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.
2024
Abstract
Manure spreading often leads to nutrient losses with negative environmental impacts, especially in cold climates where harsh winters can affect grass sward density. Nutrient efficiency in cattle slurry depends on the plant coverage at the start of the growing season. To simulate winter damage variation, random mechanical disturbance was applied to a grass field. Aerial images were obtained and analysed using the Grasision® tool to estimate plant cover. Three fixed treatments with uniform cattle slurry and N fertilizer application across all plots, and two treatments adjusting slurry and N fertilizer based on autumn or spring plant coverage were tested. Above-ground yield was measured post-first and second cut. Adjusting N rates based on spring plant coverage or using a low N rate resulted in similar agronomic N use efficiency as high N application rates, albeit with lower dry matter yield.
Abstract
Interest in dairy cow-calf contact (CCC) systems is growing, yet limited research had been focused on CCC in a pasture setting. Our study aimed to evaluate the performance of pastured dairy cows and calves with or without CCC through machine milk yield and composition, cow body condition score (BCS) and body weight (BW) decrease, and calf body weight gain (BWG). We also examined calf intake of concentrates, artificially reared calves’ milk intake, and the health of both cows and calves. Conducted on a commercial dairy freestall farm and summer farm in Norway from May to August 2021, the study included twenty cow-calf pairs: 17 Norwegian Red (NRF) and three NRF × Holstein crossbreeds. They were divided into two treatments: cow-calf contact (CC, n = 10) or early separation (ES, n = 10), each with two groups of five cow-calf pairs. CC pairs had full CCC on pasture until 6 weeks postpartum and part-time contact in weeks 7 and 8 (weaning). ES pairs were separated 1–3 h after birth, kept on separate pastures with no contact between ES cows and calves. ES calves’ received daily milk allowances of 12–14 L (weeks 0–6), reduced to 8 L (week 7) and further to 4 L (week 8). From week 9, all calves were denied access to any milk (ES) or cows (CC). During weeks 0–6, CC cows had a daily machine milk yield 23.7 kg lower/cow than ES cows. The difference was likely affected by nursing and other factors (parity and inhibited milk ejection), and persisted during weaning, with CC cows delivering 8.3 kg less/cow/day in weeks 10 and 11 postpartum. Fat and protein content in machine milk showed no significant difference, while lactose content was lower in milk from CC cows than ES cows (week 5 postpartum). CC cows had a lower BW decrease compared to ES cows (CC: 913 g/day, ES: 1415 g/day from pasture day one through week 9). ES calves had an average milk intake of 10.7 L/calf/day (weeks 0–6), and consumed more concentrates than CC calves. Calves’ daily BWG did not differ between treatments in weeks 0–6 (CC: 1340 and ES: 1250 g/day) and decreased for both treatments during weaning (CC: 1050 g/day, ES: 920 g/day in weeks 6–9). Inhibited milk ejection during machine milking was a challenge in CC cows, prompting oxytocin injections to prevent mastitis. Allowing calves full CCC or providing whole milk near ad libitum can result in similar BWG and health in calves. Further research should explore strategies to enhance milk ejection in pastured CCC cows.
Authors
Thomas Georges A Bawin Marte Marie Fossum Ranvik Sigridur Dalmannsdottir Egle Norkeviciene Rita Armonienė Erik Alexandersson Laura Elina JaakolaAbstract
Climate change is increasingly affecting agricultural systems, impacting the productivity and digestibility of forage crops that are essential for livestock feed. Understanding how forage crops respond to temperature is crucial for optimizing growth and nutritional value. Remote sensing technologies offer promising tools for monitoring plant health and predicting forage quality. As part of the project UPSCALE, this study examines the growth and spectral response of Northern and Southern cultivars under different temperature regimes. Two red clover (ʻGandalfʼ from Norway and ʻVytisʼ from Lithuania) and two timothy (ʻNorengʼ from Norway and ʻJauniaiʼ from Lithuania) cultivars were grown at controlled temperatures of 12, 15, and 18°C. A total of 168 pots (10L, ~30 plants per pot) were maintained in climate-controlled chambers at The Climate Laboratory, UiT, Tromsø. Plant growth was monitored using the PlantEye F600, providing 3D models, biomass, height, leaf area index, and stress indices (NDVI, NPCI, PSRI). Destructive sampling was conducted at three stages: pre-flowering, post-flowering, and at the end of the experiment. Leaves were scanned using Specim FX10e (VNIR) and FX17e (SWIR) hyperspectral cameras before drying for chemical analysis. Results showed distinct growth differences among the cultivars. Clovers increased in height and biomass with rising temperatures, though ʻGandalfʼ consistently yielded less biomass. Timothy ʻJauniaiʼ followed a similar trend to the clovers, while cultivar ʻNorengʼ had optimal growth at 15°C. Spectral indices did not reveal significant contrasts; ongoing hyperspectral analysis may provide further insights. The upcoming chemical analysis will integrate with hyperspectral data to identify lignin signatures for assessing forage digestibility. These findings contribute to a deeper understanding of how forage crops respond to temperature variations, to select cultivars with optimal growth and digestibility in the face of climate change.
Authors
Thomas Georges A Bawin Marte Marie Fossum Ranvik Sigridur Dalmannsdottir Egle Norkeviciene Rita Armonienė Erik Alexandersson Laura Elina JaakolaAbstract
No abstract has been registered
Authors
Ievina SturiteAbstract
No abstract has been registered
Authors
Ievina SturiteAbstract
No abstract has been registered
Authors
Ievina SturiteAbstract
No abstract has been registered
Abstract
Longer growing season has replaced two-cut with three-cut system even at higher latitudes and has an impact of persistency and use of seed mixtures. This on-going study is searching for the most appropriate seed mixtures that persist over time in a three-cut system. Six grassland seed mixtures were established at Tjøtta, 65°N coast, 11 m a.s.l in 2016, with two (2017) or three annual cuts (2018-2023) using organic fertiliser, in total 170 kg N ha–1 year–1. Four seed mixtures contained timothy (P. pratense), 30–45% whereas two seed mixtures were based on perennial ryegrass (Lolium perenne). Other grass species as well as red (Trifolium pratense) and white (T. repens) clover constituted the remaining proportion of the mixtures. The species proportion in each seed mixture was determined in spring cut in 2019 and 2022. Results for seven production years show differences for dry matter yield (DMY), DMY stability and species persistence in space and time in favour of Lolium-containing mixtures with greater DMY in all production years and with lower interannual coefficient of variation (CV%) than timothy-based seed mixtures, indicating potential species adaptability to Nordic maritime climate. Decrease of timothy proportion in the mixtures suggest negative effects of three-cut system.
Abstract
Six seed mixtures differing in number of species and their proportion of timothy (Phleum pratense L.) were tested during three/four production (ley) years in replicated field experiments at three climatically different sites in Norway; one a mountainous inland site at 61° N (Løken) and two in coastal environments, at 61° N (Fureneset) and 65° N (Tjøtta). There were significant differences in forage accumulation (FA) and digestible forage accumulation (DFA) between the three sites. There was a significant FA decline from the third to the fourth ley year for mixtures containing timothy, but not for mixtures without timothy. Estimated interannual FA- stability was higher for timothy-based seed mixtures than for mixtures without timothy at the inland site, but FA-stability was lower at the coastal sites. In the third-year herbage of timothy-based mixtures at the inland site consisted almost solely of timothy, whereas at the coastal sites meadow fescue (Festuca pratensis Huds.) and especially tall fescue (F. arundinacea Schreb.) dominated. In seed mixtures without timothy, cocksfoot (Dactylis glomerata L.) suppressed other species at the inland site, whereas at the coastal sites, tall fescue and ryegrasses (Lolium spp.) were the dominant species in the third-year herbage. Length of growing season and site-specific growing conditions were important drivers for the observed species changes. Timothy can thus be recommended for ley establishment at sites where the growing season is short (<4 months) and plant growth is intensive, but under conditions with a longer growing season it needs to be sown in mixtures with grass species that surpass the regrowth capacity of timothy.
Abstract
No abstract has been registered