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.
2018
Authors
Solveig Marie Stubsjøen Kristin Sørheim Matteo Chincarini Jon Bohlin Emma Brunberg Boris Fuchs Rupert Palme Lise GrøvaAbstract
Tick-borne fever (TBF), caused by the bacterium Anaplasma phagocytophilum and transmitted by the tick Ixodes ricinus, has considerable consequences for animal welfare and economy in the sheep industry. Non-invasive, objective methods to quantify chronic stress are needed in order to evaluate the welfare impact of disease. The aim of this study was 1) to evaluate hair cortisol (HC) and hair cortisone (HCn) as biomarkers of chronic stress in sheep with TBF and 2) to test whether there was an association between the development of TBF and con- centrations of HC, HCn and faecal cortisol metabolites (FCM) and body weight. The experiment took place in an area with a high prevalence of TBF, and thirty lambs were used in the study. Wool samples were collected in Week 0, in Week 3 (before turn out on homeland spring pasture), in Week 6 (before turn out on summer rangeland pasture) and at the end of the summer (Week 15). Faecal samples were collected every week (ie. Week 0–6 and Week 15). Symptoms of TBF developed in 15 lambs, of which all recovered from the disease after treatment with antibiotics. HC levels decreased progressively, and significantly, between Week 0, 3, 6 and 15 (p < 0.001), while HCn only decreased from Week 0 to Week 3 (p < 0.001) and then remained stable between Week 3–15. FCM increased between Week 0 and 5 (p = 0.027), and a significant association was found between increased FCM levels in Week 5 and lambs developing clinical signs of TBF (p = 0.022). We also found an association between lambs developing clinical signs of TBF and elevated HCn levels in Week 6 (p = 0.013). A slightly lower weight gain at later time points (Week 6 and 15) were found in the affected lambs compared to clinically healthy lambs. Our results indicate local production and/or metabolism of glucocorticoids in the hair follicles. This study strengthens our previous finding of a potential merit of hair cortisone as a biomarker of chronic stress in sheep.
Abstract
No abstract has been registered
Authors
Lise GrøvaAbstract
No abstract has been registered
Abstract
WOOL QUALITY OF NORWEGIAN WHITE SPÆL SHEEP BREED Lise GRØVA 1), Inger Anne Boman 2) 1) NIBIO, Norwegian Institute of Bioeconomy Research, Gunnars veg 6, 6630 Tingvoll, Norway; lise.grova@nibio.no 2) NSG, Norwegian sheep and goat association, Postboks 104, N-1431 Ås The Norwegian White Speal Sheep are characterised by their fluke-shaped and tapered short tail, dual-coated wool and the ability to thrive under harsh environmental conditions. The income in Norwegian sheep farming comes from lamb meat, wool and pelts. Today, wool is of minor economic importance, commonly accounting for less than 10% of the income. However, the interest of wool as a sustainable and local fibre is increasing. Wool quality traits of the Norwegian White spæl breed has been reported to be declining; i.e. an increase in medulated fibres and in kemp. To address this challenge, there has been developed and incorporated 1) wool quality assessment tutorials for farmers and breeders, 2) included heritability estimates of wool fleece weight and quality class in index calculations, and 3) conducted OFDA analysis of wool from breeding rams for three consecutive years. The work was initiated by the research-project KRUS - Enhancing local wool value chains in Norway (NFR 244618/E50) and has been carried out by NIBIO, the Norwegian Sheep Breeders Association (NSG), Animalia and Norilia. Wool quality assessment tutorials for farmers and breeders are available as a.pdf and video for free download from NSG webpage (nsg.no). A ‘wool evaluation kit’ with a magnifier is available for purchase, also from NSG. Implementing index estimates was made possible when including fleece weigh and fleece classification from all sheared lambs at slaughter into the Norwegain National Sheep Recording system. Further, OFDA analysis were conducted on wool from breeding rams collected autumn 2015, 2016 and 2017. The wool samples were analysed using the optical FD analyser (OFDA100; BSC Electronics Pty Ltd, Western Australia, Australia). OFDA analysis is conducted to describe wool quality traits, development of quality traits over time and also development of quality traits at different age of breeding rams. Preliminary results from this study will be presented at the conference. Keywords: sheep, wool quality, Norwegian white spæl, dual felt, double-coat
Abstract
No abstract has been registered
Authors
Kjersti Holt HanssenAbstract
The production of ash from wood has greatly increased the last years, because biofuels are increasingly being used for heating and energy production. The ash may either be viewed as a waste problem, or as a resource. Wood ash has a liming effect and contains essential nutrients (P, K, Ca, Mg) which can be exploited for soil fertilisation. With enhanced knowledge about where and how wood ash addition may increase forest growth - without having negative effects on the environment - wood ash may become a renewable nutrient source. We studied the effect of fertilizing a Norway spruce (Picea abies) stand on relatively high site index in SE Norway with ash, nitrogen, or ash + nitrogen. After five years, both current annual increment and standing volume was best in the ASH + N treatment and least in the Control plots. The field trial should be followed for a longer period of time, as the ASH + N treatment still shows an increasing growth trend after five years.
Abstract
Several studies have shown the positive effect of nitrogen fertilization on conifer growth. In young Norway spruce (Picea abies) stands, an additional effect of including a mixture of other nutrients has often, but not always, been found. We studied effects of repeated fertilization in 28 stands with young Norway spruce in central Norway. The treatments consisted of plots without nutrient addition (Control), fertilization with 150 kg N ha−1 (150 N), and fertilization with 150 kg N plus addition of P, K, Mg, B, Mn and Cu (150 N + mix), repeated three times with approximately eight years interval. There was a clear positive effect on volume increment of the 150 N and 150 N + mix treatments compared to Control, and the effect was significantly higher for 150 N + mix than for 150 N. Fertilization had a stronger effect in the first fertilization period than in the second, while the third period was intermediate. The effect of 150 N + mix was strongest at plots > 300 m a.s.l. However, this correlation may be due to geological conditions rather than elevation. Further studies are needed to find out under which edaphic conditions a nutrient mixture will increase growth substantially in young spruce stands.
Abstract
No abstract has been registered
Authors
Kjersti Holt HanssenAbstract
No abstract has been registered
Abstract
Root rot in Norway spruce (Picea abies (L.) Karst.) causes substantial economic losses to the forestry sector. In this study, we developed a probability model for decay at breast height utilizing 18,141 increment cores sampled on temporary plots of the Norwegian National Forest Inventory. The final model showed a good fit to the data and retained significant relationships between decay and a suite of tree, stand and site variables, including diameter at breast height, stand age, altitude, growing season temperature sum (threshold 5°C), and vegetation type. By comparing model predictions with recorded decay at stump height in an independent data set, we estimated a proportionality function to adjust for the inherent underestimation of total rot that will be obtained by applying a probability model derived from increment cores sampled at breast height. We conclude that the developed model is appropriate for national and regional scenario analyses in Norway, and could also be useful as a tool for operational forestry planning. This would however require further testing on independent data, to assess how well the new model predicts decay at local scales.