Epidemiological studies of piglet diarrhoea in intensively managed Danish sow herds. II. Post-weaning diarrhoea   总被引：1，自引：0，他引：1  

B Svensmark  K Nielsen  P Willeberg  S E Jorsal 《Acta veterinaria Scandinavica》1989,30(1):55-62

This study comprised 48,931 litters in 89 sow herds. During the study (1976-82) weaning age decreased from approx. 42 days to approx. 30 days. The mean incidence of post-weaning diarrhoea was 6.0% of litters weaned, with little variation by year but with considerable variation among herds. Within the individual herd increased incidence occurred over limited periods, probably associated with specific infections. Litters with diarrhoea during the suckling period had increased risk of post-weaning diarrhoea. The incidence of post-weaning diarrhoea increased with litter size at weaning. Thus, a litter of 11-12 piglets at weaning had 1.2 times higher risk than litters with 8-10 piglets. In contrast to pre-weaning diarrhoea, there was no association between parity of the sow and diarrhoea in the litter after weaning. Litters weaned below 2 weeks of age had a 2-fold risk of developing diarrhoea after weaning and a 2.4-fold higher mortality rate than did litters weaned at 6-7 weeks. Similarly, litters weaned at an individual piglet weight below 3 kg bodyweight had a 3-fold higher risk of developing diarrhoea after weaning and a 5-fold higher mortality rate than did pigs from litters weaned at a bodyweight of 7-8 kg. The incidence of post-weaning diarrhoea decreased with increasing herd size. Piglets from litters with post-weaning diarrhoea had reduced weight gains after weaning and were 2.3 days older at 25 kg bodyweight than piglets from non-diarrhoeic litters. Likewise, diarrhoea after weaning was associated with an increased incidence of diseases of the skin and respiratory tract. Thus the risk of contracting respiratory disease was 4 times greater in diarrhoeic litters.  相似文献   

马惠宁输油管道清管的风险分析及对策     

孙维中  屈涛  胡成洲 《油气储运》2001,20(2):44-45

介绍了马惠宁输油管道的施工和投产后的运行现状。由于多年运行，管道腐蚀严重，为此拟采用清管器进行内检测。对用清管器进行内检测可能产生的风险进行了分析，并提出了减小风险的对策。  相似文献   

四川乐山地区紫茎泽兰的入侵定殖和风险评估   总被引：4，自引：0，他引：4  

易建平  印丽萍  李大春  李风婷  叶军 《植物检疫》2003,17(6):333-336

本文报道了四川省乐山地区犍为县塘坝乡境内入侵新物种一紫茎泽兰的分布、发生和定殖入侵情况。结合紫茎泽兰的生物学特性和当地的地理气候特征，对紫茎泽兰入侵乐山及其近邻地区的风险进行评估。  相似文献   

发展我国洪水保险的制度思考——美国洪水保险制度的借鉴与启示     

鲜明 《四川畜牧兽医学院学报》2005,3(3):33-35

洪水保险是一项重要的非工程防洪措施.美国是世界上最早建立国家强制性洪水保险体制的国家,经过艰难曲折的探索,闯出了一条成功之路.我国的洪水保险体制还处于积极探索阶段.中美两国尽管国情差异较大,但以洪水保险作为推进洪泛区洪水风险管理的经济手段,并以立法和国家计划等措施来保障实施的作法是值得借鉴的.本文就美国洪水保险制度的发展与沿革,寻找对我国建立洪水保险制度一些有益的启示,并就此提出了一些建设性意见.  相似文献   

油气管道风险管理技术现状及对策   总被引：3，自引：0，他引：3  

冯琦  张明智  窦彦辉  崔中兴 《油气储运》2004,23(7):63-64

介绍了国内外油气管道风险管理技术的研究现状、应用成果及最新的发展趋势,对比分析了国内外油气管道风险管理技术的差距,强调了油气管道风险管理的重要性,指出了油气管道风险技术的发展方向,为油气管道安全运行提供了技术支持.  相似文献   

朱砂叶螨对两种杀螨剂的抗性遗传力及风险评估   总被引：3，自引：3，他引：3  

何林  赵志模  邓新平  王进军  刘怀 《植物保护学报》2002,29(4):331-336

在室内抗性培育的基础上,应用数量遗传学中的域性状分析法研究了朱砂叶螨对甲氰菊酯和阿维菌素两种杀螨剂的抗性现实遗传力,并对两种药剂在不同杀死率下,朱砂叶螨抗性发展的速率进行了预测。结果表明,用甲氰菊酯、阿维菌素分别连续汰选16、18代后,朱砂叶螨对两者的抗性分别为28.61和4.36倍,抗性现实遗传力分别为0.2685和0.1385。在室内选择条件下,杀死率为50％～90％时,要获得10倍抗性,甲氰菊酯需要约13～6代,阿维菌素需要约28～13代。生物源农药阿维菌素的抗性风险明显低于菊酯类药剂甲氰菊酯。试验结果为朱砂叶螨抗性治理提供了理论依据。  相似文献   

Annual bluegrass (Poa annua L.) control in bentgrass (Agrostis palustris Huds.) green with sequential application of bispyribac‐sodium combined with dinitroanilines*     

NAM‐IL PARK  YUKO SUTO  YUTAKA MIURA  NOBUO NAKATANI  SHIN‐ICHI IORI  MASARU OGASAWARA 《Weed Biology and Management》2002,2(3):159-162

  相似文献   

Effects of soil moisture conditions on the emergence of weeds and rice plants from rainfed paddy soils in north‐east Thailand     

HIROHIKO MORITA  NOBUYUKI KABAKI 《Weed Biology and Management》2002,2(4):209-212

  相似文献   

Changes in the abundance of weeds in spring cereal fields in Finland     

T Hyvönen  E Ketoja†  & J Salonen 《Weed Research》2003,43(5):348-356

  相似文献   

农药混配室内毒力测定的一种实验技术   总被引：16，自引：0，他引：16  

陈福良  郑斐能 《农药科学与管理》1997,18(4):30-31

本文介绍了一种用于测定杀菌剂之间相互作用的实验设计，笔者借且作杀虫剂混配室内毒力测定，该实验设计具有覆盖面宽，成功率高，工作量小等特点。  相似文献