾病防控、加工出口等产业环节的运营现状。调研中,广东恒兴集团、广东粤海饲料集团提供了大力的协助……     

对虾健康养殖技术

对虾养殖业是我国水产养殖的支柱性产业,为沿海农村经济的发展做出了巨大贡献。但随着其快速发展,由于盲目追求高产,养殖技术混乱,药物大量使用和滥用,养殖废水随意排放,而导致对虾的可持续发展出现一系列的问题。     

我国对虾养殖生产发展现状

据全国水产技术推广总报道，我国的海水虾类养殖业从起步到现在已走过了20个年头。1978年开始组织中国对虾的人工育苗技术攻关，于1982年获得突破性进展。1983年后，养殖规模不断扩大，养殖产量急速上升，到1992年仅10年时间，     

生产对虾饲料应注意的要点

近年来，随着国家对水产养殖业的重视，以及受国外水产养殖技术的影响，我国的水产养殖业发展迅猛。尤其是斑节对虾 (草虾 )、日本对虾 (花虾 )、墨吉对虾 (白虾 )的养殖，越来越引起养殖业主的重视。养殖业主对对虾料的要求也越来越高。由于对虾的消化系统短而且细，消化吸收能力差，所以对虾饲料的加工要求远比普通畜禽饲料的加工要求高。下面，着重探讨一下生产对虾饲料应注意的几个要点。 1水中稳定性 (耐水性 )　　对虾饲料要求在水中的稳定性时间要长，一般要求达到 2h以上。如果生产出来的颗粒饲料耐水性差，则不适应虾类的采食特点…     

得内贸者得天下——国内对虾产业发展思考

曾几何时,对虾作为水产品摆上餐桌,实属国人高档消费,北方人要吃顿虾那才叫"金贵"。上世纪80年代初开始,中国养虾业逐步兴起,对虾工厂化人工繁育技术取得阶段突破,苗种实现规模化生产,为对虾养殖业的快速发展创造了条件,使我国对虾养殖进入大发展时期。1992年,全国对虾养殖面积达到200万亩,年对虾养殖产量约20万吨,一跃成为世界对虾养殖大国。特别是1998年南美白对虾和全人工繁育技术的引进,实现了南美白对虾苗种的规模化生产,有力地推动了南方地区南美白对虾养殖业的发展。2006年全国对虾养殖总量突破100万吨,人均年消费量仅535克,刚刚过一斤。2009年全球对虾养殖总量为338万吨,其中海水养殖量为287万吨,淡水养殖量约51万吨。中国仍为全球主要对虾生产国,对虾养殖总量为130.3万吨,占全球总量的38.6%,其中海水养殖约占六成,淡水养殖约为四成。目前,从养殖品种上看,南美白对虾是我国对虾养殖业骨干品种,占国内对虾总量的73%;从养殖区域上看,淡水养殖分布相对较广,其中珠江三角洲占42%,长江三角洲为38%;而海水养殖则以广东、广西、海南、福建等南方四省为主,占全国海水养殖总量的近80%,其中仅广东养殖对虾产量近50万吨,占全国对虾养殖总量的38%,接近四成!(其他省份,广西为21%,海南为16%,福建4%)。广东是名副其实的对虾养殖大省,而湛江又是我省对虾海水养殖的重点区域。继2009年多次湛江调研后,2010年5月初,笔者再赴湛江,走访饲料企业、水产药品企业、养殖户,并在湛江南三岛就对虾养殖模式和技术需求作了调研,以期为养虾业发展提供思考。     

对虾的营养需求

对虾养殖业在渔业经济中已成为发展迅速、最具活力的一个产业，成为亚洲、美洲等发展中国家重要出口创汇的产业。近年来，随着凡纳滨对虾（南美白对虾）等优良品种的引入、对虾集约化防病养殖技术的发明与改进以及全人工苗种培育技术的突破。掀起了我国对虾养殖业的第二次高潮。营养饲料是健康养殖对虾的物质基础。掌握对虾的营养需求，选用质优、价廉的饲料直接关系到对虾养殖的经济效益。为此，作者对近年来国内外关于对虾的营养需求的研究进展作一综述。以期为对虾的营养研究和配合饲料的生产提供参考。     

新形势下畜牧饲料科技的发展趋赘

2005年氯霉素超标问题，造成我国大量的出口对虾被退回、被索赔：孔雀石绿问题再次对水产养殖业敲响警钟。     

对虾的病毒病

水产养殖业近来一直稳定地增长,许多具有重要经济价值的海洋生物如虾、龙虾、蛤、牡蛎已被人工养殖,已有的技术也能促进它们的生长量.动物营养、生理、病理这些基本兽医知识已用到这些养殖业上.本文将着重阐述对虾病毒病的病原、诊断和预防.     

疫苗与免疫(下)

4免疫方法及注意事项 4．1免疫接种方法有滴鼻、点眼、刺种、喷雾、皮下注射、肌肉注射、饮水、涂肛等方法。要采用正确的稀释和接种方法，油苗要温至室温再行注射，免得反应较大。活疫苗要现用现配，最好半天内用完，马立克氏病疫苗要在配好后1～2h内用完。     

重视科学的免疫程序

影响疫苗免疫效果的因素很多，多数人对疫苗质量比较关注，而忽视免疫程序的科学性。好的疫苗不执行科学的免疫程序也不会产生良好的免疫效果，甚至会引起较严重的经济损失。     

Protective immunity against Newcastle disease: the role of cell-mediated immunity

The role of cell-mediated immunity (CMI) in protection of birds from Newcastle disease was investigated by two different strategies in which only Newcastle disease virus (NDV)-specific CMI was conveyed without neutralizing antibodies. In the first strategy, selected 3-wk-old specific-pathogen-free (SPF) birds were vaccinated with either live NDV (LNDV), ultraviolet-inactivated NDV (UVNDV), sodium dodecyl sulfate-treated NDV (SDSNDV), or phosphate-buffered saline (PBS) (negative control) by the subcutaneous route. Birds were booster vaccinated 2 wk later and challenged with the velogenic Texas GB strain of NDV 1 wk after booster. All vaccinated birds had specific CMI responses to NDV as measured by a blastogenesis microassay. NDV neutralizing (VN) and hemagglutination inhibition (HI) antibody responses were detected in birds vaccinated with LNDV and UVNDV. However, birds vaccinated with SDSNDV developed antibodies that were detected by western blot analysis but not by the VN or HI test. Protection from challenge was observed only in those birds that had VN or HI antibody response. That is, birds with demonstrable CMI and VN or HI antibody response were protected, whereas birds with demonstrable CMI but no VN or HI antibody response were not protected. In the second strategy, birds from SPF embryos were treated in ovo with cyclophosphamide (CY) to deplete immune cells. The birds were monitored and, at 2 wk of age, were selected for the presence of T-cell activity and the absence of B-cell activity. Birds that had a significant T-cell response, but not a B-cell response, were vaccinated with either LNDV, UVNDV, or PBS at 3 wk of age along with the corresponding CY-untreated control birds. The birds were booster vaccinated at 5 wk of age and were challenged with Texas GB strain of NDV at 6 wk of age. All birds vaccinated with LNDV or UVNDV had a specific CMI response to NDV, VN or HI NDV antibodies were detected in all CY-nontreated vaccinated birds and some of the CY-treated vaccinated birds that were found to have regenerated their B-cell function at 1 wk postbooster. The challenge results clearly revealed that CY-treated birds that had NDV-specific CMI and VN or HI antibody responses to LNDV or UVNDV were protected, as were the CY-nontreated vaccinated birds. However, birds that had NDV-specific CMI response but did not have VN or HI antibodies were not protected from challenge. The results from both strategies indicate that specific CMI to NDV by itself is not protective against virulent NDV challenge. The presence of VN or HI antibodies is necessary in providing protection from Newcastle disease.     

Fish immunity and parasite infections: from innate immunity to immunoprophylactic prospects

The increasing economic importance of fish parasitoses for aquaculture and fisheries has enhanced the interest in the defence mechanisms against these infections. Both innate and adaptive immune responses are mounted by fish to control parasite infections, and several mechanisms described for mammalian parasitoses have also been demonstrated in teleosts. Innate immune initiation relies on the recognition of pathogen-associated molecular patterns (PAMPs) by pathogen recognizing receptors (PRRs). A number of PRRs, mainly Toll-like receptors (TLRs), have been characterized in fish, and some molecules susceptible of functioning as PAMPs are known for some fish parasites. A lectin-carbohydrate interaction has also been described in some host fish-parasite systems, thus probably involving C-type lectin receptors. Inflammatory reactions involving cellular reactions, as phagocytosis and phagocyte activity (including oxidative mechanisms), as well as complement activity, are modulated by many fish parasites, including mainly ciliates, flagellates and myxozoans. Besides complement, a number of humoral immune factors (peroxidases, lysozyme, acute-phase proteins) are also implicated in the response to some parasites. Among adaptive responses, most data deal with the presence of B lymphocytes and the production of specific antibodies (Abs). Although an increasing number of T-cell markers have been described for teleosts, the specific characterization of those involved in their response is far from being obtained. Gene expression studies have demonstrated the involvement of other mediators of the innate and adaptive responses, i.e., cytokines [interleukins (IL-1, IL-8), tumor necrosis factor (TNF), interferon (IFN)], chemokines (CXC, CC), as well as several oxidative enzymes [inducible nitric oxide synthase (iNOS), cyclo-oxygenase 2 (COX-2)]. Information is scarcer for factors more directly linked to adaptive responses, such as major histocompatibility (MH) receptors, T cell receptors (TCRs) and IgM. Expression of some immune genes varied according to the phase of infection, and proinflammatory cytokines were mainly activated in the early stages. Gene expression was generally higher in the target tissues for some skin and gill parasites, as Ichthyophthirius multifiliis, Neoparamoeba spp. and Lepeophtheirus salmonis, thus confirming the relevance of mucosal immunity in these infections. The existence of protective responses has been demonstrated for several fish parasites, both in natural infections and in immunization studies. Most information on the mechanisms involved in protection deals with the production of specific Abs. Nevertheless, their levels are not always correlated to protection, and the precise involvement of immune mechanisms in the response is unknown in many cases. No commercial vaccine is currently available for piscine parasitoses, although experimental vaccines have been assayed against I. multifiliis, Cryptobia salmositica and scuticociliates. The known information points to the need for integrated studies of the mechanisms involved in protection, in order to choose the optimum antigen candidates, adjuvants and formulations.     

免疫为何失败——谈影响免疫效果的九大因素

近年来，经常听到一些猪场反映搞过防疫的猪发病了，有猪瘟、有传染性胃肠炎等，使人们开始怀疑防疫的效果。我们分析了防疫的整个过程，发现防疫不理想的原因往往是由于工作不细致造成的，因为以下几种情况都会影响免疫效果。     

也谈成功免疫

1 制订适当的免疫程序免疫程序不是到处通用的，具有地域性。应根据本地本场本户的实际情况，结合种鸡场的种鸡免疫程序，以及本地传染病发生情况等资料，并征求当地防疫部门的意见，确定疫病防制的种类、时间、方法等。免疫程序中对各种疫病面面俱到是不现实的，也是不必要的。如果本地没有或本场5公里内没有，则没有必要对该病进行防疫；对资料介绍的新病，本地或临近地区没有或引种地没有，也没有必要预防，否则可能会把该病引入本场。2 防疫前的准备工作根据免疫程序，如需作实验室检验(如新城疫的抗体水平等)，在免疫时与当地化验中心…     

犬的免疫须知

很多犬场因缺少调研及准确信息,会导致犬免疫的盲目性,造成犬大量的死亡。因此,建立较完善的“犬免疫规程”是保证犬业发展的关键环节。一、自养犬的免疫1.成年犬,每年定期注射一至两次犬五(六)联苗,同时,用广谱驱虫药如丙硫苯咪唑片,按犬号登记造册。2.自繁仔犬断奶第15天,因母乳抗体逐渐消失,注射犬五(六)联疫苗和驱虫,当年生的仔犬在42,56,84日龄连续注射疫苗3次,注册登记。如果是役区应加强消毒,仔犬的免疫应提前12天注射疫苗,防疫后10天内不洗澡,防感冒,尤其是第一次注射疫苗。3.自繁自养犬,注意血缘关系,建立健全血统谱系档案,避免近…     

Assays of cellular immunity

Numerous cellular assays are available to study the response or activities of mononuclear and polymorphonuclear cells in domestic species. When the assays, most developed originally to study rodent or human cells, are adapted to the cells of domestic species, minor or major modifications have been necessary. Furthermore, interpretation of results of the assays with cells from domestic species are not always consistent with those obtained in the original system, and it should not be expected that the assays will always provide results that can be interpreted similarly among species. Application and additional experience with these techniques, as well as new techniques, will provide a foundation for our understanding of the importance of cellular mechanisms in immunity of domestic species.