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   168篇
  免费   16篇
林业   1篇
  1篇
综合类   29篇
农作物   3篇
水产渔业   2篇
畜牧兽医   142篇
植物保护   6篇
  2020年   2篇
  2019年   3篇
  2018年   9篇
  2017年   5篇
  2016年   6篇
  2015年   3篇
  2014年   6篇
  2013年   10篇
  2012年   4篇
  2011年   4篇
  2010年   15篇
  2009年   19篇
  2008年   7篇
  2007年   6篇
  2006年   2篇
  2005年   1篇
  2004年   3篇
  2003年   3篇
  2001年   5篇
  1999年   6篇
  1998年   14篇
  1997年   8篇
  1996年   12篇
  1995年   5篇
  1994年   2篇
  1993年   4篇
  1992年   5篇
  1991年   5篇
  1990年   6篇
  1989年   2篇
  1988年   2篇
排序方式: 共有184条查询结果,搜索用时 406 毫秒
121.
122.
123.
124.
125.
Calves affected with citrullinaemia are clinically normal immediately after birth. In the majority of calves the clinical course of the disease was similar. Within 24 hours of birth they become depressed; then within 3 to 4 days were observed to wander aimlessly or stand with their head pressed against a wall or fence. By day 4 to 5 they become recumbent, developed convulsions, followed by collapse and death. Oedema of the cerebral cortex is a consistent histological lesion. Citrulline concentration in blood, cerebrospinal fluid, eye fluid and cerebral tissue is greatly elevated. Information gathered from pedigrees of affected calves indicate that the defect is widely disseminated throughout the Australian Friesian population.  相似文献   
126.
A 14-month-old speyed female Boxer was presented with acute non-weight-bearing lameness in the right forelimb. Radiography revealed separation of the anconeal process, which was thence surgically removed. Histological examination of the anconeal process confirmed a primary fracture. Isolated unilateral anconeal process fracture in the dog is rare and this report includes histopathological findings of a primary anconeal fracture.  相似文献   
127.
Electrocardiographic values in Spanish-bred horses of different ages   总被引:1,自引:0,他引:1  
SUMMARY The duration of electrocardiograph wave forms and intervals were determined in 179 Spanish-bred (Andalusian) horses aged from 1 month to 17 years. The values were compared with those of other breeds, and the relationship between electrocardiographic data and age was examined. High correlation coefficients were found between PR, ST and QT intervals and the age of the horses, and an inverted relation between heart rate and age was found. A multiple range analysis was made and the results suggest that significant changes in duration values and heart rate ocurred at the age of 6 months and in the second year of life.  相似文献   
128.
Today's livestock diversity originated from the wild ancestor species and was subsequently shaped through the processes of mutation, genetic drift, and natural and human selection. Only a subset of the diversity present in the ancestral species survives in the domestic counterparts. A 2007 report released by UN Food and Agriculture Organization ' The State of the World's Animal Genetic Resources ', compiled from surveys conducted in 169 countries, found that nearly 70% of the world's remaining livestock breeds live in developing countries. The UN report was presented to more than 300 policy makers, scientists, breeders, and livestock keepers at the First International Technical Conference on Animal Genetic Resources, held in September 2007 in Interlaken, Switzerland. The conference aims were to adopt a global plan of action for conserving animal genetic resources as its main outcome. In this paper, the current and potential contributions of reproductive and molecular biotechnology are considered as tools of conserving rare breeds of livestock.  相似文献   
129.
Disease in animals is a well-known inhibitor of growth and reproduction. Earlier studies were initiated to determine the effects of endotoxin on pituitary hormone secretion. These studies found that in sheep, growth hormone (GH) concentration was elevated, whereas insulin-like growth factor-I (IGF-I) was inhibited, as was luteinizing hormone (LH). Examination of the site of action of endotoxin in sheep determined that somatotropes expressed the endotoxin receptor (CD14) and that both endotoxin and interleukin-Iβ activated GH secretion directly from the pituitary. In the face of elevated GH, there is a reduction of IGF-I in all species examined. As GH cannot activate IGF-I release during disease, there appears to be a downregulation of GH signalling at the liver, perhaps related to altered nitration of Janus kinase (JAK). In contrast to GH downregulation, LH release is inhibited at the level of the hypothalamus. New insights have been gained in determining the mechanisms by which disease perturbs growth and reproduction, particularly with regard to nitration of critical control pathways, with this perhaps serving as a novel mechanism central to lipopolysaccharide suppression of all signalling pathways. This pathway-based analysis is critical to the developing novel strategies to reverse the detrimental effect of disease on animal production.  相似文献   
130.

Objective

To investigate the course‐related and other costs involved in obtaining a veterinary education in Australia and how these costs are met. The study also aimed to identify sociodemographic and course‐related factors associated with increased financial stress.

Methods

Students from seven Australian veterinary schools were surveyed using an online questionnaire. A total of 443 students participated (response rate 17%). Responses to survey items relating to finances, employment and course‐related costs were compared with sociodemographic factors and prior research in the area of student financial stress.

Results

Respondents reported spending a median of A$300 per week on living costs and a median of A$2,000 per year on course‐related expenses. Over half of respondents received the majority of their income from their parents or Youth Allowance (56%). A similar proportion (55%) reported that they needed to work to meet basic living expenses. Circumstances and sociodemographic factors linked to perceived financial stress included requiring additional finances to meet unexpected costs during the course; sourcing additional finances from external loans; an expected tuition debt at graduation over A$40,000; being 22 years or older; working more than 12 hours per week; living costs above A$300 per week; and being female.

Conclusion

The costs involved in obtaining a veterinary education in Australia are high and over half of respondents are reliant on parental or Government income support. Respondents with certain sociodemographic profiles are more prone to financial stress. These findings may have implications for the psychological health, diversity and career plans of veterinary students in Australia.  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