全文获取类型
收费全文 | 289篇 |
免费 | 18篇 |
国内免费 | 2篇 |
专业分类
林业 | 1篇 |
基础科学 | 1篇 |
16篇 | |
综合类 | 21篇 |
农作物 | 38篇 |
水产渔业 | 10篇 |
畜牧兽医 | 214篇 |
园艺 | 1篇 |
植物保护 | 7篇 |
出版年
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 12篇 |
2017年 | 3篇 |
2016年 | 11篇 |
2015年 | 6篇 |
2014年 | 3篇 |
2013年 | 39篇 |
2012年 | 12篇 |
2011年 | 6篇 |
2010年 | 10篇 |
2009年 | 8篇 |
2008年 | 5篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2005年 | 4篇 |
2003年 | 6篇 |
2002年 | 12篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 15篇 |
1997年 | 8篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 4篇 |
1988年 | 8篇 |
1986年 | 6篇 |
1984年 | 2篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1970年 | 2篇 |
1959年 | 2篇 |
1958年 | 2篇 |
1946年 | 4篇 |
1945年 | 5篇 |
1944年 | 3篇 |
1943年 | 5篇 |
1942年 | 2篇 |
1941年 | 2篇 |
1940年 | 1篇 |
1939年 | 3篇 |
1938年 | 2篇 |
1937年 | 3篇 |
1935年 | 1篇 |
排序方式: 共有309条查询结果,搜索用时 15 毫秒
1.
2.
AIM: To compare, in cows treated with an internal teat sealant, the effect of short-acting and long-acting cloxacillin-based dry-cow therapy on somatic cell counts (SCC) after calving.METHODS: Cows from a spring-calving, pasture-based dairy farm in the Manawatu-Whanganui region of New Zealand were randomly allocated to receive either a short-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=291) or a long-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=288) at the end of lactation. Cows were managed on-farm with routine husbandry procedures through the dry period and following calving. A multivariable logistic regression model was used to determine the association between length of action of dry-cow therapy and the proportion of cows with a SCC >150,000?cells/mL at the first herd test after calving.RESULTS: Age of cow, mean SCC for the preceding season and interval from calving to the first post-calving herd test were all associated with the proportion of cows with an individual SCC >150,000?cells/mL at the first herd test (p<0.001) Treatment with the short-acting dry-cow therapy was not associated with decreased odds of cows having a SCC >150,000?cells/mL at the first herd test compared with treatment with long-acting dry-cow therapy (OR=0.724; 95% CI=0.40–1.30).CONCLUSIONS AND CLINICAL RELEVANCE: In this herd, which routinely used internal teat sealants, the use of short-acting cloxacillin-based dry-cow therapy did not result in an increased proportion of cows with elevated SSC post-calving. This was a single farm, single year study but indicates that in this herd, changing from a long-acting to a short-acting antimicrobial may have no impact on the prevalence of subclinical mastitis. 相似文献
3.
4.
5.
6.
7.
8.
9.
10.
Corti LB Merkley D Nelson OL Ware WA 《Journal of the American Animal Hospital Association》2000,36(6):548-555
Twenty dogs with patent ductus arteriosus occluded with Hemoclips were evaluated with a mean follow-up time of 799.4 days (range, 83 to 3,580 days). Significant decreases were found between pre- and postsurgical means for vertebral heart size and for echocardiographic left atrial/aortic-root ratios and percent fractional shortening (%FS). Despite a good clinical outcome, six of 20 dogs had persistent cardiomyopathy of overload with diminished %FS (28% or less) at follow-up. One dog had residual ductal flow identified five days postoperatively. Subsequent evaluations in this case at 60, 144, 226, 344, and 560 days postoperatively demonstrated gradually diminishing ductal flow. The remaining 19 dogs did not recanalize. 相似文献