水产养殖中水体污染的控制措施

随着水产养殖的工厂化,水体自污染日趋严重。如何控制污染,提高水质的质量,成为水产养殖者关心和研究的热点。1　水产养殖的自身污染传统的水产养殖是靠投饵料或施肥来获得尽可能多的水产品。生产中产生的残饵、残骸、渔体排泄物等使水产养殖产生自污染,尤其是随着养殖方式向集约化、工厂化发展,养殖密度和投饵量大大增加,残饵量和渔体排泄物也相应增加,养殖污染更趋严重。据报道,玉筋鱼养殖中,其代谢产物为投饵量的2 0 %～35 % ,残饵为投饵量的10 %～4 0 % ;鲑鳟鱼和斑点叉尾鱼回的总固体排泄物分别占投饵量的4 0 %～5 2 %和18%～6 9%。美…     

养殖黑鱼在解决好四个技术问题

近些年来 ,黑鱼市场走俏 ,池塘养殖黑鱼逐渐兴起。在鲤鱼养殖不景气的情况下 ,养殖黑鱼给养鱼户带来了可观的经济效益。但要养殖黑鱼必须解决好以下 4个问题。1　池塘选择养殖黑鱼的池塘不要太大 ,一般面积以 0 .2～ 0 .33ｈｍ2 为好。池塘水深为 1.5～ 2 .0ｍ ,底泥厚 15～ 2 0ｃｍ ,水源充足 ,排注水方便。2　鱼种投放投放鱼种的规格是根据市场商品鱼规格而定。目前 ,黑鱼个体重 0 .7～ 2 .0ｋｇ的好销售 ,因此 ,放养鱼种的规格应为每尾75～ 10 0ｇ。放养密度要依据饲料来源、饲养技术等因素确定 ,一般每 (6 6 7ｍ2 )投放鱼种 2 0 0 0～ 2…     

瑶鸡在40日龄前使用配合饲料喂养的效果

我镇推行“百万瑶鸡”养殖工程 ,发动群众养殖瑶鸡 ,走养殖致富之路。养鸡 ,除了在早期精心护理 ,如控制好温度 ,搞好防疫外 ,在 40日龄前选用优质配合饲料 ,使其生长迅速 ,体质健康 ,抗病力强 ,也是养鸡成功的关键。现将我镇2 0 0 0年瑶鸡养殖示范户 70户中 ,任选 1 0户 ,选用配合饲料的养殖效果报告如下。1　所用饲料1 .1　 1— 2 1日龄用料用金钱 (湛江 )有限公司生产的金钱 2 0 0小鸡料。营养成分 :蛋白质≥ 2 0 %、粗纤维≤ 5 %、粗灰分≤ 8%、总磷≥ 0 5 %、钙 0 7%～ 1 3%、食盐 0 2 5 %～ 0 80 %、赖氨酸 0 90 %。水分 :在 2…     

獭兔养殖技术要点

獭兔养殖成本低、效益高、行情好、易饲养。目前面积为 0 0 89～ 0 1 33ｍ2 的獭兔皮每张市价在 35～ 4 0元 ,且供不应求。一只商品獭兔的产值在 60元左右 ,其养殖成本不足 2 5元。养殖 1 0组獭兔 ( 1 0公、30母 )一年至少能繁殖 90 0只 ,一般养殖6个月 ,体重在 2 5ｋｇ以上时即可宰杀取皮。年净收益在 2万元以上。是发展前景看好的最佳脱贫致富产业项目之一。其养殖技术要点如下。1　选择优良品种　獭兔是一种皮肉兼用型兔 ,应选择体型大、毛质细腻、柔软、光亮、手感爽滑、白色或青色的法系或美系獭兔为优良品种。2　科学搭配饲料　獭…     

述评

近4年生猪养殖盈亏平衡点由4．5：1上升至6．5：1 2007年我国生猪养殖收入与成本相抵时，全国的生猪收购价格为8．8～9．0元／kg，即生猪养殖的盈亏平衡点为4．5：1；而2008年和2009年上涨至11．6～12．0元／kg，2010年继续小幅升至12．6～13．0元／kg，生猪养殖盈亏平衡点上升至6．5：1。     

獭兔养殖技术要点

獭兔养殖成本低、效益高、行情好、易饲养。目前 0 0 89～ 0 133ｍ2 的獭兔皮每张市价在 35～ 4 0元 ,且供不应求。一只商品獭兔的产值在 60元左右 ,其养殖成本不足 2 5元。养殖 10组獭兔 (10公、30母 )一年至少能繁殖 90 0只 ,一般养殖到 6个月 ,体重在2 5ｋｇ以上时即可宰杀取皮。年净收益在 2万元以上。是发展前景远大的最佳脱贫致富产业项目之一。1　选择优良品种獭兔是一种皮肉兼用型兔。应选择体型大 ,毛质细腻、柔软、光亮 ,手感爽滑 ,白色或青色的法系或美系獭兔为优良品种。2　科学搭配饲料獭兔是草食动物 ,因人工养殖全部食草…     

越冬养殖南美白对虾应注意的问题

珠江三角洲地区冬季低温时间短,气温回升快,养殖技术水平高,冬棚养殖南美白对虾的范围逐年扩大。有报道说冬棚养殖南美白对虾以每年0．53万～0．8万hm^2的速度逐年扩大。冬棚越冬高密度养殖南美白对虾1／15hm^2(亩)产750～900kg,获利l5000元已不是新闻了。     

青虾养殖业可持续发展浅析

青虾 ,又名日本沼虾 ,俗称河虾 ,广泛分布于我国各地江河、湖泊、水库、池塘及沟渠中 ,是我国淡水虾类中的一个重要种群。1　青虾养殖的优越性1 1　繁殖力强 ,能很快形成种群　青虾产卵期很长 ,每年 4～ 1 0月皆可产卵 ,并可多次产卵 ,一生可产卵 3次左右。青虾性成熟期短 ,我国长江下游 5～ 6月孵出的青虾 ,到 8～ 9月份体长达 3cm左右即可达第一次性成熟。1 2　生长快 ,养殖周期短　青虾幼体平均体长约0 2 3cm ,经 5 0～ 60d的生长 ,体长可达 2 5～ 3 0cm。一年可进行两茬养殖。1 3　肉味鲜美 ,营养价值高　青虾的肌肉氨基酸含量为 3…     

江苏省黄鳝寄生虫感染的初步调查

20 0 0～ 2 0 0 1年对江苏省洪泽、阜宁、无锡等地区养殖及野生黄鳝的寄生虫感染情况作了初步调查。查出7种寄生虫 ,其中以隐藏新棘虫、鳝锥体虫、毛细线虫、湖北双穴吸虫的感染率较高 ,分别达 97%、86 %、5 0 %和5 0 % ;感染强度大 ,最高分别达 12 7条、75条、2 5条和 18条 ,是江苏地区黄鳝养殖应重点防治的四种寄生虫     

池塘养乌鳢效益好

江苏省姜堰养殖区于 2 0 0 0～ 2 0 0 2年 ,采用池塘养殖乌鳢 ,3年取得了平均每年纯利 36 3元 /m2 的好效益。1　效益测算　 467m2 池塘 ,不足 9个月的养殖周期 ,平均每年收获乌鳢 1 1 81 3kg ,按平均售价1 7元 /kg计算 ,每年收入 2 0 0 82 1元。除去成本31 0 4 7元 (塘口费 1 0 0元 ,簖网费 30 0元 ,购买病鱼费 1 0 0 0元 ,种苗费 1 70 4 7元 )纯利润1 6977 4元 ,折合 36 3元 /m2 。在一个养殖周期内 ,平均每 1 0 0kg乌鳢消化小杂鱼 ( 1～ 6月 )1 5 0kg,死鱼 ( 5～ 9月 ) 1 5 0kg,病鱼 ( 5～ 9月 ) 5 0kg。2　池塘建造条件　池塘靠近水…     

RT—PCR对新城疫病毒（NDV）分离株的鉴定及其临床应用

采用新城疫病毒的通用引物PA PB、强毒引物PA PC、弱毒引物PA PD对11株贵州新城疫分离毒株与4株新城疫参考毒株进行了RT-PCR扩增.结果15株新城疫毒株均被PA PB引物扩增出359 bp的条带,F48E8、ND98、Fw、H2、P3、BY、L2、P1,P2被PA PC引物扩增出254 bp的条带,而PA PD引物未扩增出DNA条带;ND89、Lasota被PA PD引物扩增出254 bp的条带.而PA PC引物未扩增出DNA条带.采用3对引物对自然发病斗鸡脑、脾、咽喉试子、泄殖腔试子进行RT-PCR检测,确诊为斗鸡新城疫强毒感染,且与传统病毒分离与毒力鉴定的结果相一致.     

褪黑激素受体1a基因在内蒙古绒山羊垂体中的表达

本试验从内蒙古绒山羊脑垂体中提取总RNA,根据已发表的相近物种褪黑激素受体1a(melatonin receptor 1 a,MTNR1a)基因序列设计引物,利用实时荧光定量逆转录多聚酶链反应(real-time quantitative,RT-PCR)技术、组织原位杂交技术检测MTNR1a基因在内蒙古绒山羊垂体中的表达。结果显示,通过RT-PCR方法检测到MTNR1a基因在内蒙古绒山羊垂体中表达,利用原位杂交技术进一步确定MTNR1a基因在垂体中表达分布。结果提示,垂体是褪黑激素作用的靶器官,褪黑激素对绒山羊季节性繁殖的影响有可能是与垂体分泌的某些激素相互作用而发挥作用的。     

Evaluation of Western blotting methods using samples with or without sodium phosphotungstic acid precipitation for diagnosis of scrapie and chronic wasting disease

The purpose of this study was to enhance the sensitivity of the Western blot (WB) test for use as an alternative and confirmatory method for the diagnosis of scrapie and chronic wasting disease (CWD) in Canada by comparing 2 sample preparation procedures: an abnormal prion protein (PrPSc) concentration procedure using sodium phosphotungstic acid (PTA) precipitation and a procedure using crude sample without precipitation. A total of 100 cerebrum samples (52 sheep and 48 elk), including 66 negative (31 sheep, 35 elk) and 34 positive (21 scrapie and 13 CWD positive) samples diagnosed by using immunohistochemistry (IHC) on retropharyngeal lymph node (RPLN) and medulla oblongata at obex, were tested by using WB with the 2 sample preparation procedures. The WB using non-PTA enriched sample (crude extract) detected, on average, only 71.7% (9 of 15, 60.0% for scrapie, 5 of 6, 83.3% for CWD) of the samples that tested positive by using WB with PTA enriched samples. No case was positive by WB using crude extract but negative by WB using PTA enriched sample. No false positive was found. Serial dilution of PTA precipitated samples demonstrated that the technique increases the detection limit approximately 100 fold. Additionally, the comparison of the WB and IHC on cerebrum from all the positive cases demonstrated that WB following PTA precipitation and IHC had 100% agreement by detecting 6 positive for CWD on cerebrum; while IHC detected scrapie in only 14 out of 15 positive cerebrum samples by using WB following PTA precipitation. Phosphotungstic acid precipitation is therefore a useful adjunct to WB analysis of scrapie and CWD and tissues.     

Factors affecting the immunogenicity of Pasteurella haemolytica in mice

An appreciable level of immunity from intraperitoneal infection with Pasteurella haemolytica was established in mice by using a vaccine prepared in a conventional bacteriological culture medium, with aluminium hydroxide gel as adjuvant. The level of immunity could not be elevated by using bacteria grown in tissue culture media, enriched brain heart infusion broth, the addition of serum to the media or by using bacteria that had been harvested in the logarithmic growth phase. Although various extracts of the bacteria elicited a distinct immunity, the immunogenicity of vaccines containing bacteria could not be enhanced by augmentation with those products. The potential application of the vaccine in cattle and sheep is discussed.     

Quantitative assessment of renal cortical echogenicity in clinically normal cats

In this study, we assessed the renal cortical echogenicity of clinically normal adult cats by histogram analysis to obtain basic ultrasonographic data. Ultrasound images were taken under the following sets of conditions: (1) high contrast and low gain setting using a convex probe, (2) low contrast and high gain setting using a convex probe, (3) high contrast and low gain setting using a linear probe and (4) low contrast and high gain setting using a linear probe. Echogenicity of the region of interest (ROI) in the right and left renal cortices, liver and spleen was determined by histogram analysis; kidney/spleen (Kid/Sp) and kidney/liver (Kid/Liv) echogenicity ratios were calculated. Kid/Sp and Kid/Liv values varied among different ROI sites in the kidney when obtained using the convex probe, but were constant when obtained using the linear probe. Kid/Sp measured in the middle sites of the kidney showed similar values for the different settings; however, Kid/Liv differed between probes. The present findings suggest that determination of Kid/Sp using a linear probe is a feasible method for quantitative evaluation of renal cortical echogenicity in cats.     

穴位注射治疗鸭大肠杆菌病的初步研究

为改善家禽胴体品质和减少抗生素使用数量,根据中兽医辨证论治理论和整体的观点,采用穴位注射给药的方法对人工感染大肠杆菌病鸭作治疗保护试验,结果按氟甲砜霉素注射液推荐剂量的40％-50％给药仍有较好的治疗效果,与按100％推荐剂量胸肌注射给药的治疗组比较,差异不显著(P>0.05),而与按50％推荐剂量胸肌注射给药的治疗组比较差异显著(P<0.05),穴位注射给药有较好的疗效。试验结果显示了减少抗生素使用量和改善家禽胴体品质的治疗新方法的可行性。     

PULMONARY ANGIOGRAPHY USING 16 SLICE MULTIDETECTOR COMPUTED TOMOGRAPHY IN NORMAL DOGS

We report a canine computed tomography (CT) pulmonary angiography technique using multidetector CT (MDCT). CT pulmonary angiography using a 16 slice MDCT was performed on five healthy, anesthetized beagles. A helical acquisition with pitch of 1.4 was used. The time delay for the angiographic study was determined using a bolus‐tracking program. A dose of 400 mg I/kg of nonionic contrast medium (Iohexol 300 mg I/ml) was administered to each dog via a cephalic catheter using an angiographic power injector at a rate of 5 ml/s. In two dogs a second study, using a contrast medium dose of 200 and 600 mg I/kg was performed. Arterial enhancement of transverse and reformatted images was classified subjectively as excellent, good, or poor, and assessed objectively by measuring Hounsfield units at the right main pulmonary artery. Angiographic studies were evaluated by two radiologists to determine the number of subsegmental arterial branches visualized. The median number of subsegmental arterial branches identified was five (range: 2–7). Based on the time attenuation curve obtained by the bolus‐tracking program, there was consistent enhancement of the right main pulmonary artery beginning at 6 s and peaking at 8 s in 4/5 dogs. The contrast medium dose of 400 mg I/kg produced good to excellent vascular enhancement in the same 4/5 dogs. A dose of 200 mg I/kg resulted in poor enhancement. CT pulmonary angiography using MDCT and an automated bolus‐tracking program allows rapid, consistent evaluation of the pulmonary vasculature using a single dose of 400 mg I/kg of contrast medium.     

采用微卫星(SSR)标记研究苜蓿品种鉴定初报

苜蓿(Medicago sativa L.)是异花授粉植物,自交则衰退,品种内个体间基因型杂合,因此品种鉴定的难度较大。本文以苜蓿地方品种、育成品种和引进品种为材料,采用微卫星分子标记研究和鉴定供试苜蓿品种。结果表明:采用变性聚丙烯酰胺凝胶电泳进行PCR产物分离可以避免非特异带的出现,降低了实验误差;在品种鉴定方面,AFca1位点片段大小为148 bp的等位基因在龙牧系列品种中出现的频率明显高于其它品种,可作为品种区别的依据;在其它品种之间或与杂花苜蓿品种之间,多数的SSR位点有基本相同的基因型和等位基因,品种间的区别主要在于等位基因频率的差异,而大部分品种之间频率的差异很小,不能作为鉴定的依据,即仅靠有限的SSR位点很难区别供试苜蓿品种;通过某些品种特有性状相连锁的分子标记与其它品种之间的差异作为鉴定的依据进行探索研究,或许能真正将某些苜蓿品种与其它品种区别开。     

微波炉测定紫花苜蓿含水量的初步研究

采用微波炉加热干燥法测定紫花苜蓿含水量的结果表明．其与烘箱法测定值符合性好，具有精确度高、准确性好的特点。另外，用微波炉法与烘箱法测定值间的回归方程进行苜蓿含水量的预测，不如直接用微波炉测定效果好。     

犬血浆中塞拉菌素含量的高效液相色谱-荧光检测方法的建立

本研究以多拉菌素为内标,建立了犬血浆中塞拉菌素的高效液相色谱-荧光检测方法.用乙腈作为血浆蛋白沉淀剂,用SampliQ C18型SPE固相萃取柱进行净化,用1-甲基咪唑和三氟乙酸酐衍生化处理.色谱条件为ODS-1色谱柱(250 mm×4.6 mm),流动相为甲醇∶乙腈∶1％1-庚烷磺酸∶0.4％乙酸=40.0∶57.6∶0.9 ∶ 1.5(v/v/v/v),流速1mL·min-,进样量20μL,激发波长355 nm,发射波长465 nm,柱温30℃.方法的检测限为0.25 ng·mL-1,线性范围0.5～50.0 ng·mL-,变异系数为1.47 ％～3.31％,方法的样品平均回收率为94.0％.结果表明,所建方法准确、灵敏度高和重复性好,可用于犬体内塞拉菌素血药含量的测定.