Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2026
Sammendrag
The experiment aimed to investigate the effectiveness of a Monil virtual fence collar for small ruminants on mature Norwegian White ewes at the NIBIO Tjøtta station. The study aimed to evaluate the animals' learning ability and welfare, compare two auditory cues (Original vs. Modified; collar treatment), and examine the effects of wool (Shaved vs. Unshaved) on the efficacy of the virtual fence system. A total of 16 ewes were randomly assigned to two groups of 8, each equipped with one of the collars, and further divided based on wool treatment. Two mirrored training arenas were set up for the two groups. For two days, the collared animals had unrestricted access to graze the entire arena (VF-Off). This was followed by two days of restricted access to 2/3 of the arena using the virtual fence collars (VF-On). After the fourth day, the animals were switched to the other arena as a crossover design, and the sequence of VF-Off and VF-On was repeated. Data collected included position and cue logs from the virtual fence collars, heart rate monitors, and observation data gathered through three methods: Video Surveillance, Direct Observation Time Budget, and Pressure Marks Assessment. Our results indicate that the ewes were able to learn to avoid restricted zones effectively, relying more on auditory cues than on electrical cues. The virtual fence cueing imposed short-lived stress (acute stress), with both behavioral and physiological metrics returning to baseline levels within five minutes. Additionally, exclusively auditory cues resulted in less stress compared to cues associated with electrical stimulation. No indicators of chronic behavioral stress were observed. However, we found that the collars needed to move freely on the animals' necks to prevent pressure marks, suggesting that the ewes should be shaved around their necks before wearing the collars. While collar treatment showed no significant effects, wool treatment indicated that the shaved group was more compliant with the virtual fence system due to reduced insulation, which enhanced the effectiveness of electrical cues. During the deployment with the unshaved group, there were three instances in which the animals received an electrical cue that did not elicit the animal response, allowing for their “escape” over the virtual fence boundary. Therefore, equipping the virtual fence on shaved animals is paramount for enhancing the system's reliability. If the suggestion is followed, the system can effectively be used for sheep without compromising animal welfare.
Sammendrag
The decline of soil organic carbon (SOC) content is a major concern in agricultural soils, and reduction of tillage frequency is proposed as a measure to counteract this tendency. Here, we assessed the effect of tillage and renewal frequency on grassland SOC content based on a long–term experiment at Fureneset, Western Norway. The objective was to compare permanent and unrenewed grassland treatments with treatments ploughed and renewed 6 to 15 times from 1974 to 2016. Mean SOC content of the permanent grassland was 64 ± 9 g kg−1 (one standard deviation) at 0 to 40 cm depth and soil contained 210 Mg C ha−1, compared to 60 ± 6 g kg−1 and 190 Mg C ha−1 for grassland renewed with ploughing. Higher SOC contents were associated with reduced forage dry matter yields (DMY) of the permanent grassland, but not in frequently renewed grasslands. High SOC contents correlate with high porosity and water content, as soil properties approach those of organic soils. This may cause a wetter soil and reduced plant growth and increase soil compaction. In areas with generally high SOC contents in agricultural soils, increased carbon content due to no tillage may thus make the soils more agronomically challenging to manage
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Me fornyar enga for at avlinga skal verta større og ha betre kvalitet. Omlaupslengden er ein balanse mellom meir avling/kvalitet og kostnadar ved fornying.
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Forfattere
Akhil Reddy Pashapu Sigridur Dalmannsdottir Marit Jørgensen Mallikarjuna Rao Kovi Odd Arne RognliSammendrag
Timothy is the most important perennial forage grass species in northern Norway, a region that is predicted to experience variable winter weather conditions due to climate change. Knowledge about how timothy cultivars respond to a changing climate is crucial for safeguarding forage production at higher latitudes. In the current study, we investigated changes in gene expression under freezing and ice encasement stresses and SNP allele frequencies between temporal populations (seed generations) of the two northern-adapted timothy cultivars Engmo and Noreng. In general, there was a decrease in freezing tolerance (defined as LT 50 , the temperature lethal to 50% of the population) and an increase in ice encasement tolerance (defined as LD 50 , the duration lethal to 50% of the population) over time. Comparative transcriptome analyses identified several genes known to be involved in stress responses, such as ethylene-responsive transcription factors, dehydration-responsive element binding transcription factors, reversion to ethylene sensitivity 1, and abscisic acid repressor 1, as differentially expressed between the temporal populations of Noreng under freezing stress. Several loci with large allele frequency changes were observed to be in close proximity to the genes displaying patterns resembling shifts over time in Noreng. Very few gene expression differences between populations of both cultivars under ice encasement stress could be due to weak selection pressure during seed multiplication. There was a gradual decline in genetic diversity in populations of both cultivars over time. The results indicate that phytohormone-mediated transcriptional regulation might be one of the key mechanisms for adaptation to changing winter weather conditions at higher latitudes. These findings underscore the importance of monitoring genetic shifts during seed multiplication to maintain cultivar stability and suggest that the identified stress-responsive genes could serve as valuable targets for breeding climate-resilient forage crops.
Forfattere
Edward Carbezas-Garcia Vibeke Lind Linus Kiprotich J. Gakige Chris S. Jones Claudia ArndtSammendrag
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Forfattere
Shelemia Nyamuryekung'e Nolween Tulane Grete H. M. Jørgensen Vincent O'Flaherty Vibeke LindSammendrag
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