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携带猪呼吸道冠状病毒S基因片段的重组腺病毒的构建及鉴定 总被引:1,自引:0,他引:1
利用RT-PCR技术扩增猪呼吸道冠状病毒(Porcine respiratory coronavirus,PRCV)AR310毒株的S基因主要抗原位点片段,构建了重组腺病毒中间载体pDNR-1r-S1和表达质粒pInt.AV1.SpaT-S1。采用Cre-LoxP同源重组腺病毒系统和共转染技术构建了携带PRCV S基因片段的复制缺陷型重组腺病毒,经目的基因PCR检测和序列测定,结果表明:PRCV S基因片段已正确地插入到腺病毒基因组中;Western blot和间接免疫荧光实验证明目的片段在HEK293细胞中成功地获得了表达;子代重组腺病毒Ad5-PRCVS1的滴度为7×107 TCID50/mL。携带PRCV S基因片段重组腺病毒的构建为PRCV和TGEV重组腺病毒新型疫苗的研究奠定了基础。 相似文献
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本研究通过病毒分离、PCR和基因测序等方法,从广东某鸭场疑似“白肝病”发病鸭的肝组织样品中分离了1株鸭3型腺病毒,命名为GD2019株。序列分析结果显示,分离株fiber基因包含fiber-1和fiber-2两个片段,长度分别为1380、1443 bp。鸭3型腺病毒fiber基因非常保守,GD2019株fiber-1和fiber-2基因与已报道的鸭3型腺病毒同源性均为100%,而与其他禽腺病毒同源性则较低,亲缘关系较远。 相似文献
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《中国预防兽医学报》2016,(7)
为分析贵州地区2013年~2015年仔猪病毒性腹泻发病情况和流行特征,本研究对2013年~2015年贵州省5个不同的地州(市)采集的27个规模养猪场7 153头猪进行发病时间、发病日龄、发病率、死亡率等发病状况调查,并采用RT-PCR方法对采集的203份仔猪腹泻粪便样品进行病原核酸检测。结果显示,猪群多在冬春季节发生腹泻,发病日龄为2日龄~7日龄,猪群腹泻发病率为61.07%,病死率为71.50%;病原核酸检测结果显示:猪流行性腹泻病毒(PEDV)的阳性率为63.54%,猪传染性胃肠炎病毒(TGEV)的阳性率为0.98%,猪轮状病毒(Po RV)的阳性率为7.88%;PEDV与TGEV混合感染率为0.99%,与Po RV混合感染率为10.84%。该调查结果表明贵州地区仔猪病毒性腹泻发病率及病死率均较高,引起仔猪病毒性腹泻的主要病原为PEDV,并且出现PEDV/TGEV和PEDV/Po RV的混合感染。 相似文献
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当前养殖母猪已成为农民脱贫致富的一条重要途径,龙泉市全市母猪养殖有了长足的发展,至2007年底共存栏母猪5879头.我们对2007年断奶仔猪疾病情况进行了跟踪调查,共收到1215个散养户和37个规模养殖户的有效问卷,共调查了断奶仔猪131250头,发病7514头,其中呼吸道疾病2616头,占总发病数的34.82%,,因呼吸系统疾病疾病死亡89头.形成僵猪257头.断奶仔猪呼吸道疾病已严重制约了我市养殖业的进一步发展. 相似文献
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PCR检测犬腺病毒方法的建立 总被引:1,自引:0,他引:1
利用人工合成的两条引物,对病犬肝脏和细胞培养物冻融上清中的1、2型犬腺病毒DNA进行多聚酶链式反应(PCR)检测;再将扩增产物进行同位素标记,与纯化病毒DNA进行打点杂交。扩增产物经电泳分析结果表明,其大小与设计的引物间的序列大小基本一致;扩增产物经标记后只与犬腺病毒DNA发生杂交反应,表明其为犬腺病毒特异性核酸片段。 相似文献
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为了防治猪支原体肺炎,提高养猪业的经济效益,笔者对本县6个规模养猪场进行了调查,并采取了疫苗和药物的综合防治措施,取得了满意的效果。1流行病学调查1.1易感动物各种年龄的猪都可发病,但哺乳仔猪和断奶仔猪发病率和死亡率较高,其次是怀孕后期及哺乳母猪。在调查的6个规模猪场中,有两个猪场,哺乳仔猪和断奶仔猪发病269头,死亡247头,死亡率91.8%;育肥猪321头,死亡4头,感染率100%,死亡率1.2%。1.2传染源母猪和初产母猪是支原体携带者,病原体在扁桃体上定殖,而不被检出可达数周、数月、数年,哺乳仔猪常被带菌母猪感染。1.3传播途径呼吸道是该… 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献
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以国际标准强毒R株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离MG,并收集感染鸡所产蛋分离MG。结果表明,人工感染48小时后上、下呼吸道及肺已被全面感染,96小时气囊已被感染,120小时输卵管已能分离到MG,卵巢始终分离不到MG。人工感染鸡自144小时便能在其所产蛋中分离出MG。药物治疗能在72小时内消除感染,油乳剂苗则需24天后逐渐降低蛋内MG分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内MG,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制. 相似文献
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家兔作为一种实验动物 ,推动了繁殖技术的发展。本试验通过对不同年龄公獭兔的睾丸进行组织学观察、测定 ,研究精子的发生规律 ,为系统地进行繁殖生理工作提供依据。1 材料与方法选 60日龄、75日龄、90日龄 3个年龄公獭兔各5只 ,用外科手术法摘取两侧睾丸 ,放入 Bouin氏液中固定 ,二甲苯透明 ,石蜡包埋 ,切成 5~ 8μm切片 ,H.E.染色。在显微镜下观察 ,并进行定量组织学指标测定及差异性比较。2 结果和讨论2 .1 睾丸定量组织学指标的测定结果 见表 1。表 1 獭兔睾丸定量组织学指标 μm,个 /精细管60日龄 75日龄 90日龄曲细精管… 相似文献
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Fractures of the anconeal process of 5 pigs ranging in age from 4 to 8 months were studied radiographically and histologically. Clinically, animals with a fracture of the anconeal process had a "tight," restricted gait. In pigs at 4.5 months of age, a radiolucent line through the base of the anconeal process was composed of fibrocartilage, fibrous connective tissue, and hyaline cartilage. Subperiosteal proliferation of woven bone was located along the cranial surface of the olecranon, adjacent to the base of the anconeal process. In older animals, the radiolucent line through the anconeal process contained variable amounts of fibrous connective tissue and fibrocartilage. The proliferation of subperiosteal bone at the base of the anconeal process formed a "buttress callus" which retained a radiolucent area between the callus and the proximal surface of the anconeal process. The latter region of radiolucency was continuous with the transversely oriented line that traversed the base of the anconeal process. 相似文献