Housing of Pregnant Sows in Loose and Confined Systems–a Field Study 1. Vulva and Body Lesions,Culling Reasons and Production Results

A field study was carried out in 18 herds with loose housing of pregnant sows (loose herds) and in 18 herds with tethered or stalled pregnant sows (confined herds). Three of the loose herds were excluded due to different kind of flooring from the rest of the herds. The remaining 15 herds had partly slatted concrete floors and electronic sow feeding. The frequencies of sows with vulva and body lesions, thin sows as well as the culling reasons and production results were used as animal welfare indicators for the herds. Vulva lesions were found only in the loose herds and the mean prevalence proportion of sows with lesions within these herds was 15.2%. All vulva lesions observed in this study seemed to be caused by biting. The relative risk of vulva lesions was 2.6 times higher in the loose herds with no roughage feeding as compared to loose herds with appetite feeding of roughage. The sows in the loose herds, that had a feeding station with a mechanical hind gate had 1.8 greater risk of vulva lesions than sows in the loose herds that used a feeding station with an electronic gate.The mean prevalence proportion of sows with body lesions was 13.1% in the loose herds and 4.0% in the confined herds. Aggression between sows seemed to be the main cause of body lesions in the loose herds, while decubitus ulcers on the shoulders were the main cause of body lesions in the confined herds. Sows in loose herds that were not fed additional roughage feeding had 1.7 times greater risk of body lesions than sows in herds that used additional roughage feeding.The main culling reasons and production results were similar in the loose and confined herds. This study showed that there were welfare problems both in confined and loose herds, however, with improved management, many of the welfare problems associated with loose housing can be reduced.     

计算机判断两个表格之间相似程度的一种方法

介绍了以某表格文本为标准，借助数组，利用计算机对其它表格文本进行分类，从而实现对两个表格文本相似程度判断的一种方法。     

采用SPWM电容的单相电机研究（Ⅰ）

提出了一种用ＳＰＷＭ逆变电容替代单相双值电容电机中常规电容的方案．定性分析表明此方案取消了原电机中的离心开关，为电动机提供可连续变化的电容，使电机获得接近圆形的旋转磁场，且这种特点不随工作点的变化而变化，因而改善了电机性能，并为电机设计提供灵活性．     

山羊痘病毒粒子的电子显微镜观察

本研究室2003年以来对山羊痘病毒感染多种细胞进行了透射电镜观察。在感染的皮肤和黏膜上皮细胞浆中观察到大量不同成熟阶段的典型山羊痘病毒粒子，病毒粒子也见于巨噬细胞、成纤维细胞、血管内皮细胞胞浆内，甚至少量散在血管腔中。用山羊痘病毒分离物感染鸡胚绒毛尿囊膜形成痘斑，其上皮细胞和成纤维细胞中也可见成熟和不成熟的病毒粒子，同时感染BHK-21细胞也观察到典型的山羊痘病毒粒子。     

库尔勒香梨优斑螟触角感受器超微结构观察

为研究香梨优斑螟触角感器的种类、分布和形态特征,利用电子扫描显微镜,对香梨优斑螟成虫触角感器进行观察。结果表明:成虫触角上存在着6种化学感器,即毛形感器、刺形感器、柱形感器、耳形感器、腔锥形感器和鳞形感器,其中,毛形感器数目最多,柱形感器雄虫特有,柄节和梗节上没有发现感器。研究香梨优斑螟触角感器为其形态学、行为学和电生理学等方面的研究提供基础资料,同时对香梨优斑螟触角与其相近种昆虫触角间的差异及部分感器可能具有的生理功能进行了分析。     

电子商务对我国农村地区饲料营销的影响

随着社会经济的不断发展、互联网技术的不断成熟,虚拟化、快捷化电子商务模式的出现彻底改变了局限于特定时间和空间的传统经营模式,丰富了企业的营销方式。农村地区是我国畜牧业和养殖业发展的重点区域,饲料需求较强,如何通过电子商务积极创新营销策略增加收益,事关饲料企业的发展。本文通过阐述我国农村地区饲料营销的电子商务发展现状,进而分析电子商务对我国农村地区饲料营销的有利和不利影响,以期对饲料企业未来电子商务的发展方向进行展望。     

利用针叶指示电子废物拆解区重金属的污染

为了给评价典型区域重金属污染提供有效的生物监测方法,利用ICP-MS检测了典型电子废物拆解区及其对照区6种常见木本植物叶中13种重金属元素的含量,比较了不同种类的木本植物叶对金属元素的累积能力,并探讨了叶片中重金属的可能来源。结果表明,Hg、Mn等重金属含量在0.025~393 mg·kg^-1之间,电子废物拆解区和对照区植物叶中Hg、Sn、Sb、Co、Cr、As、V、Se和Pb等金属的含量表现出显著的区域性差异(P< 0.05)。从主成分分析结果可推测出Mn、Cu、Co、Ni、Pb、As、Sb、V和Hg的来源较为一致,可能来源于拆解导致的土壤或大气污染。"富集因子"计算结果表明,侧柏和柳杉对Hg、Cd、Se、Sn、Sb、Pb和Cu等有较好的指示作用。     

浅谈电子阅览室的读者服务与用机维护

本文从图书馆电子阅览室的实际出发，介绍了电子阅览室的服务项目及读者用机管理方法，并提出了计算机维护的具体措施，对搞好同类电子阅览室的管理具有一定的参考作用。     

电控发动机微机测试系统的设计

电控发动机能根据工况自动调整点火提前角，并提供与该工况相适应的混合气，从而实现了对汽油机所供混合气成份与点火时刻的优化控制。但电控系统结构复杂，难以用常规的仪器测试发动机的性能和诊断故障。为此，设计了以PC工控机为核心的微机测试系统。通过对电控发动机的温度、转速、点火等信号的采集和处理，来测试发动机的工作性能。系统具有可靠性高、抗干扰性强、操作方便等优点。