全文获取类型
收费全文 | 1160篇 |
免费 | 55篇 |
专业分类
林业 | 49篇 |
农学 | 20篇 |
基础科学 | 4篇 |
170篇 | |
综合类 | 114篇 |
农作物 | 25篇 |
水产渔业 | 51篇 |
畜牧兽医 | 728篇 |
园艺 | 23篇 |
植物保护 | 31篇 |
出版年
2024年 | 2篇 |
2023年 | 13篇 |
2022年 | 11篇 |
2021年 | 31篇 |
2020年 | 41篇 |
2019年 | 32篇 |
2018年 | 18篇 |
2017年 | 18篇 |
2016年 | 26篇 |
2015年 | 18篇 |
2014年 | 27篇 |
2013年 | 44篇 |
2012年 | 64篇 |
2011年 | 108篇 |
2010年 | 49篇 |
2009年 | 67篇 |
2008年 | 74篇 |
2007年 | 82篇 |
2006年 | 80篇 |
2005年 | 65篇 |
2004年 | 59篇 |
2003年 | 74篇 |
2002年 | 84篇 |
2001年 | 10篇 |
2000年 | 17篇 |
1999年 | 12篇 |
1998年 | 11篇 |
1997年 | 10篇 |
1996年 | 9篇 |
1995年 | 4篇 |
1994年 | 8篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1972年 | 2篇 |
1963年 | 1篇 |
排序方式: 共有1215条查询结果,搜索用时 15 毫秒
911.
Aline E. Pinna Carolina T. C. Okada Camila S. C. Ferreira Diego G. Campos Karen S. Possidente Rita de Cssia C. L. Morais Marcela Oliveira Marcia Carolina Salomo Alexandre Hataka 《Reproduction in domestic animals》2019,54(6):912-916
Ovarian tumours in mares represent 2.5% to 6% of the most frequent neoplasms found in the equine species, with a higher chance of benignity. This study aims to describe a case of two different tumours found in the same ovary of a mare that presented clinical signs of suppressed oestrous cycle during 5 years. After unilateral ovariectomy, the ovary was sent to the histopathology examination which determined a mixed tumour of granulosa cell and leiomyosarcoma. After treatment, the mare returned to oestrus and got pregnant in the next season. 相似文献
912.
Lené Pienaar J. Paul Grobler Michiel M. Scholtz Hannelize Swart Karen Ehlers Munro Marx Michael D. MacNeil Frederick W. C. Neser 《Tropical animal health and production》2018,50(2):399-404
The Afrikaner is an indigenous South African breed of “Sanga” type beef cattle along with breeds such as the Drakensberger and Nguni. Six composite breeds have been developed from crosses with the Afrikaner. Additionally, Afrikaner has been the base from which exotic breeds were established in South Africa through backcrossing. The study examined genetic diversity of Afrikaner cattle by genotyping 1257 animals from 27 herds in different geographic areas of South Africa and Namibia using 11 microsatellite markers. Multiple-locus assignment, performed using the Bayesian clustering algorithm of STRUCTURE, revealed three underlying genotypic groups. These groups were not geographically localized. Across herds and markers, the proportion of unbiased heterozygosity ranged from 0.49 to 0.72 averaging 0.57; mean number of alleles per locus ranged from 3.18 to 7.09, averaging 4.81; and allelic richness ranged from 2.35 to 3.38, averaging 2.67. It is concluded that a low inbreeding level of 2.7% and a moderate to high degree of variation still persists within the Afrikaner cattle breed, despite the recent decline in numbers of animals. 相似文献
913.
914.
915.
916.
Comparison of two live Bacillus species as feed additives for improving in vitro fermentation of cereal straws 下载免费PDF全文
Zuo Wang Zhixiong He Karen A. Beauchemin Shaoxun Tang Chuanshe Zhou Xuefeng Han Min Wang Jinhe Kang Nicholas E. Odongo Zhiliang Tan 《Animal Science Journal》2016,87(1):27-36
This study was performed in a 2 × 4 factorial arrangement to explore and compare the effects of inclusion of two live Bacillus additives (B. licheniformis and B. subtilis) at four doses (0, 0.25 × 107, 0.50 × 107 and 0.75 × 107 colony‐forming units (cfu)) on in vitro gas production kinetics, fiber degradation, methane production and ruminal fermentation characteristics of maize stover and rice straw by mixed rumen microorganisms in dairy cows. The pH, concentrations of ammonia nitrogen (NH3‐N) and isovalerate were increased (P < 0.05), while the methane (CH4) production, ratio of acetate to propionate, and total volatile fatty acids (TVFA) concentration were decreased (P < 0.05) by the supplementation of B. licheniformis compared with that of B. subtilis. Adding B. licheniformis and B. subtilis raised (P < 0.05) or numerically raised the maximum gas production, while decreasing (P < 0.05) or numerically lowering pH and concentrations of most volatile fatty acids. The addition of B. licheniformis increased (P < 0.05) the NH3‐N concentration but reduced CH4 production and ratio of acetate to propionate (P < 0.05), while the NH3‐N concentration was decreased (P < 0.05), and the CH4 production and ratio of acetate to propionate were increased by that of B. subtilis compared to the control. Results obtained in this research suggest that B. licheniformis would be preferred as a live Bacillus additive in comparison with B. subtilis, and its optimal dose should be 0.25 × 107 cfu/500 mg substrates. 相似文献
917.
鸡肉的健康作用和人类饮食模式 总被引:3,自引:0,他引:3
随着科学的迅速发展,与食品健康有关的细节问题逐渐暴露出来,业内人士需要获取有用的信息来指导人们选择健康食品.目前,除了母乳,没有任何一种单一食品能够满足人体需要的所有养分.只有综合膳食才能达到此要求,但是要配制一个平衡膳食需要确定不同食物给人体提供的具体养分,这就意味着饮食模式对人类健康和疾病具有一定的影响.从消费者角度看,需要从口味偏好到环境等诸多方面去提倡个人和文化价值. 相似文献
918.
Factors affecting the career path choices of graduates at the Western College of Veterinary Medicine
Jelinski MD Campbell JR Naylor JM Lawson KL Derkzen D 《The Canadian veterinary journal. La revue veterinaire canadienne》2008,49(2):161-166
The objective of this study was to describe the demographics of the Class of 2006, Western College of Veterinary Medicine, and to determine which factors influenced the graduates' career path choices. Data were collected via an on-line survey and the response rate was 95.7% (67/70). The majority (57%) of graduates were starting their veterinary career in a food animal-related (FAR) job. Two factors were significantly associated with this choice: 1) those raised in, or near, a small center (population < 10 000) were 3.4 times (P = 0.03) more likely to accept a FAR position than were those raised in a large center (> 10 000), and 2) graduates with a bachelor of science in agriculture (BSc Ag) were 4.5 times (P = 0.04) more likely to begin their career as a FAR practitioner than were those without such a degree. However, 9 of the 16 graduates having a BSc Ag had an urban upbringing. 相似文献
919.
Alexandra Brower Kelly M Homb Philip Bochsler Robert Porter Karen Woods Sue Ubl David Krueger Francine Cigel Kathy Toohey-Kurth 《Journal of veterinary diagnostic investigation》2008,20(3):297-303
Brain tissue from 12 aborted bovine fetuses submitted to the Wisconsin Veterinary Diagnostic Laboratory revealed histologic lesions that consisted of glial nodules and variable degrees of mononuclear inflammation, microhemorrhage, neuronal necrosis, and cerebral cortical cavitation. A diagnosis of Bovine herpesvirus 1 (BHV-1) abortion had been made in all of these cases through multiple testing modalities. Brain tissue from 8 of the 12 fetuses was immunohistochemically stained with a monoclonal antibody specific to BHV-1, and, in 5 fetuses, there was positive intralesional staining of neurons, glial cells, and endothelial cells. This preliminary data suggested that herpesviral infection of brain tissue led to the described neurologic lesions. BHV-1 was then amplified from brain tissue in all 12 of the fetuses and was confirmed by partial sequencing of the thymidine kinase and glycoprotein C genes. To the authors' knowledge, neurologic lesions have not previously been described in BHV-1-infected fetuses, nor has BHV-1 previously been identified in bovine fetal brain tissue. The neurologic histopathology attributed to BHV-1 infection in these cases overlaps with the neurologic lesions produced by Neospora caninum, a common etiologic agent of bovine abortion. Therefore, when bovine fetal neurologic lesions are found, both etiologies should be considered and then distinguished by using additional diagnostic tools. 相似文献
920.