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   133篇
  免费   4篇
  国内免费   1篇
林业   4篇
  3篇
综合类   32篇
农作物   4篇
水产渔业   4篇
畜牧兽医   87篇
植物保护   4篇
  2017年   2篇
  2014年   4篇
  2013年   5篇
  2012年   4篇
  2011年   9篇
  2010年   4篇
  2009年   4篇
  2008年   5篇
  2007年   4篇
  2006年   2篇
  2005年   2篇
  2003年   6篇
  2001年   2篇
  2000年   4篇
  1999年   4篇
  1998年   3篇
  1996年   3篇
  1993年   3篇
  1992年   2篇
  1991年   5篇
  1990年   2篇
  1989年   1篇
  1988年   2篇
  1987年   1篇
  1986年   4篇
  1985年   4篇
  1984年   3篇
  1983年   2篇
  1982年   1篇
  1981年   2篇
  1978年   2篇
  1977年   1篇
  1976年   1篇
  1970年   3篇
  1969年   1篇
  1967年   3篇
  1965年   1篇
  1961年   1篇
  1960年   1篇
  1953年   1篇
  1949年   1篇
  1948年   4篇
  1947年   1篇
  1943年   2篇
  1942年   1篇
  1941年   1篇
  1939年   3篇
  1938年   1篇
  1936年   1篇
  1932年   1篇
排序方式: 共有138条查询结果,搜索用时 15 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.
Blood samples were analyzed from 30 domestic cats (Felis domesticus) from the Petén region of Guatemala to determine the seroprevalence of common pathogens that may pose a potential risk to native wild felids. Eight of the cats had been vaccinated previously; however, owners were unable to fully describe the type of vaccine and date of administration. In addition, blood samples were obtained from two captive margays (Leopardus wiedii). Samples were tested for antibodies to feline immunodeficiency virus, Dirofilaria immitis, feline panleukopenia virus, feline herpesvirus, feline coronavirus, canine distemper virus, and Toxoplasma gondii and for feline leukemia virus (FeLV) antigen. Fifty percent or more of the cats sampled were seropositive for feline herpesvirus (22 of 30), feline panleukopenia (15 of 30), and T. gondii (16 of 30). Five cats were positive for FeLV antigen. Both margays were seropositive for feline coronavirus and one was strongly seropositive to T. gondii. All animals were seronegative for D. immitis. This survey provides preliminary information about feline diseases endemic to the Petén region.  相似文献   
3.
4.
5.
6.
本论文研究了饲料加工的两个关键参数(调质温度和时间)对育肥猪颗粒饲料淀粉糊化度和维生素沉积的影响。日粮配方为含30%干酒糟及其可溶物的玉米-豆粕型基础日粮。整个试验中配方保持不变。本试验采用2×3双因子设计,调质温度分别为77℃和88℃,调质时间分别15秒、30秒和60秒。此外,本试验还设置一个对照组,对照组饲料不采用调质制粒工艺,而是采用粉料饲喂。因此,本试验共有7个处理组。采集调质后制粒前(热干粉)、制粒后冷却前(热制粒)、以及制粒冷却后(冷制粒)的样品,并分析这三种样品的总淀粉率、淀粉糊化  相似文献   
7.
Two hound-type dogs from the same kennel were admitted in terminal stages of congestive heart failure. An investigation revealed the owner had been feeding the dogs cottonseed meal daily with their kibbled meal. Gossypol toxicosis from feeding this meal caused marked abnormalities in myocardial contractility. Although in severe congestive heart failure, one dog had only minimal dilatation of its heart, as revealed by thoracic radiography. Disseminated intravascular coagulopathy also was diagnosed in this dog. Gossypol is a cumulative toxin; the amount of free gossypol fed was approximately 5.4 to 5.7 mg/kg/day for an unknown duration.  相似文献   
8.
9.
Saturation in milk and meat fats   总被引:1,自引:0,他引:1  
Meat and milk products from ruminants (cows, goats, sheep, and beef animals) contribute 35 to 40 percent of the fat in the average American diet. Such fat is highly saturated, containing less than about 4 percent polyunsaturated fatty acids. The unsaturated plant lipids (fats) ordinarily consumed by the ruminant are hydrogenated (saturated) in the rumen. Transport and incorporation of this hydrogenated fat into meat and milk follows. Rumen hydrogenation does not take place until the fat is broken down to free fatty acids, thus establishing the fact that lipolysis is an essential feature of the process. Circumvention of this lipolysis may lead to more-unsaturated meat and milk fat.  相似文献   
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