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   257篇
  免费   13篇
  国内免费   1篇
林业   16篇
农学   2篇
  11篇
综合类   25篇
农作物   25篇
水产渔业   28篇
畜牧兽医   157篇
植物保护   7篇
  2023年   2篇
  2021年   2篇
  2018年   4篇
  2017年   3篇
  2016年   4篇
  2015年   5篇
  2014年   5篇
  2013年   16篇
  2012年   8篇
  2011年   4篇
  2010年   5篇
  2008年   7篇
  2007年   8篇
  2006年   9篇
  2005年   6篇
  2004年   7篇
  2003年   9篇
  2002年   8篇
  2001年   10篇
  2000年   3篇
  1999年   7篇
  1998年   3篇
  1996年   2篇
  1994年   3篇
  1993年   5篇
  1991年   6篇
  1989年   5篇
  1988年   6篇
  1987年   4篇
  1986年   7篇
  1985年   3篇
  1984年   5篇
  1983年   6篇
  1979年   2篇
  1978年   2篇
  1976年   3篇
  1974年   5篇
  1973年   2篇
  1971年   3篇
  1970年   2篇
  1969年   2篇
  1968年   4篇
  1967年   2篇
  1962年   3篇
  1937年   4篇
  1936年   6篇
  1935年   9篇
  1934年   3篇
  1925年   2篇
  1884年   1篇
排序方式: 共有271条查询结果,搜索用时 171 毫秒
1.
SUMMARY Twenty-five Thoroughbred (TB) and 25 Standardbred (SB) stables were visited to determine their feeding practices. The ingredients of the main feed of the day for a mature gelding of average size in full training were weighed at each stable. Nutrient content of diets was calculated using published data for the individual ingredients. Results are expressed as mean±sd. The estimated body weight of TB horses was 493±34 kg and 437±32 kg for SB horses. There was considerable variation in diet composition and nutrient intake between stables. The TB trainers fed 11.0±2.4 kg and SB trainers 11.8±2.5 kg per day. The concentrate component of the diet weighed 7.8±1.6 and 7.7±2.3 kg for TB and SB stables, respectively, and the roughage component for TB horses 3.3±1.4 and SB horses 4.1±1.4 kg per day. The digestible energy intake of horses at TB stables was 129±29 MJ per day and at SB stables 132±31 MJ per day. Crude protein intake of TB horses was 1452±363 g and SB horses 1442±338 g per day. There were differences in some feeding practices at TB and SB stables. Standardbred trainers fed more roughage than TB trainers. Standardbred trainers fed chaffed lucerne (alfalfa) and cereal hays as the major roughage, whereas TB trainers fed more hay. The major hay type fed by TB trainers was lucerne, whereas many SB trainers preferred clover hay. Both trainers fed oats as the major grain, but TB trainers fed slightly more maize (corn) than SB trainers. The SB trainers fed barley as part of the concentrate component of the diet, whereas TB trainers usually fed boiled barley and linseed oil in winter only. Although many trainers used vitamin and mineral supplements, this appeared unnecessary in many Instances, especially with respect to Iron. Calcium and NaCI supplementation was necessary for some diets. We concluded that while there was a wide range in feed intake and diet composition for both TB and SB horses, average nutrient intakes were similar to National Research Council (1989) recommendations for horses performing intense work.  相似文献   
2.
Factors mainly responsible for limiting animal production in the Molopo ranching area are the poor grass species composition of the veld, bush encroachment, droughts and the poor fertility status of the soil. Data illustrating the extent to which grass species composition and grass production are affected by these factors are presented and discussed. Data from earlier attempts to .solve these problems reveal that several different directions of pasture research have possibilities in such semi‐arid areas.  相似文献   
3.
4.
5.
6.
7.
8.
REASONS FOR PERFORMING STUDY: Ileus and peritoneal adhesions are the most common complications following surgery for small intestinal obstruction. Carolina Rinse (CR) has been shown to decrease reperfusion injury in intestine and other organs. HYPOTHESIS: CR decreases intestinal inflammation and subsequent scarring associated with reperfusion injury. METHODS: CR was infused intra-arterially and applied topically just prior to reperfusion in jejunum exposed to experimental ischemia. Vascular permeability, neutrophil accumulation and serosal scarring were compared in treated and untreated intestine. RESULTS: CR maintained a normal osmotic reflection coefficient and decreased migration of neutrophils into the serosa during reperfusion. After 10 days, treated intestine was normal in appearance with a trend toward less serosal scarring and fibroblast proliferation. There was a significant decrease in fibroplasia at biopsy sites in treated intestine. CONCLUSIONS: Arterial perfusion combined with topical application of CR during jejunal ischaemia decreases immediate reperfusion injury and limits post operative scarring. POTENTIAL RELEVANCE: CR should be used as a local perfusate rather than a systemic treatment; it may best be applied topically and intraluminally to avoid damaging mesenteric arteries. CR should be considered an adjunct treatment as part of overall surgical management and post operative care.  相似文献   
9.
10.
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