全文获取类型
收费全文 | 67篇 |
免费 | 13篇 |
专业分类
林业 | 1篇 |
农学 | 1篇 |
2篇 | |
综合类 | 9篇 |
水产渔业 | 1篇 |
畜牧兽医 | 64篇 |
植物保护 | 2篇 |
出版年
2023年 | 1篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 22篇 |
2012年 | 2篇 |
2011年 | 2篇 |
2010年 | 3篇 |
2009年 | 1篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2004年 | 1篇 |
2001年 | 1篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有80条查询结果,搜索用时 15 毫秒
61.
62.
A screen house experiment was undertaken to study effect of time of application of deoiled castor cake on the yield, N and P uptake by wheat crop. The results indicate that the wheat growth decreased significantly with increasing dose of castor cake, when castor cake was applied just before sowing of wheat. When castor cake was applied 10 days before wheat sowing, the dry matter yield (DMY) of wheat increased up to 0.125% dose of castor cake and reduced thereafter. But when the castor cake was applied 20 days before wheat sowing, the DMY was at par under all the doses of castor cake and better than control indicating the degradation of the toxicants produced by the castor cake. Application of castor cake can also be helpful in reducing the cost of phosphatic fertilizer. Thus it can be concluded that castor cake should be applied at least 3 weeks before sowing of the crop and keeping the field moist for degradation of the toxicants. 相似文献
63.
CASE HISTORY: Investigations were conducted to determine the cause of an acute, multi-farm outbreak of porcine respiratory disease that included diarrhoea and subsequent loss of body condition in affected pigs. A definition for post-weaning multisystemic wasting syndrome (PMWS) including both clinical and pathological features, previously developed for the pig industry in New Zealand, was applied to the current outbreak. In addition to self-reporting by owners of affected farms, local veterinarians, disease and epidemiology consultants, and animal health officials from the Ministry of Agriculture and Forestry (MAF) were involved in conducting farm visits and submission of diagnostic specimens. CLINICAL FINDINGS AND DIAGNOSIS: Pathogens known to be endemic in the pig industry in New Zealand as well as likely exotic diseases were excluded as causative agents of the outbreak. Clinical signs including dyspnoea, diarrhoea, and rapid loss of body condition were consistent with the New Zealand case definition for PMWS. Interstitial pneumonia, pulmonary oedema, generalised lymph-node enlargement, and presence of porcine circovirus type 2 (PCV2) inclusion bodies were consistently identified in affected pigs. Classical swine fever virus (CSFv), Porcine reproductive and respiratory syndrome virus (PRRSv), and Influenza virus were ruled out, using molecular and traditional virological techniques. Spread of the disease between farms was hypothesised to be facilitated by locally migrating flocks of black-backed seagulls. The original source of the disease incursion was not identified. DIAGNOSIS: Based on the consistent presence of circovirusassociated lesions in lymphoid tissues in combination with generalised enlargement of lymph nodes, histiocytic interstitial pneumonia, clinical wasting, and poor response to antibiotic therapy, a diagnosis of PMWS was made. CLINICAL RELEVANCE: PMWS should be considered in the differential diagnoses of sudden onset of respiratory dyspnoea, diarrhoea, and rapid loss of body condition in young pigs in New Zealand pig herds. 相似文献
64.
Bedrock landsliding is a dominant geomorphic process in a number of high-relief landscapes, yet is neglected in landscape evolution models. A physical model of sliding in beans is presented, in which incremental lowering of one wall simulates baselevel fall and generates slides. Frequent small slides produce irregular hillslopes, on which steep toes and head scarps persist until being cleared by infrequent large slides. These steep segments are observed on hillslopes in high-relief landscapes and have been interpreted as evidence for increases in tectonic or climatic process rates. In certain cases, they may instead reflect normal hillslope evolution by landsliding. 相似文献
65.
RW Graham EL Lundelius MA Graham EK Schroeder RS Toomey E Anderson AD Barnosky JA Burns CS Churcher DK Grayson RD Guthrie CR Harington GT Jefferson LD Martin HG McDonald RE Morlan HA Semken SD Webb L Werdelin MC Wilson 《Science (New York, N.Y.)》1996,272(5268):1601-1606
Analyses of fossil mammal faunas from 2945 localities in the United States demonstrate that the geographic ranges of individual species shifted at different times, in different directions, and at different rates in response to late Quaternary environmental fluctuations. The geographic pattern of faunal provinces was similar for the late Pleistocene and late Holocene, but differing environmental gradients resulted in dissimilar species composition for these biogeographic regions. Modern community patterns emerged only in the last few thousand years, and many late Pleistocene communities do not have modern analogs. Faunal heterogeneity was greater in the late Pleistocene. 相似文献
66.
AIM: To describe characteristics of Thoroughbred training stables in Matamata and in all other locations in New Zealand combined, over two 19-month time periods in 1996–1997 and 1998–1999, representing equal length periods immediately prior to and after the construction of a new training surface at the Matamata Racing Club. METHODS: Retrospective records covering all horses training and racing in New Zealand during two 19-month time periods (1996–1997 and 1998–1999), covering 161 locations, were obtained from New Zealand Thoroughbred Racing (NZTR). Outcome variables included whether a horse was raced again in the 6 months following any start in the first 13 months of either time period, number of race starts for every horse, and finishing position. Summary measures with confidence intervals (CI) and unadjusted odds ratios (OR), measuring strength of associations for various factors, were computed. RESULTS: The datasets contained information on 45,446 horses, 11,336 races, 5,110 trials and a total of 110,643 race starts. Horses trained at Matamata represented 8% (3,715) of the total horse datasets, and accounted for 11,977 race starts (10.8%). They were more likely to start in a race or trial in either time period and were 1.4 and 1.3 times as likely to finish first, second or third compared with horses trained at other locations in 1996–1997 and 1998–1999, respectively. A 6-month no-race period occurred for 9,306/12,584 (74%) horses that started at least once in the first 13 months of either time period. Horses trained at Matamata were less likely to have a 6-month no-race period than horses trained at other locations in both time periods. There was no effect of time period within each location on the probability of either a horse having a 6-month no-race period or of a race start being followed by a 6-month no-race period, but there was an overall effect of time and more 6-month no-race periods were observed in 1998–1999 relative to 1996–1997. CONCLUSION: Summary statistics are presented for Thoroughbred racing in New Zealand over two 19-month time periods. Differences between the populations of horses trained in Matamata compared with those trained at other locations were attributed, in part, to the fact that many of the more successful racehorse trainers in the country have stables at Matamata. As a result, the population of horses in Matamata may not be representative of the racehorse population in New Zealand. Although more likely to win or place in both time periods, the magnitude of the advantage to horses in Matamata was reduced in 1998–1999 relative to 1996–1997, and this could be due, in part, to effects of the new track surface at Matamata. There was no evidence of a rise in risk of a 6-month no-race period following any race start in those horses trained in Matamata in 1998–1999 relative to either horses trained at other locations or to horses trained in Matamata during the earlier time period. 相似文献
67.
68.
69.
Simulation of the economic impact of transmissible gastroenteritis on commercial pig production in Australia 总被引:1,自引:0,他引:1
A simulation model (AUSPIG) was used to predict the effect of an increase in piglet deaths, and a reduction in growth rate and an increase in feed conversion ratio of grower pigs on the profitability of two herds representative of the Australian pig industry caused by the introduction of transmissible gastroenteritis virus (TGE) into those herds. For each herd, mortality rates for piglets under 1 week of age of 50% and 95% were assumed to represent a 'moderate' and a 'severe' outbreak, respectively. A reduction in net revenue of 70% was predicted to occur in the 6 months after a 'moderate' outbreak of TGE (100% for a 'severe' outbreak). This represents a total loss of between $260 and $330 per breeding sow in the 12 months after infection with the TGE virus. The likely financial impact of an outbreak of TGE on an Australian piggery is substantial and should be considered when addressing quarantine issues. 相似文献
70.
AIM: To investigate risk factors for injury to the superficial digital flexor tendon (SDFT) and suspensory apparatus (SA) of the forelimbs in Thoroughbred racehorses in New Zealand. METHODS: Poisson and negative binomial regression, with exposure time represented by cumulative training days for each horse, were used to relate explanatory variables to the incidence rate (IR) of cases of inflammation of the SDFT (n=51), and injuries involving the SA (n=48) in a population of 1,571 commercially-trained racehorses over 554,745 study days. Only the first occurrence of an injury for any one horse was eligible for inclusion. Separate analyses were run for data from horses in training regardless of whether they had started in a trial or race, and using a subset of these data restricted to those preparations associated with at least one start in a trial or race. Results were reported as incidence rate ratios (IRR) and 95% confidence intervals (CI). RESULTS: Male horses had a higher risk of injury to the SA (IRR 2.57; p=0.005) and tended to have a higher risk of injury to the SDFT (IRR 1.74; p=0.09) than female horses. Increasing age was associated with increased risk of injury. Horses aged 4 and ≥5 years were 6.76 (p<0.001) and 15.26 (p<0.001) times more likely to incur injury to the SDFT, and 2.91 (p=0.02) and 3.54 (p=0.005) times more likely to incur injury to the SA, respectively, than 2-year-olds. Horses were more likely to suffer an injury to the SDFT or SA in a training preparation that was not associated with any starts in official trials or races compared with those preparations that were associated with more than one start (p<0.001), and more likely to injure the SA compared with preparations containing one start (p=0.03). The IR of injury to the SDFT tended to be lower between November–January (IRR 0.78; p=0.08) and February-April (IRR 0.75; p=0.08) compared with August–October. Incidence of injury to the SDFT or SA was not associated with the cumulative distance raced in the last 30 days of a training preparation. CONCLUSION: This study identified risk factors for injury to the SDFT and SA in Thoroughbred racehorses in New Zealand. Injuries were more likely in males, older horses and in horses in training preparations without any starts. There was no evidence of association between injury and cumulative high-speed exercise. 相似文献