Milking-Related Changes in the Surface Temperature of the Bovine Teat Skin     

Axel Isaksson  Ole Lind 《Acta veterinaria Scandinavica》1994,35(4):435

The surface temperature of the teat at rest is about 30°C in healthy dairy cows kept indoor under ordinary conditions. It usually decreases by about 1°C during manual premising teat stimulation (Hamann & Dück 1984, Eichel 1986, Hamann 1988,1992). And it usually increases above the level prior to the stimulation by up to about 2.5°C during the milk removal phase of conventional machine milking (Schneider 1981, Hamann & Dück 1984, Hamann 1985,1988,1989, Mayntz 1990, Eichel 1992). The statements made are supported by the results of our own investigations, i.e. − 0.8 and + 2.1 °C, respectively.  相似文献   

Thermal habitat use and juvenile growth of Svalbard Arctic charr: evidence from otolith stable oxygen isotope analyses     

Jane A. Godiksen  Michael Power  Reidar Borgstrøm  J. Brian Dempson  Martin A. Svenning 《Ecology of Freshwater Fish》2012,21(1):134-144

Abstract – Stable oxygen isotopes (δ¹⁸O) derived from otoliths were used to estimate mean annual water temperatures experienced by individual Svalbard Arctic charr, Salvelinus alpinus (L.), during their first four growth seasons. The analysed Arctic charr experienced a high variety of temperatures, indicating the use of different thermal habitats. A higher proportion of the juveniles experienced warmer temperatures during their first summer compared with later summers, suggesting the selective use of the shallowest littoral areas of the lake. Although the estimated temperatures were consistent with water temperatures found in High Arctic rivers and lakes during summer, they did not represent the annual variation in air temperature registered over the 20 years of otolith measurement. Furthermore, summer otolith increment width did not correlate with the experienced temperature. However, after the second year, otolith increment width was highly dependent on increment width during the previous summer. This study estimated mean summer water temperatures experienced by individual Arctic charr during the first four growth seasons providing additional evidence that stable oxygen isotope analysis can be used to provide insight into the thermal habitat use by juvenile Arctic charr.  相似文献   

Hammerstein-Wiener model for the prediction of temperature variations inside silage stack-bales using wireless sensor networks     

Esmaeil S. Nadimi  Ole Green  Victoria Blanes-Vidal  Jakob J. Larsen  Lars P. Christensen 《Biosystems Engineering》2012,112(3):236-247

Animal forage plays an important role in agriculture. To maintain the silage quality during storage, preserving it from decomposition by wrapping the harvested crop with plastic stretch film is crucial. Any failure in the preserving process permits the infusion of oxygen, which allows the growth of undesirable aerobic microorganisms and silage decomposition. To study the state of the silage, temperature inside the stack could be used as indicator of decomposition. However, no previous study has developed a model that can detect decomposition based on abnormal temperature variations inside a silage stack. The first objective of this paper was to develop a structured nonlinear model to estimate the dynamics of temperature variations measured by a wireless sensor network-based monitoring system (nRF95E) inside a silage bale and stack prior to the decomposition process. The requirement of a robust nonlinear model is that sensor nonlinearities that are inherent in nature are considered. The results showed that a Hammerstein-Wiener (HW) model with sigmoid network performed the best in terms of percentage of fit (91.70%) between the measured and simulated output. The second objective was to estimate the length of time required to detect the decomposition process after the airtight seal was punctured using the model. The error between the predicted model output and the sensor readings exceeded a preset threshold interval 17 days after the cover film was punctured and 9 days after the decomposition process was detected due to the odour released.  相似文献   

Trevor's Story          下载免费PDF全文

N. Ole Nielsen 《The Canadian veterinary journal. La revue veterinaire canadienne》2000,41(6):488

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Migration Inhibition Studies on Peripheral Leukocytes and Lymph Node Cells from Ruminants with Fascioliasis     

Ole Aalund  Knud Nielsen  Lis Eriksen 《Acta veterinaria Scandinavica》1972,13(2):290

Delayed type hypersensitivity against antigens of Fasciola hepatica has been repeatedly documented in infected hosts. Evidence has been presented to suggest that the delayed reactivity may develop earlier in the regional lymph nodes of the parasitized organ than in other lymph nodes of the body (Soulsby 1971).  相似文献   

维生素营养的新概念   总被引：1，自引：0，他引：1  

刘建辉 《国外畜牧学(猪与禽)》2001,(2):19-20

动物的维生素需要量是动态的 ,是随其基因型、生产性能高低、所用生产体系的不同而不同的 ,还随着人们对维生素功能更加深入的了解而不同。这意味着 ,维生素推荐量和维生素添加指南都需要经常更新。现在已经有了新的指南 ,其中的推荐量是根据“最佳维生素营养”的长期概念加以更新的 ,这有助于营养师保证动物的健康和性能目标不因维生素供应量的问题而受害。只有当动物有效利用了为生长、健康、繁殖和存活而通过日粮提供的养分以后才算是实现了最佳营养。虽然所有的养分 ,如蛋白质、矿物质和水 ,对于动物的功能都极为重要 ,但维生素却另有其…  相似文献   

Long-term vegetational history of a Picea abies stand in south-eastern Norway: Implications for the conservation of biological values     

Chiara Molinari  Ole Risbøl  Mikael Ohlson 《Biological conservation》2005,126(2):155-165

The development of a forest stand in south-eastern Norway during the last 9000 years is investigated by pollen and charcoal analyses. The aims are to identify factors that have influenced current biodiversity, which includes the lichen Usnea longissima, and examine the immigration and establishment of the current dominant tree Picea abies. Fire has been a variable but major disturbance factor at the site throughout the study period but has ceased during the last 100 years. Picea immigration was primarily a natural process but local establishment occurred after a major disturbance. Cultural impact began 3500 years ago during the Bronze Age, but was most intensive between AD 1600 and AD 1900. It led to the local extinction of deciduous trees and created a biodiversity bottleneck that facilitated the rise to dominance of Picea. Guidelines are proposed for future management designed to preserve and enhance local biological values.  相似文献   

How representatively can we sample soil mineral nitrogen?     

Antje Giebel  Ole Wendroth  Hannes Isaak Reuter  Kurt‐Christian Kersebaum  Jürgen Schwarz 《植物养料与土壤学杂志》2006,169(1):52-59

Spatial distribution of soil mineral‐N content (N_min) is a scale‐variant process. Precision farming assumes knowledge about the spatial distribution of N_min. Moreover, sampling in management zones is based on the assumption of spatial dependence between sampling points. In the present study, variability structure of N_min and the sources of variability were investigated. Within an agricultural landscape, N_min was investigated across a field in a nested design over four consecutive years. Temporally unstable structure of individual nests require a sampling with several nests in the field. In the investigated field, 35%–49% of the total variability derived from small‐scale variability observed at spatial distances of <5 m and from sampling and analytical errors. Differences between 10 and 26 kg N ha^–1 for the soil depth increment 0–60 cm can be expected. Uncertainty due to analytical errors were in the order of 5–10 kg N ha^–1 for a 0–60 cm layer.  相似文献   

Landscape research — exploring ecosystem processes and their relationships at different scales in space and time     

Chris van Kessel  Ole Wendroth 《Soil & Tillage Research》2001,58(3-4):97-98

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Deposition characteristics and biological effectiveness of fungicides applied to winter wheat and the hazards of drift when using different types of hydraulic nozzles   总被引：1，自引：0，他引：1  

Ole Permin  L. N. J  rgensen  K. Persson 《Crop Protection》1992,11(6):541-546

Hydraulic-fan cone, low-pressure fan and two-chamber cone nozzles were used at 1.5, 3.0 and 6.0 bar (150, 300 and 600 kPa) to deliver 140, 200 and 3001 ha⁻¹ respectively of a fungicide spray to control mildew and yellow rust in winter wheat. No significant differences in biological effect were obtained although fan nozzles deposited significantly more on the upper parts of the stems, and two-chamber cone nozzles deposited less on the flag leaf and on the upper part of the stems. Because of their higher deposit and more even distribution, fan nozzles should be preferred, operated at a pressure of 1.5–3 bar to deliver a spray volume of 140–190 lha⁻¹ at 7 km h⁻¹ and to obtain an acceptable biological effect. Higher pressure (6 bar) and volume rates gave no improvement in fungicide performance. Adding a surfactant or penetration oil did not change the volume median diameter or proportion of spray liquid in droplets < 150 μm. Less drift was found when using two-chamber cone nozzles at 3 bar than with flat-fan spray nozzles at 1.5 bar. It is concluded that the two-chamber cone nozzle is useful for fungicide application when drift must be avoided.  相似文献