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   172篇
  免费   18篇
林业   14篇
农学   2篇
  27篇
综合类   18篇
农作物   21篇
水产渔业   6篇
畜牧兽医   81篇
园艺   5篇
植物保护   16篇
  2024年   2篇
  2021年   1篇
  2020年   5篇
  2019年   8篇
  2018年   7篇
  2017年   3篇
  2016年   10篇
  2015年   2篇
  2014年   6篇
  2013年   12篇
  2012年   7篇
  2011年   14篇
  2010年   8篇
  2009年   8篇
  2008年   4篇
  2007年   9篇
  2006年   4篇
  2005年   6篇
  2004年   3篇
  2003年   3篇
  2002年   1篇
  2001年   1篇
  2000年   3篇
  1998年   7篇
  1997年   8篇
  1996年   10篇
  1994年   2篇
  1993年   4篇
  1992年   1篇
  1991年   2篇
  1990年   5篇
  1989年   1篇
  1988年   2篇
  1987年   4篇
  1986年   1篇
  1983年   3篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1978年   2篇
  1975年   1篇
  1974年   1篇
  1972年   1篇
  1970年   1篇
  1969年   1篇
  1966年   1篇
  1953年   1篇
  1943年   1篇
排序方式: 共有190条查询结果,搜索用时 11 毫秒
41.
42.
Susceptibility of cats to equine morbillivirus   总被引:7,自引:0,他引:7  
Objective To assess the susceptibility of cats to equine morbillivirus (EMV) by direct administration of the virus by subcutaneous, intra-nasal or oral routes, and following exposure to infected cats.
Design A disease transmission study, with controls, using ten cats.
Procedure Groups of cats were given the virus by the designated methods and assessed for evidence of infection by clinical examination, plus pathological and virological tests.
Results All cats administered the virus by subcutaneous, intra-nasal or oral routes became infected and developed the disease within 4 to 8 days. One of two cats in contact with affected cats also developed the disease, but two cats kept near to affected cats did not become infected. The virus was isolated from a range of tissues collected from the infected cats, and the lesions observed in affected cats were similar to those previously observed in horses naturally and experimentally infected with the virus.
Conclusion This is the first demonstration that animals can be infected with EMV by non-parenteral means, that the virus can transmit naturally between animals and confirms other reports of the similarity of EMV disease in horses and cats.  相似文献   
43.
SUMMARY: Records of 220 thoroughbred horses presented to the Randwick Equine Centre or the University of Queensland Veterinary Teaching Hospital for surgical management of carpal injury were reviewed. Details of racing performance were obtained, enabling evaluation of racing success following surgery. Age and sex matched control horses not known to have suffered carpal injury were selected from the Australian Stud Book and the Australian Racehorse Register. Control and treated populations were compared in terms of overall career racing success.
Radiographs or xeroradiographs from 198 horses were available for evaluation. The dorsomedial aspects of the distal articular surface of the radial carpal bone and the proximal articular surface of the third carpal bone were the most commonly observed locations of osteochondral fracture. Bilateral carpal injury was found to be sufficiently common to warrant routine radiographic examination of both limbs. The dorsolateral-palmaromedial oblique, flexed lateral and dorsoproximal-dorsodistal oblique (skyline) projections were the most useful views for evaluation of carpal degenerative joint disease. Surgical removal of osteochondral fractures by arthrotomy or arthroscopy was found to be a suitable method of treatment.
Arthroscopy was associated with a significantly shorter convalescent period than arthrotomy. Seventy-six percent of the treated population returned to racing following surgery. Average earnings following surgery were 20 000. However, the median value was only 1400 and 48% of the treated population failed to earn more than 1000. Male horses in both the treated and control groups performed significantly better than females. Treated horses performed significantly better than the randomly selected control population.  相似文献   
44.
Behavioral problems of farmed ostriches in Canada.   总被引:1,自引:1,他引:0       下载免费PDF全文
Ostriches farmed in Canada often have particular behavioral problems that are brought about by periods of extreme confinement during winter months. Although they still perform normal species specific behaviors such as twirling, kanteling, and kicking, abnormal behaviors become prominent when excessively confined. They include for all age groups of ostriches, feather-picking, behavioral stargazing, dietary indiscretion, pica, anorexia and adipsia, and aggression. These abnormal behaviors initiated by inadequate husbandry techniques, eventually become medical problems because of their severity.  相似文献   
45.
46.
47.
48.

Aim

A prospective, observational study to determine the prevalence of post‐exercise conditions at Australian Greyhound race meetings and to assess association with race performance and other environmental, race‐ and dog‐related factors was undertaken.

Methods

A total of 4020 starters were observed (2813 Greyhounds, 1009 trainers, 536 races, 52 race meets, 48 race dates and 11 race tracks) following a race. The presence of diaphragmatic flutter (DF), ataxia, seizure, collapse or sudden death was recorded. Risk factors were screened by univariable logistic regression prior to multivariable backward stepwise model building.

Results

In this study, 962 starters (n = 768 dogs) had DF (23.9%), 16 starters were ataxic (0.4%) and there were no observed cases of collapse, seizure or sudden death. Race track location, increasing race distance, race grade based on increasing 1st place prize value, lower (earlier) race number at the meeting, age, a previous observation of DF at the last start, females, colour (white) and better finishing position were all associated with an increased risk of a Greyhound being observed with DF. However, when logistic regression assessing the random effect of dog was performed, the presence of previous DF was not significant. In this cohort, DF was common following strenuous exercise in Greyhounds and on its own does not appear to result in reduced performance or distress to the animal.

Conclusion

The incidence of ataxia was low and collapse, seizure and sudden death were not observed. However, even though uncommon, ataxia has welfare concerns for racing Greyhounds that warrants further investigation.  相似文献   
49.
Farmer adoption of practices to build soil health can be enhanced using a knowledge network supported by programs and resources that incorporate technical, social and experiential learning pathways. University Extension plays a critical role in building and supporting the knowledge network by serving as (a) a boundary organization to create space for conversations to occur, (b) network manager to facilitate learning and (c) builder of social capital to encourage trust in the network. The North Dakota State University (NDSU) Soil Health Program was used to illustrate the above approach. Between 2014 and 2016, 32 informal discussion groups, called Soil Health Café Talks, reached 156 individuals. A knowledge network of all participants was developed using NodeXL. The 10 most influential individuals in the network included two scientists, five farmers, one crop consultant and two Extension specialists. All non‐NDSU participants received an evaluation form. Respondents increased their frequency of discussing cover crops with other individuals and increased sharing equipment across farming operations (i.e., vertical tillage implements and no‐till drills). Of the topics discussed, over 25% of respondents adopted practices using cover crops (interseeding and using cover crops for weed control and adjusting rotations to incorporate cover crops) as a result of attending Café Talks. Respondents also increased their use of NDSU Soil Health online resources such as Twitter (22%), YouTube (23%) and the web page (21%) as follow‐up information to Café Talks. Network‐based approaches have proven to be successful in encouraging on‐farm adoption of soil health‐building practices.  相似文献   
50.
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