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.
2016
Abstract
No abstract has been registered
Abstract
The effects of cutting frequency, silage fermentation pattern and legume performance in grass-clover ley on use of inputs and profitability in an organic dairy system in Mid-Norway were examined. A whole-farm linear programming model was developed to compare a three-cut and a two-cut system, either with restricted silage fermentation through acidification or untreated at low or high red clover (Trifolium pratense L) proportion in the ley. Input-output relations incorporated into the model were derived from a meta-analysis of organic grassland field trials in Norway, silage fermentation experiments, and with feed intakes and milk yields from simulations with the NorFor feed evaluation system. The model maximised total gross margin of farms with 250,000 l milk quota, and housing capacity for 45 cows. Farmland availability was allowed to vary with 40 ha as the basis. High proportion of legumes in the leys was far more important for profitability than the score on the other variables considered. With little land available, the costs of preservatives were higher than their benefits. At higher land areas applying preservatives was more profitable. Cutting systems producing silages that result in an increased intake of silage per cow, generally three-cut systems, performed relatively better at higher land availabilities.
Abstract
The effects of cutting frequency, silage fermentation pattern and legume performance in grass-clover ley on use of inputs and profitability in an organic dairy system in Mid-Norway were examined. A whole-farm linear programming model was developed to compare a three-cut and a two-cut system, either with restricted silage fermentation through acidification or untreated at low or high red clover (Trifolium pratense L) proportion in the ley. Input-output relations incorporated into the model were derived from a meta-analysis of organic grassland field trials in Norway, silage fermentation experiments, and with feed intakes and milk yields from simulations with the NorFor feed evaluation system. The model maximised total gross margin of farms with 250,000 l milk quota, and housing capacity for 45 cows. Farmland availability was allowed to vary with 40 ha as the basis. High proportion of legumes in the leys was far more important for profitability than the score on the other variables considered. With little land available, the costs of preservatives were higher than their benefits. At higher land areas applying preservatives was more profitable. Cutting systems producing silages that result in an increased intake of silage per cow, generally three-cut systems, performed relatively better at higher land availabilities.
2015
Authors
Sigridur Dalmannsdottir Marit Jørgensen Marcin Rapacz Liv Østrem Arild Larsen Odd Arne RognliAbstract
No abstract has been registered
Authors
Sigridur Dalmannsdottir Marcin Rapacz Marit Jørgensen Liv Østrem Arild Larsen Rolf Rødven Odd Arne RognliAbstract
The expected temperature rise in late summer/early autumn can change the conditions for acclimation and affect the winter survival of perennial crops. This study examined the effect of the temperature just before the onset of cold acclimation (pre-acclimation) on freezing tolerance of timothy (Phleum pratense L.), perennial ryegrass (Lolium perenne L.) and red clover (Trifolium pratense L.) populations (both cultivars and breeding populations) adapted to either northern or southern parts of Norway. Using phytotron experiments, we studied whether increasing pre-acclimation temperature delays growth cessation, affects photoacclimation and reduces freezing tolerance. Furthermore, we assessed whether these effects were related to the latitudinal adaptation of the plant material. The results showed that a rise in pre-acclimation temperature decreased both cold acclimation capacity and photoacclimation in these species. This affected the freezing tolerance, which was reduced significantly more in northern-adapted population of timothy and perennial ryegrass compared with southern-adapted populations. Red clover was less affected by temperature changes than the grasses.
Abstract
Phytoestrogens have structures similar to endogenous steroids and may induce or inhibit the response of hormone receptors. The objectives of the present study were to compare the effects of long-term vs. short-term grassland management in organic and conventional dairy production systems, compare organic and conventional production systems and assess seasonal variation on phytoestrogen concentrations in bulk-tank milk. The concentrations of phytoestrogens were analyzed in bulk-tank milk sampled three times in two subsequent years from 28 dairy farms: Fourteen organic (ORG) dairy farms with either short-term or long-term grassland management were paired with 14 conventional (CON)farms with respect to grassland management. Grassland management varied in terms of time since establishment. Short-term grassland management (SG) was defined as establishment or reseeding every fourth year or more often, and long-term grassland management (LG) was defined as less frequent establishment or reseeding. The proportion of red clover (Trifolium pretense L.) in the herbage was positively correlated with milk concentrations of the mammalian isoflavone equol. Therefore, organically produced bulk-tank milk contained more equol than conventionally produced milk, and milk from ORG-SG farms had more equol than milk from ORG-LG farms. Milk produced during the indoor-feeding periods had more equol than milk produced during the outdoor feeding period, because pastures contained less red clover than fields intended for silage production. Organically produced milk had also higher concentrations of the mammalian lignan enterolactone, but in contrast to equol, concentrations increased in the outdoor-feeding periods compared to the indoor-feeding periods. There were no indications of ertility problems on ORG-SG farms who had the highest red clover proportions in the herbage. This study shows that Production system, grassland management, and season affect milk concentrations of phytoestrogens. However, compared to soy products, milk concentrations of phytoestrogens are low and future studies are required to investigate if the intake of phytoestrogens from dairy products has physiological effects in humans.
Abstract
Interactions between soil properties and climate affect forage grass productivity. Dynamic models, simulating crop performance as a function of environmental conditions, are valid for a specific location with given soil and weather conditions. Extrapolations of local soil properties to larger regions can help assess the requirement for soil input in regional yield estimations. Using the LINGRA model, we simulated the regional yield level and variability of timothy, a forage grass, in Akershus and Østfold counties, Norway. Soils were grouped according to physical similarities according to 4 sets of criteria. This resulted in 66, 15, 5 and 1 groups of soils. The properties of the soil with the largest area was extrapolated to the other soils within each group and input to the simulations. All analyses were conducted for 100 yr of generated weather representing the period 1961-1990, and climate projections for the period 2046-2065, the Intergovernmental Panel on Climate Change greenhouse gas emission scenario A1B, and 4 global climate models. The simulated regional seasonal timothy yields were 5-13% lower on average and had higher inter-annual variability for the least detailed soil extrapolation than for the other soil extrapolations, across climates. There were up to 20% spatial intra-regional differences in simulated yield between soil extrapolations. The results indicate that, for conditions similar to these studied here, a few representative profiles are sufficient for simulations of average regional seasonal timothy yield. More spatially detailed yield analyses would benefit from more detailed soil input.
Authors
Seyda Ozkan Bente Aspeholen Åby Tomas Persson Klaus Mittenzwei Mats Höglind Øyvind Hoveid Lillian ØygardenAbstract
No abstract has been registered
Authors
Margarita Novoa-Garrido Lise Aanensen Vibeke Lind Hans Jørgen Larsen Søren Krogh Jensen Espen Govasmarka Håvard SteinshamnAbstract
No abstract has been registered
Abstract
No abstract has been registered