全文获取类型
收费全文 | 82篇 |
免费 | 2篇 |
专业分类
林业 | 2篇 |
农学 | 4篇 |
基础科学 | 1篇 |
5篇 | |
综合类 | 27篇 |
水产渔业 | 3篇 |
畜牧兽医 | 39篇 |
园艺 | 2篇 |
植物保护 | 1篇 |
出版年
2021年 | 1篇 |
2020年 | 1篇 |
2018年 | 2篇 |
2013年 | 4篇 |
2012年 | 4篇 |
2010年 | 3篇 |
2009年 | 1篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2006年 | 1篇 |
2004年 | 1篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1997年 | 1篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1973年 | 3篇 |
1966年 | 1篇 |
1957年 | 1篇 |
1954年 | 1篇 |
1948年 | 3篇 |
1927年 | 1篇 |
1898年 | 2篇 |
1883年 | 1篇 |
1881年 | 4篇 |
1880年 | 3篇 |
排序方式: 共有84条查询结果,搜索用时 15 毫秒
1.
A M Durand W H Giesecke M L Barnard M L van der Walt H C Steyn 《The Onderstepoort journal of veterinary research》1990,57(3):175-181
The prevalence of Salmonella in southern Africa in farm feeds and by-products of animal origin during 1982-1988 was determined. Salmonella occurred in 5.18% of the farm feed samples and in 9.54% of the by-product samples. Different serovars were isolated, some only once. The findings underestimate the true prevalence of Salmonella in farm feeds and by-products, and is representative of only the most severely contaminated products. The epidemiology of salmonellosis is discussed with special reference to the importance of multiple resistance to antibiotics, the increase in the number of cases of salmonellosis worldwide and "Salmonella free" feeds and foods. More detailed research on the role of farm feeds in the epidemiology of salmonellosis is required. Efforts should be made to increase awareness of the problem, to improve quality management at farm feed production plants and to develop efficient systems to monitor the hygienic safety of feeds and foods. 相似文献
2.
3.
4.
C Richardson P C Jones V Barnard C N Hebert S Terlecki W V Wijeratne 《The Veterinary record》1990,126(12):279-284
Jersey cows from several herds provided 97 fetuses and 24 calves at fixed gestational intervals between 80 and 290 days after conception. The fetuses and calves were killed, weighed and measured and, after dissection, the sizes and weights of a range of skeletal and soft tissues were recorded. Six morphological measurements emerged as most suitable for the determination of developmental age in the normal fetus. By plotting their mean values and 95 per cent tolerance limits, the rates of growth and the variability of each measurement were defined. Long bone length was the most useful single measurement for predicting the developmental age of the fetus. Brain weight, bodyweight, crown-anus length and long bone length showed curvilinear growth patterns; age prediction equations derived from these measurements are complicated to use and additional simplified formulae have been derived. The number of appendicular ossification centres also had predictive value, but it could not be used to determine fetal developmental age between 100 and 160 days gestation. 相似文献
5.
6.
Lopatto D Alvarez C Barnard D Chandrasekaran C Chung HM Du C Eckdahl T Goodman AL Hauser C Jones CJ Kopp OR Kuleck GA McNeil G Morris R Myka JL Nagengast A Overvoorde PJ Poet JL Reed K Regisford G Revie D Rosenwald A Saville K Shaw M Skuse GR Smith C Smith M Spratt M Stamm J Thompson JS Wilson BA Witkowski C Youngblom J Leung W Shaffer CD Buhler J Mardis E Elgin SC 《Science (New York, N.Y.)》2008,322(5902):684-685
7.
8.
9.
A novel chemical sensor has been developed in which the polymer ethylene-vinyl acetate is used as a controlled-release system to deliver reagents to the sensing region of an optical fiber for a homogeneous competitive immunoassay based on fluorescence energy transfer. A competition reaction is used to enable continuous measurements of the solution antigen concentration. More generally, the technique allows irreversible indicating chemistries to be used in the construction of chemical sensors that can measure continuously for long periods. Although the sensor configuration has not been optimized in all respects, data are presented for a model system in which a fluorescein-labeled antibody and Texas Red-labeled immunoglobulin G (IgG) are used. 相似文献
10.
The epidemiology of wildebeest-derived malignant catarrhal fever in South Africa differs from the worldwide accepted pattern. Here the occurrence of the disease is often not related to close contact between cattle and wildebeest, and most cases are observed during late winter and spring, when wildebeest calves are 8-10 months old. This is in contrast to the situation in Kenya and Tanzania, where most cases are encountered during autumn, when wildebeest calves are 3-4 months old. 相似文献