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1.
施学文 《福建水产》2013,35(4):307-311
为了比较两种饲料对真鲷感染刺激隐核虫的影响,试验设置试验组(Ⅰ组)和对照组(Ⅱ组),每组设3个平行试验,采用6口室内水泥池养殖真鲷3 000尾,每口投放平均体重70.0 g/尾的真鲷500尾;试验组和对照组分别投喂软颗粒饲料与鲜杂鱼糜。结果表明:真鲷在试验期间投喂软颗粒饲料和鲜杂鱼糜之后均有感染刺激隐核虫,但两者之间感染刺激隐核虫数差异显著(P<0.05),即投喂鲜杂鱼糜比投喂软颗粒饲料更容易引起刺激隐核虫的蔓延和暴发;感染刺激隐核虫的部位主要集中于鱼体鳃丝和体表。  相似文献   

2.
根据大黄鱼网箱养殖区的实际条件和大黄鱼的营养需求,以提高饲料利用率、促鱼生长、减少环境污染、易制作为目的,将研制的大黄鱼软颗粒干粉料与常用的鲜杂鱼糜以8∶5比例混合,配以0.4%的鱼肝油,通过水产湿颗粒饲料压制机压制成软颗粒饲料,并用A、B、C、D等4种不同成分含量的软颗粒饲料与鲜杂鱼糜分别投喂大黄鱼进行养殖效果比较试验。结果表明:研制的粒径0.4～1.0 cm的软颗粒饲料,圆柱体外观光滑,无开裂现象,切口整齐;保持鲜杂鱼固有风味,无腐败、霉变及其它异味;水中稳定性良好,沉降速度8.3 cm/s;其诱食效果优于鲜杂鱼糜;投喂大黄鱼,其养殖效果及经济效益优于投喂冰鲜饵料,尤其是其中的D组料(相对增重率81.0%,饲料系数1.81),效果尤其显著,可推广使用。  相似文献   

3.
为了探究饲料中添加复合益生菌对中华鳖（Trionys sinensis）生长及血液生化指标的影响,在体重为（227．47±14．42）g 的中华鳖基础饲料中分别添加复合益生菌0 mg／kg（对照组Ⅰ）、500 mg／kg（试验组Ⅱ）、1000 mg／kg （试验组Ⅲ）和2000 mg／kg（试验组Ⅳ）;试验共分4组,每组3个重复,在（30±2）℃温室中进行,投喂140 d。结果表明,各试验组均能显著提高中华鳖增重率、特定生长率和存活率（P ＜0．05）,降低饵料系数（P ＜0．05）,且Ⅲ组增重率、特定生长率和存活率最高,饵料系数最低,增重率比Ⅰ组提高了29．25％;各试验组均能显著提高中华鳖脂肪酶、淀粉酶和胰蛋白酶活力（P ＜0．05）,当添加量为2000 mg／kg 时,淀粉酶活力有所下降（P ＜0．05）;与对照组相比,各试验组均能显著降低血清中总胆固醇、尿素氮水平和谷丙转氨酶活力（P ＜0．05）,提高甘油三酯含量（P ＜0．05）,而血清中总蛋白、球蛋白、白蛋白、血糖、丙二醛含量和谷草转氨酶活力差异不显著（P ＞0．05）;各试验组均能显著提高血清中溶菌酶、谷胱甘肽过氧化物酶和超氧化物歧化酶活力（P ＜0．05）,但过量添加（2000 mg／kg）会降低其活力（P ＞0．05）。在基础饲料中适量添加复合益生菌能促进中华鳖的生长、降低饵料系数、提高肠道消化酶活性,同时还具有提高非特异性免疫和抗氧化功能,最适添加量为 1000～2000 mg／kg。  相似文献   

4.
限制饲养对肉鸭生产性能和屠体品质的影响   总被引：2，自引：0，他引：2  
选用1日龄樱桃谷肉鸭200只，随机分为两组，1个试验组，1个对照组，每组2个重复，每个重复50只。对照组1～6周自由采食，试验组1～3周自由采食，4～6周采用限制饲养（限量）。试验结果表明：6周龄时，试验组的饲料转化率比对照组提高了12．9％，差异显著（P＜0．05），但日增重降低了9．13％，差异不显著（P＞0．05）；腹脂率降低34．2％，差异极显著（P＜0．01）；皮脂率降低15．1％，差异显著（P＜0．05）；瘦肉率提高了11．9％，差异不显著（P＞0．05）。  相似文献   

5.
在福建宁德三都澳大黄鱼主养区,开展全程分别投喂市场反馈好、销量较大的某3种品牌大黄鱼配合饲料及(鲜杂鱼糜+A)饲养大黄鱼的对比试验。经过2年多来的应用试验,结果表明:配合饲料的诱食效果优于鲜杂鱼糜;大黄鱼养成投喂粗蛋白含量≥46.0%的配合饲料的养殖效果、经济效益与投喂(鲜杂鱼糜料+A)差异不显著(P0.05),但大黄鱼成活率显著提高;粗蛋白含量≥46.0%的优质配合饲料可以完全替代传统的(鲜杂鱼糜+优质配合饲料),可在大黄鱼养殖生产上大规模推广应用。  相似文献   

6.
以初始体重为20g左右的刺参幼参为实验对象,研究了不同的EM菌使用方式（G0：不使用;G1：养殖池泼洒;G2：蓄水池泼洒）及不同的换水量（0．5,1．0,1．5倍）对其生长及养殖水环境的影响。结果显示：使用EM菌及增加换水量均可显著提高刺参的增重率及成活率（P〈0．05）,二者之间的交互作用显著提高了增重率和饲料转化率（P〈0．05）,且G2使用方式优于G1使用方式;养殖水体中的氨氮、亚硝酸氮、硝酸氮、总氮、活性磷酸盐、总磷在使用EM菌和增大换水量后均显著降低（P〈0．05）;实验45天时,使用方式及换水量之间的交互作用对养殖水质无显著影响（P〉0．05）,但实验90天时,二者之间的交互作用显著影响了养殖水质（P〈0．05）。综上,建议在刺参池塘或工厂化养殖过程中,在使用EM菌的同时,可适当减少换水量,且以蓄水池直接泼洒使用为优。  相似文献   

7.
研究了饵料中添加植酸酶、非淀粉多糖酶及二者的组合酶对大菱鲆幼鱼生长、体成分以及饵料利用率的影响。在水温14．0～18．5℃将144尾初始平均体质量为（20．53±0．10） g的大菱鲆幼鱼随机分成4组,每组3个重复,每个重复放养12尾鱼,分别饲喂基础饵料（对照组）和在每千克基础饵料中添加200 mg植酸酶、100 mg非淀粉多糖酶、200 mg植酸酶＋100 mg非淀粉多糖酶的组合酶（试验组）。计42 d。试验结果表明,与对照组相比,添加外源酶显著提高了大菱鲆幼鱼的特定生长率（ P＜0．05）,且添加组合酶的特定生长率最高,较对照组提高了16．30％;但摄食率、饵料系数、蛋白质效率和成活率均无显著影响（P＞0．05）。饵料中添加外源酶对大菱鲆幼鱼的鱼体水分、粗脂肪、灰分和能量无显著影响（P＞0．05）;但鱼体粗蛋白含量均有增加（P＞0．05）,且添加非淀粉多糖酶鱼体粗蛋白含量最高（P＜0．05）。与对照组比较,添加非淀粉多糖酶和组合酶显著提高大菱鲆幼鱼的干物质、粗蛋白、磷和能量的表观消化率（P＜0．05）;添加植酸酶显著提高粗蛋白表观消化率（P＜0．05）,干物质、磷和能量表观消化率较对照组高,但差异不显著（P＞0．05）。饵料中添加外源酶显著提高大菱鲆幼鱼氮、磷贮积率,显著降低氮排放率（P＜0．05）;添加组合酶显著降低磷排放率（P＜0．05）;饵料中分别添加植酸酶和非淀粉多糖酶未显著降低磷排放率（P＞0．05）,但有下降趋势。  相似文献   

8.
周口职业技术学院王保正等，在哺乳仔猪教槽料中提前添加酪酸菌，仔猪断奶时试验组与对照组的头均增重无明显差异（P〉0．05），料重比试验组明显低于对照组（P〈0．05），育成率试验组极显著（P〈0．01）高于对照组；断奶后至转群时试验组的头均日增重和头均增重明显（P〈0．05）高于对照组，而试验组的料重比又明显（P〈0．05）低于对照组；达90kg的出栏日龄试验组比对照组提前8．1d，  相似文献   

9.
自2013年12月8日起至2014年5月5日,以养殖池塘污染沉积物为研究对象,采用室内模拟法研究了种青、暴晒、投放生石灰等方法修复淡水养殖池塘沉积物的效果。结果表明,在池塘沉积物修复期,种青组沉积物中总氮和总磷的含量、碱性磷酸酶的活性、烧失量均显著低于对照组(P0.01);生石灰组沉积物中烧失量显著低于对照组(P0.01)。覆水处理后,种青组水体中正磷酸盐、叶绿素a含量显著高于对照组(P0.01),种青组水体总磷含量低于对照组(P0.05);暴晒组水体中正磷酸盐、总磷含量低于对照组(P0.05);生石灰组水体中各项指标均无明显差异。分析结果表明,种青、暴晒、投放生石灰降低了养殖池塘底泥中营养物质的含量,其中种青组沉积物中总磷的含量降低显著,覆水后水体中总磷的含量也有明显降低,以种青组的综合修复效果最佳。  相似文献   

10.
石传林 《畜禽业》1998,(10):24-25
本试验旨在探讨加酶益生素在生长育肥猪日粮中的应用效果。试验表明,在120天试验期间,添加饲喂加酶益生素的试验组,每头猪平均日增重789．25g,未添加加酶益生素的对照组,每头猪平均日增重为673．4g,试验组比对照组提高日增重17．2％,差异极显著（P＜0．01）试验组料肉比为2．91：1,对照组料肉比为3．18：1,试验组比对照组提高饲料报酬8．5％,差异显著（P＜0．05）。  相似文献   

11.
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.  相似文献   

12.
Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.  相似文献   

13.
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality).  相似文献   

14.
There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future.  相似文献   

15.
This study investigated the efficiency of iodophor disinfection (135 ppm active iodine for 15–30 min) of non‐hardened Salmo trutta eggs against different groups of bacteria and against fungus. Egg samples were taken from non‐disinfected and from disinfected eggs, microorganisms were cultured on specific nutrient media and their mass was measured by turbidimetric methods. Bacteria and fungus mass of non‐hardened eggs could be reduced but not eliminated by iodophor disinfection with 135 ppm active iodine for 15 min. The extent of reduction was 47–65% (Experiment 1). The efficiency of disinfection increased with disinfection time as the reduction in bacteria and fungus mass was 40–55% after 15 min and 58–74% after 30 min (Experiment 2). Disinfection efficiency of iodophor solution diluted in water (reduction 49–57%) and of iodophor solution diluted in sodium chloride solution iso‐osmolar to the oocytes (reduction 52–61%) was similar (Experiment 3). The reduction in bacteria and fungus mass was persistent as it was 39–72% lower in embryos deriving from disinfected eggs than in embryos deriving from non‐disinfected ones (Experiment 4). In conclusion, the tested disinfection method is inadequate to eliminate pathogens completely but it could positively influence immune defence of eggs and embryos.  相似文献   

16.
The indiscriminate use of antibiotics and chemicals in shrimp hatcheries has led to biomagnification and that in turn could lead to rejection of a whole consignment. The application of the bioencapsulation technique as a tool for curative treatment in shrimp larvae was investigated. Herbs having antibacterial properties such as Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia (methanolic extracts) were bioencapsulated in Artemia and fed to Penaeus monodon post larvae PL 1–25. The post larvae were reared in a medium inoculated with pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Vibrio sp. Post larvae reared in the non-inoculated water and fed with non-enriched Artemia exhibited 90% survival, highest specific growth rate (12.43%) and reduced bacterial load. P. monodon reared in the bacterial inoculated water and fed with the non-enriched Artemia exhibited the lowest survival (10–30%), specific growth rate (8.42–9.1%) and increased bacterial load (2.86 × 103 to 3.76 × 105 cfu/g). The methanolic extracts of the herbs helped to increase survival and specific growth rate and reduced bacterial load in the P. monodon culture system. Among the three herbal extracts, P. corylifolia enriched Artemia fed post larvae showed the tendency to higher survival (>50%), growth rate (11.5 averaged) and low bacterial load (1.12 × 105 cfu/g). This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

17.
The sea raven, Hemitripterus americanus, is a sit-and-wait, low metabolic rate, marine teleost. The objective of this study was to determine i) whether cortisol implantation (50 mg. kg-1) for 7 days altered hepatocyte metabolism, and hepatocyte responsiveness to epinephrine, glucagon and insulin, and ii) whether 8 weeks of food-deprivation modified the above response. Cortisol implantation significantly increased hepatocyte total glucose production and oxidation from alanine compared to the sham group. There was no cortisol effect on glycogen breakdown, suggesting that the activation of other pathways, including gluconeogenesis, are required to account for the increased glucose production. Epinephrine-mediated (10-5M) glycogen breakdown and insulin-mediated (10-8M) total glucose production were enhanced in hepatocytes of cortisol implanted sea ravens, but there were no change in any glucagon (10-7M) effects. The enhanced glycogen breakdown in the absence of similar increases in total glucose production with epinephrine indicates mobilization of carbohydrate reserves for endogenous use by the liver. Food-deprivation for 8 weeks significantly decreased condition factor, plasma cortisol concentration and liver glycogen content in the sea raven, but had no effect on plasma glucose concentration. Hepatocyte total glucose production and flux rates from alanine increased significantly with food-deprivation. Moreover, food-deprivation increased responsiveness of total hepatocyte glucose production to the actions of glucagon and insulin, but not to epinephrine; none of these effects were modified by cortisol implantation. Our results indicate that cortisol in the sea raven exerts both a direct and an indirect or permissive effect on hepatocyte metabolism by modifying hepatocyte responsiveness to epinephrine and insulin stimulation. Cortisol implantation did not modify the effects of glucagon or food-deprivation in this species.  相似文献   

18.
Important environmental processes for the survival and recruitment of early life stages of pelagic fishes have been synthesized through Bakun's fundamental triad as enrichment, concentration and retention processes (A. Bakun, 1996, Patterns in the Ocean. Ocean Processes and Marine Population Dynamics. San Diego, CA, USA: University of California Sea Grant). This conceptual framework states that from favourable spawning habitats, eggs and larvae would be transported to and/or retained in places where food originating from enrichment areas would be concentrated. We propose a method for quantifying two of the triad processes, enrichment and retention, based on the Lagrangian tracking of particles transported within water velocity fields generated by a three‐dimensional hydrodynamic model. We apply this method to the southern Benguela upwelling ecosystem, constructing putative maps of enrichment and retention. We comment on these maps regarding main features of the circulation in the region, and investigate seasonal variability of the processes. We finally discuss the results in relation to available knowledge on the reproductive strategies of two pelagic clupeoid species abundant in the southern Benguela, anchovy (Engraulis encrasicolus) and sardine (Sardinops sagax). Our approach is intended to be sufficiently generic so as to allow its application to other upwelling systems.  相似文献   

19.
This study evaluated the effects of three levels of loading density (200, 300 and 400 g L−1) and four levels of duration (1, 3, 6 and 9 h) on the mortality, plasma cortisol and chloride levels and growth of rohu Labeo rohita fingerlings in a transport simulation. While total immediate mortality was low (4–12%), delayed mortality was high (27–49%). Initial capture and handling were found to constitute the most stressful phase as indicated by elevated plasma cortisol. The levels of cortisol continued to rise at 6 and 9 h after transport, with the highest level observed at 9 h after transport. The level of plasma chloride fell after transport across all density levels and treatment durations. Specific growth rate (SGR, %/day) and total bacterial density (cfu/g) were not different between and within treatments, and between treatments and the controls. This study demonstrates that transport has a profound effect on the stress responses of rohu fingerlings. Although the level of immediate mortality was low, the higher level of delayed mortality has serious implications in terms of production inefficiency for grow-out farmers.  相似文献   

20.
  • 1. The common name ‘tilapia’ refers to a group of tropical freshwater fish in the family Cichlidae (Oreochromis, Tilapia, and Sarotherodon spp.) that are indigenous to Africa and the southwestern Middle East. Since the 1930s, tilapias have been intentionally dispersed worldwide for the biological control of aquatic weeds and insects, as baitfish for certain capture fisheries, for aquaria, and as a food fish. They have most recently been promoted as an important source of protein that could provide food security for developing countries without the environmental problems associated with terrestrial agriculture. In addition, market demand for tilapia in developed countries such as the United States is growing rapidly.
  • 2. Tilapias are well‐suited to aquaculture because they are highly prolific and tolerant to a range of environmental conditions. They have come to be known as the ‘aquatic chicken’ because of their potential as an affordable, high‐yield source of protein that can be easily raised in a range of environments — from subsistence or ‘backyard’ units to intensive fish hatcheries. In some countries, particularly in Asia, nearly all of the introduced tilapias produced are consumed domestically; tilapias have contributed to basic food security for such societies.
  • 3. This review indicates that tilapia species are highly invasive and exist under feral conditions in every nation in which they have been cultured or introduced. Thus, the authors have concluded that, despite potential or observed benefits to human society, tilapia aquaculture and open‐water introductions cannot continue unchecked without further exacerbating damage to native fish species and biodiversity. Recommendations include restricting tilapia culture to carefully managed, contained ponds, although exclusion is preferred when it is feasible. Research into culture of indigenous species is also recommended.
Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

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