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.

2022

Sammendrag

Management of Scots pine (Pinus sylvestris L.) in Norway requires a forest growth and yield model suitable for describing stand dynamics of even-aged forests under contemporary climatic conditions with and without the effects of silvicultural thinning. A system of equations forming such a stand-level growth and yield model fitted to long-term experimental data is presented here. The growth and yield model consists of component equations for (i) dominant height, (ii) stem density (number of stems per hectare), (iii) total basal area, (iv) and total stem volume fitted simultaneously using seemingly unrelated regression. The component equations for stem density, basal area, and volume include a thinning modifier to forecast stand dynamics in thinned stands. It was shown that thinning significantly increased basal area and volume growth while reducing competition related mortality. No significant effect of thinning was found on dominant height. Model examination by means of various fit statistics indicated no obvious bias and improvement in prediction accuracy in comparison to existing models in general. An application of the developed stand-level model comparing different management scenarios exhibited plausible long-term behavior and we propose this is therefore suitable for national deployment.

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Sammendrag

Background Eimeria spp. are widespread apicomplexan parasites known to cause coccidiosis in livestock, resulting in reduced animal welfare and productivity, particularly in sheep. The treatment options are limited, and there is an emerging development of resistance against registered pharmaceuticals. Spruce bark is rich in plant secondary metabolites (PSM), such as condensed tannins, which are bioactive compounds previously shown to have antiparasitic activity. Here, we examined the anticoccidial properties of bark extract of Norway spruce (Picea abies) against a field isolate of ovine Eimeria spp. by treating Eimeria-infected pre-ruminant lambs with water-extracted bark daily for 12 days. We hypothesised that the bark extract would reduce the faecal oocyst excretion and, consequently, the severity of diarrhoea. Results Oral administration of spruce bark extract significantly reduced the excretion of Eimeria oocysts in milk-fed lambs post treatment till the end of the trial 22 days post infection. This difference in oocyst excretion between the treated and the untreated infected animals increased with time. Compared to the untreated and the sham-infected control group, the group treated with bark extract had softer faeces and reduced milk intake during the treatment period. After discontinuing the treatment, the treated animals got a more solid and formed faeces compared to that of the untreated control group, and the milk intake increased to the level of the sham-infected, untreated control group. The bark extract treated animals had a lower body weight and a lower mean daily body weight gain throughout the whole duration of the experiment. Conclusions Bark extract from Norway spruce showed marked anticoccidial properties by reducing the faecal oocyst count and associated diarrhoea in young lambs. Simultaneously we experienced detrimental effects of the treatment, displayed as reduced feed intake and daily body weight gain. Therefore, we suggest conducting similar studies with lower bark extract dosage to explore the possibilities of a better trade-off to reduce the negative impact while maintaining the antiparasitic effect. Keywords: Coccidia, Coccidiocide, Eimeria, Industrial by-products, Sheep

Sammendrag

Maarud fabrikker på Disenå ønsket å finne en god løsning på hvordan man kunne sirkulere ulike nærings avfall strømmer fra fabrikken. Komposteringsløsning ble valgt siden avfallet, som ikke er av animalsk opprinnelse, egner seg godt for kompostering og vil kunne bli til næringsrik kompost. Det biologiske avfallet som består av slam fra avløpsrenseanlegget, stivelse og ødelagt potet fra fabrikken er rent og en viktig ressurs å sirkulere. NIBIO har vært behjelpelig med å sikre en god og trygg prosess for kompostering av avfallet. Rapporten beskriver en risikovurdering av prosessen for å forhindre at mulig planteskadegjørere overlever kompostering og at en streng strategi for hygienisering er lagt til rette for drift av anlegget. Rapporten beskriver også oppbygningen av et komposteringsanlegg med fysisk inndeling i ren og ulike urene soner. God soneinndeling er en forutsetning for å sikre at ikke mulig smitte overføres til ferdig kompost. Rapporten beskriver en rekke laboratoriestudier hvor ulikt avfall er utprøvd i forskjellige blandingsforhold for å sikre temperatur over 55-70 °C over tilstrekkelig tid. Erfaringene fra laboratoriestudiene har deretter blitt utprøvd på store ranker som vendes slik at all masse eksponeres for høye temperaturer. Alle ranker overvåkes kontinuerlig med 4 trådløse temperaturfølere som sender data tilbake til kontrollrommet hvor informasjon kan logges på monitor og overføres til en database på PC. Operatørene følger daglig opp på prosessen slik at 100% av ranken holder seg over 55-70 °C både før og etter vendinger i 28 dager. Etter 2 års utprøving er det utviklet ulike resepter tilpasset sommer og vinter forhold. Slam mengden i resepten har blitt optimalisert slik at næringsinnholdet målt som Total N ligger på ca. 20 g/kg TS og Total P 6-7 g/kg TS. Over tid er det laget en empirisk modell for å vise hvor lang tid de ulike ranker skal ligge under aktiv fase, ettermodningsfase og til moden siktet kompost på ren grønn sone. Beregninger i modellen viser at prosessen trenger 33 uker fra avfallet blandes til komposten er ferdig modnet. Totalt ble det produsert 600 m3 kompost i prosjektet fra høsten 2020 til sommeren 2021 fordelt på 4 ulike batcher. Varedeklarasjoner for disse er laget og alle kompostbatcher har høy næringsverdi, kvalitets klasse 0 for innhold av tungmetaller og de inneholder ingen fremmedlegemer. Ingen cyster av PCN og patogene mikroorganismer er blitt påvist i noen av kompostrankene.

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Sammendrag

Compatibility and synchrony between specialized tissues of the pistil, female gametophytes and male gametophytes, are necessary for successful pollination, fertilization, and fruit set in angiosperms. The aim of the present work was to study the development and viability of embryo sacs, as well as fertilization success, in relation to the fruit set of the cultivars ‘Mallard’, ‘Edda’, ‘Jubileum’, and ‘Reeves’, under specific Norwegian climatic conditions. Emasculated, unpollinated, and open-pollinated flowers were collected at the beginning of flowering, and on the 3rd, 6th, 9th, and 12th days after flowering, from all four plum cultivars over two years (2018/2019). Ovaries were dehydrated, embedded in paraffin wax, sectioned, stained, and observed under a light microscope. Results showed the existence of synchronization between successive phases in the development of the embryo sac and individual phases of flowering. All plum cultivars had higher percentages of viable embryo sacs, fertilized embryo sacs, and fruit set in 2018 than in 2019. These differences may be related to the very low temperatures during the post-full-flowering period in 2019, and to the low adaptation of some studied cultivars to unfavorable conditions. In our study, the cultivar ‘Jubileum’ showed the highest percentage of viable embryo sacs, fertilized embryo sacs, and fruit set compared to other cultivars, i.e., the best low-temperature adaptation.