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   189篇
  免费   17篇
林业   9篇
农学   5篇
  4篇
综合类   14篇
农作物   5篇
水产渔业   2篇
畜牧兽医   158篇
园艺   1篇
植物保护   8篇
  2023年   5篇
  2021年   2篇
  2020年   6篇
  2019年   5篇
  2018年   5篇
  2017年   5篇
  2016年   6篇
  2015年   4篇
  2014年   4篇
  2013年   8篇
  2012年   8篇
  2011年   8篇
  2010年   11篇
  2009年   3篇
  2008年   8篇
  2007年   3篇
  2006年   5篇
  2005年   8篇
  2004年   6篇
  2003年   7篇
  2002年   3篇
  2001年   5篇
  2000年   2篇
  1999年   2篇
  1998年   5篇
  1997年   4篇
  1996年   7篇
  1994年   2篇
  1993年   3篇
  1992年   8篇
  1990年   3篇
  1989年   2篇
  1987年   2篇
  1986年   2篇
  1982年   1篇
  1981年   2篇
  1980年   2篇
  1979年   3篇
  1978年   4篇
  1977年   1篇
  1976年   2篇
  1974年   1篇
  1973年   1篇
  1971年   2篇
  1970年   6篇
  1969年   1篇
  1968年   3篇
  1967年   2篇
  1966年   2篇
  1961年   1篇
排序方式: 共有206条查询结果,搜索用时 15 毫秒
1.
2.
Precipitating antibodies against bluetongue were detected in sheep and goat serum samples collected from animals slaughtered in Baghdad abattoir. Out of 294 sheep serum samples and 110 goat serum samples examined, 28 and 18 samples respectively showed precipitating activity. In addition, examination of sheep serum samples collected from localities where clinical cases similar to bluetongue were previously reported revealed the presence of bluetongue precipitating antibodies in 101 sera out of 198 samples examined. This is the first report confirming the occurrence of bluetongue in Iraq.  相似文献   
3.
4.
5.
Hauck R  Hafez HM 《Avian diseases》2007,51(4):880-883
Three coated plant extracts (RepaXol and two experimental formulations) were tested for their minimal lethal concentration for histomonads in vitro and the effect of those substances on the bacterial growth in the histomonadal culture. After 48 hr, RepaXol and experimental formulation B were lethal to histomonads at a concentration of 1.25 microl/ml. Experimental formulation C was lethal at a concentration of 2.5 microl/ml. All products also decreased the growth of bacteria at concentrations inhibiting the growth of histomonads.  相似文献   
6.
Numerous culture-based diagnostics are available on the Australian and international markets for on-farm detection of bacterial pathogens in milk. Use of such diagnostics may provide an opportunity to improve the prudent use of antimicrobials in udder health management. Farms are low-resource settings in terms of diagnostic microbiology capacity. The World Health Organisation has identified criteria for the evaluation of diagnostic tests in low resource settings based on Accuracy, Sensitivity, Specificity, User-friendliness, being Rapid or Robust, Equipment-free and being Deliverable (ASSURED). Here, we review how those criteria can be interpreted in the context of microbiological diagnosis of mastitis pathogens, and how on-farm diagnostics that are currently available in Australia perform relative to ASSURED criteria. This evaluation identifies multiple trade-offs, both with regard to scientific criteria and with regards to convenience criteria. More importantly, the purpose of testing may differ between farms, and test performance should be evaluated relative to its intended use. The ability of on-farm mastitis diagnostics to inform mastitis treatment decision-making in a timely and cost-effective manner depends not just on test characteristics but also on farm-specific pathogen prevalence, and on the farm enterprise's priorities and the farm manager's potential courses of action. With most assay evaluations to date conducted in professional laboratories, there is a surprising dearth of information on how well any of the diagnostic tests perform on-farm and, indeed, of the on-farm decision-making processes that they aim to inform.  相似文献   
7.
Preparations derived from plants were the original therapeutic interventions used by man to control diseases (including parasites), both within humans and livestock. Development of herbal products depended upon local botanical flora with the result that different remedies tended to develop in different parts of the world. Nevertheless, in some instances, the same or related plants were used over wide geographic regions, which also was the result of communication and/or the importation of plant material of high repute. Thus, the Nordic countries have an ancient, rich and diverse history of plant derived anthelmintic medications for human and animal use. Although some of the more commonly used herbal de-wormers were derived from imported plants, or their products, many are from endemic plants or those that thrive in the Scandinavian environment. With the advent of the modern chemotherapeutic era, and the discovery, development and marketing of a seemingly unlimited variety of highly efficacious, safe synthetic chemicals with very wide spectra of activities, herbal remedies virtually disappeared from the consciousness--at least in the Western world. This attitude is now rapidly changing. There is a widespread resurgence in natural product medication, driven by major threats posed by multi-resistant pest, or disease, organisms and the diminishing public perceptions that synthetic chemicals are the panacea to health and disease control. This review attempts to provide a comprehensive account of the depth of historical Nordic information available on herbal de-wormers, with emphasis on livestock and to provide some insights on potentially rewarding areas of "re-discovery" and scientific evaluation in this field.  相似文献   
8.
Four meat turkey and one turkey breeding flocks were surveyed for antibodies against reticuloendotheliosis virus (REV) at different intervals using commercial enzyme-linked immunosorbent assays. In addition, serum samples collected from 18 flocks at different ages were also tested for antibodies against REV. No antibodies were detected in any of the four meat turkey flocks that were surveyed. In the breeder flock, 20%) of tested samples from 1-day-old poults were positive. Between the fourth and 12th weeks all samples that were tested yielded negative results. At 16 weeks of age 15% of samples yielded a positive reaction, but antibodies could not be detected 4 weeks later. Examination of serum samples from 18 different flocks at various ages revealed that antibodies could be detected in five flocks. The percentage of positive sera per flock ranged between 10 and 40%.  相似文献   
9.
Contents The sources and characteristics of endocrine disrupting compounds (EDCs) are reviewed and discussed with respect to their potential effects on farm animal health, welfare and productivity. The importance of certain properties of these compounds in relation to the expression of their biological effects is addressed together with potential routes of exposure. It is concluded that little is known of factors affecting the tissue concentrations of EDCs in farm animals, the concentrations that are required to perturb physiological function in these species, the effects of prolonged exposure to low doses, the effect of cocktails of EDCs and other pollutants or the responses of specific organs and physiological systems that are affected by EDCs. Much of the available information pertaining to EDCs is derived from epidemiological studies of wildlife species and from laboratory animal studies and while these studies have significant limitations, they are considered to be valuable indicators of potential effects in farm animal species. The results of such studies, together with the small amounts of data from studies of ruminants, indicate that there may be significant effects of exposure to environmental levels of EDCs on farm animal health, even although effects are not generally apparent in practice, at this time.  相似文献   
10.
Investigations on different Ornithobacterium rhinotracheale "ORT" isolates   总被引:1,自引:0,他引:1  
The aim of the present investigation was to determine the antigenic relationship between different Ornithobacterium rhinotracheale (ORT) isolates and to serotype field isolates obtained from turkey and chickens. Different antigen extractions (heat-stable, proteinase K-stable [lipopolysaccharide], and sodium dodecyl sulfate [SDS] extractions) were prepared from each serotype (A, B, C, D, E, and G) as well as from 21 ORT field isolates and examined in agar gel precipitation (AGP) and enzyme-linked immunosorbent assay (ELISA) tests. The field isolates were cultured from turkey (16 isolates) and chicken (5 isolates) flocks showing respiratory manifestations. Monospecific reactions were obtained with heat-stable as well as proteinase K-stable antigens prepared from serotypes A, C, D, E, and G in AGP tests. On the other hand, with the same antigen preparations from a strain of serotype B in AGP tests, cross-reactions with antisera prepared against serotypes A and E could be detected. The cross-reactions were observed mostly between 48 and 72 hr. In applications of SDS-antigen preparations in AGP tests, cross-reactions between all serotypes except serotype C were detected between 24 and 72 hr. Testing all antigen preparation in ELISA, different cross-reactions were observed and the evaluation of the results is very difficult. Serotyping of the field isolates in AGP tests by using heat-extracted antigens showed after 24 hr that 10 out of 16 isolates from turkey belonged to serotype B, five to serotype A, and one to serotype E. Results obtained after 48-72 hr revealed cross-reactions between serotype B and E in 11 cases and between A and B in two cases. All five isolates obtained from chicken reacted after 24 hr only with serum against serotype A. After 48-72 hr, two isolates showed cross-reaction with antiserum against serotype B. Similar results were obtained with proteinase K-stable antigen.  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