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161.
162.
非典型新城疫是指在家禽中发生的临床表现和解剖变化不典型的新城疫(ND),是在商业禽群中广泛应用ND疫苗以后出现的ND发病形式。虽然中国家禽业的典型ND已经得到较好的控制,但非典型ND时有发生。幼龄鸡发生时,可表现精神沉郁、羽毛松乱、翅膀下垂、瘫痪或站立不稳、食欲减退或废绝、呼吸急促、咳嗽、口流粘液、拉黄绿或黄白色粪便等症状,随着病程的延长可表现歪脖、腿麻痹等神经症状,死淘率明显增加; 相似文献
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164.
我国水产种业发展的几点思考 总被引:1,自引:0,他引:1
对我国水产种业发展的现状进行了总结与评价,对水产种业发展的机遇与挑战进行了分析。根据国家水产业发展的有关文件和产业发展趋势,从科技创新、体系建设和政策措施方面提出了加快水产种业发展的建议。 相似文献
165.
ELISAs based on rNcGRA7 and rNcSAG1 antigens as an indicator of Neospora caninum activation 总被引:1,自引:0,他引:1
Hiasa J Kohara J Nishimura M Xuan X Tokimitsu H Nishikawa Y 《Veterinary parasitology》2012,187(3-4):379-385
Bovine abortion caused by the Apicomplexa parasite Neospora caninum is a major economical problem in the livestock industry worldwide. However, the relationship between N. caninum infection and abortion is still unknown. Our study aimed to elucidate the relationship between parasite-specific antibody responses, parasite stages and abortion. In experimentally infected cattle, anti-NcGRA7 IgG1 antibody was predominantly detected during the acute infection stage, while the production of anti-NcSAG1 IgG1 antibody was observed during both acute and chronic stages. Furthermore, levels of anti-NcGRA7 IgG2 antibody were lower than those of anti-NcSAG1 IgG2 antibody. When tested on cattle with Neospora-associated abortion, positive rates of the anti-NcGRA7 IgG2 antibody were significantly lower than those of the anti-NcSAG1 antibody, although there was no difference in IgG1 antibody-positive rates between the two antigens. In addition, anti-NcGRA7 IgG2 antibodies were not detected in cattle for more than 30days after abortion. Our results suggested that anti-NcGRA7 and anti-NcSAG1 antibodies are suitable indicators for the activation stage of N. caninum infection and broad detection of the infection, respectively. In conclusion, the use of recombinant NcGRA7 and NcSAG1-based ELISAs will be useful for evaluating the abortion risk associated with N. caninum infection. 相似文献
166.
Huang X Xuan X Yokoyama N Katayama Y Anzai T Igarashi I 《Veterinary parasitology》2006,140(1-2):158-161
Two enzyme-linked immunosorbent assays (ELISA) with recombinant protein as antigens were evaluated by comparison with the indirect fluorescent antibody tests (IFAT) for the detection of specific antibodies to Babesia caballi and Babesia equi, respectively in 380 sera from experimentally infected, uninfected, and field horses. The high concordances of 92.4% (351/380) and 98.2% (373/380) between ELISA and IFAT for B. caballi and B. equi, respectively suggest that ELISA, especially for B. equi infection, could be alternative to the corresponding IFAT for serodiagnoses of equine piroplasmosis, although some improvements are required in ELISA for B. caballi. 相似文献
167.
Miyama T Inokuma H Itamoto K Okuda M Verdida RA Xuan X 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(12):1371-1373
The clinical usefulness of antibodies against Babesia gibsoni detected by ELISA with recombinant P50 was examined in dogs in an area where B. gibsoni infection was endemic. Only 8 among 14 dogs with acute type B. gibsoni infection without a previous history of infection were positive. This high percentage of false-negative results is thought to be a weak point of ELISA as a diagnostic tool. However, 14 other anemic dogs with a confirmed history of B. gibsoni infection were all positive, thus confirming the higher sensitivity of ELISA in detecting a history of infection. 相似文献
168.
Nishikawa Y Xuan X Kimura M Otsuka H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1999,61(10):1113-1117
A recombinant canine herpesvirus (CHV) which expressed glycoprotein B (gB) of pseudorabies virus (PrV) was constructed. The antigenicity of the PrV gB expressed by the recombinant CHV is similar to that of the native PrV. The expressed PrV gB was shown to be transported to the surface of infected cells as judged by an indirected immunofluorescence test. Antibodies raised in mice immunized with the recombinant CHV neutralized the infectivity of PrV in vitro. It is known that the authentic PrV gB exists as a glycoprotein complex, which consists of gBa, gBb and gBc. In MDCK cells, PrV gB expressed by the recombinant CHV was processed like authentic PrV gB, suggesting that the cleavage mechanism of PrV gB depends on a functional cleavage domain from PrV gB gene and protease from infected cells. 相似文献
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为探究有机无机肥配施对旱地冬小麦减肥增效的内在机制,依据7年长期定位试验,采用裂区设计,设5个氮水平(0、75、150、225、300 kg·hm-2)为主处理,配施有机肥(用量30 t·hm-2)和不施有机肥为副处理,单施化肥处理分别记为N0、N75、N150、N225、N300,配施有机肥处理分别记为MN0、MN75、MN150、MN225、MN300。在分蘖、拔节、开花、灌浆、成熟期采集植株地下(0~20 cm根系)和地上部分,对籽粒产量及其构成因素、氮素吸收利用状况进行研究。结果表明,随施氮量增加,冬小麦有效穗数、穗粒数先增加后减少,而千粒质量则逐渐下降。配施有机肥处理有效穗数较单施化肥处理整体提高7.1%。MN150处理籽粒产量最高,达到6 311 kg·hm-2。单施化肥处理籽粒对氮素的吸收主要通过花前氮素转运,而配施有机肥处理花前氮素转运和花后吸收对籽粒氮素积累作用同等重要。与单施化肥相比,有机无机肥配施花前氮素转运量、花后氮素积累量分别提高9.80%、33.10%。花前氮素转运以茎秆为主,花后氮素积累量在MN150处理最高。配施有机肥显著提高氮素利用率和农学效率,降低施氮量在增加氮素利用率与农学效率的同时提高了氮素收获指数。适量增施氮肥显著提高叶片硝酸还原酶活性,单施化肥和配施有机肥分别在N225、MN150处理达到最高,有机无机肥配施下,硝酸还原酶活性在分蘖、拔节、开花和灌浆期分别提高25.94%、12.88%、9.90%和12.35%。综合来看,有机无机肥配施下施氮量为150 kg·hm-2时既能促进冬小麦植株对氮素的吸收利用,又有利于保证西北旱地冬小麦稳产高产。 相似文献