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1.
通过利用巳交尾的亲虾与未交虾同池产卵,使己交尾的越冬虾所排出多余精子,给未交尾的越冬亲虾产出的卵子受精,使其受精率达47.7%-56.6%,提高了越冬亲虾的利用率,降低了育苗成本,是保护自然海区亲虾的有效措施。  相似文献   

2.
营养对亲虾的繁育性能具有重要作用,亲虾的繁殖能力和幼体质量与饲料中营养物质的来源和含量密切相关。本文从蛋白质、脂类、碳水化合物、类胡萝卜素和维生素等方面综述了近年来国内外营养素对亲虾性腺发育、繁殖和幼体质量的影响,旨在探究不同营养素对亲虾繁育性能的影响,为亲虾的营养学研究及优质配合饲料的开发提供借鉴。 [关键词] 亲虾|营养|繁育性能  相似文献   

3.
1亲虾的选留 我国用于人工繁殖的亲虾,一般来源于成虾养殖池中,其选留标准为:  相似文献   

4.
通过利用已交尾的亲虾与未交尾亲虾同池产卵,使已交尾的越冬虾所排出多余精子,给未交尾的越冬亲虾产出的卵子受精,使其受精率达47.7%-56.6%,提高了越冬亲虾的利用率,降低了育苗成本,是保护自然海区亲虾的有效措施。  相似文献   

5.
克氏原螯虾人工诱导繁殖的初步研究   总被引:3,自引:0,他引:3  
为提高克氏原螯虾育苗过程中亲虾的成活率,利用福尔马林、高锰酸钾、食盐、聚维酮碘和溴氯海因对购进的亲虾进行消毒试验,结果表明:经上述5种常用药物浸泡消毒后,亲虾成活率分别比对照组提高25%、40%、5%、10%和15%,对亲虾采用高锰酸钾消毒效果较好;为提高克氏原螯虾亲虾的抱卵率,采用盐水诱导、雌虾去单侧眼柄诱导、盐水诱导+雌虾去眼柄双重诱导3种不同人工诱导方式诱导亲虾,促使其性腺发育,试验结果显示,经3种诱导方式诱导的亲虾抱卵率分别比对照组提高20%、31%和39%,双重诱导的平均产卵率高于单因子诱导。  相似文献   

6.
为保证越冬亲虾质量,提高成活率,对留用越冬的亲虾,一般要采取初选、复选和暂养3道程序。初选在起捕现场进行,根据要求挑选数量较多的亲虾,放在室内水池暂养一段时间,逐渐淘汰不合格亲虾,在放入越冬池之前进行1次复选。越冬亲虾的挑选、暂养、复选可参照下列标准操作。  相似文献   

7.
近年来,我国南方沿海省份从东南亚一些国家大量引进斑节对虾亲虾进行人工雷殖虾苗,促进了养虾业的发展。但随同亲虾带进的班节对虾杆状病毒病,危害其子代和敏感虾类,给养虾业造成巨大经济损失。因此,寻找一种简单、快速、准确和经济实用的检测该病的方法,已成为同行们和养虾业者的迫切期望。为此,作者通过两年多来的探索和检疫实践,采用虾粪和肝胰脏样本压片法可快速查出班节对虾杆状病毒(MBV)包涵体,为及时采取防范对策提供科学依据,对亲虾和幼体虾苗的检疫或普查具有现实意义。l村招和方法1.l虾粪样品检查法1.1.1样品的…  相似文献   

8.
为了解天津市对虾肝肠胞虫(EHP)流行情况,2015—2017年从汉沽区、大港区、塘沽区、宁河区、静海区、津南区和西青区等7个对虾养殖主产区,采集养殖对虾及饵料生物等样品,应用PCR法进行EHP检测。检测结果显示:在2015—2017年分别检测的79、105、140批次样品中,EHP阳性率分别为56.96%、69.52%、29.28%;在凡纳滨对虾的仔虾、幼虾、中成虾养殖阶段均可检出EHP,但幼虾、中成虾的阳性率高于仔虾;鱿鱼、沙蚕和桡足类等对虾饵料生物携带有EHP。结果表明,天津市EHP流行率呈显著下降趋势,说明严格控制亲虾品质及引进无病毒感染种苗、加强检疫监测等措施,可以有效控制EHP流行。  相似文献   

9.
文章旨在研究不同水平虾青素对秀丽白虾亲虾抗氧化、繁殖及免疫能力的作用。试验选取3种等氮等脂饲料,通过加入加丽素红(含虾青素),使饲料内虾青素含量分别达到5%、10%、15%,依次标记为低、中、高3种含量组。试验选择雌雄亲虾各90尾,随机分配到18个培育池,每池10尾雌(雄)虾,试验为期10周。结果表明:(1)低含量组谷胱甘肽还原酶活性低于其余2组(P <0.05),高含量组过氧化氢酶活性高于其余2组(P <0.05)。(2)3组亲虾性腺指数、产卵数量等含量无显著差异(P> 0.05);中含量组雌虾卵黄蛋白含量高于高含量组(P <0.05),与低含量组无显著差异(P> 0.05)。(3)高含量组溶菌酶活性、转化生长因子含量高于其余2组(P <0.05),低含量组核因子含量低于其余2组(P <0.05),高含量组总一氧化氮合酶活性低于其余2组,白介素含量随虾青素含量增加而提升(P <0.05),3组无显著差异(P <0.05)。综上所述,使用合理含量的虾青素饲料可提升亲虾的抗氧化与免疫力,提升卵黄蛋白含量,从而提升亲虾的繁殖能力。  相似文献   

10.
(一)亲虾培育 1.亲虾来源:大部分来源于自然海区,北方地区多从台湾、广东、福建等省海洋捕捞中调运,也有少部分从人工养殖的日本对虾池中选择个体大、健壮的亲虾,经过越冬后供育苗使用。 2.光照要求:亲虾暂养需弱光,一般光照强度在500勒克斯以下。亲虾暂养室,可挂黑色窗帘,或用黑片将池上口盖严。  相似文献   

11.
试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。  相似文献   

12.
Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.  相似文献   

13.
14.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

15.
Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.  相似文献   

16.
Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.  相似文献   

17.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

18.
The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.  相似文献   

19.
<正>1.INTRODUCTION Ensuring transportation network security is one Of the most daunting challenges confronting homeland security agencies today.Significant research has been dedicated.To model and analyze the vulnerability of transportation systems,while notably fewer studies propose specific strategies for deploying defensive technologies to safeguard these systems.  相似文献   

20.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

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