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
Authors
Svein SolbergAbstract
No abstract has been registered
Authors
Tore SkrøppaAbstract
No abstract has been registered
Authors
Tore SkrøppaAbstract
No abstract has been registered
Authors
Tore SkrøppaAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
Large areas of cultivated grasslands are annually abandoned and no longer used for production in Norway. Such areas will over time be encroached by shrubs and trees. Knowing that access to spring and autumn pastures is a limiting factor for sheep farmers, we tested the effect of grazing abandoned grassland on sheep production. We also assessed herbage production by looking at plant community development, pasture production, herbage quality and pasture utilization by sheep and heifers. The experiment was run for two consecutive years; 2014 and 2015. The sheep production was assessed by studying one sheep flock with 83(88) ewes(lambs) in 2014 and 77(106) ewes(lambs) in 2015, which was assigned each year with respect to age of ewe and number of lambs born to three treatments: 1) control; common farm procedure with short spring grazing period before summer grazing on range pasture, 2) spring extended; 4 weeks extended spring grazing period on abandoned cultivated grassland before summer grazing on range pasture, 3) whole season grazing on abandoned grassland. Assessment of herbage production was done by sheep grazing the whole area for one month in spring and autumn. During the summer, the area was assigned to three replicated treatments: a) control with no management, b) grazing heifers and c) grazing sheep with offspring. The stocking rate was 1.8 LU/ha, in both b and c, for a duration of one month. Pasture production and herbage intake was estimated using grazing exclosure cages. Weight gain from birth to autumn as well as slaughter weight were significantly (P<0.05) higher in lambs assigned to treatment 2 with four weeks extended spring grazing period (259 g/day and 15.7 kg) compared to treatment 1 (238 g/day and 14.3 kg) and treatment 3 (216 g/day and 13.2 kg). Herbage consumed during the summer period was on average 211 g DM/m2 and the pasture utilization was 55%. The annual consumption and utilization was 336 g DM/m2 and 62% in the grazed treatments and 28 g DM/m2 and 15% in the control, respectively. Total annual pasture production was on average 72% higher in the grazed treatments compared to the control. There was no difference between the grazed treatments on annual herbage production, herbage intake or pasture utilization. The use of abandoned cultivated grassland for extended spring grazing improved weight gain and slaughter weight of lambs. Further, grazing stimulated herbage production
Abstract
One way to protect timber in service against basidiomycete deterioration is by means of acetylation via reaction with acetic anhydride. The reason why acetylated wood (WAc) is resistant against decay fungi is still not exactly understood. The aim of this study was to contribute to this field of science, and Postia placenta colonisation after 4, 12, 20, 28 and 36 weeks was observed at Three acetylation levels of Pinus spp. sapwood. Mass loss (ML) and wood moisture content (MC) data reflected the acetylation levels. The initial equilibrium MC (EMC) proved to be a good indicator of subsequent ML. Genomic DNA quantification showed P. placenta colonisation in all samples, also in samples where no ML were detectable. The number of expressed gene transcripts was limited, but the findings supported the results of previous studies: WAc seems to have some resistance against oxidative mechanisms, which are part of the metabolism of P. placenta. This leads to a delay in decay initiation, a delay in Expression of genes involved in enzymatic depolymerisation, and a slower decay rate. The magnitudes of these effects are presented for each acetylation level. The data also imply that there is no absolute decay threshold at high acetylation levels, but instead a significant delay of decay initiation and a slower decay rate.
Authors
Anne-Kari Holm Inger Sundheim Fløistad Knut Asbjørn Solhaug Benedikte Watne Oliver Lars Olav BrandsæterAbstract
No abstract has been registered
Authors
R. Venancio G.J. Moraes R.C. Castilho N.S. Iwanicki G.F. Moreira Lise Grøva Karin Westrum Ingeborg KlingenAbstract
Tick-borne diseases, such as anaplasmosis and babesiosis, are of major concern for Norwegian sheep farmers. Ticks can be controlled on and off the host, usually with the long-term, high-rotation use of chemicals. Fungal pathogens, predatory mites and ants are thought to be important tick killers in nature. However, the prevalence and diversity of predatory mites in tick habitats has barely been evaluated. It is known that most soil mite species of the cohort Gamasina (order Mesostigmata) are predators. Until now, 220 mesostigmatid species have been reported from Norway, most of them belonging to the Gamasina. One of the first recommended steps in a biological control program involves the determination of the fauna in the pest habitat. The objective of this study was to determine the groups of gamasines co-occurring with I. ricinus in sheep grazing areas in Isfjorden and Tingvoll in Western Norway. A total of 2,900 gamasines of 12 families was collected. The most numerous families were Parasitidae (46.9%) and Veigaiidae (25.7%), whereas the most diverse families were Laelapidae, Macrochelidae, Parasitidae and Zerconidae. Our results showed that the tick density was significantly related only to locality, elevation and rainfall. Differences in the prevailing environmental conditions resulted in more outstanding differences between Gamasina abundances than diversities. Based on our present knowledge of the potential of different gamasine groups as biological control agents, the results suggested that laelapid mites should be among the priority groups to be further evaluated for their role in the natural control of I. ricinus in Norway.