首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   176篇
  免费   12篇
综合类   18篇
水产渔业   2篇
畜牧兽医   165篇
植物保护   3篇
  2023年   1篇
  2021年   1篇
  2020年   8篇
  2019年   4篇
  2018年   1篇
  2017年   3篇
  2016年   12篇
  2015年   4篇
  2014年   6篇
  2013年   16篇
  2012年   2篇
  2011年   4篇
  2010年   6篇
  2009年   12篇
  2008年   5篇
  2007年   4篇
  2006年   4篇
  2005年   3篇
  2002年   2篇
  2001年   3篇
  2000年   1篇
  1999年   7篇
  1998年   16篇
  1997年   9篇
  1996年   6篇
  1995年   4篇
  1994年   6篇
  1993年   7篇
  1992年   7篇
  1991年   7篇
  1990年   5篇
  1989年   4篇
  1988年   6篇
  1987年   1篇
  1979年   1篇
排序方式: 共有188条查询结果,搜索用时 343 毫秒
81.
Benign masses in the pericardium of two dogs   总被引:1,自引:0,他引:1  
Two miniature Schnauzer dogs were treated for pericardial masses. In one dog the mass consisted of necrotic fat that was attached to the apex of the pericardium by a pedicle. No obvious communication with the abdomen was present. The second dog had a peritoneopericardial hernia associated with a chronic cystic haematoma. In each case the mass was presumed to have arisen following congenital displacement of the omentum into the pericardium. The pericardial mass was removed and subtotal pericardectomy performed in both dogs. Recovery was complete in each case.  相似文献   
82.
83.
Objective To estimate the specificity of an absorbed enzyme-linked immuno-sorbent assay kitd for Johne's disease (JD) when used in mature cattle populations resident in northern Australia.
Design Blood samples were collected from beef cattle in northern Queensland, the Northern Territory and northern Western Australia, and from dairy cattle in northern Queensland. The specificity of a serological test for JD was estimated by testing the blood samples with an absorbed ELISA kit. Further samples were collected from cattle with positive ELISA results to determine the presence or absence of infection with Mycobacterium avium subsp paratuberculosis .
Procedure During 1995 and 1996, blood, tissue and gut contents were collected from beef cattle at abattoirs in Queensland and the Northern Territory; and blood and faecal samples were collected from dairy cattle in herds assessed to be most at risk for JD in northern Queensland. The blood samples were tested using an absorbed ELISA kit. Tissues and gut contents from beef cattle that had positive ELISA results were cultured for M avium subsp paratuberculosis , and tissues were examined histo-logically. Faecal samples from dairy cattle with positive ELISA results were cultured for M avium subsp paratuberculosis .
Results Estimates of specificity for this absorbed ELISA in mature northern Australian cattle were 98.0% (97.0 to 98.8%, 95% CI) in beef cattle, and 98.3% (96.7 to 99.3%, 95% CI) in dairy cattle.
Conclusion Estimates of specificity in this study were lower for beef cattle from the Northern Territory and northern Western Australia and for dairy cattle from northern Queensland than those quoted from studies on cattle in southern Western Australia. This should be considered when serological testing using the JD ELISA is carried out on northern Australian cattle.  相似文献   
84.
85.
Twenty four normal, confined mares were unable to lower their heads for 24 or 48 h. In 21 mares this resulted in increases in the proportion of neutrophils and/or numbers of bacteria in transtracheal aspirates. In eight mares the changes in tracheal washes were accompanied by clinical evidence of mild respiratory disease. In three additional cases respiratory signs were accompanied by systemic illness. These changes reversed once the mares were able to lower their heads. Haematological changes (absolute neutrophilia and/or hyperfibrinogenamia) were mild and occurred more commonly in horses restrained for 48 h. The results suggest that keeping the heads of healthy horses raised leads to an increased bacterial burden in their tracheobronchial secretions. These changes appeared to be related to head posture effects and not simply confinement in stocks. These findings give further weight to the theory that postural drainage may facilitate clearance of bacteria from the tracheobronchial tree. The possible relevance of such findings to post-transportation pneumonia in horses is discussed.  相似文献   
86.
A series of blood and urine samples was collected from each of eight normal foals between birth and eight weeks. Blood chemistry relating to renal function was evaluated as well as physical and chemical characteristics of urine. During the first 4d of life it was impractical to suggest meaningful normal values due to wide variation among foals and with time. Serum urea and plasma creatinine fell markedly to levels less than those previously reported for normal adult horses, while urine, mildly hypersthenuric at birth, rapidly became hyposthenuric. There was also a marked proteinuria during the first 48h. After 4d clinicopathological values stabilised. Urea and creatinine remained at subadult levels and hyposthenuria was maintained. While there was some variation with time, generally the urinary activity of gamma-glutamyl transpeptidase (GGT) and alkaline phosphatase (AP) was greater in foals than in adults; plasma potassium, the creatinine clearance ratio of potassium (% Cr K), serum inorganic phosphate and the creatinine clearance ratio of phosphate (% Cr PO4) were greater than in adults while plasma chloride and the creatinine clearance ratio of chloride (% Cr Cl) were lower in foals than in adults. Urinary pH was acidic and epithelial cells and calcium oxalate crystals more prevalent in the urine of foals than in that of adults. The information presented here will be useful in the diagnosis and management of renal disease and azotaemia in foals.  相似文献   
87.
Objective To investigate wool organophosphorus concentrations resulting from a range of farm pesticide application methods.
Design Random sampling of wool for pesticide residues and on-farm interviews to determine associated treatments.
Procedure Tasmanian fleece wool lots were sampled at random and tested for organophosphorus residues. The grower was identified and the pesticide treatments applied to the sheep were ascertained by on-farm interview.
Results The residue concentrations showed a large variation that was not accounted for by differences in treatments by growers. Organophosphorus concentrations were proportional to the number of treatments applied, and inversely related to the time between pesticide application and the subsequent shearing, and were significantly influenced by the method of application. After allowing for the time of application, plunge dipping resulted in pesticide residue concentrations 2 to 2.5 times greater than shower dipping, using spray races or hand jetting, and the use of these methods caused larger residues than the use of jetting races.
Conclusions We recommend that plunge or shower dipping should not be used more than 7 weeks after shearing, nor at higher concentration than the standard dose rate used for lice control, whereas jetting may be satisfactory for up to 7 months after shearing, provided only one application is administered.  相似文献   
88.
89.
Bacteroides nodosus involved in several outbreaks of ovine footrot over a number of years were subjected to DNA restriction endonuclease analysis. Individual isolates were found to have characteristic Bam HI profiles which permitted their accurate identification and differentiation from other isolates. Bam HI profiles of B. nodosus isolates were used in epidemiological investigations involving consecutive outbreaks of footrot on individual and neighbouring farms. The relationship of given isolates to a common source could be established by this means. Restriction endonuclease analysis provides an additional epidemiological tool in ovine footrot investigations as it accurately identifies interstrain differences in a manner not possible by conventional bacteriological and serological means.  相似文献   
90.
Tuberculosis (TB), due to infection with Mycobacterium bovis was diagnosed in a flock of alpaca in Ireland in 2004. An epidemiological investigation was conducted to identify the risk of TB for farmed alpaca where TB is endemic, the origin of the infection, the potential for alpaca-to-alpaca transmission and appropriate control measures. The investigation focused on the alpaca flock (including the farm, animal movements and breeding, feeding and flock health practice), the disease episode (including animal disease events and subsequent control measures) and TB infection risk in the locality. The TB risk to alpaca is high in areas where infection is endemic in cattle and badgers and where biosecurity is inadequate. It is most likely that the source of infection for the alpaca was a local strain of M. bovis, present in cattle in this area since at least 2001. Genotyping of isolates identified a single variable number tandem repeat (VNTR) profile in both cattle and alpaca in this region. Although a tuberculous badger was also removed from the vicinity, bacterial isolation was not attempted. On this farm, infection in alpaca was probably derived from a common source. Alpaca-to-alpaca transmission seems unlikely. Two broad control strategies were implemented, aimed at the rapid removal of infected (and potentially infectious) animals and the implementation of measures to limit transmission. Tests that proved useful in detecting potentially-infected animals included measurement of the albumin-to-globulin ratio and regular body condition scoring. Skin testing was time consuming and unproductive, and early detection of infected animals remains a challenge. The flock was managed as a series of separate groupings, based on perceived infection risk. No further TB cases have been detected.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号