论改进中小型养禽场经营管理与企业诊断（下）

企业和人一样，也会生病。企业诊断就是给企业看病。     

农电企业管理信息系统的研究与开发

编者按1997年将是农电企业计算机应用向纵深发展的一年。在全国各行各业联网大潮的推动下，农电企业今后一段时期的主要技术课题将是建设计算机网络，实现企业信息共享，使生产管理工作步入现代化的轨道。针对当前农电企业计算机应用水平落后、人才债乏、经济条件有限等问题，本栏将有针对性地向全国读者介绍适合我国国情及农网特点的、具有一定代表意义的县（市）局建设、管理、使用计算机网络以及开发计算机网络应用软件的成功经验和典型示例。本期介绍的是黑龙江省尚志市电业局借助高校人才、技术优势开发的企业MIS系统。目前，该系统…     

咖啡短体线虫分子鉴定

本实验采用单条线虫法提取DNA,rDNA-ITS-PCR技术扩增目的片段(ITS1、5.8S、ITS2和部分的18S和28S),将此片段纯化回收,克隆测序分析,与GenBank比对,结果为:该种群的基因序列与AY561436(基因库编号)的相似度为92.3%,与AB053485的相似度为91.3%.分子鉴定结果与形态鉴定该线虫为咖啡短体线虫.     

渗滤取水技术在浠水县南城水厂的

渗滤取水技术主要是集取河床潜流水和河床渗透水。取水原理是利用取水系统自身运行产生的诱渗方式,诱导河水下渗,穿过滤床表面滤膜（泥膜）及河床下砂卵石层,形成取水的持续补给。再通过河底反向钻孔群、过滤器进入渗滤孔及汇水系统,并经过河床底部基岩中开凿的水平输水隧道等工程措施取出地表,实现取水和制水一体化。该技术适用于取水河段河流保持有一定的迳流量且为流动水体,河床下有足够厚度和分布面积的砂卵石层天然滤床,具有稳定的基岩地层。取水构筑物由渗流孔群、汇水硐室、输水隧道、集水竖井等组成。介绍了浠水县南城水厂采用该项技术的应用实例及设计参数,可供类似工程参考。     

温度应力对钢筋混凝土结构影响及构造措施

本文论述了温度应力、温度荷载的取值,并根据实际情况提出了结构设计和施工时裂缝控制的构造措施。     

巩固畜牧产业发展 助推乡村振兴

<正>农村养殖业生产的形式比较单一,分为家庭散养户和小型规模化养殖场两种。随着农村劳动力的转移,大量劳动力外出务工,从而使家庭散养户逐渐减少。同时受非洲猪瘟和新冠肺炎疫情的影响,猪价持续走低,对畜牧产业的发展构成了一定威胁。为更好地巩固畜牧产业的发展,解决养殖过程中存在的实际问题,获得更好的社会效益和经济效益,稳定农民收入,助推乡村振兴,提出相应的解决措施来巩固畜牧产业,确保畜牧产业平稳健康的发展。     

中小型猪场市场调查及建场类型

加入世界贸易组织后,国内畜牧业面临机遇和挑战,从分散、小规模、传统的生产方式逐步向规模化、集约化和现代化方向发展,规模化生猪养殖将是发展的必然趋势。但许多养殖户由于资金、技术及场地等限制不可能建立大型养猪场,多为中小型。通过生猪市场调查、分析和对养殖场类型及特点的归纳,正确指导从业人员科学兴办中小型猪场,提高养殖效益走上致富道路,为养殖户科学办好中小型猪场提供技术支撑和参考。     

Progression of Mycoplasma hyosynoviae infection in three pig herds. Development of tonsillar carrier state, arthritis and antibodies in serum and synovial fluid in pigs from birth to slaughter

In this investigation, natural infection with Mycoplasma hyosynoviae was followed in groups of individual pigs in three different herds with regard to occurrence of tonsillar carrier state, clinical arthritis and development of antibodies in serum and in synovial fluid. Antibodies were detected by a polyclonal enzyme-linked immunosorbent assay (ELISA) developed for experimental use. The infection with M. hyosynoviae progressed very differently in the three herds investigated. In one herd, the infection was apparently limited to adult pigs. In a second herd, all pigs became tonsillar carriers of M. hyosynoviae, but no mycoplasma-related arthritis nor any serological response was demonstrated within the growing-finishing period. In the third herd investigated, tonsillar infection was detected in all pigs, clinical cases of M. hyosynoviae arthritis followed and a moderate serological response was observed in some, but not all, pigs. In all three herds, M. hyosynoviae infection was carried in the tonsils of the adult pigs, but it was only occasionally transmitted from sows to piglets. Maternal antibodies were transferred to the piglets and persisted for approximately 8-12 weeks. After weaning, some pigs became infected before 20 weeks of age, while others did not. In the majority of cases, the tonsillar infection was established from 11 weeks of age or older. A latent tonsillar infection was present for a period of several weeks within the group of investigated pigs before cases of generalized infection and arthritis were seen. In some cases, generalization of M. hyosynoviae infection in the blood and in joints was observed in spite of the detection of an active serological response a few weeks earlier. The present work suggests that generalization of the infection and development of arthritis may depend on age, immunity, virulence factors and/or infection pressure; in some herds maybe combined with certain triggering mechanisms such as stress and lowered general resistance.     

Mycoplasmas isolated from the respiratory tract of cattle and goats in Tanzania

A microbiological study of the mycoplasma flora in the respiratory tracts of cattle and goats in selected regions of Tanzania is described. In the examination of cattle, mycoplasmas were isolated from 60 (17.8%) of the 338 examined lung samples, 8 (47.1%) of the 17 lymph nodes, 4 (13.3%) of the 30 pleural fluid samples and 4 (3.9%) of the 103 nasal swabs examined. All the isolates were identified as Mycoplasma mycoides subsp. mycoides, Small Colony type except for one isolate from pleural fluid which was identified as Mycoplasma arginini. M. mycoides subsp. mycoides, Small Colony type was isolated from samples originating from Dodoma, Iringa, Mbeya, Morogoro and Shinyanga regions where outbreaks of contagious bovine pleuropneumonia had been reported. In the examination of goats, mycoplasmas were isolated from 54 (34.0%) of the 159 examined lung samples, 41 (18.1%) of the 226 nasal swabs and 4 (40.0%) of the 10 pleural fluid samples. The species demonstrated were Mycoplasma capricolum subsp. capripneumoniae, M. mycoides subsp. mycoides, Small Colony type Mycoplasma ovipneumoniae and M. Capricolum subsp. arginini. The isolation of M. capripneumoniae in the Coast and Morogoro regions confirmed the presence of contagious caprine pleuropneumonia in the regions.     

Increasing prevalence of Mycoplasma bovis in Danish cattle

A study on the prevalence of mycoplasmas in pneumonic bovine lungs was performed on material submitted for diagnostic purposes at the Danish Veterinary Laboratory, Copenhagen. Among the 50 examined cases 43 (86.0%) were found to be infected with mycoplasmas. The predominant mycoplasmas were Ureaplasma spp. (72.0%), M. dispar (48.0%) and M. bovis (24.0%). Other mycoplasmas were M. bovirhinis (20.0%) and M. bovigenitalium (6.0%). Among the infected lungs multiple species infections were predominant (76.7%) over single species infections (23.3%) with M. dispar-Ureaplasma (25.6%), M. bovis-Ureaplasma (18.6%) and M. dispar-M. bovirhinis-Ureaplasma (11.6%) infections being the most frequently encountered combinations. There appears to be an increasing prevalence of M. bovis (24.0%) as compared to earlier reports (0.6-2.0%), thus calling for special attention upon this mycoplasma. Pulsed field gel electrophoresis (PFGE) analysis of 11 field isolates of M. bovis from 9 different farms revealed different profiles except for 2 isolates which were recovered from the same farm. Because mycoplasmas belonging to the 'M. mycoides cluster' were not encountered during this study; it appears that the Danish cattle population is still free from this group of mycoplasma in spite of their presence in some other European countries.