Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2018
Authors
Knut Egil Bøe Guro Dragsund Grete Helen Meisfjord Jørgensen Eileen E. Fabian-WheelerAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
In recent years, slatted floors made of materials like fiber composite and plastic have been introduced in animal housing systems. These modern floor types are claimed to have low heat conductivity and hence be “better” for the sheep than expanded metal, but the actual preference in sheep has not yet been tested. The aim of this study was to investigate the preference of ewes for different floor materials at low ambient temperatures. The experiment was performed in a non-insulated building and the indoor air temperature varied from -11.8 to + 3 °C. Each experimental pen measured 3.0 x 2.0 m (total 6.0 m2) and were divided into two equal sections (A and B). A total of 30 non-pregnant ewes were sheared and allocated to one of ten stable groups with three animals per group. Five different floor types – expanded metal, slatted floor made of fiber composite, slatted floor made of plastic, solid floor made of wood and solid floor consisting of a rubber mat, were installed in section A and B in the experimental pens. Groups were habituated to all floor material combinations and systematically rotated through the ten pens. Behaviors were scored from 20 hour video recordings using instantaneous sampling at 10 minute intervals. In addition, heat conductivity properties of the five different floor materials were tested. On days with low temperatures, the ewes were standing or walking more, resting less, eating or drinking more and resting more in physical contact than on days with higher temperatures. When given the choice, ewes showed clear preferences for standing/walking and resting on solid floor materials than on slatted floors. This is consistent with earlier preference tests on sheared sheep. Ewes did not seem to show a clear preference for one slatted floor material over another for resting. The proportion of time spent standing/walking in the pen was steadily reduced as air temperature in the barn increased. The present experiment suggests that none of the floor combinations had thermal properties that adversely affect resting and other general behaviors of the animals. The heat conductivity properties were similar among the slatted floors. In conclusion, the claimed favorable thermal properties of plastic slatted floors and fiber composite were not confirmed. There must be other properties of the floor than heat conductivity that influences the preference in ewes.
Abstract
No abstract has been registered
Abstract
In recent years, slatted floors made of materials like fiber composite and plastic have been introduced in animal housing systems. These modern floor types are claimed to have low heat conductivity and hence be “better” for the sheep than expanded metal, but the actual preference in sheep has not yet been tested. The aim of this study was to investigate the preference of ewes for different floor materials at low ambient temperatures. The experiment was performed in a non-insulated building and the indoor air temperature varied from -11.8 to + 3 °C. Each experimental pen measured 3.0 x 2.0 m (total 6.0 m2) and were divided into two equal sections (A and B). A total of 30 non-pregnant ewes were sheared and allocated to one of ten stable groups with three animals per group. Five different floor types – expanded metal, slatted floor made of fiber composite, slatted floor made of plastic, solid floor made of wood and solid floor consisting of a rubber mat, were installed in section A and B in the experimental pens. Groups were habituated to all floor material combinations and systematically rotated through the ten pens. Behaviors were scored from 20 hour video recordings using instantaneous sampling at 10 minute intervals. In addition, heat conductivity properties of the five different floor materials were tested. On days with low temperatures, the ewes were standing or walking more, resting less, eating or drinking more and resting more in physical contact than on days with higher temperatures. When given the choice, ewes showed clear preferences for standing/walking and resting on solid floor materials than on slatted floors. This is consistent with earlier preference tests on sheared sheep. Ewes did not seem to show a clear preference for one slatted floor material over another for resting. The proportion of time spent standing/walking in the pen was steadily reduced as air temperature in the barn increased. The present experiment suggests that none of the floor combinations had thermal properties that adversely affect resting and other general behaviors of the animals. The heat conductivity properties were similar among the slatted floors. In conclusion, the claimed favorable thermal properties of plastic slatted floors and fiber composite were not confirmed. There must be other properties of the floor than heat conductivity that influences the preference in ewes.
Authors
Roland Bol Gerard Gruau Per-Erik Mellander Rémi Dupas Marianne Bechmann Eva Skarbøvik Magdalena Bieroza Faruk Djodjic Miriam Glendell Philip Jordan Bas van der Grift Michael Rode Erik Smolders Mieke Verbeeck Sen Gu Erwin Klumpp Ina Pohle Maelle Fresne Chantal Gascuel-OdouxAbstract
No abstract has been registered
Authors
Per-Erik Mellander Philip Jordan Marianne Bechmann Ophélie Fovet Mairead M. Shore Noeleen T. McDonald Chantal Gascuel-OdouxAbstract
No abstract has been registered
Authors
Jian Liu Peter J. A. Kleinman Helena Aronsson Don Flaten Richard W. McDowell Marianne Bechmann Douglas B. Beegle Timothy P. Robinson Ray B. Bryant Hongbin Liu Andrew N. Sharpley Tamie L. VeithAbstract
Winter manure application elevates nutrient losses and impairment of water quality as compared to manure applications in other seasons. In conjunction with reviewing global distribution of animal densities, we reviewed worldwide mandatory regulations and voluntary guidelines on efforts to reduce off-site nutrient losses associated with winter manure applications. Most of the developed countries implement regulations or guidelines to restrict winter manure application, which range from a regulative ban to guidelines based upon weather and field management conditions. In contrast, developing countries lack such official directives, despite an increasing animal production industry and concern over water quality. An analysis of five case studies reveals that directives are derived from a common rationale to reduce off-site manure nutrient losses, but they are also affected by local socioeconomic and biophysical considerations. Successful programs combine site-specific management strategies along with expansion of manure storage to offer farmers greater flexibility in winter manure management.
Abstract
Recent technological breakthroughs of optical sensors and analysers have enabled matching the water quality measurement interval to the time scales of stream flow changes and led to an improved understanding of spatially and temporally heterogeneous sources and delivery pathways for many solutes and particulates. This new ability to match the chemograph with the hydrograph has promoted renewed interest in the concentration-discharge (c-q) relationship and its value in characterizing catchment storage, time lags and legacy effects for both weathering products and anthropogenic pollutants. In this paper we evaluated the stream c-q relationships for a number of water quality determinands (phosphorus, suspended sediments, nitrogen) in intensively managed agricultural catchments based on both high-frequency (sub-hourly) and long-term low-frequency (fortnightly-monthly) routine monitoring data. We used resampled high-frequency data to test the uncertainty in water quality parameters (e.g. mean, 95th percentile and load) derived from low-frequency sub-datasets. We showed that the uncertainty in water quality parameters increases with reduced sampling frequency as a function of the c-q slope. We also showed that different sources and delivery pathways control c-q relationship for different solutes and particulates. Secondly, we evaluated the variation in c-q slopes derived from the long-term low-frequency data for different determinands and catchments and showed strong chemostatic behaviour for phosphorus and nitrogen due to saturation and agricultural legacy effects. The c-q slope analysis can provide an effective tool to evaluate the current monitoring networks and the effectiveness of water management interventions. This research highlights how improved understanding of solute and particulate dynamics obtained with optical sensors and analysers can be used to understand patterns in long-term water quality time series, reduce the uncertainty in the monitoring data and to manage eutrophication in agricultural catchments.
Authors
Rachel Cassidy Philip Jordan Marianne Bechmann Brian Kronvang Katarina Kyllmar Mairead ShoreAbstract
Achieving an operational compromise between spatial coverage and temporal resolution in national scale river water quality monitoring is a major challenge for regulatory authorities, particularly where chemical concentrations are hydrologically dependent. The efficacy of flow-weighted composite sampling (FWCS) approaches for total phosphorus (TP) sampling (n = 26–52 analysed samples per year), previously applied in monitoring programmes in Norway, Sweden and Denmark, and which account for low to high flow discharges, was assessed by repeated simulated sampling on high resolution TP data. These data were collected in three research catchments in Ireland over the period 2010–13 covering a base-flow index range of 0.38 to 0.69. Comparisons of load estimates were also made with discrete (set time interval) daily and sub-daily sampling approaches (n = 365 to >1200 analysed samples per year). For all years and all sites a proxy of the Norwegian sampling approach, which is based on re-forecasting discharge for each 2-week deployment, proved most stable (median TP load estimates of 87–98%). Danish and Swedish approaches, using long-term flow records to set a flow constant, were only slightly less effective (median load estimates of 64–102% and 80–96%, respectively). Though TP load estimates over repeated iterations were more accurate using the discrete approaches, particularly the 24/7 approach (one sample every 7 h in a 24 bottle sampler - median % load estimates of 93–100%), composite load estimates were more stable, due to the integration of multiple small samples (n = 100–588) over a deployment.