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11.
A cross-sectional study of the seroprevalence to Borrelia burgdorferi sensu lato and granulocytic Ehrlichia spp. in Swedish horses was conducted to evaluate associations with demographic, clinical and tick-exposure factors. From September 1997–1998, blood samples from 2018 horses were collected from the animals presented to veterinary clinics affiliated with the Swedish Horserace Totalizator Board (regardless of the primary cause for consultation). Standardized questionnaires with information both from owners and attending veterinarians accompanied each blood sample. The apparent seroprevalences to B. burgdorferi s. l. and granulocytic Ehrlichia spp. were 16.8 and 16.7%, respectively. The northern region had the lowest seroprevalences. Four logistic models were developed (controlling for demographic variables). In the disease model of seropositivity to B. burgdorferi s. l., age, breed, geographic region, the serologic titer to granulocytic Ehrlichia spp., season and the diagnosis coffin-joint arthritis were significant. In the tick-exposure model of B. burgdorferi s. l., pasture access the previous year and gender were significant. Age, racing activity, geographic region, season and the serologic titer to B. burgdorferi s. l. were associated with positivity to granulocytic Ehrlichia spp. In the tick-exposure model of granulocytic Ehrlichia spp., pasture access was a risk factor. An interaction between racing activity and geographic region showed that the risk of positive serologic reactions to Ehrlichia spp. was increased in the horse population in the south and middle of Sweden, but only among horses not used for racing. Except for the positive association between coffin-joint arthritis and serologic reactions to B. burgdorferi s. l., there were no significant associations in the multivariable models between non-specific or specific clinical sign or disease with seropositivity to either of these agents.  相似文献   
12.
Dairy operations in states representing 86% of the United States’ national dairy herd were surveyed regarding the occurrence of common dairy diseases or disorders (digestive, respiratory, gastrointestinal, lameness, mastitis, navel infection) in specified production groups (weaned heifers, unweaned heifers, adult cows), and the most common antimicrobial preparation used to treat these conditions. Within disease and production group, disease frequency and characteristics of primary antimicrobial (drug class, availability, spectrum of activity, extra-label usage, withdrawal times) were compared among herd sizes (30–99, 100–499, and ≥500 cows) using chi-square or t-tests that accounted for the sampling design. The most common diseases were mastitis and lameness in cows, and gastrointestinal disease in unweaned calves, affecting 16, 11, and 15% of the target populations, respectively. Herd-level disease prevalence tended to increase as herd size increased, whereas within-herd prevalence tended to decrease as herd size increased. Broad-spectrum antimicrobials were selected as primary treatments by a majority of operations for nearly all diseases surveyed. When treating gastrointestinal disease, navel infection, or reproductive disorders, a majority of operations selected primary treatments not specifically labeled for that condition. Selection of over-the-counter preparations tended to decrease as herd size increased, whereas selection of broad-spectrum preparations tended to increase with herd size.  相似文献   
13.
[目的]估计厦门市规模禽场新城疫病原学流行率。[方法]采用横断面研究在厦门市允许禽类养殖的4个区,共计450个规模禽场开展了新城疫病原学的流行病学调查。通过概率抽样,随机抽取129个禽场,共采集了5160份咽喉-泄殖腔拭子,采用荧光RT-PCR 方法检测新城疫病毒。[结果]厦门市规模禽场新城疫病原学群流行率为0.8%(95% CI 0.0-2.1),规模鸡群、鸭群和鹅群的病原学流行率分别为1.9%(95% CI 0.0-4.4)、0%和0%。[结论]这个调查结果表明目前厦门市规模禽场的新城疫已经达到国家中长期防治规划中达到控制标准的要求。  相似文献   
14.
The objectives of this study were to establish normal values for relative echogenicity (RE) and cross-sectional area (CSA) of the flexor tendons and ligaments of the metacarpal region of Purebred Spanish horses (PBSH), and to determine the effect of body mass index (BMI), age, sex and forelimb on these variables. Transverse ultrasonographic images were obtained using 20 normal PBSH (10 females, 10 males; 2–25 years of age; BMI 132.04–152.25; not in training). The images were digitised and values for CSA and RE were determined for each structure.The suspensory ligament was the most echogenic and the largest structure, and the superficial digital flexor tendon was the least echogenic and smallest of the tissues examined. The tendons and ligaments of the metacarpal region in PBSH showed similar RE but smaller CSAs when compared to other breeds.  相似文献   
15.
We carried out a cross-sectional study during 2003 and 2004 to establish the prevalence and risk factors associated with floor type for commonly observed foot lesions in pigs aged 6, 8 and 14 weeks. The overall prevalence of foot lesions was 39.6% in 2283 pigs from 90 representative pig farms in England. The most prevalent lesions were heel/sole bruising (7.1%), heel/sole erosion (10.8%), heel flaps (8.4%) and toe erosion (11.6%). Pigs were kept on either solid (41%), partly slatted (28%) or fully slatted (31%) floors. Of the 104 pens with a solid floor, 26% of pens were outside with straw bedding on a soil base, 33% were indoors with deep bedding on solid concrete, 25% were partly deeply bedded on solid concrete and 16% were sparsely bedded on solid concrete. Only six of the pens with partly slatted floors were bedded.Multilevel logistic-regression models were built using data from 100 farms to examine the risks for individual foot lesions with prevalences >5%. The prevalence of toe erosions was positively associated with deep bedding, whereas deep bedding and soil floors were negatively associated with the prevalence of heel/sole erosions. Heel flaps and heel/sole bruising were both associated with slatted floors, possibly indicating a common aetiology. The greatest reduction in prevalence of all these lesions, from AFp calculations, would be achieved by moving pigs from slatted floors onto solid floors.  相似文献   
16.
Two domestic shorthair cats, a 6-month-old castrated male and a 7-month-old intact female, were diagnosed with complex congenital heart disease. Transthoracic echocardiography in both cats revealed a dilated arterial trunk overriding the interventricular septum with a large ventricular septal defect. The pulmonary trunk and branch pulmonary arteries were not visible using standard echocardiographic views in either cat. The differential diagnosis for both cats included truncus arteriosus communis vs. pulmonary atresia with ventricular septal defect. Each cat underwent computed tomography angiography to determine the origin and extent of the pulmonary blood supply and to better define extra-cardiac anatomy. Computed tomography angiography led to a diagnosis of truncus arteriosus communis with unrestricted pulmonary blood flow in one cat, whereas the other cat was diagnosed with pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals serving as the primary source of pulmonary blood flow. Computed tomography angiography allowed for the ante mortem differentiation of truncus arteriosus communis from pulmonary atresia with ventricular septal defect in these two cats, leading to an accurate diagnosis and providing valuable information to therapeutic decision-making for each case.  相似文献   
17.
A cross-sectional study of the seroprevalence to Borrelia burgdorferi sensu lato and granulocytic Ehrlichia spp. in Swedish horses was conducted to evaluate associations with demographic, clinical and tick-exposure factors. From September 1997–1998, blood samples from 2018 horses were collected from the animals presented to veterinary clinics affiliated with the Swedish Horserace Totalizator Board (regardless of the primary cause for consultation). Standardized questionnaires with information both from owners and attending veterinarians accompanied each blood sample. The apparent seroprevalences to B. burgdorferi s. l. and granulocytic Ehrlichia spp. were 16.8 and 16.7%, respectively. The northern region had the lowest seroprevalences. Four logistic models were developed (controlling for demographic variables). In the disease model of seropositivity to B. burgdorferi s. l., age, breed, geographic region, the serologic titer to granulocytic Ehrlichia spp., season and the diagnosis coffin-joint arthritis were significant. In the tick-exposure model of B. burgdorferi s. l., pasture access the previous year and gender were significant. Age, racing activity, geographic region, season and the serologic titer to B. burgdorferi s. l. were associated with positivity to granulocytic Ehrlichia spp. In the tick-exposure model of granulocytic Ehrlichia spp., pasture access was a risk factor. An interaction between racing activity and geographic region showed that the risk of positive serologic reactions to Ehrlichia spp. was increased in the horse population in the south and middle of Sweden, but only among horses not used for racing. Except for the positive association between coffin-joint arthritis and serologic reactions to B. burgdorferi s. l., there were no significant associations in the multivariable models between non-specific or specific clinical sign or disease with seropositivity to either of these agents.  相似文献   
18.
19.
In Norway, as in many other European countries, income from forestry has become marginal to owners’ household economies and most employment of forest-owner households is now undertaken off the property. Also, many forest owners have focused increasingly on other revenue-earning activities on their properties, such as providing recreational services. It is a challenge in all kinds of production to find the optimal way of converting inputs into outputs, i.e., to be technically efficient. Extent of financial dependency on income from forestry differs between part-time and full-time forest owners. Since the two groups have different livelihood strategies, it is plausible that full-time forest owners have more professional forest management practices. Data for a cross-section of 3,249 active (i.e., harvesting) forest owners were extracted from the 2004 Sample Survey of Agriculture and Forestry representing the year 2003. A stochastic production frontier analysis was applied to evaluate forest management efficiency impacts of important factors including property and owner characteristics, outfield-related and agricultural activities, off-property income and geographical location in central or remote areas. It was found that many forest owners are technically inefficient, and there exist opportunities for improved performance. Off-property income was found to have an estimated negative impact on technical efficiency, the inefficiency arising (weakly) with increasing share of household incomes from outfield activities, and properties in urban centred areas are less efficient than those in remote areas. One policy implication of the study is that a potentially substantial efficiency increase might be achieved from allowing small inefficient woodlots to merge into larger units of forestry production. Also, providing support for forest management plans may improve efficiency.  相似文献   
20.
农田碳汇管理措施对农业生产影响的评价   总被引:1,自引:0,他引:1  
实施必要的农田碳汇管理措施在减缓并应对全球气候变化的影响中发挥着积极的作用。在这种背景下,采用经济学上的生产函数来评价碳汇管理措施对农业生产的影响成为当前国内外学术界研究的热点问题之一。在全球气候变化的背景下,作为中国粮食主产区之一的华北平原,其农业生产明显受到气候变化的影响。从某种程度上看,华北平原农业生产的进一步发展将直接受制于气候变化及其与减缓气候变化效应密切相关的实施农田碳汇管理措施所产生的综合影响。该文以华北平原为案例区试验并测算了碳汇管理措施对农业生产的影响。研究结论对区域水平实施碳汇管理措施以及在适应并应对气候变化影响的背景下,实现农业生产的发展具有指导价值。  相似文献   
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