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.
2011
Forfattere
Tore SkrøppaSammendrag
Det er ikke registrert sammendrag
Forfattere
Tore SkrøppaSammendrag
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Forfattere
Tore SkrøppaSammendrag
Det er ikke registrert sammendrag
Forfattere
Tore SkrøppaSammendrag
Det er ikke registrert sammendrag
Sammendrag
The northernmost range of beech (Fagus sylvatica L.) is in southern Norway and consists of two distinct and isolated distributions, a single population at Seim in West Norway and several adjacent populations in Vestfold, East Norway. The modest beech pollen deposits beyond these main distributions suggest that the Norwegian beech distribution has never been an extension of the south Scandinavian range. We used genetic markers and historical sources to trace the ancestor populations for the beech at Seim and Vestfold, hypothesising Denmark as the most likely source. Nuclear inter-simple sequence repeat markers, amplified by polymerase chain reaction (PCR), were applied to estimate genetic distances between beech populations in Norway, England and Denmark. The variation in chloroplast DNA polymorphism was estimated using PCR-restriction fragment length polymorphism. The nuclear genetic data indicate Denmark as a source for the beech in Norway, although the data are less certain in the case of Seim than in that of Vestfold. The populations from South England were genetically different from most Scandinavian populations. The genetic variation within Norwegian populations was only slightly lower than that of the English and Danish populations, questioning birds as vectors for dispersal. Thus, the pollen data and our results are in accordance with the intentional introduction and documented human migrations across Skagerrak before and during the Viking Age.
Forfattere
Snorre Stuen Lise Grøva Erik Georg Granquist Karin Sandstedt Ingrid Olesen Håvard SteinshamnSammendrag
A comparative study of clinical manifestations, haematological and serological responses after experimental infection with Anaplasma phagocytophilum in two Norwegian sheep breeds Background: It has been questioned if the old native Norwegian sheep breed, Old Norse Sheep (also called Norwegian Feral Sheep), normally distributed on coastal areas where ticks are abundant, is more protected against tick-borne infections than other Norwegian breeds due to a continuously high selection pressure on pasture. The aim of the present study was to test this hypothesis in an experimental infection study. Methods: Five-months-old lambs of two Norwegian sheep breeds, Norwegian White (NW) sheep and Old Norse (ON) sheep, were experimentally infected with a 16S rRNA genetic variant of Anaplasma phagocytophilum (similar to GenBank accession number M73220). The experiment was repeated for two subsequent years, 2008 and 2009, with the use of 16 lambs of each breed annually. Ten lambs of each breed were inoculated intravenously each year with 0.4 ml A. phagocytophilum-infected blood containing approximately 0.5x106 infected neutrophils/ml. Six lambs of each breed were used as uninfected controls. Half of the primary inoculated lambs in each breed were re-challenged with the same infectious dose at nine (2008) and twelve (2009) weeks after the first challenge. The clinical, haematological and serological responses to A. phagocytophilum infection were compared in the two sheep breeds. Results: The present study indicates a difference in fever response and infection rate between breeds of Norwegian sheep after experimental infection with A. phagocytophilum. Conclusion: Although clinical response seems to be less in ON-lambs compared to NWlambs, further studies including more animals are needed to evaluate if the ON-breed is more protected against tick-borne infections than other Norwegian breeds.
Sammendrag
Den flåttbårne sjukdommen sjodogg forårsaket av bakterien Anaplasma phagocytophilum som er overført av flått (Ixodes ricinus) (Øverås 1972, Stuen 2003) er en av de største utfordringene for velferden hos sau i beiteperioden. Sjodogg gir høy feber og redusert immunitet. Det finnes få effektive forebyggende tiltak mot sjodogg. Lam får råmelk med immunglobuliner fra mor etter fødsel og denne passive immuniteten som overføres kan til en viss grad hjelpe lammet å handtere infeksjoner generelt, inntil lammet selv kan utvikle immunitet. Smitteforsøk har vist at svært unge lam er resistente mot sjodogg, men at det ikke skyldes antistoffene alene (Stuen et al. 1992). Formålet med dette arbeidet var å teste effekten av å eksponere lam for naturlig sjodogg-infeksjon i løpet av første leveuke på tilvekst og forekomst av sjukdom i feltforsøk.
Sammendrag
Tidlig beiteslipp av lam på flåttinfiserte beiter slik at lammene utsettes for smitte når de er unge (1-2 uker gamle) har en positiv effekt på tilvekst og kan anbefales som tiltak for å redusere tap i form av tilvekst på grunn av A. phagocytophilum infeksjon.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag