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61.
During the summer of 1990 deaths, occurred in racing camels (Camelus dromedarius) associated with a specific disease syndrome. Clinical signs included pyrexia, coughing, lachrymation, oedema of the throat and submandibular region and enlargement of submandibular lymph nodes. In terminal cases nervous signs were present and sometimes there was bloody diarrhoea and vomiting. Of 480 camels at least 70 animals were affected with the disease and about 40 died. Morbidity and mortality was greater in camels recently imported. Consistent necropsy findings were extensive petechial and ecchymotic haemorrhage beneath the epicardium, endocardium and visceral pleura and in the mediastinal lymph nodes, and haemorrhagic oedema of the pharyngeal and laryngeal areas. Haemorrhages occurred more variably in abdominal organs and on the omasal and abomasal mucosa. Bronchopneumonia, omasitis and abomasitis were observed on microscopic examination, together with liver and kidney lesions of presumed toxic origin. Fungal hyphae and, occasionally, the characteristic conidial morphology of Aspergillus fumigatus were seen in sections and direct smears from lesions in the respiratory and alimentary tracts. A fumigatus was cultured from trachea, bronchi, bronchioles, lung tissue, heart blood, omasum, abomasum, ileum and submandibular lymph nodes. Whether the role of Aspergillus in the overall syndrome is primary or secondary has not been established; no other potential aetiological agent has been identified.  相似文献   
62.
With the advancement of assisted reproductive biotechnologies, preselecting the sex of offspring has become an important goal for cattle and other livestock breeding as well as for research. The aim of this study was to investigate the feasibility of producing enriched pools of X‐ or Y‐chromosome‐bearing sperm by vertical swim‐up through a long, narrow column. Sperm recovered from the top portion of the column was predominantly Y‐bearing (60%, p < 0.05), which were capable of fertilizing matured oocytes and produce significantly more male embryos compared with standard swim‐up protocol.  相似文献   
63.
当前安徽特色农业呈不断发展趋势:专业化和产业化不断增强、基础设施逐步改善、科技扶持力度不断增强、农业旅游等功能有所拓展。但是也存在优良品种保护和开发力度不够,生产技术水平相对较低,基层农技推广和农村实用人才难以满足需求,基础设施建设投入不足,主产区生态环境保护不够,产业化有待推进,休闲、观光旅游功能拓展缓慢等问题。建议从五个方面推进安徽特色农业可持续发展:加强基层农业科技人才开发;推进特色农业产业化发展;加强优良品种开发与保护;完善农业基础设施建设;保护生态环境,发展农业旅游。  相似文献   
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