全文获取类型
| 收费全文 | 81篇 |
| 免费 | 10篇 |
专业分类
| 林业 | 3篇 |
| 农学 | 1篇 |
| 综合类 | 9篇 |
| 农作物 | 2篇 |
| 水产渔业 | 1篇 |
| 畜牧兽医 | 64篇 |
| 园艺 | 1篇 |
| 植物保护 | 10篇 |
出版年
| 2023年 | 1篇 |
| 2021年 | 2篇 |
| 2019年 | 1篇 |
| 2018年 | 4篇 |
| 2017年 | 5篇 |
| 2016年 | 2篇 |
| 2015年 | 1篇 |
| 2014年 | 3篇 |
| 2013年 | 10篇 |
| 2012年 | 1篇 |
| 2011年 | 1篇 |
| 2010年 | 4篇 |
| 2009年 | 4篇 |
| 2008年 | 3篇 |
| 2007年 | 3篇 |
| 2006年 | 1篇 |
| 2005年 | 3篇 |
| 2004年 | 2篇 |
| 2003年 | 2篇 |
| 2001年 | 1篇 |
| 2000年 | 3篇 |
| 1999年 | 3篇 |
| 1998年 | 4篇 |
| 1997年 | 4篇 |
| 1996年 | 2篇 |
| 1995年 | 1篇 |
| 1994年 | 4篇 |
| 1993年 | 2篇 |
| 1992年 | 5篇 |
| 1990年 | 3篇 |
| 1989年 | 3篇 |
| 1988年 | 3篇 |
排序方式： 共有91条查询结果，搜索用时 15 毫秒
21.
The financial losses due to retained placenta in Dutch dairy cattle were estimated by using two different methods of calculation. A data-set containing the birth records of 160,188 Meuse-Rhine-Yssel cows provided data on the reproductive performance of cows with and without retained placenta. The fertility of cows after retention of the placenta appeared to be affected. An economic calculation made by adding the losses due to increased calving interval, increased culling rate, loss of milk production and the costs of veterinary treatment and drugs revealed that the total loss due to retained placenta was 471 pounds per year for a 100-cow farm with an average incidence of the condition (6.6 per cent). For a 'problem' farm with a 30 per cent rate, the loss was 2139 pounds per year. A computer farm simulation model, based on a stochastic determination of events, was used to make calculations for circumstances closely resembling those on farms. A 6.6 per cent rate of retained placenta caused a small but significant decrease in net return on labour and management; however, a 30 per cent rate caused highly significant changes. The economic effects of retained placenta were similar in magnitude in herds of high or low productivity and high or low fertility. Sensitivity analysis showed that the greatest financial losses were caused by loss of milk production, followed by the number of animals suffering from complications. The financial losses in herds with an average rate of retained placenta were thus of limited economic importance and therapeutic measures alone should be adequate.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
22.
Testosterone and androstenedione were measured in the plasma of mature tom-cats before, during and after anesthesia with thiopentone, ketamine, xylazine and alphaxolone/alphadolone. Samples were collected via an indwelling jugular catheter at 30 min intervals before anesthesia (5 samples) and during the recovery phase (8 samples), and at intervals of 15 min during anesthesia (7 samples). Thiopentone and ketamine anesthesia significantly depressed testosterone and androstenedione concentrations during and after anesthesia. Xylazine significantly increased testosterone concentrations during anesthesia but they returned to pre-anesthetic concentrations during recovery. Androstenedione concentrations were significantly depressed during the recovery phase from xylazine anesthesia. Alphaxolone/alphadolone anesthesia had no significant effect of testosterone concentrations but significantly increased and androstenedione concentrations during anesthesia and recovery. Testosterone and androstenedione concentrations in cats were significantly altered by these 4 commonly used anesthetics and this must be taken into account if hormone concentrations are measured while cats are anesthetised. 相似文献
23.
24.
Ataxia and paralysis in cats in Australia associated with exposure to an imported gamma-irradiated commercial dry pet food 总被引：1，自引：1，他引：0
Between June 2008 and March 2009, 87 cats in Australia developed symmetrical hindlimb ataxia, paraparesis, tetraparesis, paraplegia or tetraplegia in association with eating an imported, irradiated dry pet food. This communication reports the clinical signs and outcomes of those cats. 相似文献
25.
ABSTRACT Different levels of thrips resistance were found in seven Capsicum accessions. Based on the level of feeding damage, host preference, and host suitability for reproduction, a thrips susceptible and a resistant accession were selected to study their performance as Tomato spotted wilt virus (TSWV) sources and targets during thrips-mediated virus transmission. Vector resistance did not affect the virus acquisition efficiency in a broad range of acquisition access periods. Inoculation efficiency was also not affected in short inoculation periods, but was significantly lower on plants of the thrips resistant accession during longer inoculation access periods. Under the experimental conditions used, the results obtained show that transmission of TSWV is little affected by vector resistance. However, due to a lower reproduction rate on resistant plants and a lower preference of thrips for these plants, beneficial effects of vector resistance might be expected under field conditions. 相似文献
26.
27.
28.
29.
Rooney HC Van't Klooster JW van der Hoorn RA Joosten MH Jones JD de Wit PJ 《Science (New York, N.Y.)》2005,308(5729):1783-1786
How plants recognize pathogens and activate defense is still mysterious. Direct interaction between pathogen avirulence (Avr) proteins and plant disease resistance proteins is the exception rather than the rule. During infection, Cladosporium fulvum secretes Avr2 protein into the apoplast of tomato leaves and, in the presence of the extracellular leucine-rich repeat receptor-like Cf-2 protein, triggers a hypersensitive response (HR) that also requires the extracellular tomato cysteine protease Rcr3. We show here that Avr2 binds and inhibits Rcr3 and propose that the Rcr3-Avr2 complex enables the Cf-2 protein to activate an HR. 相似文献
30.