全文获取类型
收费全文 | 252篇 |
免费 | 23篇 |
专业分类
林业 | 3篇 |
农学 | 4篇 |
25篇 | |
综合类 | 36篇 |
农作物 | 10篇 |
水产渔业 | 7篇 |
畜牧兽医 | 180篇 |
园艺 | 1篇 |
植物保护 | 9篇 |
出版年
2022年 | 2篇 |
2020年 | 6篇 |
2019年 | 9篇 |
2018年 | 8篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 10篇 |
2013年 | 26篇 |
2012年 | 5篇 |
2011年 | 11篇 |
2010年 | 13篇 |
2009年 | 14篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 8篇 |
2002年 | 8篇 |
2001年 | 3篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 16篇 |
1997年 | 12篇 |
1996年 | 8篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1983年 | 2篇 |
1978年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1972年 | 4篇 |
1971年 | 1篇 |
1967年 | 2篇 |
1963年 | 2篇 |
1962年 | 1篇 |
1960年 | 2篇 |
1954年 | 1篇 |
1950年 | 1篇 |
1945年 | 1篇 |
1924年 | 1篇 |
排序方式: 共有275条查询结果,搜索用时 15 毫秒
71.
72.
Molluscum contagiosum in chimpanzees 总被引:2,自引:0,他引:2
73.
Zinsstag J Ankers P Njie M Smith T Pandey VS Pfister K Tanner M 《Veterinary parasitology》2000,89(1-2):71-78
Offspring-dam regression was used to estimate the heritability of strongyle faecal egg counts (FEC) of traditionally raised West African N'Dama cattle in the Central River Division in The Gambia. Faecal samples were taken monthly from June-October 1992, and again from July-October 1993, including 179-463 dams and their calves sampled on each occasion. The only proven genetic relationship was the dam-offspring relationship. Gastrointestinal strongyle FEC was expressed as epg (eggs per gram faeces). Regression of offspring FEC on dam FEC, showed a heritability (h(2)) of 0.18 (95% Confidence Limits 0.10, 0.25). Heritabilities were higher at the beginning and end of the rainy season than during the months of the peak rainy season. This is in line with earlier suggestions that genetic control of faecal egg counts is most effective during periods of low parasite transmission. There was a significant (p<0.001) increase in heritability of 0.086+/-0.018 with each year of age of the corresponding offspring. In view of the virtual absence of national cattle breeding systems in West Africa, which are a precondition for exploitation of heritable traits in cattle, integrated control using improved management and strategic prophylaxis remain the methods of choice to control gastrointestinal nematodes in the given conditions. 相似文献
74.
75.
G Pugliesi SC Scolari FS Mesquita M Maturana Filho ER Araújo D Cardoso JN Sales I Martin M Sá Filho CM Bertan M Binelli 《Reproduction in domestic animals》2014,49(4):e35-e39
This short communication reports the impact of endometrial biopsies, uterine flushings and follicular fluid aspiration procedures at day 6 post artificial insemination (AI) on pregnancy rates. In Experiment 1, cows were timed AI (TAI) and assigned to the following treatment groups: control (n = 37), uterine flushing (n = 35) and endometrial biopsy (n = 38). On day 30 post AI, pregnancy rates were 40.5%, 33% and 28.5%, respectively (p > 0.1). Pregnancy rate on day 60 was lower (p < 0.004) in flushed cows than in the controls. In Experiment 2, oestrus was detected and cows were assigned to flushing (n = 32) or biopsy (n = 33) treatments 6 days after AI, which resulted in pregnancy rates of 31% and 36%, respectively (p > 0.1). In Experiment 3, cows were, 6 days after TAI, randomly assigned to the following treatments: control (n = 84) or aspiration of the largest follicle (n = 73). Pregnancy rates on day 30 post AI were 63.5% for the control group and 53% for the aspirated group (p > 0.1). In conclusion, uterine flushing and endometrial biopsy negatively affect pregnancy rates, but neither procedure can be considered to be incompatible with pregnancy maintenance. Follicular aspiration during pregnancy does not interact with pregnancy success. The amount and quality of samples obtained are compatible with the use of cellular and molecular analysis of uterine variables from cows that failed or succeeded on maintaining pregnancy. 相似文献
76.
CM Balao da Silva C Ortega Ferrusola JM Gallardo Bolaños M Plaza Dávila P Martín‐Muñoz JM Morrell H Rodriguez Martínez FJ Peña 《Reproduction in domestic animals》2014,49(6):1021-1027
Flow cytometry is considered the only reliable method for the separation of X and Y chromosome bearing spermatozoa in equines. The MoFlo SX DP sorter is highly efficient, allowing the production of foals of the desired sex. However, to achieve acceptable pregnancy rates the currently used protocol requires working with fresh semen obtained close to, or at, the sorting facility. An alternative protocol was tested during two consecutive breeding seasons. Fresh stallion semen was cooled for 20 h, during which staining with Hoechst 33342 took place. On the following day, this sample was flow sorted and compared with spermatozoa from the same ejaculate that had been sexed on the previous day. All sperm parameters evaluated remained unchanged when fresh sorted and refrigerated sorted semen were compared. Pre‐sorting storage at 5°C did not alter sperm velocities nor kinetics, viability or membrane permeability, production of reactive oxygen species, mitochondrial membrane potential or DNA fragmentation index of the sorted sample. The findings open for the possibility of using semen from stallions housed far from the sorting facilities. Processed and stained sperm could be shipped refrigerated on the previous day, sorted and inseminated on the next day. 相似文献
77.
Jinquan Feng Andrew McGloneDavid Tanner Anne WhiteShane Olsson Mary Petleylan Woolf 《Postharvest Biology and Technology》2011,61(1):29-34
The effect of penetration speed on flesh firmness (FF) measurement by motorised penetrometer was examined for ‘Hayward’ (Actinidia deliciosa var. deliciosa) and ‘Hort16A’ (Actinidia chinensis Planch. var. chinensis) kiwifruit. Data was collected for penetration speeds varying from 4 to 40 mm s−1 using stored fruit of FF ∼10 N; a typical minimum FF threshold for export from New Zealand. Measurements were made on a number of instruments (Instron, GUSS FTA, HortPlus, TA.XTplus), using fruit from different orchards and in each of two different seasons. As expected, FF values increased with increasing penetration speed. A firmness-speed model was developed, based on the Maxwell rheological model for viscoelastic materials, which proved adequate in describing the FF data in terms of the effect of penetration speed. The effect of penetration speed was not adversely influenced by cultivar, season or instrument type. Within the range of fruit firmness examined - stored fruit below 20 N - it was concluded that the firmness-speed model could be successfully used to compare firmness values generated using instruments operating at different penetration speeds. 相似文献
78.
79.
80.
LM Seibert V Parthasarathy CM Trim SL Crowell-Davis 《Veterinary anaesthesia and analgesia》2003,30(2):112-112
Pain management is an important post-operative concern. Pain scales may rely on the observer's subjective assessment of the level of discomfort and may not correlate with physiologic or pharmacologic measures of pain. The purpose of this study was to develop an objective measure of behavior in healthy pain-free horses recovering from anesthesia that could be used for comparison with the behavior of horses recovering from a surgical procedure.
Focal sampling with videotape and observation was done on five healthy horses before anesthesia to establish baselines. Behavioral measures included head turns, tail swishes, eyelid aperture/size, ear position, angle of neck, weight shifts, and ambulation. Physiologic measures included heart rate, respiratory rate, and temperature. The horses were anesthetized for 2 hours with isoflurane, and in the recovery stall, data were collected continuously on videotape from the time of extubation to standing. Focal sampling of 15 minutes was repeated at 1, 2, 4, and 24 hours after the horses returned to their stalls. Video data were analyzed using the Noldus Observer Video Analysis System.
A wide variation in behavior was observed between horses in the recovery stall. Observations at 1, 2, and 4 hours revealed change from the up/forward ear position to the down ear position, and a decrease in weight bearing of the hind limb from a baseline of 11–12 minutes out of 15 minutes to 7–9 minutes with an increase in toe pointing. Time spent standing was similar to baseline of 93.8%, and the neck angle was not changed from baseline of 173.5°. Values had returned to baseline at 24 hours.
Changes in behavior were induced by anesthesia alone and must be taken into consideration when evaluating analgesic treatments. 相似文献
Focal sampling with videotape and observation was done on five healthy horses before anesthesia to establish baselines. Behavioral measures included head turns, tail swishes, eyelid aperture/size, ear position, angle of neck, weight shifts, and ambulation. Physiologic measures included heart rate, respiratory rate, and temperature. The horses were anesthetized for 2 hours with isoflurane, and in the recovery stall, data were collected continuously on videotape from the time of extubation to standing. Focal sampling of 15 minutes was repeated at 1, 2, 4, and 24 hours after the horses returned to their stalls. Video data were analyzed using the Noldus Observer Video Analysis System.
A wide variation in behavior was observed between horses in the recovery stall. Observations at 1, 2, and 4 hours revealed change from the up/forward ear position to the down ear position, and a decrease in weight bearing of the hind limb from a baseline of 11–12 minutes out of 15 minutes to 7–9 minutes with an increase in toe pointing. Time spent standing was similar to baseline of 93.8%, and the neck angle was not changed from baseline of 173.5°. Values had returned to baseline at 24 hours.
Changes in behavior were induced by anesthesia alone and must be taken into consideration when evaluating analgesic treatments. 相似文献