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
Grete Helen Meisfjord Jørgensen Knut Egil BøeSammendrag
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Forfattere
grete h m jørgensenSammendrag
Paddock size and enrichment - the effects on horse behavior Grete H.M. Jørgensen1 and Knut E. Bøe2 1Bioforsk Norwegian Institute for Agricultural and Environmental Research, 8860 Tjøtta 2Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, UMB, 1430 ås Corresponding author: +47 40 76 67 69 e-mail grete.jorgensen@bioforsk.no New regulations for horse keeping in 2005 suggested a paddock size of at least 300 m2 per horse and that every horse should have at least 2 hours turnout per day. Some of this time could however be replaced with forced exercise if the horse was kept in a box and not in a tie-stall. Whether this paddock size is large enough and how exercise affects horse behavior and activity during turnout has not been studied in detail. Horses are very motivated for social contact and several stereotypic behaviours like waving and pacing could be related to frustration and the wish for contact with conspecifics. Many commercial products for environmental enrichments are now available, both with the aim to reduce boredom and to keep horses occupied in harmless activities when kept individually. How horses use such "toys" is however scarcely studied. We performed several studies to investigate issues related to paddocks and turnout. Our results show that horses were more active in large paddocks (10 x 45m), spending less time standing and more time walking, exploring and eating grass from under the fence than in small (10 x 15m) and medium sized paddocks (10 x 30m). Horses in the large paddocks also travelled a longer distance than in the small and medium paddock size. When kept in individual paddocks, the dominating behaviours during turnout were standing (51.5% of tot obs) and eating grass from under the fence (27.1%). Horses that were exercised daily for 45 minutes in a walking pace became more passive, spending more time standing (52.9%) and less time walking (5.1%) during turnout, compared to when not exercised (standing: 44.4%; walking: 9.2%). When kept in groups the same horses spent only 5.3% of their time standing and 74.4% of their time eating grass from under the fence. This is probably an effect of social facilitation. Very few incidents of aggressive interactions were recorded when the horses were kept in social groups, but bouts of social grooming were observed. The items that were edible (straw, ball filled with concentrates, branches) received the most attention from the horses regardless of being kept individually or in groups. Straw and a ball filled with concentrates were the most popular items. Peat, a plastic ball and a cone were investigated less than 0.5% of total observations. A scratching pole was used (1.7 - 2.2% of tot obs), but due to horses using it in rather short intervals, it was difficult to catch all events with our recording methods. The ability to eat grass was more important for reducing passive standing than the access to items, both for horses kept individually (correlation between eating grass and passive standing R=-0.97; P
Forfattere
Aparna Tiwari Adam Vivian-Smith Roeland E. Voorrips Myckel E.J. Habets Lin B. Xue Remko Offringa Ep HeuvelinkSammendrag
Background Parthenocarpy is a desirable trait in Capsicum annuum production because it improves fruit quality and results in a more regular fruit set. Previously, we identified several C. annuum genotypes that already show a certain level of parthenocarpy, and the seedless fruits obtained from these genotypes often contain carpel-like structures. In the Arabidopsis bel1 mutant ovule integuments are transformed into carpels, and we therefore carefully studied ovule development in C. annuum and correlated aberrant ovule development and carpelloid transformation with parthenocarpic fruit set. Results We identified several additional C. annuum genotypes with a certain level of parthenocarpy, and confirmed a positive correlation between parthenocarpic potential and the development of carpelloid structures. Investigations into the source of these carpel-like structures showed that while the majority of the ovules in C. annuum gynoecia are unitegmic and anatropous, several abnormal ovules were observed, abundant at the top and base of the placenta, with altered integument growth. Abnormal ovule primordia arose from the placenta and most likely transformed into carpelloid structures in analogy to the Arabidopsis bel1 mutant. When pollination was present fruit weight was positively correlated with seed number, but in the absence of seeds, fruit weight proportionally increased with the carpelloid mass and number. Capsicum genotypes with high parthenocarpic potential always showed stronger carpelloid development. The parthenocarpic potential appeared to be controlled by a single recessive gene, but no variation in coding sequence was observed in a candidate gene CaARF8. Conclusions Our results suggest that in the absence of fertilization most C. annuum genotypes, have parthenocarpic potential and carpelloid growth, which can substitute developing seeds in promoting fruit development.
Forfattere
Atle Mysterud Leif Egil Loe Barbara Zimmermann Richard Bischof Vebjørn Veiberg Erling MeisingsetSammendrag
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Forfattere
Gunda Thoeming H. Saucke Geir Kjølberg KnudsenSammendrag
The pea moth Cydia nigricana (Lepidoptera: Tortricidae) is a major pest in pea growing areas. Alternative pest control techniques are needed since efficient control options are scarce. A strong correlation between the seasonal flight period of C. nigricana and the phenology of the pea plant Pisum sativum (Fabaceae) has been shown in field studies in Northern Hesse, Germany, in the years 2006 – 2008. In continuative studies we are investigating the olfactory space between pea moth and pea plant, intending the identification of volatile cues encoding host recognition and host finding in pea moth females, and the use of these volatile compounds for the pest management of the pea moth. In two-choice experiments in insect cages the preference between potted pea plants of different phenological development stages were tested, using male and female C. nigricana (mated and non-mated). Mated females clearly prefer flowering pea plants, whereas, non-mated females and males showed no preference. In wind tunnel experiments the upwind orientation of C. nigricana towards the odour of pea plants of different phenological development stages were tested, using potted pea plants (A) and headspace collections of pea plants (B) as odour source. In both wind tunnel set ups (A and B), the preference of mated females for the pea flower has been confirmed and additionally, high attraction of mated females for the late bud stage was recorded. Overall, the flower and the late bud stage of P. sativum seem to be the most important phenological development stage for the host finding behaviour of C. nigricana. In ongoing studies we are identifying and characterising the behavioural active volatile compounds of the pea plant, using GC-MS (coupled gas chromatography – mass spectrometry) and GC-EAD (coupled gas chromatography – electroantennographic detection).
Sammendrag
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Sammendrag
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Sammendrag
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Forfattere
Michael W.I. Schmidt Margaret S. Torn Samuel Abiven Thorsten Dittmar Georg Guggenberger Ivan A. Janssens Markus Kleber Ingrid Kögel-Knabner Johannes Lehmann David A.C. Manning Paolo Nannipieri Daniel Rasse Steve Weiner Susan E. TrumboreSammendrag
Globally, soil organic matter (SOM) contains more than three times as much carbon as either the atmosphere or terrestrial vegetation. Yet it remains largely unknown why some SOM persists for millennia whereas other SOM decomposes readily—and this limits our ability to predict how soils will respond to climate change. Recent analytical and experimental advances have demonstrated that molecular structure alone does not control SOM stability: in fact, environmental and biological controls predominate. Here we propose ways to include this understanding in a new generation of experiments and soil carbon models, thereby improving predictions of the SOM response to global warming.
Forfattere
Nils VagstadSammendrag
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