Tore Sivertsen

Dr. Tore Sivertsen

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Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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4 December 2018 in Toxins
Verified
Journal Article
Open access
PDF file
Amin SayyariAmin Sayyari
Amin Sayyari
Silvio UhligSilvio Uhlig
Silvio Uhlig
Christiane Kruse FæsteChristiane Kruse Fæste
Christiane Kruse Fæste
TFTore Framstad
Tore Framstad
TSTore Sivertsen
Tore Sivertsen
Deoxynivalenol (DON) contamination of feed may result in reduced growth, feed refusal, immunosuppression, and health problems in swine. Piglets can be exposed to DON via placenta before birth and via milk during lactation. The extent of early-life exposure of piglets to DON is, however, not fully known. This study was therefore aimed at investigating DON uptake in sows fed with naturally contaminated diets, DON transfer across placenta during late gestation, and transfer of DON to piglets via colostrum and milk. Forty-four crossbred sows were evaluated from day 93 ± 1 of gestation until weaning of piglets and fed with feed made from naturally DON-contaminated oats at three concentration levels: (1) control (DON < 0.2 mg/kg), (2) DON level 1 (1.4 mg DON/kg), and (3) DON level 2 (1.7 mg DON/kg). The transfer of DON to the piglets was evaluated in 15 sows, with repeated sampling of blood and milk from the sows and blood samples from five piglets of each litter. The piglet/sow plasma DON ratio and milk/plasma (M/P) DON ratio in sows were calculated to estimate the degree of transfer. Piglet/sow plasma ratios were 2.14 at birth, 2.30 within 12–36 h after parturition, 0.08 on day 7, 0.16 on day 21, and 0.20 at weaning. M/P ratios were 0.92, 1.11, 0.94, 1.21, and 0.90, respectively. The results indicate that DON is efficiently transferred across placenta and into milk. However, the low piglet/sow plasma ratios at mid-lactation to weaning indicate that the piglets were most strongly exposed to DON in early life, despite the high M/P ratios and efficient secretion of DON in milk throughout the entire lactation.

20 June 2014 in Acta Agriculturae Scandinavica, Section A — Animal Science
Verified
Journal Article
Closed access
TSTore Sivertsen
Tore Sivertsen
TGT. H. Garmo
T. H. Garmo
SLS. Lierhagen
S. Lierhagen
ABA. Bernhoft
A. Bernhoft
ESE. Steinnes
E. Steinnes
To obtain a better knowledge basis for the correct supply of Cu to sheep in Norway, a systematic, countrywide investigation of element composition of pasture plants was conducted, with emphasis on natural pastures. Samples of pasture grass, herbs, willow shrub leaves and bilberry (N = 575) from 142 locations were analysed for Cu, Mo, S and Fe. A large geographical variation was observed for Mo concentration and Cu:Mo ratio, a somewhat smaller variation for Fe, while Cu and S concentrations showed limited geographical variation. The Mo variation led to a Cu:Mo ratio 20 in 62% of samples, confirming that the trace element composition of Norwegian sheep pastures may represent a risk of Cu deficiency as well as Cu overload, depending on location. A considerable botanical variation was also observed, in particular for Cu and Mo.

1 November 2018 in Porcine Health Management
Verified
Journal Article
Open access
PDF file
Amin SayyariAmin Sayyari
Amin Sayyari
TFTore Framstad
Tore Framstad
AKAnette Kristine Krogenæs
Anette Kristine Krogenæs
TSTore Sivertsen
Tore Sivertsen
The most prevalent Fusarium mycotoxin in grains is deoxynivalenol (DON). Contamination of swine feed with DON can result in reduced consumption and poor growth performance. Gestating and lactating sows need sufficient feed intake for fetus development during late gestation and milk production and body maintenance during lactation. Therefore, there is considerable concern in modern piglet production about the effects of DON contamination in sow feed. Most previous studies in sows have been done under experimental conditions, with DON levels ≥2.8 mg/kg feed. The aim of the current field trial was to investigate the effects of feeding grains that are naturally contaminated with more realistic levels of DON on sows during late gestation and lactation. In a commercial, high-yield specific pathogen-free piglet production unit, 45 Norwegian Landrace × Yorkshire sows were fed three diets from 93 ± 1 days of gestation until weaning of the piglets, and average daily feed intake (ADFI), body weight (BW), production and reproduction performance, as well as sow blood parameters were recorded. Diets were made from naturally contaminated oats, with three concentration levels: 1) control (DON < 0.2 mg/kg), 2) DON level 1 (1.4 mg DON/kg), and 3) DON level 2 (1.7 mg DON/kg). Sows that were fed DON level 1 and 2 diets showed a 4–10% reduction in feed consumption during lactation, compared with sows in the control group. However, the DON-contaminated diets did not significantly affect sow BW or backfat thickness. Similarly, there were neither effects on production or reproduction performance, nor on blood parameters in the sows. The effects on skin temperature were variable. Naturally contaminated diets with realistic, moderately increased DON levels, fed during late gestation and lactation in a modern high-yield piglet production farm, had limited effects on sow health and production.

20 June 2014 in Acta Agriculturae Scandinavica, Section A — Animal Science
Verified
Journal Article
Closed access
TSTore Sivertsen
Tore Sivertsen
TGT. H. Garmo
T. H. Garmo
SLS. Lierhagen
S. Lierhagen
ABA. Bernhoft
A. Bernhoft
ESE. Steinnes
E. Steinnes
In order to obtain a more comprehensive knowledge basis for the supply of essential elements to sheep on pasture in Norway, a systematic, countrywide investigation of element composition of pasture plants was conducted, with emphasis on natural pastures. Samples of pasture grass, herbs, willow shrub leaves and bilberry (N = 575) from 142 locations were analysed for the essential trace elements Se, Co, I, Zn and Mn, and for the major elements Ca, P, Mg, Na and K. A large and systematic geographical variation was observed for Se, I and Na, while concentrations of Zn and of most major elements showed limited variation with sampling site. Se concentrations were inadequate in the majority of samples from all plant species. Marked botanical variation was noted for Co and Zn, and willow shrub leaves were identified as a valuable source of these elements in natural sheep pastures.

1 February 2003
Verified
Journal Article
Closed access
TSTore Sivertsen
Tore Sivertsen
AJAnne Jørgensen
Anne Jørgensen
ABAksel Bernhoft
Aksel Bernhoft
GSGunnar A Sylliaas
Gunnar A Sylliaas
HJHilde Magda Juul
Hilde Magda Juul
BBBørge Baustad
Børge Baustad