浅析高锌对断奶仔猪的影响

<正>锌是继铜、砷之后发现的又一高效微量元素促生长添加剂。锌作为多种关键酶的辅助因子,在动物的能量和蛋白质代谢中发挥着重要的作用,因而是动物机体所必需的微量元素之     

中草药制剂在水产养殖中的应用效果

为充分了解中草药在水产养殖中的应用效果,分别从抗菌消炎、免疫、促生长、益生菌协同作用四个方面,综述了中草药制剂在在水产养殖中的实际应用情况。天然中草药含有生物碱、苷类、糖类、有机酸、挥发油、黄酮、鞣质、树脂、油脂、色素、糖肽、氨基酸和多种常量及微量元素,在以下四个方面具有比较明显的作用:(1)多种中草药具有明显的抑菌、杀菌效果,而且对多种病原寄生虫也有很好的抑制作用;(2)有200余种中草药具有多种免疫活性,可影响和调节动物机体的免疫功能;(3)多种中草药含有一些未知的促生长活性的物质,具有增强食欲、促进机体代谢和消化酶分泌、提高营养物质利用率、促进水生动物生长发育的作用;(4)益生菌与中草药协同作用前后,多糖等成分含量变化明显,协同作用效果明显优于单纯使用中草药组。因此,中草药做为纯天然的绿色产品,是原来所用单一成分的鱼类药物所无法替代的。     

纳米硒在水产动物营养中的研究进展

<正>硒(Se)作为水产动物必需的微量元素之一,对机体有多种生理功能(如免疫、生长发育、繁殖等),并能在体内产生富集。在饲料中添加硒会对水产动物产生一定的影响。硒摄入过量或不足,都会对机体产生危害,只有适量地摄入硒才能保证水产动物的健康生长,增强其抗氧化能力和自身免疫力。硒最重要的功能是通过谷胱甘肽过氧化物酶(GSH-Px)发挥抗氧化性,在还原型谷胱甘     

硒对畜禽生产性能的影响

硒是畜禽生长代谢必需的微量元素之一,适量的硒对畜禽机体有着积极作用,文章综述了硒对畜禽免疫功能、抗氧化作用、抗应激作用和提高繁殖性能的影响,提出了未来的研究开发和利用的方向。     

西伯利亚鲟和欧洲鳇肠道菌群的比较分析以及棉籽蛋白替代部分鱼粉对欧洲鳇肠道菌群的影响研究

正肠道作为一个大型的生态系统,存在数量巨大的微生物,肠道健康会直接影响到动物对饲料中营养物质的消化吸收以及机体自身的生长性能。肠道菌群是动物机体不可缺少的组成部分,在维持肠道健康、抵抗病原菌的入侵、调节物质代谢、能量吸收、器官发育以及机体免疫等方面发挥着重要作用。肠道菌群的种类和数量在动物健康时是处于稳定平衡状态的。外界环境状态、     

对虾促生长剂的应用试验

近年来,对虾养殖面积不断扩大,虾病逐年增多,产量和效益受到影响,为了寻求一条增产增效的途经,我们于1990年7月引进对虾促生长剂——莱研一号。该剂是由多种微量元素和一些高营养原料配制而成。主要作用是增强对虾消化、循环系统的功能,促使对虾生长,增强对虾体质,提高其免疫抗病能力,从而达到提高产量降低成本,提高经济效益的目的。     

元素硒对水产动物影响的研究进展

硒是一种动物和人都必需的微量元素,它通过脱碘酶间接影响动物的生长性能,也可以通过谷胱甘肽过氧化物酶(GSH-Px)和多种具有生物活性的硒蛋白影响动物的抗氧化能力和免疫功能,但过量的硒也会导致机体中毒。本文综述了硒对水产动物的生长性能、抗氧化能力及免疫功能的影响,同时介绍了它与维生素E的协同作用,探讨了有机硒和无机硒以及硒蛋白分子学研究,展望了硒在水产动物研究和应用中的发展方向。     

锌的生物学功能及其对水产动物影响的研究进展

正锌是目前已发现的15种微量元素中具有最多生理功能的元素,存在于大多数器官、组织和体液中(Chvapil M等,1973)。锌参与动物正常生长、骨骼发育以及多种生理活动,同时锌也参与超过300种酶系以及多种大分子物质的构成,但是锌的摄入量过高会引起动物呕吐、腹泻、血管内溶血、心律失常和抽搐等中毒症状(Sunuwar L等,2017)。近年来国内外专家学者对锌的生物学功能及其对动物的生长性能、饲料利用、肉质品质、机体抗氧化能力及免疫力等方面作用的研究不断深入并取得一定成果。本文就锌的生物学功能、对水产动物生长、免疫、抗氧化等方面的研究进行综述,并对今后锌的应用前景进行展望,     

利用中草药免疫增强剂提高南美白对虾抗病毒病的养殖试验

中草药含有复杂的活性有效成分，且具有活性刺激、营养、调节等作用，增强对虾等动物的非特异性免疫力，从而提高其抗病毒能力。特别是黄芪、杜仲、枸杞子等含有多糖、甙、黄酮和微量元素等多种成分的中草药，对免疫系统具有广泛的影响，是一种免疫促进剂。本试验使用不同的两组配方中草药制剂，采用相同制剂添加量30g／kg．d，在夏秋季节投喂南美白对虾。试验表明，对虾桃拉病毒的平均发病率较对照池低42．7％，含黄芪等高配方的制剂相对含黄芪等低配方的发病率低2．5％．添加中草药制剂喂养的对虾池平均成活率比对照池高18．8％。结果表明，中药复方对南美白对虾生理代谢，免疫功能的调节，机体抗病力的提高有促进作用。中草药制剂能防控南关白对虾病毒性疾病的发生。     

中草药在渔业生产中的应用

一、促鱼生长和改善水环境的作用中草药的有效化学成分有：多糖、生物碱、甙类、有机酸类、挥发油类，此外其营养成分还有油脂、树脂、糖类、蛋白质、氨基酸、维生素、常量元素、微量元素等，该有效成分既能促进机体糖代谢、蛋白质和酶的合成，又能刺激性腺发育，促进生长，故常被用来作诱食剂、降低饵料系数、提高成活率或改善水环境等。二、免疫作用经动物的试验表明：中草药中黄芪皂甙和黄芪多糖Ⅰ、Ⅱ有增强机体免疫活性的作用，对体液免疫、细胞免疫和免疫调节作用有广泛影响。部分中草药的有效成分在抑制病原微生物的同时，还能激发动…     

A future vision for disease control in shrimp aquaculture

Aquaculture is the fastest‐growing animal production sector, and shrimp production already exceeds that of the capture fishery. Viruses and bacteria account for the majority of disease losses for shrimp farmers. Viral pandemics in the mid 1990s and, more recently, a bacterial pandemic from 2009 to 2015 have led to the conclusion that future, sustainable shrimp aquaculture will depend on the development of more efficient, biosecure production facilities that cultivate specific pathogen‐free (SPF) shrimp, genetically improved for growth and disease tolerance or resistance. Major requirements for development, maintenance, and use of SPF stocks in aquaculture are effective pathogen surveillance and disease prevention methods. When protective measures fail and diseases occur in production ponds, there are currently only a few approved and practical therapeutic methods available for use with bacterial pathogens and none so far for viral pathogens. To improve existing methods of prevention and therapy and to develop new ones, research is being carried out on the nature of shrimp–pathogen interactions. Promising results have been obtained at the laboratory level for possible applications involving the use of immunostimulants for “immune priming” or “trained immunity” of RNA interference and of endogenous viral elements. Some of these promising new directions are discussed.     

微量元素对水华发生、发展的影响

微量元素作为藻类营养因子的一部分,对藻类生长具有重要作用,而藻类(特别是微囊藻)的大量增长则会造成"水华"现象。本文综述了各种微量元素对水华藻类生长的影响及其影响机理,进而得出结论:微量元素对水华藻类的生长影响趋势为低浓度促进生长,高浓度抑制生长,而藻类对微量元素有一定的富集作用;在微量元素中,铁元素对水华的发生、发展至为重要,在某种情况下有可能成为水华发生、发展的限制因子;其他元素(如稀土元素和重金属元素等)在水华发生、发展中则起辅助作用。     

共轭亚油酸及其在动物营养中的应用研究进展

共轭亚油酸(CLA)是亚油酸同分异构体的混合物,CLA多见于反刍动物畜产品中。CLA与人及动物的健康密切相关,CLA在畜产品中的富集对人的许多疑难病症具有深远意义,本文综述了CLA调节动物脂肪代谢和免疫机能,提高生产性能,改善畜产品品质等生物学功能。     

Trace elements in waters of inland,low‐salinity shrimp ponds in Alabama

Trace element concentrations in waters of 10, inland, low‐salinity shrimp ponds in Alabama tended to be greater than those found in normal seawater – molybdenum, boron and silicon were exceptions. Concentrations of most trace elements varied greatly among ponds on individual sampling dates, and average concentrations based on all sampling dates in individual ponds also varied considerably. The analytical method used, digestion of water samples in nitric acid followed by inductively coupled plasma atomic emission spectrophotometry, measured total concentrations of trace elements – free ions, hydrolysis products, ion pairs, coordination compounds (chelated forms) and particulate forms. Free ions are the toxic forms of most trace elements and the ionic concentration is much less than the total concentration of a trace element. Based on total concentrations of trace elements, it is doubtful that free‐ionic concentrations of trace elements were great enough to harm shrimp. The fact that no negative correlations were noted between trace element concentrations and shrimp survival and production supports this conclusion. However, positive correlations (P < 0.05) between shrimp survival and production and increasing concentrations of zinc, cobalt and iron should be investigated further to ascertain if additions of these elements to ponds might improve shrimp performance.     

饲料添加剂在水产动物生长、营养及免疫中的应用进展

饲料添加剂是在基础饲料的生产加工或使用过程中添加微量物质,具有强化基础饲料营养价值,节省饲料成本,提高动物生产性能,改善肌肉品质等作用.目前国内外对饲料添加剂的研究众多,为突出饲料添加剂对水产动物在不同方面的影响,本文综述了饲料添加剂对水产动物生长性能、营养成分及免疫中的应用进展.     

Growth and nutrient conversion of white shrimp Litopenaeus vannamei (Boone) and Nile tilapia Oreochromis niloticus L. in an integrated closed recirculating system

We investigated the effects of the stocking density of white shrimp (Litopenaeus vannamei) on shrimp and tilapia growth and nutrient conversion in an integrated closed recirculating system both with and without Nile tilapia (Oreochromis niloticus). A 2 × 3 factorial design involving tilapia presence/absence and shrimp stocking densities of 40, 80 and 120 m^?2 was applied, using a tilapia:shrimp ratio of 0.025. There were no significant interactions between tilapia presence and shrimp stocking density in terms of shrimp growth performance or feed utilization. The presence of tilapia had no effect on the shrimp growth rate, survival rate or total weight gain (%). Shrimp growth declined significantly with increased shrimp stocking density, but the growth of tilapia was not significantly different among the three shrimp densities tested. The conversion of feed nitrogen and phosphorus into total harvested animal biomass was significantly higher in the presence than in the absence of tilapia. The nutrient conversion rate at the lowest shrimp density (40 m^?2) was significantly higher than at the highest density tested (120 m^?2).     

Dietary astaxanthin levels affect colour,growth, carotenoid digestibility and the accumulation of specific carotenoid esters in the Giant Tiger Shrimp,Penaeus monodon

The carotenoid astaxanthin (Axn) plays a vital role in shrimp pigmentation, with direct influence on product quality, and forms a significant cost component of shrimp aquaculture feeds. However, the effects of dietary Axn on other measures of shrimp physiological performance are varied, and the efficiency of carotenoid uptake from the diet and deposition in shrimp tissues is poorly defined. This study fed juvenile shrimp (Penaeus monodon) diets that contained 0, 25, 50 or 100 mg kg^?1 Axn for 6 weeks. Shrimp fed carotenoid‐free diets had significantly reduced colour and growth than those fed carotenoids, but survival was unaffected. Carotenoid digestibility improved as dietary carotenoid levels increased, and was 98.5% in shrimp fed 100 mg kg^?1 Axn. After 6 weeks, whole body carotenoid levels were significantly depleted in 0 or 25 mg kg^?1 fed shrimp, compared with those fed 50 or 100 mg kg^?1 or compared with initial shrimp. This study also showed that Axn monoesters were enriched with saturated fatty acids, whereas Axn diesters were enriched with monounsaturated and polyunsaturated fatty acids. Combined, these studies demonstrate that a total dietary carotenoid intake of between 25 and 50 mg kg^?1 Axn is required for normal shrimp growth and health in P. monodon. Evidence suggests that there is a functional role for the accumulation of carotenoids and the formation of specific Axn fatty acid esters, and these may be linked to the metabolism, storage, mobilization or deposition of Axn within various tissues.     

Effect of bioflocs on growth and immune activity of Pacific white shrimp,Litopenaeus vannamei postlarvae

The bioflocs technology (BFT) for shrimp production has been proposed as a sustainable practice capable of reducing environmental impacts and preventing pathogen introduction. The microbial community associated with BFT not only detoxifies nutrients, but also can improve feed utilization and animal growth. Biofloc system contains abundant number of bacteria of which cell wall consists of various components such as bacterial lipopolysaccharide, peptidoglycan and β‐1, 3‐glucans, and is known as stimulating nonspecific immune activity of shrimp. Bioflocs, therefore, are assumed to enhance shrimp immunity because they consume the bioflocs as additional food source. Although there are benefits for having an in situ microbial community in BFT systems, better understanding on these microorganisms, in particular molecular level, is needed. A fourteen‐day culture trial was conducted with postlarvae of Litopenaeus vannamei in the presence and absence of bioflocs. To determine mRNA expression levels of shrimp, we selected six genes (prophenoloxidase1, prophenoloxidase2, prophenoloxidase activation enzyme, serine proteinase1, masquerade‐like proteinase, and ras‐related nuclear protein) which are involved in a series of responses known as the prophenoloxidase (proPO) cascade, one of the major innate immune responses in crustaceans. Significant differences in shrimp survival and final body weights were found between the clear water and in the biofloc treatments. mRNA expression levels were significantly higher in the biofloc treatment than the clear water control. These results suggest that the presence of bioflocs in the culture medium gives positive effect on growth and immune‐related genes expression in L.vannamei postlarvae.     

投喂策略对水产动物生长生理及行为特征影响研究进展

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。     

虾肝肠胞虫感染对脊尾白虾肠道菌群的影响

为探究虾肝肠胞虫(Enterocytozoon hepatopenaei, EHP)感染对脊尾白虾(Exopalaemon carinicauda)肠道菌群的影响,本研究基于16S rRNA基因的测序结果,对感染EHP的脊尾白虾肠道菌群进行了分析。结果显示,感染虾与健康虾肠道菌群差异较大,且其肠道菌群结构多样性显著低于健康虾。研究发现,病虾中归属于变形菌门(Proteobacteria)的脱硫弧菌科(Desulfovibrionaceae)、弧菌科(Vibrionaceae)、未分类蓝细菌科(unidentified Cyanobacteria)、支原体科(Mycoplasmataceae)和未分类α变形菌科(unidentified Alphaproteobacteria)为优势菌,而归属于厚壁菌门(Firmicutes)的乳杆菌科(Lactobacillaceae)、双歧杆菌科(Bifidobacteriaceae)、芽孢杆菌科(Bacillaceae)及噬几丁质杆菌科(Chitinophagaceae)细菌在健康虾中占据优势地位。EHP侵蚀导致感染虾肠道内潜在致病菌显著增加(P<0.05),增加了其他疾病的易感性。此外,通过Tax4Fun功能预测,发现感染虾肠道菌群主要用于新陈代谢,从而抵抗EHP侵染,维持机体正常功能;健康虾肠道菌群则多用于个体生长与环境信息处理,进而保证生长与存活。本研究从虾肠道菌群结构方面入手,进一步探究了EHP感染对脊尾白虾肠道菌群的影响,以期为EHP的防治提供帮助。