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Can extract from Norwegian spruce bark control coccidiosis in suckling lambs?


Coccidiosis is a serious disease caused by Eimeria spp. in young lambs in Norway. Re-sistance against anticoccidial chemicals has been demonstrated in conventional sheep farm-ing. In organic farming we are looking for natural plant sources to increase animal health and welfare. Condensed tannins (CT) have showed effect against coccidia in several trials. Extract from Norwegian spruce bark (Picea abies), a waste product from the wood industry, was shown to contain CT in a Norwegian study. In our trial we tested the effect of bark extract from Norwegian spruce against Eimeria spp in young lambs. The extract was prepared by hot water extraction followed by evaporation and freeze drying. 24 naïve lambs were randomly grouped, 16 of them were inoculated with 100 000 Eimeria oocysts each for three days at 3 weeks of age, and eight of the 16 were treated with bark extract for 12 successive days post infection. The CTg per lamb per day correspond to 0.05% BMW. A control group of eight lambs was not infected or treated. Individually faeces samples were collected and analysed for faecal score and oocysts. Clinically observations and weight gain were measured.
In this trial the bark extract was found to have a significant effect on the development of Eime-ria spp. oocysts in the lambs (p<0,001). The extract was given by a stomach tube, and had a negative effect on the lambs appetite as long as it was administered.




  • Research Council of Norway (RCN) / 268264
  • Regional research fund Midt-Norge / 607326




  • Kristin Sørheim
  • Berit Marie Blomstrand
  • Juni Rosann E. Johanssen
  • Inga Marie Aasen
  • Håvard Steinshamn
  • Heidi L Enemark


  • Norwegian Centre for Organic Agriculture
  • SINTEF Industry / Biotechnology and Nanomedicine
  • Norwegian Institute of Bioeconomy Research
  • Norwegian Veterinary Institute




Animal Husbandry Alliance of International Federation of Organic Agriculture Movements


Organic Animal Husbandry systems – challenges, performance and potentials-Proceedings of the IAHA Video-Conference on Organic Animal Husbandry - 21. and 22. September 2020 linked to the 20th Organic World Congress of IFOAM 2021


57 - 61

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